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CSG 15 (Rev. 12/99) 1

MINISTRY OF AGRICULTURE, FISHERIES AND FOOD CSG 15Research and Development

Final Project Report(Not to be used for LINK projects)

Two hard copies of this form should be returned to:Research Policy and International Division, Final Reports UnitMAFF, Area 6/011A Page Street, London SW1P 4PQ

An electronic version should be e-mailed to [email protected]

Project title NEW DEVELOPMENTS IN NEAR INFRARED REFLECTANCESPECTROSCOPY: A FACT FINDING MISSION

MAFF project code LS3609

Contractor organisationand location

ADAS Nutritional Sciences Research Unit, Alcester Road,Stratford-on-Avon, Warwickshire, CV37 9RQ

Total MAFF project costs £ 20,037

Project start date 01/02/00 Project end date 31/03/01

Executive summary (maximum 2 sides A4)

1. The development of near infrared reflectance spectroscopy (NIRS) and its application to animal nutrition,agricultural and food science has increased considerably in the last decade. During this time, there has beena substantial increase in both the range of NIRS-based applications and new advances in NIRSinstrumentation, calibration methods and software developments.

2. Advances in new aspects of NIRS technology and subsequent new applications often occur extremelyrapidly. For this reason, up to date knowledge, including any drawbacks of this technology, is generally onlyavailable from the leading scientists and technologists in this field.

3. The objective of the project was to obtain relevant new information on NIRS and other related techniquesduring a series of fact-finding visits to world experts. A key requirement was to identify emerginginformation regarding NIRS, which may have the potential to fulfil the current and future researchrequirements of, DEFRA.

4. Visits and/or discussions were held with 29 leading experts on NIRS from Europe, Japan, Australia and theUSA between February 2000 and March 2001. A questionnaire was prepared as a general guide in order toestablish the scope of the Project under the two main themes: (1) new developments in NIRS applicationsand (2) new developments in instrument technology, calibration methods and software. An importantobjective of the face-to-face interviews was to obtain personal views on these topics. Therefore, not everyindividual visited was able to comment on all aspects of the questionnaire. A detailed report, listing thequestions raised and the views expressed, was produced following each visit.

Projecttitle

NEW DEVELOPMENTS IN NEAR INFRAREDREFLECTANCE SPECTROSCOPY: A FACT FINDINGMISSION

MAFFproject code

LS3609

CSG 15 (1/00) 2

5. The results of the Project confirmed that NIRS is a vital technology to both the feed and food industries andthat considerable opportunities exist for the development of new approaches in the UK based on the successof work on-going elsewhere across the world. The Project has shown that the application of NIRS isenormous and offers considerable potential for future developments. NIRS also appears to be at anextremely important stage of development and the newly emerging technologies, such as diode arrays, offerconsiderable scope for the further development of NIRS applications.

6. The evidence from the interviews highlighted that NIRS will continue to be applied mainly to the predictionof specified parameters. However, this will be accompanied by changes in how the analysis may becompleted. Such changes will include analysis of samples in their fresh-state (e.g. fresh forages, wholecereal grains and seed legumes, complete diets and whole fruits), greater in-line monitoring of feed and foodmanufacturing processes through the use of fibre-optic probes and a move away from laboratory-basedanalysis (e.g. diode array instruments). It is also likely that the range of parameters to be predicted willincrease and will include, animal based measurements (in vivo digestibility, intake, feed preference), qualityand sensory attributes of foods etc.

7. The results also showed that NIR spectra can be used directly (without the need for calibration) to provideinformation about specific samples including the ability of NIRS to authenticate or discriminate betweensample types or between different variants of a particular sample (e.g. non-genetically modified fromgenetically modified; rice grain authentication).

8. There is considerable interest in the development of large databases or libraries of NIR spectra of feed andfood samples. Such developments may lead to new calibration approaches and may utilise the benefits ofrapid communication through the Internet.

9. While the potential for the continued development of NIRS in the feed and food industries is clear, theresults of the review also highlighted that further work is required, particularly with respect to the transfer ofcalibrations between instruments when using fresh (undried) samples and for the transfer of calibrations toand between diode arrays. It also suggested that the scope for developing large databases of NIRS spectra isalso limited at present by the low number of institutes/organisations with suitable databases of sample NIRspectra.

10. Overall, the results of the Project confirmed that NIRS is a vital technology to the feed and food industriesand that considerable opportunities exist for new developments to take place in the UK based on the resultsof work on-going elsewhere. It was also concluded that NIRS is at an extremely important stage ofdevelopment and that the newly emerging technologies, such as diode arrays, offer considerable scope for thefurther development of NIRS applications. At such an important stage in the development of NIRS it isessential that the UK develops a greater understanding of the potential of this technique, particularly thenewly emerging technology, and to ensure a integrated programme of research is undertaken to realise its fullpotential.

Projecttitle


MAFFproject code

LS3609

CSG 15 (1/00) 3

Scientific report (maximum 20 sides A4)INTRODUCTION

The application of near infrared reflectance spectroscopy (NIRS) to animal nutrition, agricultural and foodscience has increased considerably in the last decade (Givens et al., 1997; Givens and Deaville, 1999). It is arapid and non-destructive technique that can predict the composition of organic material because of theinteraction between NIR radiation and mainly hydrogen bearing functional groups (C-H, N-H and O-H). Ofparticular note in the UK has been the widespread adoption of NIRS as a means of predicting the in vivodigestibility value of grass silage (Baker et al., 1994). Importantly, one of the outcomes of the currentSustainable Livestock LINK Project ‘Feed into Milk’ will be a suite of NIRS-based feed analyses which will beavailable for adoption by the industry. The developments in NIRS in the UK have had an enormous impact onthe speed of uptake of nutritional research by farmers and the agricultural feed industry, and the recent Foresightdocument (Office of Science and Technology, 1998) confirms the continuing need to develop rapid means ofcharacterising animal feedstuffs.

There has been considerable progress in the development of NIRS technology and its application in both thefood and feed industries. These developments have evolved essentially in two separate although connecteddirections. Firstly, the range of applications for which NIRS is being used has increased substantially. Inanimal nutrition this has included the use of NIR spectra from fresh (undried) forages and whole cereal grains,the NIRS prediction of more biologically valuable components of feeds (e. g. in vivo digestibility; fermentationacid content of silages) and the use of NIR difference spectra in order to describe feed digestion in spectralterms (Deaville and Givens, 1998). Other new applications include the use of discriminant analysis of NIRspectra to authenticate feeds and foods, and the analysis of milk for pathogens. These and other newlydeveloping approaches could have considerable potential in the future concerning feed and food safety, andanimal health.

The second type of development includes the advances in NIRS instrument technology, chemometric methodsand software. Notable new technologies include the use of Fourier transform NIRS (FT-NIRS) which giveshighly accurate spectra, FT-NIRS coupled with microscopy, two dimensional NIR correlation spectroscopy,together with new approaches for gathering spectra (e.g. fibre optic probes). It is also noteworthy that NIRimaging has just started to be explored and some commercial NIR imaging systems seem likely to be availablesoon. Many of these new technologies seem to offer the potential for the development of new applications forNIRS which may be highly relevant to animal and human nutrition, feed and food safety, and the environment.For instance, FT-NIR microspectroscopy offers the possibility of rapid detection of small amounts of animalproteins in animal feeds.

Whilst there is a relatively large volume of scientific papers on these topics, developments in technology areoften so rapid that up to date knowledge and indeed any drawbacks are generally only available from the leadersin this science. Therefore, the objective of this study was to obtain relevant new information on NIRS andrelated techniques during a series of fact-finding visits to world experts. A key requirement was to identifyemerging information on NIRS and other physical techniques, which may have potential to fulfil the present andfuture research requirements of, DEFRA.

APPROACH

Schedule of visitsThe Project was completed in the form of a ‘fact-finding mission’, which relied almost entirely on making visitsto and undertaking interviews with leading scientists and technologists. This approach was adopted to ensure

Projecttitle


MAFFproject code

LS3609

4

that the most recent information relating to developments in NIRS technology was obtained, and so that anypitfalls or disadvantages of any emerging approaches that would not necessarily be reported in the literaturecould be probed during the interviews.

Visits and/or discussions were held with 29 leading experts on NIRS from Europe, Japan, Australia and USAbetween February 2000 and March 2001.

Questionnaire on NIRS developments

A questionnaire was prepared as a guide in order to establish the scope of the Project. Since the developmentsin NIRS have been in the areas of (1) applications and (2) instrument technology, chemometric methods andsoftware, the questionnaire was constructed by asking a number of suggested questions under these two mainheadings (1 and 2 above). The full details of the questionnaire used are given below. However, an importantobjective of all the discussions was to obtain personal views from the leading individuals included in theProject. Therefore, not every individual interviewed was able to comment on every section of the questionnaire.In addition, individual responses to the questionnaire reflected the range in personal experience and expertise.

_________________________________________________________________________________________QUESTIONNAIRE: NEW DEVELOPMENTS IN NEAR INFRARED SPECTROSCOPY AND

FUTURE POTENTIAL OF THE TECHNIQUE

Background information relating to current applications of NIRS

Current and future potential of NIR technology

1. Current and future applications of NIR technology

• Highlight new or emerging applications of NIR technology and other physical techniques for food and feedanalysis/evaluation.

• Present a view of the likely developments to be made in NIR technology applications to food and feedanalysis in the next decade.

• Consider if there are known applications in other industries which may have potential in the food and feedindustries but which have to date not been exploited.

• Describe current and future requirements for food and feed analysis and the potential of NIR technology tofulfil this role. Consider potential limitations of NIR technology in this respect.

• Describe the potential of NIR to provide qualitative information on food and feed samples as well asquantitative compositional information.

• Consider the application of NIR technology to intact (unprocessed) food and feed samples.

• Are there developments required in NIR instrumentation in order to allow the potential of the NIR techniquein the future.

Projecttitle


MAFFproject code

LS3609

5

2. Current and future developments in NIR instrumentation, chemometric methods and software

• Consider new and future developments in NIR instrumentation including FT-NIR, diode arrays, NIRmicroscopy, fibre optics, etc.

• Highlight the potential for combining NIR and other technologies during analysis (e. g. NIR and MIRcorrelations).

• The potential of NIR imaging techniques in qualitative and quantitative applications.

• Consider new and future developments in chemometrics and software, including calibration approaches.

• Highlight the potential for networks of NIR instrument within the food and feed industry.

_______________________________________________________________________________________

RESULTS AND DISCUSSION

A complete copy of the individual fact-finding visit reports is given in the Project report.

The information contained within the individual fact-finding reports represents a wide range of views, and ofpast and current experiences of NIRS technology. While some believed that NIRS had progressed beyond thestage of research into one of application and implementation, it is clear from the review that there is asignificant amount of NIRS related research still on-going across the world. Much of the research is takingplace using current NIRS technology (e.g. NIR scanning monochromators). However, it is also clear that thenewly emerging technologies, in particular the new diode array instruments, will present an importantopportunity in the future to extend the scope of the application of NIRS in both feed and food industries.Without doubt the newly emerging technologies are at a stage of considerable development, but will requirefurther research in order for their potential to be fully realised.

The application of NIRS has largely been based on a predictive approach and generally involving the analysis ofsamples within a laboratory environment. The evidence from the review highlights that the technology willcontinue to be applied to the prediction of specified parameters. What does emerge, however, is thatincreasingly there will be a departure from the current approach on how the predictive analysis will be carriedout. This will include analysis of samples in their fresh-state (e.g. fresh forages, whole cereal grains and seedlegumes, complete diets and whole fruits), greater in-line monitoring of feed and food manufacturing processesthrough the use of fibre-optic probes and a move away from laboratory-based analysis. The potential for NIRSto be used at the site of application will largely be achieved through the very important developments takingplace with NIRS instrumentation including, the new diode array instruments and the increased miniaturisationof instruments. It is also likely that the range of parameters to be predicted will increase and will include,animal based measurements (in vivo digestibility, intake, feed preference), quality and sensory attributes offoods etc. The results highlight that important information on the nutritional characteristics of animal feedsmay be gained from the NIR spectra of faeces. Early evidence suggests that faeces-based calibrations may beindependent of diet composition or animal species. It is also clear that NIRS is seen as being able to play anumber of important predictive roles, with various applications having different requirements of NIRS. Whilesome analytical approaches may require a high level of precision (e.g. prediction of feed quality), otherapplications may use the technique as a screening tool (e.g. analysis of breeding lines) and therefore demand alower level of precision.

Projecttitle


MAFFproject code

LS3609

6

Since NIR spectra contain all the information relating to the complex interaction of NIR radiation with themolecular bonds within a sample, there is a widely held view that the spectra can be used directly to provideinformation about specific samples (without the need for calibration). This has been widely demonstratedthrough the ability of NIRS to authenticate or discriminate between sample types or between different variantsof a particular sample (e.g. rice grain authentication; non-genetically modified from genetically modified). Thespectra of samples will also allow important developments to be made in understanding important processesthrough monitoring changes at specific points within a series of spectra. Certainly several of the reportshighlight that further work is required in order to maximise the potential use of NIR spectra and will certainlybe an area of continued development.

The progress made in the application of NIRS technology has been due largely to the developments inchemometrics and computer capabilities. While many expressed the need for further developments in the fieldof chemometrics there was clearly a view that the development of large databases and the use of artificial neuralnetworks had great potential. The development of databases, possibly utilising the benefits of the Internet, maylead to an increased level of co-ordination between laboratories both within and between different countries.This approach may also lead to a greater degree of co-ordination between different scientific disciplines innationally/internationally important research areas. The important developments in crop tissue testing (e.g. rice,wheat and barley) highlight the benefits of the co-ordinated approach undertaken by cereal chemists,spectroscopists and soil scientists. This work has had considerable impact on the management of these crops,thereby reducing the impact of these systems on the environment.

Overall, the review highlights a significant number of opportunities for the application of NIRS. These include:

• The rapid predictions of all the chemical and nutritional properties of fresh forages at the point of harvest(e.g. use of forage maize parameters as indicators of maize silage quality). Also, the prediction of thenutritional value of whole cereal grain prior to processing. These applications may also involve the use ofnewly emerging technologies where analysis can be completed at the site of application (e.g. instrumentsmounted to forage and grain harvesters).

• Prediction of rumen parameters from animal diets/dietary ingredients and the parameters required by the newfeed evaluation systems/models being developed (including nutrient degradation, microbial proteinproduction).

• Analysis of faeces to support feed analysis, health status (e.g. worm burden, nutrient deficiency) and animalbehaviour (e.g. feed selection and feed preference). The analysis of faeces has important implications to bothintensive and extensive animal systems (e.g. hill and upland situations).

• Use of NIRS as a whole farm management monitoring tool (e.g. dairy production) through the analysis offeeds/whole diet, milk (e.g. urea content), urine (e.g. nitrogen, purine derivatives), blood, and faeces.

• Prediction of carcass composition and quality (in-line), distinction between fresh and previously frozen meat,between animal breeds and between meats from animals of different ages.

• Prediction of sensory attributes of foods including taste, flavour etc.

Projecttitle


MAFFproject code

LS3609

7

• Development of crop tissue testing in order to match nutrient applications to crop requirements throughoutits development. Also to assess soil nutrient status (e.g. nitrogen, carbon) and sewage sludge, manure andcompost composition.

• Prediction using plant canopies to a lesser or greater extent (e.g. nitrogen content of leaves,pesticide/fungicide treatment of single, whole cereal grains, detecting vegetation change in species-richgrasslands, weed competition in standing crops).

• Opportunity for the development of large spectral databases or libraries and for the opportunity to expand theuse of networks including the use of the Internet for on-line retrieval of sample spectra for calibrationdevelopment.

• Greater scope for the direct use of spectral information for sample identification (e.g. geographical origin,food and feed type and classification, organic vs. non-organic standards).

• Expansion of in-line NIRS analysis (e.g. manufacturing processes) and the possibility to alter processconditions based on the predicted analysis.

The potential for the continued development of NIRS in the feed and food industries appears enormous. Atpresent, NIRS appears to be at an important stage of development particularly with respect to the developmentof diode array technology. However, further work is required particularly with respect to the transfer ofcalibrations between instruments when using fresh (undried) samples and for the transfer of calibrations to andbetween diode arrays. The scope for developing large databases of NIRS spectra is also limited at present bythe low number of institutes/organisations with suitable databases of sample NIR spectra. NIRS is also likely tobe limited to the analysis of macro-nutrients although in itself this may not be a limitation but a realisation ofthe scope of the technology. Greater consideration is therefore required to understand better how othercomplementary technologies can be used together with NIRS in order to provide the full range of parametersrequired in any given situation.

CONCLUSIONS

The results of the Project confirm that NIRS is still a very relevant and indeed vital technology to the feed andfood industries. Considerable opportunities are available for the technology transfer of work on-goingelsewhere to situations in the UK. It is also concluded that NIRS is at an extremely important stage ofdevelopment and that the newly emerging technologies, such as diode arrays, offer considerable scope for thefurther development of NIRS applications. At such an important stage in the development of NIRS it isessential that the UK develops a greater understanding of the potential of this technique and to ensure a greaterdegree of co-ordination and co-operation in the research and development of this technology. It is clear fromthe visits made that within both the EU and the world at large, the UK lags behind in fully researching andexploiting the value of this technology.

RECOMMENDATIONS FOR FURTHER RESEARCH

1. Application research

1. Development of the use of diode arrays for the direct prediction of whole diet, fresh grass and silage, andwhole grain analysis. Diode array instruments have the capacity of being mounted on harvesting machines,diet mixers etc. The research will need to integrate the NIRS and engineering aspects.

Projecttitle


MAFFproject code

LS3609

8

2. Investigate the potential of NIRS to discriminate between for e.g. non-genetically modified and geneticallymodified feeds/samples. Also to discriminate between other feeds and foods (e.g. analysis of meat todetermine the age of the animal at slaughter).

3. Determine the potential of faeces and NIR spectra of faeces for both nutritional purposes and animal healthaspects.

4. Study the potential of NIRS for predicting the nutrient status of soils, composts and manures.

5. Establish an NIRS-based tissue testing analysis for cereal crops and grasslands, and to improveenvironmental aspects of these systems.

6. Investigate the potential of NIRS for managing hill and upland ecosystems and botanically diverse swards.This work may have both environmental and animal health benefits.

7. Development of large databases or libraries of NIR spectra of feed and food samples in order to improvetechnology transfer of research results and increase national and international co-operation.

8. Investigate the potential for a greater degree of co-ordination of NIRS research within nationally co-ordinated Projects within the UK and EU. Also to establish a national organisation of NIRS users in order tosubstantially increase the profile of NIRS in the UK.

2. Technology research

1. Compare diode array and scanning monochromator instruments for nutritional purposes. To include theability to transfer calibrations between the different instrument types.

2. Assess the value of artificial neural networks (ANN) compared with other calibration approaches including‘local’ calibrations.

3. Development of imaging technology.

REFERENCES

Baker, C. W., Givens, D. I. and Deaville, E. R. (1994). Prediction of organic matter digestibility in vivo of grasssilage by near infrared reflectance spectroscopy: effect of calibration method, residual moisture and particlesize. Animal Feed Science and Technology, 50: 17-26.

Deaville, E. R. and Givens, D. I. (1998). Regions of normalised near infrared reflectance difference spectrarelated to the rumen degradation of fresh grass, grass silage and maize silage. Animal Feed Science andTechnology, 72: 41-52.

Givens, D. I. and Deaville, E. R. (1999). The current and future role of near infrared reflectance spectroscopy inanimal nutrition: a review. Australian Journal of Agricultural Research, 50: 1131-1145.

Projecttitle


MAFFproject code

LS3609

9

Givens, D. I., De Boever, J. L. and Deaville, E. R. (1997). The principles, practices and some futureapplications of near infrared reflectance spectroscopy for predicting the nutritive value of foods for animals andhumans. Nutrition Research Reviews, 10: 83-114.

Office of Science and Technology (1998). Foresight for Agriculture, Horticulture & Forestry. DTI, London,17pp.

Please press enter

MAFF PROJECT: LS3609

NEW DEVELOPMENTS IN NEAR INFRAREDREFLECTANCE SPECTROSCOPY: A FACT

FINDING MISSION

ADAS NUTRITIONAL SCIENCES RESEARCH UNIT

Report to: Dr David Garwes

Head, Livestock Sciences Unit

DEFRA Chief Scientist’s Group

Cromwell House

Dean Stanley Street

London SW1P 3JH

Tel: 0207 2381545

Fax: 0207 2381540

Prepared by: Mr Eddie Deaville

ADAS NSRU

Alcester Road

Stratford-on-Avon

Warwickshire

CV37 9RQ

` Tel: 01789 266704

Fax: 01789 415667

Period of Investigation: February 2000 - March 2001

Date of issue of report: 19 July 2001

No of pages in report: 107 (numbered pages)

No of copies of report: 4 (of which 1 held by ADAS)

This is copy number 4 issued to ADAS NSRU

PRINCIPAL WORKERS

Mr E R Deaville Senior Research Scientist ADAS NSRUProf. D. I. Givens Head of Research Unit ADAS NSRUDr B. R. Cottrill Senior Research Scientist ADAS NSRU

AUTHENTICATION

I declare that this work was done under my supervision according to the proceduresdescribed herein and that this report represents a true and accurate record of the resultsobtained.

.................................................. E R DEAVILLEStudy Director

Date ............................. 2001

Report authorised by: .................................................................

Prof. D. I. GivensHead of UnitADAS Nutritional Sciences Research UnitAlcester RoadStratford-on-AvonCV37 9RQTel: 01789 266704Fax: 01789 415667

Date .............................................. 2001

Quality Management in ADASADAS operates a single company wide Quality Management System (QMS), which isdesigned to be fully compliant with the externally accredited standards (GLP,NAMAS and ISO 9001) to which parts of the business operate. The QMS ensuresthat all work is controlled by documented plans and carried out by properly trainedstaff, using suitable equipment and facilities. Techniques are documented in StandardOperating Procedures authorised by management and issued in a controlled manner,and all work is checked before release to the customer.

Each R&D study is controlled by a Protocol approved by the Study Director and at theend of the study, the raw data, together with a copy of the final report, are formallyarchived or otherwise securely retained.

All aspects of the QMS are subject to formal audit by our independent QualityAssurance Unit, and in addition where required, by the appropriate externalcertification authority.

CONTENTS

Page No.

Title page

Principal workers

Authentication

EXECUTIVE SUMMARY 1

RECOMMENDATIONS FOR FURTHER RESEARCH 3

INTRODUCTION 5

APPROACH 6

Schedule of visits 6

Questionnaire on NIRS developments 7

RESULTS 10

DISCUSSION 102

CONCLUSIONS 106

REFERENCES 106

1

NEW DEVELOPMENTS IN NEAR INFRARED REFLECTANCESPECTROSCOPY: A FACT FINDING MISSION

EXECUTIVE SUMMARY

1. The development of near infrared reflectance spectroscopy (NIRS) and its

application to animal nutrition and agricultural and food science has increased

considerably in the last decade. During this time, there has been a substantial

increase in both the range of NIRS-based applications and new advances in NIRS

instrumentation, calibration methods and software developments.

2. Advances in new aspects of NIRS technology and subsequent new applications

often occur extremely rapidly. For this reason, up to date knowledge, but also

drawbacks are generally only available from the leading scientists and technologists

in this field.

3. The objective of the project was to obtain relevant new information on NIRS and

other related techniques during a series of fact-finding visits to world experts. A

key requirement was to identify emerging information regarding NIRS, which may

have the potential to fulfill the current and future research requirements of,

DEFRA.

4. Visits and/or discussions were held with 29 leading experts on NIRS from Europe,

Japan, Australia and the USA between February 2000 and March 2001. A

questionnaire was prepared as a general guide in order to establish the scope of the

Project under the two main themes: (1) new developments in NIRS applications

and (2) new developments in instrument technology, calibration methods and

software. An important objective of the face-to-face discussions was to obtain

personal views on these topics. Therefore, not every individual visited was able to

comment on all aspects of the questionnaire. A detailed report, listing the

questions raised and the views expressed, was produced following each visit.

2

5. The results of the interviews confirmed that NIRS is still a vital technology to both

the animal feed and food industries and that considerable opportunities exist for the

development of new approaches in the UK based on the success of work on-going

elsewhere across the world. The results show that the application of NIRS is

enormous and it offers considerable potential for future developments. NIRS also

appears to be at an extremely important stage of new development and the newly

emerging technologies, such as diode arrays, offer considerable scope for the

further development of NIRS applications.

6. Evidence from the review highlighted the fact that NIRS will continue to be

applied mainly to the prediction of specified parameters but that this will be

accompanied by changes in how the analysis may be completed including, analysis

of samples in their fresh-state (e.g. fresh forages, whole cereal grains and seed

legumes, complete diets and whole fruits), greater in-line monitoring of feed and

food manufacturing processes through the use of fibre-optic probes and a move

away from laboratory-based analysis (e.g. diode array instruments). It is also likely

that the range of parameters to be predicted will increase and will include, animal

based measurements (in vivo digestibility, intake, feed preference), quality and

sensory attributes of foods etc.

7. The results also showed that NIR spectra can be used directly (without the need for

calibration) to provide information about specific samples including the ability of

NIRS to authenticate or discriminate between sample types or between different

variants of a particular sample (e.g. non-genetically modified from genetically

modified; rice grain authentication).

8. There is considerable interest in the development of large databases or libraries of

NIR spectra of feed and food samples. Such developments may lead to new

calibration approaches and may utilise the benefits of rapid communication through

the Internet.

9. While the potential for the continued development of NIRS in the feed and food

industries is clear, the results of the review also highlighted that further work is

3

required, particularly with respect to the transfer of calibrations between

instruments when using fresh (undried) samples and for the transfer of calibrations

to and between diode arrays. It also suggested that the scope for developing large

databases of NIRS spectra is also limited at present by the low number of

institutes/organisations with suitable databases of sample NIR spectra.

10. Overall, the results of the Project confirmed that NIRS is still a very vital

technology to the feed and food industries and that considerable opportunities exist

for new developments to take place in the UK based on the results of work on-

going elsewhere. It was also concluded that NIRS is at an extremely important

stage of development and the newly emerging technologies, such as diode arrays,

offer considerable scope for the further development of NIRS applications. At

such an important stage in the development of NIRS it is essential that the UK

develops a greater understanding of the potential of this technique, particularly the

newly emerging technology, and to ensure an integrated programme of research is

undertaken to realise its full potential.

RECOMMENDATIONS FOR FURTHER RESEARCH

1. Application research

1. Development of the use of diode arrays for the direct prediction of whole diet, fresh

grass and silage, and whole grain analysis. Diode array instruments have the

capacity of being mounted on harvesting machines, diet mixers etc. The research

will need to integrate the NIRS and engineering aspects.

2. Investigate the potential of NIRS to discriminate between for e.g. non-genetically

modified and genetically modified feeds/samples. Also to discriminate between

other feeds and foods (e.g. analysis of meat to determine the age of the animal at

slaughter).

3. Determine the potential of faeces and NIR spectra of faeces for both nutritional

purposes and animal health aspects.

4

4. Study the potential of NIRS for predicting the nutrient status of soils, composts and

manures.

5. Establish an NIRS-based tissue testing analysis for cereal crops and grasslands, and

to improve environmental aspects of these systems.

6. Investigate the potential of NIRS for managing hill and upland ecosystems and

botanically diverse swards. This work may have both environmental and animal

health benefits.

7. Development of large databases or libraries of NIR spectra of feed and food

samples in order to improve technology transfer of research results and increase

national and international co-operation.

8. Investigate the potential for a greater degree of co-ordination of NIRS research

within nationally co-ordinated Projects within the UK and EU. Also to establish a

national organisation of NIRS users in order to substantially increase the profile of

NIRS in the UK.

2. Technology research

1. Compare diode array and scanning monochromator instruments for nutritional

purposes. To include the ability to transfer calibrations between the different

instrument types.

2. Assess the value of artificial neural networks (ANN) compared with other

calibration approaches including ‘local’ calibrations.

3. Development of imaging technology.

5

INTRODUCTION

The application of near infrared reflectance spectroscopy (NIRS) to animal nutrition

and agricultural and food science has increased considerably in the last decade (see

recent reviews by Givens et al., 1997; Givens and Deaville, 1999). It is a rapid and

non-destructive technique that can predict the composition of organic material because

of the interaction between NIR radiation and mainly hydrogen bearing functional

groups (C-H, N-H and O-H). Of particular note in the UK has been the widespread

adoption of NIRS as a means of predicting the in vivo digestibility value of grass

silage (see Baker et al., 1994). Importantly, one of the outcomes of the current

Sustainable Livestock LINK Project ‘Feed into Milk’ will be a suite of NIRS-based

feed analyses which will be available for adoption by the industry. The developments

in NIRS in the UK have had an enormous impact on the speed of uptake of nutritional

research by farmers and the agricultural feed industry, and the recent Foresight

document (Office of Science and Technology, 1998) confirms the continuing need to

develop rapid means of characterising animal feedstuffs.

There has been considerable progress in the development of NIRS technology and its

application in both the food and feed industries. These developments have evolved

essentially in two separate although connected directions. Firstly, the range of

applications for which NIRS is being used has increased substantially. In animal

nutrition this has included the use of NIR spectra from fresh (undried) forages and

whole cereal grains, the NIRS prediction of more biologically valuable components of

feeds (e. g. in vivo digestibility; fermentation acid content of silages) and the use of

NIR difference spectra in order to describe feed digestion in spectral terms (see

Deaville and Givens, 1998). Other new applications include the use of discriminant

analysis of NIR spectra to authenticate feeds and foods, and the analysis of milk for

pathogens. These and other newly developing approaches could have considerable

potential in the future concerning feed and food safety, and animal health.

The second type of development includes the advances in NIRS instrument

technology, chemometric methods and software. Notable new technologies include

the use of Fourier transform NIRS (FT-NIRS) which gives highly accurate spectra,

6

FT-NIRS coupled with microscopy, two dimensional NIR correlation spectroscopy,

together with new approaches for gathering spectra (e.g. fibre optic probes). It is also

noteworthy that NIR imaging has just started to be explored and some commercial

NIR imaging systems seem likely to be available soon. Many of these new

technologies seem to offer the potential for the development of new applications for

NIRS which may be highly relevant to the topics of animal and human nutrition, feed

and food safety, and the environment. For instance, FT-NIR microspectroscopy offers

the possibility of rapid detection of small amounts of animal proteins in animal feeds.

Whilst there is a relatively large volume of scientific papers on these topics,

developments in technology are often so rapid that up to date knowledge and indeed

drawbacks are generally only available from the leaders in this science. Therefore, the

objective of the study was to obtain relevant new information on NIRS and related

techniques during a series of fact-finding visits to world experts. A key requirement

was to identify emerging information on NIRS and other physical techniques, which

may have potential to fulfill the present and future research requirements of, DEFRA.

APPROACH

Schedule of visits

The Project was completed in the form of a ‘fact-finding mission’, which relied

almost entirely on making visits to and undertaking discussions with leading scientists

and technologists. This approach was adopted in order to ensure that the most recent

information relating to the developments in NIRS technology was obtained. It also

provided a means of probing for any pitfalls or disadvantages of any emerging

approaches that would not normally be reported in the literature but which might be

disclosed in discussion.

Visits and/or discussions were held with 29 leading experts on NIRS from Europe,

Japan, Australia and USA between February 2000 and March 2001. Details relating

to the place and affiliation for each of those contacted as part of the study are given in

Table 1.

7

Questionnaire on NIRS developments

A questionnaire was prepared as a guide in order to establish the scope of the Project.

Since the developments in NIRS have been in the areas of (1) applications and (2)

instrument technology, chemometric methods and software, the questionnaire was

constructed by asking a number of suggested questions under these two main headings

(1 and 2 above). The full details of the questionnaire used are given below. However,

an important objective of all the discussions was to obtain personal views from the

leading individuals interviewed. Therefore, not every individual seen was able to

comment on all sections of the questionnaire. In addition, individual responses to the

questionnaire reflected the range in personal experience and expertise.

_____________________________________________________________________

QUESTIONNAIRE: NEW DEVELOPMENTS IN NEAR INFRAREDSPECTROSCOPY AND FUTURE POTENTIAL OF THE TECHNIQUE

Background information relating to current applications of NIRS



• Highlight new or emerging applications of NIR technology and other physicaltechniques for food and feed analysis/evaluation.

• Present a view of the likely developments to be made in NIR technologyapplications to food and feed analysis in the next decade.

• Consider if there are known applications in other industries which may havepotential in the food and feed industries but which have to date not been exploited.

• Describe current and future requirements for food and feed analysis and thepotential of NIR technology to fulfill this role. Consider potential limitations ofNIR technology in this respect.

• Describe the potential of NIR to provide qualitative information on food and feedsamples as well as quantitative compositional information.

8

• Consider the application of NIR technology to intact (unprocessed) food and feedsamples.

• Are there developments required in NIR instrumentation in order to allow thepotential of the NIR technique in the future.

2. Current and future developments in NIR instrumentation, chemometric methods and software

• Consider new and future developments in NIR instrumentation including FT-NIR,diode arrays, NIR microscopy, fibre optics, etc.

• Highlight the potential for combining NIR and other technologies during analysis(e. g. NIR and MIR correlations).

• The potential of NIR imaging techniques in qualitative and quantitativeapplications.

• Consider new and future developments in chemometrics and software, includingcalibration approaches.

• Highlight the potential for networks of NIR instrument within the food and feedindustry.

__________________________________________________________________

9

Table 1. Schedule of visits to NIRS experts during fact-finding study

Place Name Affiliation1. Europe Dr J. Andrieu INRA, Centre de Clermont-Ferrand-Theix, 63122 Saint Genès-Champanelle, France

Dr J. De Boever Department Animal Nutrition and Husbandry, Melle-Gontrode, BelgiumDr P. Dardenne Agricultural Product Quality Dept., Agronomical research Centre of Gembloux - CRAGx,

Chaussée de Namur, 5030 Gembloux, BelgiumDr A. Davies Norwich Near Infrared Consultancy, Norwich, UKMr A. Jervis ADAS Analytical Laboratory, Wolverhampton, UKMr V. Mehta Zeiss, Welwyn Garden City, UKDr I. Murray Scottish Agricultural College, Craibstone, Aberdeen, UKDr C. Paul Institute of Grassland and Forage Research, Braunschweig, Germany

2. Japan Dr F. Terada (during visit to UK) Department of Animal Nutrition, National Institute of Animal Industry, Tsukuba

3. Australia Dr A. Blakeney Cereal Solutions, North Ryde, New South WalesDrs S. Baker, D. Henry, R. Dynes CSIRO, Centre for Mediterranean Agricultural Research, Wembley, Western AustraliaDr D. B. Coates CSIRO, Tropical Agriculture, Davies Laboratory, Townsville, QueenslandMr P. Flinn Agriculture Victoria, Pastoral and Veterinary Institute, Hamilton, VictoriaDr C. Greensill School of Biological and Environmental Sciences, Central Queensland University,

Rockhampton, QueenslandMr J. Guthrie Queensland Department of Primary Industries, Rockhampton, QueenslandMr S. Staunton and Miss S. Johnson Bureau of Sugar Experiment Stations, Gordonvale, QueenslandDrs R. Van Barneveld and Y. Ru andMr J. Kruk

SARDI, Pig and Poultry Production Unit, University of Adelaide, South Australia

Dr I. Wesley BRI, North Ryde, New South Wales

4. USA Drs W. Barton (III), D. S. Himmelsbachand R. Windham

Richard B Russell Research Centre, Athens, Georgia

Dr K. Norris Consultant, ex USDA BeltsvilleDr R. Schuman Foss-NIRSystems, Silver Springs, MarylandDr J. Reeves Agricultural Research Services, Maryland

10

RESULTS

The reports of the individual fact-finding visits are reproduced in their entirety withinthis section.

11


Person(s) visited: J. Andrieu

Date: 23 October 2000

Address: INRA, Centre de Clermont-Ferrand-Theix, 63122 Saint Genès-Champanelle

Email address: [email protected]

Author of report: D. I. Givens

Background information relating to current application of NIRS

Most of the NIRS-related work done by INRA Theix in recent years has been used todevelop calibrations for predicting chemical composition and nutritive value (e.g.organic matter digestibility (OMD), voluntary intake (VI) using sheep) of forages suchas hay and maize silage. Most of the work has been in the SPIRAL project. Twoapproaches have been used. Firstly, direct prediction using reference samples forchemical composition and OMD, and secondly predicting OMD and energy valueindirectly from enzymatic digestibility (method of Aufrère). The work has used theFoss 6500 instrument.

Some work developing NIRS calibrations to predict the energy value of compoundfeeds for pigs and ruminants has also been done. This was reported in full by Aufrèreet al. (1996) but essentially showed that NIRS was superior at predicting digestibilityand energy value than empirical models based on chemical composition or enzymaticdigestibility.




[nil response]


Future applications of NIRS will include the ability to be able to predict rapidly theentire chemical /nutritional data of fresh forages at the time of harvest. Some work

12

has been done on the prediction of nutritive value of maize silage using freshforage before ensiling. For example, the prediction of degradability using freshforage preserved by freezing in liquid N has been examined.


[nil response]


The work on forages mentioned above will be extended to the prediction of PDIvalue by NIRS but as yet not all the reference data are available. The referencemethod used is nitrogen degradability in situ or using an in vitro protease method.

For the prediction of voluntary intake (VI) the project will also be extended but atpresent NIRS cannot directly predict VI because VI data are difficult to obtain. It isexpected that only indirect prediction will be used and the work will be limited tomaize silage. The reference method used will be dry matter (DM) or NDFdegradability in situ but the work has not yet been done. This is based on datawhich examined the relationship between VI in dairy cows and DM degradabilityalthough the relationship was not very good (r2 = 40%). The prediction of VI fromOMD measured in sheep explained slightly less of the variability (r2 = 35%). Dataon NDF degradability are not available as yet.

In the future, the prediction of rumen parameters by NIRS examination of the dietwill need exploration. INRA plans work on this topic but at present, there are notsufficient samples.


NIRS has a major role in the development of tables of feed composition includingin vivo data. In this way information to be used by ration formulation software andextension workers can be rapidly updated and made available.

The in situ technique when used to measure for example NDF degradability isheavily dependent on lost of chemical analysis of bag residues. The use of NIRS topredict the composition of residues has been examined and appears successful.


All the work on maize silage described above was carried out using material driedat 80oC for 48h but more recently the use of NIRS to predict maize silagedegradability has compared scanning fresh and dried material. The fresh approachis very interesting, as it is rapid and can be used to assess DM content. In addition,

13

studies using NIRS on the relationship between chemical composition and DMcontent, and DM and NDF degradability of fresh maize plants are ongoing (usingfresh and dried material). More work is needed on fresh material.


[nil response]

2. Current and future developments in NIR instrumentation, chemometrics and software


[nil response]


[nil response]


[nil response]


Research on this area has been done mainly by D. Bertrand. Most calibrationsdeveloped at Theix use MPLS models with or without scatter correction (normallythe SNV-D approach). Modeling aspects need more research as this is a crucialtopic and there needs to be a closer relationship between the nutrition and modelingdisciplines.


[nil response]

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Person(s) visited: J. De Boever

Date: 23 November 2000

Address: Department Animal Nutrition and Husbandry, Melle-Gontrode (near Gent), Belgium




The NIRS instrument (Technicon) was purchased in 1988. Work started in 1990 withthe first task being to predict the chemical composition (fat, protein) of fresh milkfrom individual cows. In connection with feeding experiments with dairy cattle at theInstitute, 100 to 150 samples need to be analysed every week. NIRS was chosen overIR for milk work because the NIRS machine had been purchased for feed evaluationand was available. A transflectance cell is used with homogenised milk pumpedthrough. The calibrations work very well, but there is a need in every working sessionfor an adjustment for bias and slope by analysing 15 to 20 samples by referencemethods.

The real feed evaluation work started in response to the needs of the feedmanufacturing industry to predict the chemical composition, digestibility, net energyvalue etc. of firstly feed ingredients and later also for the main forages maize andgrass silages. This work was done in collaboration with the Flemish feed industryover three years. Calibrations were then distributed to the feed manufacturingindustry who are mainly working with filter instruments (Infralyser 450). This workfinished in 1996 (papers in Animal Feed Science and Technology on maize, grasssilages and compound feeds). The questions relating to compound feeds came fromthe Belgian Feed Inspection Service. Since this work finished, the feed industry hasnot been prepared to put more funds into research as it thought it had all theinformation it wanted. The calibrations have been modified but the companies havenot organised into a network so this information is not known by all.

New work on in vitro, in situ and gas production techniques has gone on. In themeantime NIRS has been used by the Institute to predict the chemical composition ofbeef meat (water, fat, protein). Work to predict fatty acid make up of meat directlyhas also been done but concentration of fatty acids is too low. It may be possible todo this on extracted fat.

15



• Highlight new or emerging applications of NIR technology and other physical techniques for food and feed analysis/evaluation.

NIRS technology is needed for the new feed evaluation systems/models that arebeing developed, to include the prediction of nutrient degradation characteristics,microbial protein production etc. The new models will be based on many difficultparameters to measure, which in practise will need NIRS. In addition, a project incollaboration with INRA and universities in Italy and Spain is looking at the use ofNIRS for predicting the chemical composition and digestible energy (DE) value ofrabbit feeds. The DE values are based on in vivo measurements. A database ofmore than 100 compound feeds for rabbits is being developed and it is intended tohave a common calibration for all participating laboratories. The developedcalibrations are firstly destined for use on institutes' own compound feeds andindustry is not yet involved.

Very considerable use is now made of in situ degradation data and this is likely tocontinue for the foreseeable future. Some work has already been done to predict insitu parameters (solubility, degradation rate etc. of protein) by NIRS but thecalibrations are not entirely satisfactory. NIRS is very capable at predicting proteinconcentrations but to predict effective degradability of protein is difficult as theresponse of the animal is not always present in the sample. New work willexamine a set of maize silages (n=27) with data on degradability of DM, OM,NDF, N and starch to examine NIRS for predicting rumen fermentable organicmatter, fermentable cell walls, resistant starch and other factors. The in situ data arebased on the incubation of fresh maize silage chopped in a meat cutter. The use ofNIRS to predict cell wall digestibility in vitro will also be studied.


[nil response]


[nil response]

• Describe current and future requirements for food and feed analysis and thepotential of NIR technology to fulfil this role. Consider potential limitations ofNIR technology in this respect.

The prediction of meat composition etc. on the slaughter line to define better whatits use would be a very valuable application. pH, water holding capacity, shearforce etc. are current predictors of meat quality but the ability to predict these onthe carcass would be invaluable. Some work has started on this topic with pig

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meat but the calibrations for pH and shear force are not as good as traditional useof NIRS but may be good enough for classification of quality category. More workon this topic is definitely needed.


[nil response]


The use of NIRS to predict the composition of whole grains for poultry would bemost useful as it would enable the selection of grain very early in the buyingprocess before any processing of the grain had taken place.


[nil response]



The role of fibre optics to allow the prediction of the composition of manures,slurries etc. is a possibility, which needs exploration.


[nil response]


[nil response]


The development of the concept of locally weighted regressions is interesting andneeds further work.


17

[nil response]

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Person(s) visited: P. Dardenne


Address: Agricultural Product Quality Department, Agronomical Research Centre of Gembloux – CRAGx, Chaussée de Namur, 24, 5030-Gembloux, Belgium




Pierre Dardenne started using NIRS 20 years ago with work on forages (grasses),legumes and other feeds (cereals). The work then switched to compound feedingredients and more recently it has moved more towards study of human foodsincluding cheese, meat, drinks, fruit juice, apples etc. Also some work has beenstarted on soils to measure nitrogen and carbon, together with some work monitoringwheat crops (nitrogen in leaves) during the growing season to optimise fertiliserapplication.

Most of the work on forages has been to predict chemical composition (protein, fibre,Van Soest fractions, sugars, starch, fat, etc.) but has included some animal relatedmeasurements (e.g. digestibility, voluntary intake). There has also been a largeprogramme of work on forage maize for silage with a database now containing some4000 samples collected over 15 years. Most of the maize breeders (Limagrain,Pioneer, Novartis etc.) now use these calibrations, as does NIAB in the UK. Theprediction of digestibility uses calibrations based on the Aufrère cellulase methodand/or De Boever cellulase method. Data bases exist for in vivo digestibility but themodels are not used routinely due to the difficulty to maintain and update the modelswith new samples. There is a network of many instruments, which are matched toPierre Dardenne's instrument and each year, each laboratory selects about 10-20samples which are sent to Dardenne's laboratory for wet chemistry. These results areused to check and if necessary adjust the calibrations. These data are of course alwaysone year late! The calibrations are now quite stable and few changes are needed.



19


Dardenne's laboratory has been working for two years with the Perkin Elmer NIRSmicroscopy system to detect meat proteins in feeds, as an alternative to classicalmicroscopy. The system has worked quite well but is rather slow due to having toscan too many particles, about 600 per sample, which takes half a day. It is, however,possible to improve this technique, particularly if the software could be improved. Itis also likely that the next development will be image analysis. Dardenne's laboratoryco-ordinates an European project (http://stratfeed.cragx.fgov.be) to improve anddevelop methods in this field.

It was felt that use of NIRS for sample identification would be useful, for exampleindicating that a sample originated from a certain geographical region. Anotherapplication would be for identifying food type and hence perceived quality, forexample to distinguish between chicken meat produced from intensive and more'organic' type production systems. Some work has been done which was able todistinguish meat from birds slaughtered at 42 days old compared with thoseslaughtered at about 80 days old.

Pierre Dardenne reported that there was a poster at the last International NIRSSymposium in Chambersburg examining the use of NIRS to predict the presence ofGM soya beans. (Roussel, S. A., Hardy, C. L., Hurburg, Jr, C. R. and Rippke and G.R., 1999. Identification of Genetically Modified Soybeans by Near-InfraredSpectroscopyIRS (DIG has emailed Sylvie Roussel ([email protected]) to obtainmore details).

The prediction of available amino acids has been shown to work reasonably well (e.g.van Kempen, T., and Bodin, J-C., 1998). Near-infrared reflectance spectroscopy (NIRS)appears to be superior to nitrogen-based regression as a rapid tool in predicting thepoultry digestible amino acid content of commonly used feedstuffs (Animal FeedScience and Technology 76, 139-47) but the availability of reference samples is still abig problem. It was felt that obtaining a copy of the Proceedings of the 1999 9th

International NIRS Conference in Verona worth getting.


[nil response]


[nil response]


20

Developing countries have a need for much improved and expanded feedcharacterisation. NIRS has much potential for feed applications in developingcountries to replace old laboratories and wet chemistry with simple NIRS systems.This will improve feed quality assessments and improve the efficiency of animalproduction. The approaches must be simple to use and simple to maintain.

The safety of food is as important as composition and in particular, there is concernabout the levels of pesticide residues, mycotoxins and dioxins. At present, NIRScannot measure these compounds because their concentrations are too low. There hashowever, been some claims that NIRS can measure PCBs in extracted fat. In addition,with wheat, barley and maize grains the pesticide/fungicide protection is on theoutside of the grain and it is possible to use NIRS to predict these compounds seed byseed. More work is needed on these topics.

The food industry is increasingly required to declare the nutritional value of foods.One novel approach for prepared plates of food sold in cafés, supermarkets etc. wouldbe to have NIRS built into the microwave oven to predict the energy value of the plateof food. This could also be a means of the declaring energy/nutritional value duringcooking at the plant. With present technology, this would be too expensive to have inthe home.

The use of NIRS to assess taste/sensory analysis requires more work to be done.Many samples are needed and other techniques using PLS /artificial neural networksmay be more promising.


It is probable that scanning with a diode array instrument at slaughter could measuredifferences in fat content although probably not fatty acid make up because fatty acidconcentrations are too low.


Wet calibrations need a more robust approach since the biggest problem relates tosamples of low dry matter content being much less homogeneous than dried, milledsamples. As a result, there is a need to scan more than one sample with maybe 10minutes required to measure several replicates of one sample. It is also more difficultto match instruments with wet calibrations because with dried samples maybe 30sealed samples can be used whereas for wet samples, some 30 large sealed samplesare needed and it is almost impossible to do. Often it is done with only one sample,just correcting the calibration for bias but not for slope differences. Wet calibrationsfor maize silage are particularly difficult because of the heterogeneous nature of thematerial.


21

[nil response]

2. Current and future developments in NIR instrumentation, chemometrics andsoftware


Diode array technology is the emerging application for use in the field. PierreDardenne's laboratory has recently bought a Perten DA7000 and two Zeiss Coronainstruments to put on harvesters for next season. They will have one on a forageharvester for grass and one on a combine harvester for wheat. One aim is to havewheat composition very quickly and the other is to combine this with GPSinformation to have grain yield, quality and geographical position. The Zeiss diodearray instruments are also good for use in the laboratory because they are easy to use,can deal with big samples and are very fast. They are also much cheaper thantraditional instruments but there is still a lot of work to do to test the transfer abilitybetween the old and new types of instrument and also between Zeiss instruments.

Industrial applications also have much potential for the new instruments, particularlywhere there is a flow process such as in feed manufacture, milling, biscuit making etc.New technology hand-held instruments are also emerging and may lead medicalapplications such as to measure for e.g. blood glucose.

Fibre optics are not that useful for laboratory applications and they need to be muchcheaper for on farm etc. use.


It is possible to combine MIR and NIR but more work is needed on its application.


The developments in instrumentation that are needed mainly relate to making themcheaper. NIR imaging is probably the next big step. Pierre Dardenne's assistantrecently went to US to test an imaging system but at present the system is veryexpensive (>10 million BF; >£150k). However, if the approach proves successful andcan examine some 50 samples per day it would be very valuable being much quickerthan classical microscopy (maybe two samples per day) for detecting meat and itsorigin.


In chemometrics, the development of artificial neural networks (ANN) is probably thenext big step. However, ANN needs very big datasets because there are many ways in

22

which the weights are calculated, but has the big advantage of making no linearassumptions. There is an NIR grain network managed by Foss-Tecator with theirInfratec system. This now has thousands of instruments all over the world and theynow propose only one calibration for everywhere. The database now contains 40,000spectra each with only 100 datapoints (850-1050 nm). These 40,000 samples havebeen collected from all countries with laboratory N and moisture values. Thecalibrations can cope with all the situations. The architecture of the ANN used is verysecret but is better than PLS calibration. However, the power of the same approachwith the full spectral range (1100 to 2500 nm) and merging of large databases of feeds(maybe 10000 to 20000 feed and feed ingredient samples) could be enormous andlead to something that would work everywhere. To have such a large database couldbe the next key development in this area. Pierre Dardenne proposed that we shouldtry to set up a project on this. Because there are so many weights involved in theANN algorithm, there is some kind of discrimination (as well as prediction) withinANNs themselves so that when a new spectra is seen it can recognise, which group itis from. Some ANN software now uses PLS scores as input data but for now it isperhaps better to use the raw spectral data. Iowa State University (seehttp//grainnet.ae.iastate.edu; http//www.iowagrain-org) has developed a web sitewhere it is possible to send files of Infratec's whole cereal seed spectra and receiveback automatically the estimated protein and moisture values.


The other big step is related to access to the Internet with a big database on the serverwith each instrument/PC connected to the Internet. Each time samples are examined,the spectra are sent to the server and data predicted on the server with the ‘local’concept. The program on the server will choose maybe 100 to 300 samples to createits calibration and send back the predicted data. This concept would have no fixedpredictive models, one database and everything that is measured can be traced. Theusers will also only pay for what they use. This is a logical extension of the networkconcept and is the future. CRAGx intend to implement this tool on its own webserver using this concept and the package developed by John Shenk and his team(Foss-ISI, InfraSoft International, PA, USA).

At present, there are networks, but each time an equation is updated it has to be sent toall members on the network and there is always the risk that not all members are notusing the same version. With the new concept, everyone has the same level ofservice. Any outliers can be quickly incorporated. Foss-ISI is working on theconcept. The network operator website will have a private site that will allow accessto a list of calibration equations and spectral files can already be sent there. Theserver will send back a file of predicted data automatically.

There is however, a lack of research institutes who have databases, which could bemerged. In order to work towards the EU objectives of food security and safety someinitiative should be made now to include public institutes dealing with animal feedsincluding compound feeds. This would create a consortium of centres, which wouldput data onto a central server for the group to use and create rules/charges for accessto others. There would be a need to build our own program to deal with the spectra to

23

avoid being linked with commercial software. There would also be a need for a goodstatistician to create the software package within the server and to include spectralrecognition at the same time. Ultimately these tools would also be able to help thefarmer.

24


Person(s) visited: A. Davies

Date: 2 April 2001

Address: Norwich Near Infrared Consultancy, Norwich, UK

Email address:

Author of report: A. Davies (edited by E. R. Deaville)


[nil response]



NIR spectroscopy is a very powerful technique for detecting change. Tony Davies hasbeen urging the industry to use it as a monitoring technique that would give themwarning of a problem much more quickly than the present ‘wait and see whathappens’ approach. While serious problems are rare, the consequences can be veryserious for the victims who (in the worst cases) die. We are considering spending vastsums of money to protect a small proportion of rail users from avoidable accidents.

• Likely developments in the Application of NIR analysis in the UK

Tony Davies does not expect any new developments in NIRS to occur in the UKsince there is no UK research base in NIR spectroscopy and a determination in theacademic community to ignore it!

The only successful area is pharmaceutical analysis. Much of what thepharmaceutical industry does with NIR spectroscopy could also be done in the foodindustry but the pharmaceutical industry only does it because of legal requirements.

Tony Davies has been trying to discuss the idea of determining the age of beefcattle by NIR with representatives from the Food Standards Agency since the onlyavailable technique at present is to read the documentation.


• Instrumentation

25

Lower cost hand-held instruments based on solid state optics – fixed grating usedwith detector arrays (CCD InGaAs etc.) have been developed by many companiesand they have many applications in the food area.

NIR microscopy has been used for the detection of animal tissue in animal feedsand as these instruments become, faster and cheaper new opportunities in food andfeed analysis will occur. In the pharmaceutical industry, they have been able todeduce which component of a tablet was responsible for water vapour absorption.There is no other technique capable of achieving this result.

There is the possibility of enormous potential for crop analysis when theAmericans get their earth orbiting NIR imaging system running (they have beenvery unlucky with satellite failures). Tony Davies is not aware of any UK interestbut some day a vast amount of information will be available every time the satelliteis overhead.

• Chemometrics

In 1987 Tony Davies proposed a new method of using NIR spectroscopy forquantitative analysis (CARNAC), based on the comparison of the spectrum of theunknown (test) sample and members of a large database. ISI has developed avariant of this approach, which is proving quite successful. Tony Davies iscurrently in the process of up-dating the CARNAC method using some more recentdevelopments (such as wavelet compression). Database analysis couldrevolutionise the quantitative application of NIR spectroscopy because it ends thecalibration/validation system bottleneck.

Instruments all around the world could be utilising databases from computerssituated anywhere in the world with a reliable communications system (even theUK).

26


Person(s) visited: A. P. Jervis

Date: 16 February 2001

Address: ADAS Analytical Laboratory, Wolverhampton, UK


Author of report: A. P. Jervis and E. R. Deaville


ADAS has been involved in the development of NIRS as a rapid method of analysis,particularly for forage (grass silage) evaluation for more than 15 years. Work carriedout, together with SAC and DANI, resulted in the development of an NIRS calibrationfor the direct prediction of the in vivo organic matter digestibility (OMD) of grasssilage. During the long period of use of the prediction, it was reported thatapproximately 80% or more of all the grass silages in the UK were evaluated usingthis prediction equation. Traditionally all calibration equations were developed usingdried and milled samples but with the developments in NIRS technology many sampletypes are now evaluated using fresh, undried samples (requiring no samplepreparation). The range of routine analyses carried out using NIRS at the ADASAnalytical Laboratory include grass (dried and milled) for crude protein (CP), watersoluble carbohydrates (WSC) and modified acid detergent fibre (MADF); straw (driedand milled) for OMD; grass silage and maize silage (fresh, undried) for a full range ofsilage quality parameters; cereal grain (whole, unmilled) for nitrogen and dry mattercontent.




More recently, NIRS has been used to monitor vegetation change in samples ofvegetation taken from species-rich grasslands and for distinguishing species ofbirch trees based on scanning their leaves. Also, used to rapidly determine the weedto crop biomass ratio in order to determine weed thresholds and optimise herbicideuse. Initial studies have also indicated a potential for NIRS for undertaking a multi-component analysis of sewage sludge for dry matter, nitrogen and ammonia, andfor determining potential mineralisable nitrogen content of compost.

27

Based on the evidence in the published literature Andrew Jervis feels that NIRShas a role to play in determining meat quality (e.g. proximate analysis) andcompost quality (e.g. organic matter, nitrogen, dry matter, ammonia-nitrogen).Further work is required to determine the potential for NIRS to predict measures ofmeat quality (e.g. tenderness, sensory characteristics), discrimination of fresh andfrozen-thawed meat, monitoring ecology sites for habitat suitability for differentflora and fauna.


Move towards more portable devices requiring diode array technology to includemore of the NIR bandwidth.


Development of on combine N sensing providing yield maps with satellitepositioning.


One of the major limitations of NIR technology is its inability to determine lowlevels of constituents.


Use of PLS discriminant analysis, potentially for butter, coffee. Used for teablends where the blend is identified and then a quantitative equation is applied foreach group that is calibrated for.


Perten DA 7000-scanning of whole chicken carcasses (JNIRS vol8 No.1 2000).


Move towards solid state instruments.


28


[nil response]


[nil response]


[nil response]


Use of neural networks for non linear calibrations.


Need for consistent predictions across member machines and remote calibrationand maintenance of machines.

29


Person(s) visited: I. Murray

Date: 19 January 2001

Address: Animal Biology Division, SAC, Ferguson Building, Craibstone Estate, Bucksburn, Aberdeen AB21 9YA




[nil response]




Qualitative and quantitative, quality control and authenticity checking, move toimaging in the visible and NIR regions, sample presentation being highly flexibleincluding micro-spectroscopy, automatic instrument diagnostics, flags andwarnings. Auto sample recognition and calibration model selection. An exampleof the use of discriminant analysis of NIR spectra is given on the attacheddocument (Murray et al.). This shows that NIRs spectra can detect small amountsof meat meal in fish meal.


[nil response]


[nil response]

30


[nil response]


[nil response]


[nil response]


[nil response]



Optical instruments.

Smaller, faster, cheaper, rugged task dedicated, bolt-on and research grade, pre-dispersive, post-dispersive, prism, grating, interference filter wheels, AOTF, CCD,Diode array, no moving parts, interferometers, fast non-contact, cloned andnetworked, on-line with closed loop feedback control in manufacturing and foodelaboration, fibre optic remote and ‘in vivo’ presentation possible, imaging tissuesand organs. Automatic sample queuing.


[nil response]


[nil response]


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Computers and software

Smaller, faster, cheaper, task dedicated, cloned and networked, refer spectra world-wide for analysis. Trend to use spectra alone without preoccupation with‘reference method’. Spectral library search techniques. Optimised pre-treatmentmaths and new algorithms of various kinds. Perhaps better spectral interpretation.Chemometrics used more extensively by non specialists, ‘aliasing’ to matrixbecomes more accepted as a method, use as an ‘omni-analyser’ for testingcommodities and as a ‘xenoprobe’ for detecting outliers, foreign specimens ornatural products that may have been adulterated, contaminated or otherwisetampered with (see paper by Murray et al. attached).

Internet used for on-line networking, shared access spectral libraries and publiccalibration models made available for cloned instrument spectra.


[nil response]

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Person(s) visited: Dr C. Paul (with inputs from Peter Flinn, Agriculture Victoria,Australia and Michael Rode, Carl Zeiss Jena GmbH)

Date: 25 January 2001

Address: Federal Agricultural Research Centre (FAL), Institute of Crop and Grassland Science, Bundesallee 50, D-38116 Braunschweig.




In the early 1980s the Director of the Institute went to the United States and found outabout the work that Karl Norris had done together with John Shenk and others onassessing forage quality by NIRS. As it was clearly an instrumental technique, thequestion arose about how to get hold of the hardware. Then there was an attempt totake a spectrometer from the visible range, which had the possibility of beingextended into the NIR region, equip that with an integrating sphere, self built andsome software. There was a team of one physicist and one animal nutritionistinvolved but the whole project was abandoned after two years or so because it becameclear that this home made approach was totally ineffective.

Then the project was transferred to Christian Paul and it was agreed that he could takea completely fresh look at everything. He wrote letters to people like Karl Norris andJohn Shenk and others who warned against reinventing the wheel and therefore FALprepared to obtain a long scanning monochromator. The question then arose as towhether they should buy the 6250 as a single beam instrument or the TechniconInfralyser 500 as a double beam instrument. A key question was in terms of software,i.e. NSAS versus ISI. The Infralyser approach was soon dropped because ChristianPaul realised that especially in the UK there was a very active group of for e.g. IanCowe and Ian Murray and with others from grain applications like Brian Osborne, andall these people were mostly using the 6250 approach. Accordingly, in 1983/1984FAL bought a 6250.

At the same time, Christian Paul also bought, in connection with people from theadvisory service, a Neotec 101S, a grain quality analyser. This was a tilting filterinstrument which could be calibrated from the same software that was used for the6250 and it was possible to show at the same time that the instrument was applicableto the FAL sort of forage quality applications. Also, it could be used by people in theadvisory service for assessing, on freshly cut forage, the increase in crude fibre and the

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decrease in crude protein that occurs as the plant matures. Therefore, the wholeapproach was immediately implemented in the early 1980s as a monitoringprogramme for the grassland farmers to know when they should be cutting grass forsilage.

In the early 1980s average crude fibre contents of 280 to 300 g/kg DM were seen ingrass silage with a resulting low energy content. This had to be changed and so it wasdecided that target crude fibre contents of 250 g/kg DM in silage must be achieved.To account for conservation losses, a target of 230 g/kg DM was aimed for in grass atcutting and the scheme was reported widely by farmers magazines on a weekly basisand later on even on a daily basis. Also, the increases in crude fibre and decreases inenergy value in the forage in the north German plain were communicated to thefarmers by the radio and telephone services. This was one immediate, practicalapplication which worked very well, it provided a lot of information and was the firstapplication which had created some kind of publicity for FAL and for themethodology itself.

Subsequently Christian Paul went to the oilseed rape breeders who had, since the early1970s, been doing a lot of experiments on changing the oil composition and theglucosinolate content of oilseed rape. They already had effective methods of singleseed analyses and highly effective quality control, but it was proposed that they have alook at NIRS. Work was then started at FAL testing rapeseed with NIRS and thatwent so well that the rapeseed industry and the breeders carried forward with FAL andin conjunction with the University of Göttingen two or three more projects basicallyall aiming to develop NIRS calibrations. In fact, they went further and managed to setup a network among the oilseed rape breeders to obtain unified calibrations for drymatter content, protein content, oil content and interestingly glucosinolate content.The latter was difficult as glucosinolate content in the newer oilseed rape varieties wasgetting very low. They are now below 20 µmoles per gram of seed. Glucosinolate hasso little absorption in the NIR that the work that was done was really of high qualityand in fact, the calibrations are still in use in Germany and also in Sweden. They arealso being tested in Canada. This work was a major achievement in terms of rapeseedbreeding for improved quality.

At the same time FAL also had continuous contacts with the maize breeders, foragemaize breeding being the most important forage crop here in Central Europe. Thefirst couple of years were devoted to testing whether NIRS performed adequately.This was confirmed and calibrations were adapted, developed further and put onto anetwork. Eventually in the mid 1990s FAL had set up an experimental network ofmore than 20 scanning instruments in many different laboratories, private, governmentand regional. They all used the same calibrations developed at FAL and eventuallythis network was transferred to (including the personnel) to the German Associationof Official Agricultural Chemists. They are still maintaining this network now and itis one of the self financing projects there.

The maize calibrations are also used for variety testing and it was a majorachievement to convince the German Federal Variety Testing Office (FVTO), a veryconservative institution, that NIRS was appropriate to be used. After the FVTOjoined the project the whole scheme of quality values and quality maize, whether in

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breeding or variety testing was revolutionised. The whole approach was thenobviously extended into the advisory system for testing forage maize and silage.

Overall, all these experiences have shown that you have got to have available togethera good instrument and a good chemometric software package. Also, the more it isclear that how samples are prepared is crucial and obviously the reference methodshave to be maintained up to modern day standards.




Christian Paul really thinks that the technology has not yet fully matured but that anew step has been reached using new hardware and software tools which bring thetechnology much closer to the producer or the consumer and he believes that it is aquestion of fantasy and courage to think of new fields of application. For instance,Palo Berzaghi from Italy, in terms of animal feeding, wants to bring an NIRinstrument into the feed mixer, not just for quality control on the mixing but alsofor having information which is really at the interface between the mixed diet, thecow and the various components that are used in the total mixed ration. Also tohave something which records what was actually fed. The question is then what doyou expect from that and where do you start? How can you go with yourexpectations, how do you make sure that you’re not creating illusions?

One thing for sure is that we can assess much better than we were able topreviously, the dry matter content of the actual feed and with all the compoundinformation that you have in this spectrum, you could place in such a feed mixer,your NIR instrument not only at the outgoing side but also at the incoming side.You could have control over the mixing and this way you could then go back fromthe spectrum of the mixed feed to the spectra of the incoming feeds and make amuch better control of mixing. That is just one example, but other examplesinclude putting such instruments on agricultural harvesters, starting with the easyflowing agricultural products for e.g. grains and seed like rapeseed. You would notwant to work immediately with sugar beet for instance, but then you could integratethis into precision agriculture, so that you will then have a check on what thefarmer has harvested and what he delivers from the farm. You could haveequivalent methodology working for the feed purchaser so that not only a few sub-samples of the huge load are taken but the total stream scanned and actually samplespectroscopically the whole stream of goods. That is a very essential point. So far,quality control has always been limited to sub-samples and the big errors arise outof sampling error.


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NIRS may be valuable in the future for grading fruit and indeed work of this type isbeing done in Australia.

On-line direct control by NIRS will be a key feature, particularly with the advent ofdiode array instruments. It is likely that many features of NIRS that have beenlearnt in agricultural applications will be translated into the food industry.


[nil response]


[nil response]


It is disappointing that no animal nutritionists out in the advisory field have seenthe potential of faeces analysis for supporting feed evaluation. Christian Paulthinks that this method has a lot of potential benefits for this but it is not being usedfor any significant extent whatsoever. Earlier work showed that it was possible toestimate the fibre and nitrogen content of faeces and from the nitrogen content, theorganic matter digestibility of the feed consumed by the animals can be predicted.That has many benefits in terms of grazing animals especially range animals but itcan also be useful for housed animals. The approach could also be used at farmlevel to determine the extent to which different fractions of feeds had been digested(e.g. starch) and could also be used to check very quickly for pathologicalconditions. Diode array instruments may become a tool of the veterinaryprofession too. It would be possible to also look at all animals in a herd and assesswhich ones could digest most starch etc. thus giving a better concept of whole herdin terms of both nutritional and health status. These data could also be used incombination with feed data obtained using the same instrument. FAL data suggestthat faecal calibrations are independent of the dietary composition making theapproach attractive and flexible.

Alkanes have also been used to predict voluntary intake but there is a problemmeasuring alkanes by NIRS, and FAL has not done that. It may be necessary tohave some stage of isolating or fractionating the alkanes. In Australia Peter Flinndid not actually use NIRS to predict the level of alkanes but used the voluntaryintake values predicted by alkanes to calibrate the NIRS. One of the interestingtopics that the alkane people are working on is not just to predict intake but topredict botanical composition of what is consumed.

The particular approach used at FAL was to assess selected grazing because whenanimals are in a grazing situation it is very difficult to establish what the animals

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actually eat, rather than what is on offer, and there can be a large differenceespecially at low grazing intensities. One of the reasons that perhaps the faecalapproach has not taken off is simply the natural resistance against handling thesamples. People just do not like working with faeces.


With regard to sample preparation Christian Paul realised, from the literature andfrom the developments which are ongoing, a continuing trend away from veryclosely controlled situations where you are basically looking at a close to idealdiffuse reflector, for e.g. a ground and dried forage where you are basically lookingat minute particles of forage dry matter prepared by whatever methods. Insituations examining the forage as it was presented to the animal, the use of freshforage allows it to be done without the many artefacts arising in the samplepreparation process. In the grain industry, the same thing has taken place. Withwhole grains, there was previously a heavy reliance on the combination bandregion of the NIR spectra. This was going further and further down to that regionwhich is represented by the Infratec near the upper end of the silicon detector rangewhich is used for sampling whole grains and also whole forages. FAL madeattempts along these lines to use an Infratec meat analyser to study grass silagewith some success. However, it was realised that the whole scanningmonochromator approach was a very slow one and too slow especially for movingthe whole field of application further and closer to where forages or grains areproduced or utilised.

This is where diode array systems came in to the picture and this is where ChristianPaul had a feeling that a whole new stage was opening up where we could use theknowledge gained previously for much more interesting applications, but alsomuch more demanding ones. These applications will be more demanding becauseits quite obvious that when you take an NIR instrument and place it close to thesheep that are being fed forages and excrete faeces where you take the same foragesfrom the sheeps' mouth put them into the NIR instrument and take the faeces afterthey have cooled down from the sheep crate and put them into the NIR instrumentthat is an environment where lots and lots of problems are created. However, it is ademanding and very interesting field.


There are currently some problems related to the fact that software and hardwarehave not been optimised to each other. Both must be considered and developedtogether. In addition, more attention is needed to ensure reproducibility betweenmachines. For example, one of the biggest sources of variation between the samemake of instrument (for e.g. NIRSystems single beam instruments) is the situationand characteristics of the ceramic. The ceramic is needed for referencing the celland if the ceramic is dirty, it is different to the ceramic, which is clean so it giveseither a bad or a good reference. The closer you get to the practical application themore likely you are to get dirt on the ceramic reference. This will influence results

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and as has been seen on for e.g. the diode array machines installed on harvesters.Special precautions were applied to ensure that the ceramic remains clean.



When FAL got hold of the first diode array NIR instrument from Zeiss, theinstrument was still not in a compact form but delivered in pieces with themeasuring head linked up with light fibres to the sensor and so on, and thatcontrolled from a notebook PC. Also it was doubtful if Zeiss were really interestedin small agricultural customers like research institutes, because they were used totalking to large companies, which like Hewlett Packard, bought their componentsand built them into instruments themselves. It was not that Zeiss tried hard to sellthe instrument to FAL but that FAL had to really try hard to buy it from them!

As indicated by Michael Rode, Zeiss has really entered the market rather thanstaying outside and providing components to people who are in the market.Previously they had nobody who was able to think in terms of certain qualityassessments, certain ready made products. Zeiss now confirm that the direction inwhich they will go is to develop special and single applications. These applicationsare now showing some successes. In a few years NIR instruments may be sittingon agricultural harvesters, not just on some but on many harvesters. Thus, moreinstruments will be sold to agricultural engineering companies than to laboratoriesand because of the large numbers, the price of the instruments will fall. They willalso eventually replace the conventional grating instruments in the laboratory.

A lot of research has recently been carried out by FAL on the experimentalinstallation of diode array instruments on plot-size forage and combine harvesters.The pictures below show some views of this and the copy of a recent posterpresentation is included to give some details of calibration etc. performance.

Diode array instruments in the laboratory

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Diode array instrument mounted on plot forage harvester

Diode array instrument mounted on plot combine harvester

Poster display on forage analysis on the forage harvester

The big challenge is to ensure that an analysis done on one machine gives the sameresult on another. For testing laboratories, the emphasis will change from samplescoming in to managing a network and ensuring that instruments give the samevalues.

Diode array

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Potential for using Internet information and coupling with for e.g. GPS data onharvesters. Some work with grass has demonstrated the benefits of coupling NIRSand data from visible spectra. For instance as grass matures it becomes moresusceptible to diseases and whilst NIRS showed that losses in water and solublecarbohydrates had occurred, the visible range showed that a green-red shift hadoccurred which provides additional information on what had occurred.

Some attempts are now underway at this group at FAL to develop tests on volatilefermentation products in fresh silages by an electronic nose (e-nose). It is felt thatthe combination of NIRS tests for major nutrients and e-nose tests for such volatileconstituents may form a complementary analytical approach in quick and yetcomprehensive silage quality tests.


[nil response]


Michael Rode proposed that one valuable development would be managementsoftware for spectra to allow you to work with virtual data. The software willknow what type/format the raw data are stored and use it without any actions by theoperator. The software will be able to handle automatically all data formats andyou will therefore be able to work with a virtual or data in other applications (e.g.Excel). This will make the use of the data much easier. A common standardoutside of the normal software/hardware barriers would effectively be created.

Christian Paul is very supportive of developing further the concept of localcalibrations. An example of its benefit was shown in a study where FAL had 700grass silages scanned fresh in an Infratec meat analyser over the range 200 to 300g/kg dry matter content collected over several years from Northern Germany and sorepresented silages used in practice. There were two or three independentvalidation sets developed later and separate from the calibration set. The spectrallibrary of 700 samples was taken and a global calibration developed across themand compared with local calibrations. Local means that first the unknownspectrum is tested against the whole spectral dataset, similar spectra are selectedand virtually combined into a new calibration. There is therefore one regressiononly done for that one prediction to be made. The benefits of the local approachwere particularly noticeable for dry matter content (R2 0.88 global, 0.98 local; SEP3.0 global, 1.5 local). Local calibrations allow linear relationships to be used in anon-linear world.


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What is needed is networks of comparable instruments working to a comparable endgoal. These are difficult to form as users have been brought together with mutualbenefits. For e.g. in the FAL forage maize work the introduction of instruments wasgradual. With confidence more groups joined in and is still the basis of integratedforage quality and variety testing.

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Person(s) visited: Dr F. Terada (during visit to the UK)

Date: 18 September 2000

Address: Department of Animal Nutrition, National Institute of Animal Industry, MAFF, Tsukuba, Japan.


Author of report: E. R. Deaville


Research into the use of NIRS began in the 1980s and started with examining thepotential of the technique for feed evaluation. In the early 1990s, the Ministry ofAgriculture extended the NIRS research in order to establish a feed evaluation servicebased on NIRS. Initially the focus of the feed evaluation service was the prediction ofchemical composition (e.g. dry matter, crude protein etc.). However, there is now agrowing requirement for quality assessments to be made including, silage quality, fruitnitrate nitrogen content and mineral contents. In agreement with other countriesacross the world, the development of NIRS in Japan is being driven by the need for abetter description of feed quality. NIRS has been used to estimated the compositionand nutritive value of grass, analysis of edible oil (sunflower), and to identify fattyacid composition differences using principal component analysis (PCA).

In Japan, dairy farms currently comprise of approximately 50 dairy cows althoughthere is growing interest to increasing cow numbers. Milk quality is judged in termsof milk fat and protein contents, and somatic cell counts, and together these can beused to detect changes in animal status. Also, the price of milk depends largely on fatand protein contents. During the development of NIRS for analysing liquid samplesthe work carried out in Japan demonstrated the suitability of NIRS to predict milkcomposition and udder health (from the prediction of somatic cell counts). Milkanalysis was carried out using NIR transmittance (1 mm cell thickness) and used topredict values determined in milk by MIR analysis. Initially, milk samples werescanned following homogenisation. However, due to the unpredictability of theresults the use of NIR transmission spectroscopy on raw milk was investigated andhas been successfully developed to measure the NIR spectrum of wholeunhomogenised milk.

Different feeding regimes and feed sources to those present in the calibration dietshave been studied to determine their effect on the accuracy of the predicted fat andprotein content of milk. The diet did not affect the prediction of milk fat content but

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did affect the prediction of milk protein content. Due to the effect of dietary proteinon the composition of milk, further work to include a wide range of milk samples isrequired. This work is also in-line with the need to increase milk protein content (butreduction in milk fat) due to the impact of milk protein content on human health.

One of the major advantages of NIRS is the ability to develop techniques, which donot rely on chemicals, which may otherwise be discharged to the environment.




Work is on-going in Japan in order to investigate the potential use of NIRS as awhole dairy farm monitoring tool. Milk urea is a good indicator of the health statusof a cow and is an index of the adequacy of the protein:energy ratio of the diet (atthe herd level) and the efficiency of protein utilisation. Feed protein degradabilityis correlated with blood urea nitrogen, which is the primary source of urea in milk.Conventional methods of analysis are time consuming and do not fulfill therequirements for rapid information for routine dairy cow management. Althoughthe Milkoscan (MIR) is the practiced method for crude protein, the presentobjective is to determine if NIRS can be used to predict (in addition to protein, fat,and lactose) the nitrogenous components in milk in order to develop a continuoussystem to monitor the nutritional status of dairy cows and to evaluate milk qualityby NIRS (true protein, casein and milk urea). Also to determine if NIRS can beused to predict the degradable and digestible nitrogen contents of forages and otherfeeds. The results to date suggest that NIRS can be used to predict accurately crudeprotein, true protein and casein but not to predict milk urea. Further work isrequired to investigate the use of NIRS to predict urea in defatted milk or in theclear supernatant of precipitated milk samples. An alternative approach may be topredict urea in urine to give an indication of urea status. Urine is also being used topredict total nitrogen, and creatinine and allantoine (used to calculate microbialprotein supply). Although possible to predict nitrogen content, it has not beenpossible this far to predict the other parameters with either long or shortwavelengths. There is also interest in being able to predict the short chain fattyacid composition in rumen fluid (although no indication was given to this approachbeing restricted to research institutes).

Use of NIRS to evaluate meat quality. This would be particularly important inJapan owing to the high cost of specialist cuts of beef.


[nil response]

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NIRS for being used to analyse blood in humans but not in cattle. This could be avery important development since the blood of dairy cows and beef animals isconsidered as being important for shaping the physiological and nutritional statusof live animals. This type of information would be used to control the nutritionand health of animals through adequate feeding and management. Sensorsenabling this analysis are being developed in Japan. Blood plasma has beenanalysed for total protein, albumin, urea nitrogen, glucose, triglyceride,phospholipid, cholesterol and minerals. High accuracy was found with total andfree cholesterol and with phospholipid however, total protein, albumin and ureanitrogen requires further development. A direct measurement system is also beingconsidered for cattle blood in combination with ultrasonic equipment used tomeasure blood flow and thus detect stress (stress increases blood flow).


[nil response]


[nil response]


Possibility of being applied to live body composition and collection of live bodymeasurements. Techniques have been developed for the measurement of wholefruit including the potassium concentration of melons and nitrate nitrogen levels infruit.


[nil response]

2. Current and future developments in NIR instrumentation, chemometrics and software.


While NIRS analysis has focused on using the wavelength range from 1100 to2500 nm these instruments are very expensive. Instruments utilising the region

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between 600 to 1100 nm are required in order to reduce the price of instruments(20 to 30% of the cost of a full wavelength instrument). Short wavelengthinstruments have been developed in Japan and have been used for milk analysis.Further work is required to research the potential of the short wavelengthinstruments for forage analysis.


[nil response]


[nil response]


Two-dimensional (2-D) correlation spectroscopy has been used to try to identifyspectral information, which is not readily accessible from one-dimensional spectra.Dr Terada and colleagues have investigated the potential of 2-D correlationspectroscopy to evaluate NIR spectra of milk. To date their work has revealed theexistence of a number of ‘buried’ bonds which may aid the interpretation of theNIR wavelengths selected during calibration development for milk analysis.Further work is required in this area and future work will involve more detailed 2-D correlation analysis of both milk and blood.


In Japan, there is already experience of 42 prefective laboratories sharing NIRSinstruments in a network.

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Person(s) visited: Anthony Blakeney


Address: Cereal Solutions, PO Box 201, North Ryde, New South Wales, Australia.

Email address: [email protected],.au



Anthony Blakeney is a cereal chemist by training and has long been associated withthe developments of NIRS in Australia. Formerly at BRI Australia, he has recentlyestablished his own private consultancy business, which includes undertaking contractwork involving the use of NIRS. He has been very much associated with thedevelopment of NIRS for tissue testing. Initially this focused on the rice crop ofAustralia but has also been extended to testing of wheat and other cereals. A shorthistory of the tissue testing service is given in the abstract reproduced below from the9th Australian Near Infrared Spectroscopy Conference (5-6 April 2000, Horsham,Victoria, Australia).

_____________________________________________________________________

THE NIR TISSUE TESTING SERVICE: 13 YEARS OF EXPERIENCEGraeme Batten, Anthony Blakeney, Susan Ciavarella

The Rice NIR Tissue testing Service developed at Yanco Agricultural Institute (seereferences) has been offered to rice producers through the Ricegrowers’ Co-operativeLimited in Leeton for 13 seasons. It is an essential management tool for optimisingcrop nitrogen management and is worth an estimated 9 to 10 million (Australian)dollars in yield. In addition correct nitrogen management leads to reduced impact ofcropping on the environment.

In 1987-88 a pilot study by NSW Agriculture and Ricegrowers’ Co-operative Limitedconfirmed that the analysis of rice crops for nitrogen, using near infrared spectroscopy(NIR) could assists rice producers determine the best rate of nitrogen fertiliser to applyto their rice crops. There has been an increase in the number of farmers using theservice provided by the Ricegrowers’ Co-operative Limited so that over 5000 riceshoot samples are analysed each season. The amount of nitrogen in the shoots iscalculated from the NIR nitrogen analysis and the weight of the shoots supplied by the

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grower. Within 24 to 48 hours, most producers are advised on the amount of fertilisernitrogen, if any, that their crop needs to produce the most economical yield.

For the Pilot study in 1987-88 rice producers only received a tissue nitrogenconcentration analysis on each sample and an average nitrogen fertiliserrecommendation. The Rice NIR Tissue test has now evolved to provide informationon nitrogen, starch, sulphur, phosphorus, moisture and preliminary data on zinc andpotassium. With further development, it may be possible to make recommendationson the need for potassium and zinc applications to rice crops.

In this paper we will discuss, from personal experience, the relative importance to thesuccess of the Tissue testing service of NIR hardware, software options, samplecollection, sample drying, data recording, the tracking of samples through the NIRlaboratory, techniques to stream line analysis of large sample sets, and interpretationof results.

References

Batten, G. D., Blakeney, A. B., Glennie-Holmes, M. G., Henry, R. J., McCaffery, A.C., Bacon, P. E. and Heenan, D. P. (1991). J. Sci. Fd. Agric. 54:191-197.

Batten, G. D., Ciavarella, S. and Blakeney, A. B. (1999). Australian Grain(Ricegrower), 9(6), xvi-xvii.

Batten, G. D., Blakeney, A. B. and Ciavarella, S. (1994). A tissue testing service forrice producers. pp473-476. In E. Humphreys, EA Murray, WS Clampett and LGLewin (Eds.) “Temperate Rice - achievements and potential” NSW Agriculture,Griffith.

Batten, G. D., Blakeney, A. B. and Ciavarella, S. (1994). An interactive database foruse with the rice tissue testing service. Ibid. pp477-484._____________________________________________________________________

The tissue testing work has also been extended to wheat and details relating to thework completed have been published (e.g. McGrath, V. B., Blakeney, A. B. andBatten, G. D., 1997. Fructan and nitrogen ratio as an indicator of nutrient stress inwheat crops).




The application of NIRS to tissue testing rice and wheat in Australia has directrelevance to the UK. The success of the approach highlights an important potentialrole of NIRS in the UK for tissue testing wheat and other cereals, and may have a

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role to play in grassland management. The tissue testing approach has importantenvironmental benefits.

Also, work is on-going involving single cereal grain analysis. The potential for thisapproach is huge and could play an important role in cereal breeding.


[nil response]


[nil response]


[nil response]


[nil response]


[nil response]


[nil response]



Greater use of diode arrays and the use of instruments at the site of application.


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[nil response]


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NEW DEVELOPMENTS IN NEAR INFRARED SPECTROSCOPY ANDFUTURE POTENTIAL OF THE TECHNIQUE

Person(s) visited: Sue Baker, D. Henry, Robyn Dynes and C. White

Date: 23-24 November 2000

Address: CSIRO, Centre for Mediterranean Agricultural Research, Wembley, Western Australia, Australia.




The application of NIRS is focused on developing rapid methods for assessing thenutritional value of feeds, particularly for ruminants. NIRS has reduced the labourrequirement for routine feed evaluation and the approach is now a routine laboratoryassessment method. A lot of work has been carried out using hay in order to determinecomposition and aspects of nutritional quality and also interested in the application ofthe method to predict intake. Work is on-going within the group to understand thefactors controlling intake and also the factors governing ‘preference’ for a givensample of feed over another. Similar work is referred to in the interview with PeterFlinn. Because of the importance of forage trading in Australia the group have beenclosely associated with the export hay market and the commercial operators involvedin this venture. This involvement is very closely linked to a need to developinstrument technology, which can be used in-line, and at close proximity to the pointof forage sale. The technique has also been used in the prediction of alkane content offeeds as part of the program to understand ‘preference’ and feed intake.




[nil response]


[nil response]

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[nil response]


Greater requirement for analysis to be carried out at the site of application andaway from laboratory-based analysis. Although this can be met in part by thedevelopments in diode array technology there is a need to address concernsregarding the problems of instrument matching, calibration transfer etc.

Although the developments in the application of NIRS to feed and food analysisare wide ranging, increasing problems over intellectual property rights etc. maybecome a major limitation to the development of NIRs in the future.


[nil response]


[nil response]


[nil response]



[nil response]


There is considerable interest in combining GPS data with aspects of quality data(e.g. from diode arrays) in order to obtain nutrient maps or nutrient yield based oncolour indices.

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[nil response]


Perceived that processing of NIRS data may be limited by the software currentlyavailable. Need to develop processing capabilities which are not restricted bysoftware approaches etc. and which give the user greater flexibility. In practice, thismay be difficult due to the wide ranging requirements of NIRs users.


[nil response]

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Person(s) visited: D. B. Coates


Address: CSIRO, Tropical Agriculture, Davies Laboratory, Townsville, Queensland, Australia.




In the early 1990’s David Coates was working on phosphorus and cattle nutrition inQueensland and trying to identify a tool(s), which could be reliably used for diagnosticpurposes. He tried using faecal phosphorus content as a diagnostic tool but neededconcurrent information on the nitrogen and energy status of the animal in order for thefaecal phosphorus index to be useful. He therefore began to think about the possibilityof obtaining the information on nitrogen and energy status (digestibility) from faeces.He wondered if the nitrogen content and digestibility of faeces could provide usefulinformation on the diet nitrogen and digestibility status. While working withRaymond Jones (IGER, UK) David Coates became aware of work being done by JerryStuth (US) using NIRS on faeces to predict dietary crude protein and digestibility (e.g.Lyons, R. K. and Stuth, J. W., 1992. Faecal NIRS equations for predicting diet qualityof free-ranging cattle. Journal of Range Management, 45: 238-244). David Coatesthen made a visit to the US in order to investigate the work carried out by J Stuth andit was there that he gained his introduction to NIRS technology. He found that theapproach being used in the US coincided with his own requirements in Australia andset about to gain funding to ‘mirror’ the work carried out by J Stuth. David Coatesbegan to work with Peter Flinn (Victoria, Australia) in order to access an NIRSinstrument and was very pleased with the first preliminary calibration equation.Based on the results David Coates was given the opportunity in about 1997 topurchase, in conjunction with a local university, an NIRSystemsTM scanning 6500monochromator.

The approach, which is being used by David Coates, is quite different to theconventional approach used for feed evaluation purposes. Wet chemical analysis isbeing done on dietary samples but he is scanning faecal samples and then developingcalibration equations using the spectral data from faeces. This approach has met withsome resistance from others working in the field of NIRS although he believes that thesuccess of the approach must be judged only on the basis of the results. David Coatesfeels that faecal composition is highly correlated to what the animal eats although he

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highlights that other factors are also responsible for altering faecal composition. Forexample, individual animals may have different faecal composition even on a constantdiet. Therefore, work is needed to understand how important these factors are indetermining the accuracy of the faecal NIRS approach. David Coates has extended thework of J Stuth to include δ13C values since he had already been using this as anadjustment factor in his earlier work. He has also measured faecal nitrogen contentsince it being used by others to assess if animals require additional nitrogensupplementation from non-protein nitrogen (NPN).

David Coates has also been involved in developing calibration equations for routineforage evaluation (e.g. CP, digestibility, NDF, ADF). To date his work has beencompleted on dried and milled samples rather than on the fresh sample. One of themain factors influencing the development of NIRS for predicting composition is theexpense of completing wet chemistry. David Coates also highlights that it is importantto judge the success of the NIRS calibrations according to the needs of the givensituation since it may not always be necessary to have a very precise calibration if theinformation is generally beneficial. This is an opinion shared by many who see thatNIRS can have a role to play at many different levels according to the given situation.Sampling technique, particularly when collected by beef producers in the field, is amajor factor affecting both the accuracy but also the validity of the predicted results. Itis important to analyse a representative sample of what the animal might eat but inNorthern Queensland this is very difficult to judge. In these situations, there may bemore than 200 different plant species growing which are available for animals to eat.This is a very different situation to temperate grasslands used for grazing cattle anddairy cows. The biggest problem with the faecal analysis approach is that it isimpossible to validate the results of samples sent in for analysis.




More recently, David Coates has also been trying to predict the growth rates ingrowing cattle directly from faecal analysis. This would be really useful to the beefindustry since most of the cattle are grazing extensively in Northern Australia. Inthese situations, it is not possible to monitor what animals eat and therefore it isdifficult to manage their nutrition (i.e. when to introduce supplements, when tomove to a different grazing area or to a feedlot). This approach is still in the earlystages of development but the indications look promising. The faecal NIRS data onnitrogen content also contains information reflecting the changes in season within agiven year and year-to-year differences.

He is in the early stages of developing the work on faeces to be able to predictdietary ADF and NDF contents and believes that this may provide an improvementover simple digestibility.

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David Coates also feels that there may be an opportunity to study the parasiteburden of animals from faecal NIRS analysis. He has also been looking at someaspects of sugar quality in sugar cane juice and feels that future applications mayinvolve monitoring water quality for pollution etc.

David Coates also highlighted other work on-going in Australia in order toconserve koalas. Koalas seem to be quite selective in what Eucalypt leaves they eatoff a tree, and even on the same tree, they will only eat certain leaves. Theirselection does not seem to be only associated with the age or tenderness ofindividual leaves. Although no differences can general be detected NIRS was ableto detect differences in the leaves. Based on these results it may be possible toprovide a way of managing koala numbers.

David Coates believes that his work involving faecal NIRS analysis has helped todevelop a line of questioning which may not have occurred if he has remainedusing wet chemical approaches. This has given him an insight into the data withinpublished nutritional tables and has questioned whether they are right or wrong; hebelieves they are wrong in terms of Australia’s tropics. Protein requirements tendto be over estimated since cattle are performing better than predicted. Once disease,parasites etc. are controlled the factor most affecting animal production is feedquality and quantity. However, feed quality has never been able to be measured inthe extensive situation encountered until David Coates began his work with faecalNIRS analysis. The information provided through this approach has providedgreater information on diet quality and will have direct benefits in terms of moreeffective cattle management. It is also providing an understanding of whatcomponents of the vegetation animals are eating and this in turn aids understandingof sustainability and other environmental aspects. For instance, David Coates hasshown that trees, which many producers want to remove, are making a fairly goodcontribution to the diet of cattle grazing on certain vegetation for a certain period.

The development of tissue testing for rice and wheat has been an importantdevelopment in Australia and has potential for use elsewhere too.


David Coates said it is difficult to know what will be the future applications ofNIRS but feels that new applications are emerging all the time. He thinks that themedical field will be one of the most important topics in the future. The Meat andLivestock Commission in Australia have developed an alliance with an engineeringcompany and a meat quality testing company in order to develop instrumentationfor carcass evaluation. The Commission has been working in meat research forsome time but are looking to improve the speed of developments. They haveconcluded that tenderness is essentially a function of the amount of collagen in themuscle tissue and that taste is based on the balance of the different fat components(e.g. marbling and intra muscular fat). David Coates could see an opportunity forNIRS to characterise a series of meat quality attributes such as colour, pH, fat,collagen and tenderness etc., and could be developed for use in abattoirs etc. Itwould also be useful if NIRS could be used to discriminate between sources of

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meat (e.g. different breeds, grass vs. concentrate fed animals etc.). A furtherquestion, which arises, is can NIRS be used to assess any of the parameters of meatquality in vivo (in the living animal).


[nil response]


[nil response]


[nil response]


[nil response]


[nil response]



Believes that diode arrays will play an important role in future NIRS-basedanalysis.


[nil response]


[nil response]

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Need for greater understanding of sample population structuring and calibrationapproaches. This is particularly important for ‘‘users’ of the NIRS technology whooften work without the support of chemometricians etc.


[nil response]

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Person(s) visited: P. Flinn


Address: Agriculture Victoria, Pastoral and Veterninary Institute, Hamilton, Victoria, Australia.




Peter Flinn became interested in the development of near infrared reflectancespectroscopy (NIRS) as a rapid method for predicting the nutritional quality of foragesin about 1983/84, initially in collaboration with Dr Ian Murray at SAC Aberdeen. Atfirst, Peter Flinn did not have his own NIRS instrument and hence the reason for thestrong link with Ian Murray. Based on the results of the work carried out with IanMurray and following the acquisition of an NIRS instrument, Peter Flinn’s workresulted in the formation of FEEDTEST, a commercial NIRS-based analysis serviceprovided by Agriculture Victoria. All calibration equations were developed usingdried and milled forage samples and is still the basis of the present analysis service.Calibration equations are regularly monitored and expanded to include new sampleswith data relating to protein and sugar content, different fibre fractions and overalldigestibility.




Peter Flinn highlighted that there were three main topics where his work involvingNIRS would focus in the short term; to improve the prediction of grain digestibilityvalues, application of NIRS for meat quality assessment (e.g. pork quality,discriminate between lamb and mutton), and wool analysis (wool fibre diameterand wool yield).

Forage is traded commercially on both domestic and export markets, and there is agrowing interest in developing an assessment of animal ‘preference’ for forages

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exported to Japan in particular. Currently, the potential palatability of a forage iscrudely judged by the perceived level of sweetness in the mouth of the foragepurchaser. Therefore, the potential of NIRS for predicting the water solublecarbohydrate and individual sugar (fructans, fructose, glucose and sucrose)contents of hay samples has been investigated as a means of providing a reliableassessment of sweetness (believed to be related to palatability). The findingssuggest that NIRS may have a role in predicting total water soluble carbohydratecontent and fructan content, however, further research is required to determine therelationship between water soluble carbohydrate content and/or individual sugarcontents with animal preference for a given forage (hay) sample. Determination ofthe factors affecting animal preference is the subject of research across a number ofcentres in Australia and future research will also include an assessment of the roleof NIRS for predicting measures of forage preference by animals.

Within a nationally coordinated cereal grain project (factors affecting grain qualityfor animals) NIRS is being used to determine its potential for predicting thecomposition and nutritional characteristics of grains for pigs, poultry, sheep andcattle. NIRS is also being used to predict the digestibility of grain-fractions atdifferent sites in the gastro-intestinal tract, including starch digestibility in therumen and small intestine, using reference data derived from in vitro techniques.To date, initial calibrations have been developed for predicting composition, invivo digestibility, and total and some individual short chain fatty acids. NIRSpredicted values of in vitro digestibility suggest, at this stage of the project, thatNIRS may be used as a tool for screening different grains intended for livestockfeeding.

In the future Peter Flinn believes there will be a greater emphasis on taking theinstrument to the sample rather than the present convention of taking samples tothe instrument. He also predicts an increase in on-line applications. He feels thatsome people believe that NIRS has had its day on the basis that the number ofapplications of NIRS has now plateaued after the dramatic interest over severalyears. However, Peter Flinn does not know of any other technique that could takeits place at this stage and believes it is a technique, which is here to stay. Thepresent number of papers published on NIRS, particularly in the agricultural andfood area, is lower than was the case a few years ago, one reason being the sensethat for some it is past its research phase and therefore it is a matter ofimplementation. However, Peter believes that NIRS has a bright future ahead, withthe emphasis being on smaller more portable instruments and greater speed.

After working with NIRS for the best part of fifteen years, Peter is convinced thatNIRS is still a very relevant and very powerful technique but there will always belimitations to what you can do with it, and it will always be a dangerous method inthe wrong hands.


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In the near future Peter Flinn hopes that routine NIR calibrations will be developedfor use on fresh (undried) silage/forage, although he does have some concernregarding this approach.

Currently, in vitro digestibility is used to predict in vivo digestibility values butthere are problems due to the lack of standardisation of both in vivo and in vitrotechniques. In the future Peter Flinn wishes to develop NIRS for the directprediction of in vivo values as currently carried out in the UK. To this end PeterFlinn is involved in work, using standard protocols, involving the feeding of aseries of hay samples in order to determine in vivo digestibility, intake andpreference across four different animal species (sheep, cattle, dairy cows andhorses). NIRS is an integral part of this work and will be used to predict in vivo-derived values across a more extensive range of animal species. However, PeterFlinn is also concerned about how to treat sample ‘outliers’ when calibrationapproaches are used for predicting in vivo values. In this situation (routine analysisservice) it is not possible to use the reference (in vivo) method to check theaccuracy of the NIRS predicted value. The question which therefore remains iswhether the NIRS predicted value should be reported but stating that it may beassociated with a greater level of error than normal or repeat the analysis using achemical or biological method? Experience in FEEDTEST has shown thatsometimes the NIRS predicted values and chemical/biological values are in closeagreement while at other times they are in very poor agreement


[nil response]


Peter Flinn does not anticipate that NIRS will be particularly useful for microconstituents, even though there are some examples where this has been carried outPeter believes there are limitations. In Australia, the use of NIRS to detect chemicalresidues in agricultural products has been discussed and some of the environmentaluses of NIRS have certainly come to the fore in recent conferences. Work beingdone in Canada and parts of Scandinavia are studying nutrients in lake beds.Mineral analysis by NIRS is certainly something of interest in Australia andworkers have looked at calibrations for calcium, phosphorus and other trace metals,however, Peter believes that work has shown that .it is possible to get a reasonableestimate of calcium, magnesium, phosphorus, potassium, and sodium in forage byNIRS but is difficult for predicting trace elements. Prediction of trace elementsappears to be effected by forage type. Mineral analysis is particularly difficult sinceit is only their association with other molecules that give rise to the spectrum andwithout an effect on other molecules they cannot be measured. For example, it isnot possible to estimate the level of calcium and phosphorus in a mixed feed whenlimestone is added to the feed. Because of these problems, Peter’s view is thatNIRS should be limited to analysing macro elements.

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Expensive to derive calibration equations for in vivo derived parameters owing tothe cost of developing a large database of reference values.


Increasing interest in the use of NIR spectral data for use in discriminate analysis.Apart from this approach it is likely that NIRS will be generally used in apredictive sense and therefore rely on the reference analysis.


There is certainly an interest in developing the use of NIRS for wool analysis. Inparticular the ability to measure wool characteristics in situ would be particularlybeneficial.


[nil response]



Diode arrays are of increasing importance to many working in the field of NIRS.Peter Flinn described that he would shortly be spending a six-month visit with DrChristian Paul (Germany) in order to be involved in the development of the newdiode array instruments. Peter Flinn believes that peoples expectations ofcommercial feed testing services are increasing. When NIRS was first introducedin the mid/late 1980s, it was quite revolutionary to be able to demonstrate that feedanalysis could be completed within a few days. The speed of analysis wasrevolutionary compared with previous methods. However, one of the mainproblems for commercial laboratory services is often still the length of time it takesfor a sample to reach the laboratory rather than the analysis time. Increasingly theemphasis is on the speed of analysis and the need for immediate results with nowaiting time. For instance an immediate assessment of hay or grain nutritive valuemay be required in order for the commodity to be traded (both on the domestic andinternational markets).

Peter Flinn believes that the diode array instruments are a very attractive optionbecause they have no moving parts and they appear to be more robust, smaller,cheaper and faster. A 6500 spectrometer can be configured to scan very quickly andso the instrument manufacturers argue that if the instrument can be configured inthis way, the level of electronic noise and performance of the instrument is still

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superior to the diode array instrument. This is open to debate as is the questionregarding calibration transferability across diode arrays. Although Peter Flinn hasnot worked with diode arrays previously, he will be investigating their potentialand looking into the issue of calibration transfer during his time in Germany.

Calibration transfer between instruments may become a problem for the smallerportable instruments. Although the access to these instruments will be a greatadvantage in many areas Peter Flinn has concern for all aspects of the qualitycontrol of the instruments and their predicted values. How will users of thistechnology know that they are getting the right answer? How will the accuracy ofcalibrations be checked and updated? For example, what would happen if usersencountered a non-typical growing season. While the computer software mayidentify sample outliers, would users of these instruments know which course ofaction to take? Some of these problems could lead to enormous possibilities fordisputes, for example between a grain farmer and grain purchaser who both havedifferent instruments predicting the same quality (e.g. protein). If such cases are toarise in the future then the NIR technique may be wrongfully blamed for being atfault. Inevitably, this would still require standard chemical techniques to beundertaken to settle the dispute.


[nil response]


[nil response]


At present, discussions are taking place regarding ‘local’ calibrations versusnetworks and the concept of global calibrations and whether it would be possible tohave a whole range of parameters that would work equally well across differentcountries. However, one of the underlying issues surrounding the use of globalcalibrations is the effect of different reference methods on the accuracy of thecalibration.


Australia has an extremely large land mass and this can add considerable delay inreceiving samples at the main feed testing stations. One approach to over come thiswould be to establish a network of NIRS instruments, which are spectrallymatched. However, this raises a number of questions including, what options areavailable in order to protect intellectual property (IP) rights during the transfer ofcalibrations to private instruments, payment of royalties, etc. The patenting of NIR

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calibrations is also becoming a major concern. The wide differences betweenorganisations in their IP regulations may also limit the development of NIRS in thefuture.

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Person(s) visited: C. Greensill


Address: School of Biological and Environmental Sciences, Central Queensland University, Rockhampton, Queensland, Australia.




Col Greensill has spent the past few years working as part of a group involved in thedevelopment of physical techniques, including NIRS, in order to measure qualityparameters for whole fruits. Since added value can be given to fruit with guaranteedsweetness, or sugar content, this has been his main area of research to date. His workbegan with melons and has published several papers (e.g. Journal of Measurement,Science and Technology) in this area over the last four years. Recent work hasinvolved the design of an optical arrangement in order to determine the depth ofpenetration of NIR light. Mapping the ‘brix’ and light penetration demonstrated thatlight is penetrated to the seed cavity (~ 50-60 mm).




A prototype instrument is being used for analysing melons and now they are in aposition to study other commodities (once funded is agreed). Recently, there hasbeen interest in determining if NIRS can be used to predict if the correct levels offungicide have been added to cut timber. Although it might be expected that therewould be zero penetration of NIR light in wood the chemometrics suggest that thisis probably not the case.


[nil response]

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[nil response]


Col Greensill believes that the problems of standardisation may be one of the mostserious limitations of NIRS in the future, particularly if calibration equations haveto be developed on individual instruments. Standardisation requires samples, whichare similar to those, used in the calibration set, although it is not often clear whythis should be the case. Col Greensill has investigated this from a fundamentalview point by looking at the photometric response of each pixel of the diode andadjusting each one. However, this is not all that is required. He has tried todetermine if each pixel is linear for different spectra.


Col Greensill thinks that discriminate analysis is perhaps easier than qualitativeanalysis. He is using qualitative analysis to classify fruit based on differentparameters such as ‘brix’ value. Using PLS, he is able to alter the criterion forselection into different groups. Generally he does not use discriminant analysistechniques and feels that much more work could be done on model regressiontechniques. Although there is some good work being done with chemometrics, ColGreensill thinks that improvements can be made in order to help understanding.PLS for example minimises the squared variance, but he believes that it should useanother parameter. They are using Mahalanobis distance for identifying outliersalthough he does not think it is a very good outlier detector since it relies on the useof mean spectra. This is not a good approach when a sample set contains a lot ofoutlier and instead should use the median spectra.


This work addresses a serious issue in the fruit industry since the brix content ofmelons can vary between 5 and 15, and by grading into those above 10/11 brix thenit is possible to guarantee sweetness at a premium cost. Currently melons are beinggraded in the packing-houses prior to distribution and dispatch to supermarkets andother retail outlets. However, this approach relies heavily on the integrity of thetransport system and the retailer. What we need is for them to adhere to a protocol,for example, for storage temperatures and conditions, and also for the retailers notto leave the fruit on the shelves for too long. Col Greensills group can see that therewould be a place for a supermarket-placed instrument. With a single scan the NIRinstrument, depending on the calibration, can tell a number of things about theconstituents of a fruit from the spectral information. For example, it may be able tomeasure sweetness but also that a particular melon has reached a stage where it has

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started to disintegrate structurally and needs to be thrown away. NIRS is also ableto predict the density of fruit. So far Col Greensill has measured sugar and acidcontents, and density (destiny being linked to water content and dry matter) ofcitrus fruits. He is planning to complete work involving taste panels for melons andis confident that he will be able to discriminate on the basis of taste.


The principle areas for NIRs are the detectors and chemometrics. The detectorslargely are driven by the applications. Some of the research that is being done byNASA may provide beneficial information to spectroscopists. Lead sulphide hasbeen used as a detector from 1000 to 2500 nm although it is fairly ‘noisy’ over2200 nm.



Owing to the sensitivity of the detectors and the optics, people originally usedreflectance spectroscopy so they could get a better signal. However, reflectancesuffers from a lot of specular reflectance, which needs to be removed. Also, a greatdeal of information comes from quite close to the surface of the sample and so thealternative, and increasingly more popular, is to use transmission spectroscopy.Fortunately biological tissues are very transparent to NIR and hence the reason whythe approach works. Sample transparency means that coefficients are fairly low andthat longer path lengths are required. Therefore while designing a probe, ColGreensill used transmittance and reflectance principles since whole fruit needed tobe analysed without contact while moving through the grading process.

Col Greensill is conducting some work using lasers although he highlights that thewavelengths need to be chosen carefully. This can be hazardous and does not givevery much flexibility but he doubts if lasers are competitive since they are veryexpensive compared to the cost of monochromatic light sources and diode arrayinstruments. Also, although FTIR is well known he believes it has got a lot morepossibilities.

In terms of instrumentation, Col Greensill is in no doubt that the NIRSystems 6500(scanning monochromator) is a good, old style unit although it is prone to vibrationand other things. However, there are now a number of new compact units availableon the market, which are extremely robust. The diode array instruments have nomoving parts and have a holographic grating, which has both advantages anddisadvantages. While detectors have improved, there is still a need for greaterimprovement. Col Greensill’s old spectrometer application was based on prisms,which is 18th century technology. Everyone moved away from these 50 years agoor more to the new higher resolution instruments but in reality a higher resolutionis not needed and in fact prisms can give more resolution than is needed and a

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higher throughput. Therefore, Col Greensill believes it is worthwhile investigatingwhat is the extent of the range of instruments currently available.

Diode array instrument have the inherent problem that no two arrays are identicalalthough some manufacturers like Zeiss are particularly quality conscious and willaim to minimise the variation. Not only is each pixel of the array slightly differentfrom its clone but the wavelength alignment is also different and is probablycompounded, and so matching is definitely likely to be more difficult than forinstruments such as the NIRSystems 6500. There is no doubt that standarisation isa problem and is an area in which Col Greensill is currently working. He hasinvestigated a series of techniques (including direct standardisation, doublewindow direct standardisation, fire and impulse response, wavelength transformsand single correction). He believes that wavelength transforms are promising andthat they have enormous benefits too. He has also developed a ‘combinationtechnique’ which performed the best of all and consistently. He has thereforeshown that it is possible to use this technique to clone the spectra of diode arrayinstruments. However, he has also found that if you generate a calibration using Xn

spectra from one instrument and you update that model with spectra from adifferent instrument, it is possible to obtain similar results to the complicated‘combination technique’ approach. The number of spectra to add is the mainquestion but details of this are given in the paper recently submitted forpublication. Col Greensill does not believe that the potential for the diode array todeteriorate is a major issue. His approach simply involves assessing a newreference against some base point in order to identify ‘drift’. From a quality pointof view, it is prudent to keep going back to a base reference, which can be doneautomatically, even for on-line applications.

For the diode array, the transfer of calibration equations will be the biggest issue.Col Greensill is very interested in the developments taking place in Germany withthe diode arrays and also reported that a US company are selling grain harvesterswith diode array instruments for analysing grain for moisture content, protein andoil. These data can then be used to give grain protein content maps acrossfields/farms. For example, moisture and protein mapping in conjunction with GPSallows for the application of fertiliser to be applied according to the rate required atdifferent sites across a field. This approach could have significant environmentalimplications. In New Zealand Peter Sharo is also working with diode arrays foranalysing grassland/pasture although Col Greensill is not sure if he is using theZeiss instrument being used by Christian Paul.

Col Greensill is in no doubt that small, hand-held NIR instruments will beavailable for use in the future. He was involved in the design of one about fouryears ago and a number of companies are now trying to manufacture it. He believesthat there are a wide array of instruments around at present that should be easilyadaptable to use as small hand held instruments.


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Like other people, Col Greensill is investigating the potential of other non-invasivephysical techniques such as x-rays etc. Also opportunities exist to use differentphysical techniques in combination so that it would be possible to sort fruit onsweetness by NIR and detect skin blemishes using another approach (e.g. imaging).A combination of x-rays and NIRS might be used to detect differences in density orultrasonics may provide information on internal structure of a sample rather thanjust chemical composition.


[nil response]


Col Greensill believes that NIR would have no applications without thedevelopments, which have taken place in chemometrics. Essentially increasedcomputing power and chemometric approaches have allowed NIR to become auseable technology. Although approaches such as PLS has been around for twentyyears, he believes that more effort is required in the field of chemometrics in orderto develop new approaches. Neural networks also have many advantages althoughskill and caution are required in their use but for non-linear applications, they aredefinitely one of the best approaches.


[nil response]

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Person(s) visited: Dr J. Guthrie

Date: 14 December 2000 (by email correspondence)

Address: Queensland Department of Primary Industries, Rockampton, Queensland


Author of report: J. Gutherie (edited by E. R. Deaville)

Background information relating to the current application of NIRS

[nil response]




The use of soft/back scatter x-rays and tunable lasers.


[nil response]


[nil response]


[nil response]


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[nil response]


John Guthrie works in the field of developing non-invasive assessments of theeating quality of intact fruit. The biggest problem related to this area is therobustness of the NIRS calibration models since he is working with living,respiring tissue and therefore, the calibrations cannot be 'set and then forgotten'. Inorder to be of practical use in fruit grading, NIRS calibrations for assessing fruitinternal quality attributes must exhibit a degree of robustness, robustness beingdefined as the ability of the calibration equation to endure and predict withacceptable accuracy across the parameters of variety, district and time, for theattribute of interest. In the food industry, the use of quality assurance requiresspecifications that are definable and can be measured objectively, preferably in-lineon every item non-destructively. The use of NIRS offers this ability. To date JohnGuthrie has been working in the fruit packing environment in conjunction with in-line colour and size sorting of whole fruit.

The technologies developed and developing in the fruit industry could be applied toother uses for non-invasive assessment. For example, the work could be applied toinsect detection in fresh cut salads.


The next step in the work being done by John Guthrie will require theminiaturisation of the instrumentation and a move into both the field and thesupermarket. In these environments size and simplicity of use will be the majorconsiderations rather than speed of spectral acquisition (in-line must acquirespectra in milliseconds rather than seconds).



[nil response]


[nil response]


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[nil response]


Work is required on calibration robustness (building of databases, sampleselection, math pre-treatments etc.) and calibration transfer.


[nil response]

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Person(s) visited: S. Staunton and Sarah Johnson


Address: Bureau of Sugar Experiment Stations, Gordonvale, Queensland, Australia.




The cane sugar industry is extremely important to many areas of Australia includingQueensland. In recent years, there has been a significant decline in the price of canesugar and consequently there is growing pressure to reduce the moneys spent on sugarcane research. Both Steven Staunton and Sarah Johnson are based at the Bureau ofSugar Experiment Stations (BSES), Gordonvale, Northern Queensland. StevenStaunton has been very closely associated with the sugar cane industry over recentyears and particularly with the in-line measurements of sugar cane/sugar at the sugarprocessing centres. Sarah Johnson has been very much involved with the sugar canebreeders and in the adaptation of the available NIRS instrumentation in order to beable to meet the demands of the current research program.




The in-line application being developed by Steven Staunton involves a direct light5000 scanning instrument from France, a cadmium cooler, a back up vortex cooler,and either serial or network connections for communication of the results andcontrol. Serial connections have fibre optic drivers and software communicateswith the mill in order to integrate sample information with the results. The mainlimitation for the first commercial model was being able to control the temperatureof the fibre optic probe (damaged at about 32 degrees) since the probe needed to bein close proximity to the application. The system in use is called the Cane AnalysisSystem (C.A.S.) and is in-line and real time, with results being collected every 20seconds. A suite of equations (12/13 parameters) have been developed including,the prediction of total solubles, total insolubles, extraneous matter, and ash, sucroseand moisture contents. Every 20 seconds the results of the analysis are fed back to

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the processing control unit in order for them to monitor the quality of the sugarcane coming into the factories. At present there is no automatic control of theprocessing system and is still managed manually. On the data provided on thequality of the raw sugar cane the control unit may act to increase the level ofphosphoric acid addition (aids in the process of clarification), alter the crushingrate depending on the level of insolubles etc. Adjustments can also be made to thechemical addition to the clarification process depending on the level of ash present.Ash is an important parameter to measure since this information is needed to feed-back to the boilers generating the heat for the system since the high ash values areassociated with higher moisture content and a reduced calorific value of thematerial needed to run the factory. Much effort trying to devise automatic controlstrategies based on the accumulated data over a number of years. CAS is alsobeing used in the quality assessment of the sugar cane entering the factory (ash,extraneous matter = leaf content + tops + dirt - water shoots). The data relating tothe amino nitrogen and ash contents of the material entering the factory are feddirectly back to the farmers in order to give them an indication of how theyperformed on their ‘blocks’ (each consignment of sugar cane is linked toinformation relating to field/site location etc.). It is hoped that the informationrelating to poor quality will result in a change in current practices by some growersor at least to identify to the millers who is producing poor quality cane. Althoughpoor quality cane is sometimes unavoidable (due to flooding, wind damage etc.)often it is due to the grower trying to cheat the system through poor managementpractice. It is essential to bring about a change in the approach of the growers inorder to ensure a high quality product enters the mill. In turn, this will maximisethe profit to the cane grower. Poor quality material can also result in substantialdamage to milling equipment. With the aid of the NIRS analysis, Steven Stauntonis beginning to see a change in perception from the growers. The software enablestrends across all farmers to be studied between and within seasons, and for growersto be compared with the average producer for example. The software is also ableto provide data on the performance of different sugar cane varieties and differentsugar cane harvesters. The information is going to be tied into the GPS dataavailable in order to develop cane quality maps for given areas based on a numberof variables associated with the production of the crop.

The mills are currently using the data derived on the cane in order to raise overallquality and to define premium cane, standard cane and substandard cane. Atpresent it does not affect the base price received by the grower but any extrarevenues that come to the mill from making high quality sugar, are pooled and thenspread amongst the growers depending on the quality of their cane. This approachshould stop those growers who may deliver in 3 tonnes of dirt for every tonne ofcane since they will not share the additional bonus and this is particularityimportant at the time when the cane industry is experiencing low sugar prices.Payment is based on total soluble solids, total insoluble solids and sugar content.Currently soluble solids and sugar content are measured routinely in the laboratorybut the insolubles, since it takes about 2 hours to do an individual analysis, ispredicted by NIRS. Further work is required to move the payment system to anNIRS-based prediction of the relevant parameter(s) such as sugar content. Thedevelopments in NIRS are also proving useful in trying to quality control differentlaboratories since analytical data has rarely been challenged previously. This work

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has resulted in the identification of laboratories where the are mistakes in the dataor in the methodology used.

The CAS system, which Steven Staunton has been involved with, was built withthe intention of being very generic so that its application could be extended to otherareas of application. In 2000, he started new work on the analysis of crystallisedsugar and the initial prediction equations are quite promising. Although the workis in the development stage, he is confident that only a short time is required for itto be used commercially. The crystalline sugar is being analysed for sugar content,moisture content (since this influences storage), grain size and grain colour (this isvery important to the refineries). He is looking at statistical controls in ordertighten up the range in quality and to standardise payment.

One of the major incentives for introducing the use of NIRS into the sugar canebreeding program was to reduce the huge analytical costs involved and to speed upthe time taken to obtain the results required. The immediacy of the NIRS approachand the multiply analyses obtained in a single step were a major benefit to theprogram of research being developed. Initially the work was severely restricted bythe sample cells available for scanning the cane samples using a NIRSystems 6500monochromator. This required the development of a new sample measurementdevise in order to increase the speed of analysis and therefore increase samplethroughput, and also to improve the accuracy of the measured values for a fairlyheterogeneous sample type. A new cell was made which was 1 m in length andwas designed to be automatically carried in front of the light source and detectorsin order to allow 95 sample scans and 35 reference scans. This enabled 30 samplesto be analysed per hours. The cell has subsequently been made smaller (0.5 m).

Initially the analysis was focused on clean sugar cane stalks in order to assessvarieties undergoing field trials. However, in about 1997 the analysis was changedto allow suckers to be included with the cane stalks. Even more recently, theleaves and the miscellaneous material have also been incorporated into theanalysis. This more closely reflects the type of material arriving at the sugar canemills. The analysis is very much focused on the prediction of the potential andrealised commercial cane sugar content. This allows an estimation of what is thepotential sugar yield from the standing crop and what is the realised yield followingharvest and milling. This information may be used to identify areas of anypotential loses during the harvest and processing of cane.

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2

Harvesting sugar cane in Northern Queensland, Australia.


For the sugar cane industry it is hoped that this will include farm nutrient and farmyield information for sugar, insolubles, impurities and ash contents. Thesepotential developments are also applicable to many other products/commodities.Further development of in-line factory control of processes and control ofcommodity payment based on NIRS analysis. Greater potential of NIRS forpollution monitoring.


Steven Staunton believes there are probably many applications of NIRS, whichmay have relevance to food and feed analysis. This should be the focus of a moredetailed review to identify technology transfer opportunities.


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Requirement to reduce labour use in analytical services and to reduce the cost ofanalysis through greater automation of analysis. Future analytical approaches musthowever remain quality based and may need to fulfill the requirements of variousexternal quality systems. There is a greater need to develop approaches in order tobetter integrate growers and processors, and improve overall quality ofcommodities through their closer association. Significant emphasis on thedevelopment of techniques to provide ‘real time’ analyses/results. Currentlimitations of NIRS include problems of bias and precision.


[nil response]


A number of examples show that NIRS has great potential in this area although thepotential is dependent on specific samples. Since solids uses reflectancespectroscopy the approach is dependent on the surface properties of the sample.


Steven Staunton feels developments are required in order to increase the speed ofcollection of spectra (at the same signal:noise ratio or better), standardisation ofinstrumentation for each product (without bias) and better chemometric approachesfor non-linear/skewed data.



Developments are likely to include signal:noise ratio and speed. Presently StevenStaunton is using holographic grating NIRS reflectance. He feels OAAFT looksvery promising and that diode arrays are the future technology.


Feels there are good opportunities to combine NIRS with other technologies.


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Feels this has very good potential. Aerial analysis for use for yield (and quality)and disease/pest damage measurement.


Although MPLS is widely used in calibration work, this approach is not suitablefor skewed distributions of data (long tails).


The demonstration of the potential of networks of NIRS instruments is already areality in a number of situations and forms a major part of the developmentsundertaken by Steven Staunton in the sugar cane industry. Use of globalcalibrations will require calibrations to be transferred across instruments,development of support systems without the need for calibration expertise by allusers. Large databases may result in improved calibration equations. Changes tocalibrations need to be implemented quickly across all users. Advantage forresearch cost to be spread across network of users.

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Person(s) visited: R. Van Barneveld, Y. Ru and J. Kruk


Address: SARDI, Pig and Poultry Production Unit, University of Adelaide, South Australia, Australia.




The Institute comprises both pig nutrition and poultry research facilities and anutrition research laboratory. Additional facilities include both experimental andcommercial feed milling capabilities and a commercial piggery. The overall aim ofthe pig and poultry production institute is to ‘improving the efficiency of use of feedingredients in both pig and poultry diets’. The use of NIRS forms an essential part ofthe pig and poultry research programs. A NIRSystems 6500 scanning monochromatoris used for analysis of samples in both the reflectance and transmission modes.




Use of NIRS to predict the digestible energy (DE) content of cereals for pigs. Thiswork has proved very promising and the group is now investigating ways ofcommercialising the calibration equations. An issue remains regarding the need toidentify laboratory-based ‘correlates’ in order to be able to predict samples, whichare identified as outliers following NIRS analysis. NIRS is also being used topredict the effect of enzymes on DE content of cereals and the effect of heatchanges on protein quality of feeds (reactive lysine content). Work being done todetermine the potential of NIRS to predict the apparent metabolisable energy(AME) content of cereals for poultry appears very promising. The group areinvolved in the coordinated feed grains project in order to improve the predictionof grains intended for animal feeding (rather than being seen as by-products of thepremium grains intended for human consumption). The group is also involved inthe national work on-going to determine the factors controlling feed preference andthe role that NIRS plays in this respect.

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Greater emphasis on in-line applications (e.g. NIRS prediction of cereal grainquality in the mill/processing stations).

To be able to predict the effect of treatments (e.g. enzymes) on feed quality.


[nil response]


[nil response]


[nil response]


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Emphasis on the use of diode arrays.


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Discrimination techniques to identify different classes of grains.


[nil response]


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Person(s) visited: I. Wesley


Address: BRI, North Ryde, New South Wales, Australia.




Ian Wesley is very much involved in the spectroscopy of the work being done at theinstitute and has worked closely with those involved in understanding the effects ofprocessing on the quality of bread dough etc. Although used mainly for prediction-based approaches, he has used NIRS for obtaining a greater understanding ofsignificant steps involved in a process. NIRS plays an essential role in the workundertaken and the institute and has the advantage of comprising those who areworking in a coordinated manner from a number of disciplines (e.g. spectroscopy,statistics, applied scientists etc.). This approach has led to a greater advancement ofNIRS technology in their field of research and development.




Ian Wesleys work within the Grain Industries Centre for NIR is trying tounderstand the underlying spectroscopic and chemical basis to NIR calibration andtherefore goes beyond the simple approach of using NIRS as a predictive tool.While NIR is very good at measuring parameters such as protein and moisturecontents, there has always been a strong interest in using NIRS to measure more‘fuzzy’ parameters. These are sometimes linked to traditional laboratorymeasurements but which themselves are not fully understood. The extensibility ofdough is a classic example of this since it is related to a number of chemicalcomponents in the dough and also probably to how the dough is mixed. Owing tothe importance of extensibility to the baking industry, there has been a greatincentive to try to develop a rapid assessment for its measurement. However, IanWesley feels that the industry are beginning to realise that this is not going tohappen since the literature contains many references to calibrations for extensibility

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and mineral content etc. which tend to be unrepeatable and unusable. He thinks thatif NIR is going to progress beyond being application led, the most important thingis to start treating it as spectroscopy and not as NIR. He is also consideringexpanding his work into mid-IR and Raman spectroscopy due to the additionalinformation these approaches may provide.

A lot of the NIRS-based research in Australia is taking place in the wheat or grainindustry and is aimed at developing breeding programs. Grain receival centres areoperated by various marketing boards and are generally only interested in grainprotein and moisture contents. Variety identification is also of interest since itwould allow different grains to be segregated on this basis and therefore targetgrain markets more efficiently. However, increased segregation of wheat forexample would lead to an increase in storage facilities and costs which may not beeconomically viable. Techniques developed to undertake this analysis would alsoneed to be accurate since there would be serious economic implications to graingrowers. Presently at receival centres there are disagreements over the NIRSpredicted protein and moisture contents and so in the short to medium term it isunlikely that NIRS will be adopted for measuring other ‘fuzzy’ qualitymeasurements. However, Ian Wesley believes that the greatest scope forprogressing the use of NIRS is as a tool to the plant breeder. Plant breedersgenerally have tens of thousands of individual lines and need strategies to be ableto make best use of their financial resources, time, greenhouses etc. It is importantto be able to develop a system in order to screen the growing material in order tosave time and money in growing plant material with no advantage. In other words,when you throw out the bottom third, you can be absolutely sure that at best youare only throwing out a few that are potentially all right. This is linked to cerealscience in order to determine how quality is affected by composition includingprotein content, protein composition, starch composition, water content, geneticbackground etc. This will involve tissue testing which is interesting since itinvolves using a test method at an early stage to then make a judgment on thefuture potential of a plant material. Ian Wesley believes this is a very excitingproposition and an important future application of NIRS. This approach could alsobe applied to forage testing in order to determine at an early stage the potential fora particular forage material to fulfill the requirements for e.g. intake potential, milkand meat production. In terms of tissue testing etc. NIRS has the advantage that thework can be completed with little or no sample preparation and could potentiallybe carried out in the field. This would be possible with the new diode arraysinstruments since they are easily transported.

Ian Wesley is also looking at process control including water binding, which isimportant in a lot of food systems, and extrusion which is essentially crystallisation(water is involved in this too). Water is involved in the many processes, whichresult in gelatinisation. Now with the new fast instruments, such as the diode arrayinstruments, it is possible to monitor these changes spectroscopically. Previouslythese changes could only be studied by stop-starting the processes while now it ispossible for the NIR instruments to be built into commercial production lines. Hiswork is able to spectroscopically follow the water absorbence peak and thereforestudy how water contributes to the process. Ian Wesley believes the use of NIRS in

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process control is going to be another area of increasing interest and is likely to bedeveloped by the major food processors.


[nil response]


[nil response]


[nil response]


Ian Wesley believes that the whole issue of obtaining a rapid and non-destructivemethod for authentication of commodities is going to become increasinglyimportant. Prior to moving to Sydney, his work in the UK (Plymouth) included theuse of NIRS for determining the adulteration of olive oil and for identifying oliveoil types. Since olive oil is a high-value commodity which can be easily dilutedwith low value oils, such as peanut oil and seed oils, there is a great deal of interestacross the world in the potential of NIRS in this field. He also completed similarwork concerning the adulteration of fruit pulp with vegetable matter and alsostudied variety identification of fruits (e.g. apples) using NIRS. A lot of work onvariety identification of fruit is being done in Australia at Wagga Wagga and afurther group in Queensland are measuring the brix content of apples although themain interest of their work is variety identification. Increasingly, situations arearising where it is necessary from both a commercial and food/feed issue thatcontrols are required to check labeling and declarations (e.g. authentication ofItalian extra virgin olive oil). Although there is a range of chemical methods (e.g.HPLC, GC) other rapid and easy to use methods are required. Allied to the role ofNIRS is the need for portable instruments that can be used in the field. An initialbenefit would be able to use NIRS to raise concern regarding the quality of acommodity.


[nil response]

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[nil response]



Ian Wesley feels the Foss series of instruments such as the 6500 are still probablysome of the best instruments available but they are now receiving increasedpressure from new instruments such as the diode arrays. Presently it is possible toover come some of the problems of signal to noise ratio by completing fastmultiple scanning since the diode arrays can produce spectra at ~ 10 or 20 persecond if required. Although the spectra contain a lot of ‘noise’ at this level it ispossible to obtain a good quality spectrum in about 10 seconds and it’s gettingfaster all the time. The problem of matching for diode arrays is again linked to theproblem of how we currently deal with the raw data. Standardisation of instrumentsusing a single sealed cell of a standard material involves computing point by pointoffsets; scanning the same sample on a master and slave instrument and thensubtracting the spectra one from the other. Standardisation using a set of ~ 20samples involves linear regression analysis at each point in order to calculatecoefficients. Ian Wesley feels that from the raw spectral data it should be possibleto compensate instrument to instrument differences by taking the spectrum of astandard material, which you could define, and then changing the raw data.However, the problems of matching remain while working at the log 1/R level.

Ian Wesley agrees that the transfer of calibrations is the biggest issue with diodearrays, and it’s an issue that has been side stepped by the instrument manufacturers.Transfer of calibrations is only an issue if you can not afford to calibrate everymachine (usually this is the case). However, measurement of peak area, or aparticular peak(s) does not require calibration. The approach depends on whetherthe user is interested in the actual number or interested in monitoring whethersomething has changed since the last time it was measured or trying to determinethe magnitude of samples i.e. larger or smaller than another sample. If two sampleshave got the same spectra then the samples have got to be the same since the NIRspectrum is an electro magnetic manifestation of the physical and chemicalproperties of the sample as presented (as packed in the cells for analysis) to theinstrument. Monitoring a process requires the identification of a feature in thespectrum that can be used to show when a process changes or the process hasstopped. If interested in following a drying process this may simply involvemonitoring the intensity of the water peak with drying time. This approach does notrequire a calibration but to monitor the fall in the height of the water peak toaround zero.

The problem of matching instruments comes from the absorbence axis since thewavelength axis is easily fixed by using any of the wavelength standards. Work

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presented several years ago involved a mathematical process for transferring dataacross instruments which seemed to work in simple systems (e.g. purifiedmaterials, chemical mixtures) however Ian Wesley is not aware of anyone who hastried to apply it to natural products.

A monochromator has the distinct disadvantage that it has got lots of movingmechanical parts and lots of shiny surfaces that are very sensitive to things in theatmosphere. So diode arrays are better and already Zeiss have got a diode arrayinstrument that goes up to 2400 nm.


[nil response]


[nil response]


Ian Wesley is also trying to move away from just looking at log 1/reflectance (R).However he is still waiting to see work done to take a serious look at comparingdifferent processing techniques of the raw data in order to see if there is a loss ofinformation by using log 1/R. Log 1/R has the distinct advantage that themeasurements are generally directly proportionate to the amount of sample since itis based on absorbence. However, in most cases with NIR it is used in reflectionmode so even at its best it is an approximation and may not be suitable for moredetailed analysis. This would be important if it was important to analyse for proteincomposition as opposed to the protein content or wanting to detect the presence orabsence of particular chemical entities. Ian Wesley would very much like to seework done which goes back to the raw data and see if the developments incomputing technology can confirm if we are making the most use of the rawspectral data.


[nil response]

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Person(s) visited: Drs F. Barton, R. Windham and D. Himmelsbach

Date: 12 March 2001

Address: US ARS Quality Assessment Research Unit, Athens, Georgia


Author of report: B. R. Cottrill

Background information relating to the current application of NIRS

A major part of Barton’s work, and that of his department, is currently in exploringthe potential of NIRS to assess food quality. This is largely driven by legislativerequirements. Under the Nutrition Labeling and Education Act of 1990, for example,manufacturers of cereal or grain products must declare total dietary fibre (TDF)contents, normally taking three days using conventional analyses. However, they haverecently developed the use of NIRS for determining the TDF and insoluble fibrecontent in both cereal and grain products. Partial least squares (PLS) regression wasused to generate three Raman and three NIR models for the spectroscopicdetermination of TDF and insoluble fibre of a wide variety of cereal foods. First-derivative data provided the best NIR model, and for all three NIRS models, the rootmean standard error of prediction (RMSEP) ranged from 2.4 to 2.9%. For somesample types, it appeared that the Raman method was limited by its samplingtechnique and could be improved with more densely packed, larger-area specimens.The regression vectors of the Raman models were easier to interpret than for the NIRSmodels. In this and other studies, the NIRS and Raman models tended to have verydifferent sets of outliers and un-correlated errors in TDF determination. For a singlespectral type, the prediction errors of various pre-processing methods are partiallycomplementary. The samples were very diverse in terms of composition, but the mainproblem groups were identified as the high-fat, high-bran, and high-germ samples, aswell as those containing synthetic fibre additives. Raman models performed better onthe high-fat samples, while NIRS models perform better with high-bran and high-synthetic samples. Raman models were better able to accommodate a wheat germsample, even though this sample type was poorly represented by the calibration set,confirming the view that there is currently no single technique that is better thananother in all situations.

Barton and colleagues have worked for five years to build a database of over 200product samples, including many trade-marked U.S. snacks and cereal products. Theyhave developed mathematical formulas and measurement guidelines that make itpossible to predict fibre levels even for high-sugar or high-fat products, and have now

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patented the process. Since its original development, the NIRS model has beenmodified (‘expanded’) to include samples with high sugar and crystalline sugarcontents.

Having developed robust calibrations for dietary fibre, Barton’s group has focused ondeveloping NIRS calibrations for protein in diverse cereal food products. Using ascanning monochromator (wavelength range 1100 to 2500 nm) on milled cerealproducts (n=147 calibration samples) a nitrogen calibration was developed, usingmodified PLS (MPLS) as the regression method. The standard error of crossvalidation (SECV) and R2 for nitrogen were 0.090% and 0.973, respectively.Independent validation samples (n=72) were predicted with a standard error ofperformance (SEP) of 0.079% nitrogen and R2 of 0.984. Because of the diversity ofgrains in the data set, crude protein was calculated using two nitrogen-to-proteinconversion methods, and two PLS models were developed for the prediction of crudeprotein. Crude protein was predicted with a similar precision to nitrogen and theresults for both protein models were within the precision required for US nutritionlabeling legislation. As a result, they have shown that NIRS can be used for rapid andaccurate prediction of nitrogen and crude protein content in a heterogeneous group ofcereal products comprised of a wide cross-section of grains and formulations.

Other on-going studies on food include the determination of end point temperature incooked ground beef by NIRS. Currently, the development of NIRS models for feedauthentication is very important to the US ARS, largely for labeling purposes. Theyhave developed calibrations that allow discrimination of different forms of coffee (e.g.Kenyan or Costa Rican), the origin of Ginseng (Korean or not) and characterisation ofrice. The US Government takes the threat of bio-terrorism very seriously, particularlyby the introduction of pathogenic agents. As a result, Barton’s group is collaboratingon the development of spectral sensors (‘artificial noses’) and multiple pulse laserswith enhanced spectroscopy which give detection down to 109. It has already beendemonstrated that it is possible to classify different strains of E. coli by NIRS,however, even with these improved levels of detection Barton did not consider thatNIRS would be capable of detecting at gene level (i.e. genetically modifiedorganisms).

Although Barton’s group is not currently involved in developing calibrations for theprediction of compositional quality of fresh foods, work by others has demonstratedthat it is possible to predict by NIRS the carbohydrate content of fresh fruit (e.g.citrus, bananas, kiwi fruit). This technology has generally been developed using diodearrays, and considerable levels of accuracy have been achieved. This offers thepotential for assessing fruit quality in a rapid and non-destructive way, thus allowingbetter grading and pricing of fruit and potentially less waste.

Methods are also being developed for the qualitative evaluation of commodities, e.g.the development of instrumentation for rapidly measuring the surface energy ofcommodity fibre, yarns, and textile products (surface energy of natural fibres andyarns is an important physical property which may significantly affect the strength ofyarns spun from the fibres or textiles woven from the yarns).

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The ‘LOCAL’ utility in the Infrasoft International (ISI) software has been examined asa means of improving the interpretation of large sample data sets. In one study, adatabase comprising 2203 samples of wheat, representing wheat in commercial tradecollected over a five year period, with both NIRS spectra data and protein data wasexamined. The results showed that the ‘LOCAL’ approach was as good as specificPLS calibrations for sub-classes of products and precise enough for use for regulatorypurposes. The use of the ‘LOCAL’ approach may have other advantages, such aseasier calibration update and transferability, and the possibility to includeauthentication and classification as part of the model.

Other studies have examined the use of two-dimensional (2D) vibrationalspectroscopy to study degradation of lignocellulose of plant material affected bywhite-rot fungi. The results of this study confirmed that the 2D technique allowsdegradation processes to be characterised and provides a rapid method of observingthe differing effects of the fungi on plant cell walls.

Barton’s group is collaborating with researchers in Japan (Drs Maeda and Ozaki) tostudy the effectiveness of fluoride glass fibre for near infrared light fibre spectroscopy.Using this fibre, on a Fourier transform (FT)-NIR spectrophotometer, the fibreshowed good transmission characteristics in the 1000 to 2500 nm region. FT-NIRspectra in this region were measured for palmitic acid, potassium ferricyanide,silicone grease and sugar by using the fluoride glass fibre. The spectra obtained, andtheir second derivatives, had a high signal-to-noise ratio at least up to 2500 nm.

Diode arrays

Barton confirmed that these have significant potential, particularly where rapidanalysis is required, e.g. in production lines. The complexity of the array will bedetermined by the particular analyses required. For individual substances, it ispossible to select critical wavelengths, and select specific diodes to measure thosewavelengths. This will reduce the complexity of the array, and make calibration andmatching much simpler. A pre-requisite is, of course, that you know the criticalwavelengths for the constituent that you wish to test.

The Department are currently exploring the potential of indium gallium arsenide(‘InGaAs’) detector arrays which cover a wider spectrum (800 nm to 1700 nm) thanmany detectors currently available. Barton’s group are using this technology to detecttrace levels of contaminants while Feldhoff and workers in Germany havedemonstrated the potential of InGaAs arrays to identify packaging waste when a nearinfrared spectrometer with an InGaAs array spectrograph is combined with neuralnetworks. According to Barton, this group showed that the spectra could be classifiedby neural networks with an identification rate of better than 98% when the array waslocated on an industrial conveyor belt with an integration time of 6.3 milliseconds persample. This process, therefore, if confirmed, could provide a valuable tool for on-line identification of packaging materials in waste treatment plants.

Neural networks

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These have considerable potential in certain situations. An important feature of thesenetworks is their adaptive nature where ‘learning by example’ replaces ‘programming’in solving problems. This feature makes such computational models very appealing inprocesses where there is little or an incomplete understanding of the problem to besolved, but where training data is available. Another major advantage is the intrinsicparallel architecture, which allows for fast computation of solutions when thesenetworks are implemented on parallel digital computers or, ultimately, whenimplemented in customised hardware.

Barton described the development of neural networks to identify bacteria. Diffusereflectance-absorbence FT-NIR was used successfully to analyse 19 hospital isolates,which had been identified by conventional means to one of six species of E. coli.Principal components analysis of the FT-NIR spectra showed that this method failedto form six separable clusters (one for each species) and thus could not be used toidentify these bacteria based on their FT-NIR spectra. In contrast, it was shown thatneural networks could be trained by ‘supervised’ learning (using the back-propagationalgorithm) with the principal components scores of derivatised spectra to recognisethe strains from their FT-NIR spectra. These results confirmed that the combinationof FT-NIR and neural networks could provide a rapid and accurate bacterialidentification technique

Remote sensing

Barton confirmed that remote sensing is now widely used, based on satellite imaging,and using NIR technology. Predictions are less effective for native grasslandsprimarily because an increase in the complexity of the canopy, a decrease in thebiomass and thus canopy closure, and the presence of standing dead and senescentbiomass. While correlations coefficients (R2) for crops of 0.9 or more have beenachieved, for rangelands they are generally in the 0.6 to 0.7 range. Even though thevariability for biomass estimates in rangelands is lower, remote sensing is being usedfor evaluating rangeland condition and productivity. Another area where remotesensing is having an impact is in the assessment of the biochemical properties offorages or crops. Analytical spectroscopy of organic mixtures using NIR wavelengthsin the 700 to 2500 nm range is now a well establish technique in the analysis offorages. The same principles are being used to attempt to estimate foliagebiochemical properties with the use of remote sensing. In both cases, the models arebased on the fact that different biochemical compounds have different spectralsignatures and that mixed signatures can be in theory separated with the use ofderivative transformations. While remote sensing is a technology with a lot ofpotential, to fully understand these signals and predict future changes in agro-ecosystems as a result of variations in external constraints (from management toclimate change), process orientated models are required. These can use real- or near-real time remote sensing data (like vegetation cover, standing live biomass, soilmoisture levels) as inputs, and produce as an output predictions about future systemproperties.

Barton also made reference to the use of NIR to monitor pollution by remote sensing.The use of arrays fitted to microlite aircraft are being used in industrial areas fordetecting emissions from smokestacks. This technology is currently under test in

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Hawaii, but initial results look promising and if successful, this technology is likely tobe adopted widely by environmental enforcement agencies throughout the US.

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Person(s) visited: Dr K. Norris and Mr R. Schumann

Date: 14 March 2001

Address: Foss-NIRSystems, Silver Springs, Maryland, America



Pharmaceuticals

Over the past five years there has been considerable interest from pharmaceuticalindustries in the use of NIRS for testing raw materials and finished products. Thepotential of NIRS as a means of assessing the composition of tablets non-destructivelyis a major advantage in pharmaceutical industries. However, NIRS has not yet beenaccepted as an approved analytical technique and the FDA, who are responsible forregulatory controls, have yet to approve the use of NIRS as an official method oftesting or for quality control. A group, set up by the pharmaceutical industry, hasrecently been established to liase with the FDA in order attempt to establish NIRS asan approved method for regulatory and quality control purposes. At present, it isuncertain when or if this approval will be granted. Many of the NIRS instrumentmanufacturers are developing standards and methods of testing, and instrumentmatching for the pharmaceutical industry.

Instrument matching

Variability between NIRS instruments is clearly a problem where commoncalibrations are being used. Workable techniques for matching instruments are seenas a major objective by many. It has been suggested (by Karl Norris) that satisfactorymatching can be achieved by treating the data using a ratio of two second derivatives,although he admitted that this approach was not accepted by all. He however believesthat this approach can take care of most of the differences that occur betweeninstruments, although the approach still needs to be tested widely.

Tecator have done a lot of work on instrument matching, particularly with cerealgrains. They have developed a calibration set which they have marketed world-wide,together with their machines. This works well because they are using well definedproducts (cereal grains) scanned using a fairly narrow range of instruments. Thespectra have been gathered world-wide from many thousands of samples and so as aresult, they have been able to develop robust models for specific cereal grain types

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which have very wide application, and which can accommodate between-instrumentvariation.

Tecator are now doing the same for forages. In a number of centres in the USAnetworks have been set up where instruments are tightly matched. Although it is notpossible to eliminate completely between-instrument variability, there are a number ofcommercially available techniques for standardising machines, which can reduce asignificant proportion of the variability.

Artificial Neural Networks (ANN)

Karl Norris recognises that artificial neural networks (ANN) is a very powerfultechnique, but it still requires good calibration samples. There are those who suggestthat this technique will provide greater accuracy; however, whatever technique isadopted it is essential to start out with a good calibration standard, which includes allthe instrument variability from a wide range of instruments. Only in this way will agood prediction accuracy will be achieved.

Foss are currently examining the potential of ANN, and are undertaking many studiesto see how applicable this technique will be in the food, agriculture (for forages) andsugar industries. The current feeling is that ANN will not be taken up as much by theanimal feed industry as perhaps in other industries, e.g. pharmaceuticals. ANNcurrently gives very mixed results and therefore Foss is looking at enhancing thedevelopment of the ‘LOCAL’ calibration facility with the Infrasoft International (ISI)software. This approach also has strengths and weaknesses, and works better in somesituations than others. There is unlikely to be a single approach that will be applicablein all situations. Some highly complex techniques have been developed, which only afew individuals know how to use. Modified partial least squares (MPLS) regressionhas become a standard chemometric technique and is widely understood and used, andseems robust enough in the majority of situations.

Near vs. mid-infrared analysis (NIR vs. MIR)

Foss and NIRSystems currently have no plans to move outside of the visible and NIRregions and are concentrating their research in these topics. The main problem withmid-infrared (MIR) analysis is sample preparation, whereas with NIR there is theoption of either no-sample or sample preparation. It is not possible to make atransmitter station for a pharmaceutical tablet for MIR. When developing calibrationsfor animal manure, for example, there are not the same constraints on samplepreparation. These can be dried, ground etc., whereas the pharmaceutical industryrequires a process that can assess the composition of a whole tablet, withoutsubjecting it to any processing.

Diode arrays

Foss is not involved with diode arrays at the moment although the technique has a lotof merit and could solve a lot of problems. However, there is a big problem inmatching instruments. Where, for example, you have 512 diodes in an array, thiseffectively means that you have 512 spectrometers (every diode is another

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spectrometer). Therefore, there is a much bigger matching problem. If the applicationworked and benefits really came through, there may be more interest in developing thetechnique. However, one of Foss’s objectives is to produce global models(instruments) that are somewhat similar to the next one. Diode arrays currently do notfit in with this objective.

Diode arrays have one major advantage, namely speed. It is possible to obtain resultsmuch more quickly, i.e. several hundred spectra per second. In agriculture, there isgenerally less demand for speed, unless it is part of a process, in which case itbecomes more attractive. Under special conditions, it may also be possible to obtainlower levels of detection, but in general, there is no inherent reason why diode arraysshould have higher levels of detection than NIR. However, it is very expensive todevelop the calibrations for diode arrays, and these have to be able to be carried by theprocess.

The detection limit is influenced by the signal noise ratio. To reduce signal noise,need to take measurements over a longer period of time. To get detection of materialat very low concentration, need to measure the sample over many minutes. Inpharmaceuticals, some constituents are at very low concentrations. However, it ispossible to measure these because the path length is extremely long, even though youmay be measuring tablets 3 mm thick. Therefore, the weak signal is magnified by thepath length. With water, it is possible to measure down to 1% with very highaccuracy without destroying the sample.

Some diode arrays are readily available in the short wavelength region from 500 to1000 or 1500 nm. These are based on silicon detectors and are relatively inexpensive.The development of these has been funded largely by camera manufacturers. If diodearrays are going to be used for on-farm applications, Karl Norris feels that these arethe instruments that are likely to be used. The Tecator grain instrument is using onlywavelengths in the 850 to 1050 nm region. They are not using diode arrays at present,but for silicon-based diode arrays this is the ideal region, and is likely to be the nextarea of development. It should be possible to build diode array spectrometers for thispurpose using that technology. If you want to extend the range, then indium galliumarsenide (InGaAs) arrays are required which can go up to 1700 nm, although these arecurrently significantly more expensive.

While Karl Norris accepts that current diodes may be less stable, and diode arrays aremore difficult to match and stabilise, he believes that this is something that diodearray manufacturers will be able to do something about once requirements for thetechnology are understood by diode array manufacturers. The technology is stillrelatively new and the problems can theoretically be solved in combination withimproved chemometric methods. Currently, however, the low-cost diode arrays offerconsiderable potential, and they will become more widely used as people come torecognise their potential, particularly for the analysis of a set of specific constituents.Using this approach, it should be possible to develop low-cost instruments for use onfarm. Fred McClure is currently working in this area, and there are a number of diodearray companies, e.g. Oceanoptics, manufacturing these instruments. They are notaiming at farm markets at present, but are manufacturing low-cost small portablespectrometers for general application.

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Detection of residues (e.g. pesticides)

In general, NIR is not a suitable technology for the detection of residues. However,this is an area that Foss are interested in and is trying to develop NIR for this purpose.To begin with, it is necessary to develop an instrument with a good signal noise ratio.This could be achieved with an instrument using two lasers. Lasers only put outradiation in the region that you want to measure, in contrast to ‘conventional’ NIRSmethods, which apply a broad range of radiation. The latter put a lot of energy on thesample, resulting in the risk of damage to the sample. However, using lasers it shouldbe possible to increase the energy many hundreds of times, and get an improvement insignal noise ratio. Such instruments are available which cover a limited region of thespectra, but are very expensive. However, this technology is the one most likely tosolve the problem of rapid analysis for residues. This approach would also requirethat the correct wavelength is identified although it was suggested that this could bedone now. It is essential that the instrument is very stable both in terms of wavelengthand energy in order to make the measurements. This is not a simple problem but theyare likely to be developed largely because lasers are important to the communicationsindustry and is the source of the money and research needed to develop theseinstruments.

Development of databases and global models

Considerable effort is being directed by instrument manufacturers into thedevelopment of large databases and global models. This is a similar approach to thatused in the development of the grain models, which are now widely used (e.g. theGrain Inspection Laboratory, Kansas). However, feeds and forages pose differentchallenges and problems. Foss are identifying key partners around the world toparticipate in the development of databases for both forages and feeds (includesCentral Laboratories in the UK) with the objective of developing global calibrations(models). Ownership and maintenance of the models would be by the instrumentmanufacturer. The effects of this on competitiveness and trade are clear.

Foss perceive that there will be fewer analytical chemists in the future, and fewerscientists that will want to make a career out of infrared ‘science’. Therefore, theyhave a number of instrumentation and software projects on-going around the worldwith the overall aim of simplifying NIRS. They are looking to design instruments andsoftware that are easier to use, that do not require an understanding of chemometrics,but that will operate at the push of a button. Attention will focus on processingsystems that are easily ‘integratable’ with existing plant and machinery, for analysis ofboth ingredients (raw materials) and finished products. They are currently working onthe development of process control systems for sugar manufacturing, with the abilityto detect sugar levels, soil contamination etc. in the incoming cane and thecomposition of material during various stages of processing.

Product development

The main emphasis appears to be on improving signal strength. There are likely to bemany new markets opening up, driven primarily by new regulations (e.g.

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environmental, health), but for these a better signal strength will be required. Thiswill not necessarily require manufacturers to focus on a narrower range ofwavelengths; Foss anticipate that they will continue with the current wavelengths, butgreater emphasis and development will be given to sample preparation, handling andpresentation to the instrument.

With regards to the identification of unknown feed ingredients (i.e. policing statutorydeclaration of ingredients of compound feeds), neither Norris nor Schumann believedthat it would be possible to identify levels of ingredient inclusion in compound feedsusing NIRS since there are too many unknowns. Foss are more interested inidentifying specific contamination, both mineral and microbiological (e.g. pathogens).However, they will only develop into topics where they believe there is a reliableapplication of NIR. Norris is of the view that NIR has been over-sold as being able todeliver far more than it reliably can. Given a sufficiently large data set, it is usuallypossible to derive combinations of these data points, which will give correlations.However, all too frequently these have not been tested rigorously enough againstindependent data sets.

For forages, Foss are focusing on developing universal calibrations (models) whichstandardise results and provide standardised solutions. The main problem withforages, as compared to grain, is the between laboratory variation. This is a problemwith grain analysis, but on a much smaller scale, due largely to the fact that thevariability in grain composition tends to be much smaller than with forages. Also,because when measuring fibre, for example, sample presentation is critical. Variationin scanning discs between manufacturers can produce significantly different results. Asimilar problem was encountered with use of different cling film to wrap fresh foragesin the UK.

Justification for the development of ‘global’ calibrations by an individual laboratorycan be enormous. At the same time, Foss are able to access a more extensivedatabase, with greater sample variability, than any one single laboratory is likely to beable to do. Foss are unlikely to put purchasers of NIR machines in a situation wherethey have to purchase calibrations, i.e. machines and software will continue to be soldseparately so that individual laboratories will be able to develop their own software ifrequired. Increasingly, laboratories do not want to or are unable to develop theexpertise needed to develop calibrations, therefore, an overall goal is to provide acomplete service (i.e. instruments and calibrations) for those who require it.

Characteristics of forages

Schumann and Norris both believe that NIRS is capable of identifying‘characteristics’ of feeds, e.g. digestibility, rumen degradability, and otherconstituents. Although there have been mixed results, the problem appears to be inthe development of the reference method. The information is definitely in the spectra;the challenge is in getting the information out.

Interpretation of spectra

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Norris is of the view that it is important to be able to interpret the spectra since thisunderstanding will enable a greater chance of improving the robustness of NIRScalibrations. The advantage of working in pharmaceutical industries is that there is anarrow range of known materials going into a tablet and therefore the spectroscopy ismuch simpler than dealing with feeds and forages. One of the concerns that KarlNorris has is that finished feeds (e.g. compound feeds) are a mixture of ingredientscontaining proteins. The proteins are all different, and the individual proteins do notnecessarily have a common NIR band. Therefore, it is asking a lot of thespectroscopic technique to tell you how much protein is present due to the mixture ofproteins. Given this scenario, it is amazing that the system works a well as it does.

Research currently being done in Japan (based on original research by Procter andGamble), whereby using two dimensional (2D) correlations they are able to look atinteractions within the spectra. The original work was done on simple materials buthave now moved on to look at milk. This approach could help a lot in understandingwhy one spectrum does better than another spectrum for a given test.

Applications in the food industry

Norris confirmed that in Japan fruit is now being sorted by NIRS, primarily for sugarcontent, using diode arrays. One of the machines he has seen consisted of 12 x 250watt lamps, with samples moving very quickly along a conveyor belt. Analysis ofindividual fruits are being done in a few milliseconds. There are competingcompanies in Japan making these machines. One such company is setting up amanufacturing plant in Italy to produce portable diode arrays for use in supermarkets,where it will be possible for customers to test a few samples of fruit to ensure quality.There was some doubt as to whether this technology would be adopted or desirable inthe USA. It raises questions regarding what would happen to all the unselected fruitand concern that it would lead to extra cost and/or extra waste? It may be adopted bysorting and distribution centres, so that ‘premier quality’ fruit can be identified andcommand a price premium.

Remote analyses

Traditionally, the practice has been to bring samples to the NIRS instrument.Increasingly, spectrometers are being used remotely. Future developments will bemoving towards ‘at-line’ environments. There are a number of approaches beingconsidered at the farm level and these are likely to form the next generation ofinstruments. Remote probes are currently widely used in the pharmaceutical industryfor product identification. Where it was once necessary to analyses each batch ofincoming material to confirm its authenticity, a process that might have taken severaldays, – it is now possible to obtain immediate confirmation of the material using aprobe. However, this is relatively easy since the probes have been programmed torecognise a relatively narrow range of ingredients, and therefore require a narrowspectral range. Systems that provide product recognition and compositional analysis(e.g. determining protein and oil content) of cereal grains entering a feed mill arebeing developed. They need to be ‘process friendly’ and to link in with least-costformulation software.

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Future developments

The future developments of NIRS for feed and forage analysis is likely to focus onglobal calibrations and enhancements in chemometrics. Public fears and perceptions,and regulations will drive new applications of NIRS technology. For example, in theUSA there is increasing concern over phosphorus contamination of the environmentand the role phytic acids have to play in this. Attention is therefore focusing onmeasuring phytic acid contents of grains.

The future of NIRS will also depend on persuading the FDA, and other regulatoryauthorities, that it is a credible method of analysis. Instrument manufacturers clearlysee this as a major challenge, and one that if won will significantly enhance prospectsfor NIRS technology. In this sense, Europe is ahead of the USA in that there is adocument with the European Commission with the aim of getting approval to useNIRS as a normal analytical tool. The ultimate objective, in the pharmaceuticalindustry at least, is to have an in-line system of measuring every tablet that passesalong a conveyor. However, Norris believes that this is unlikely to be achievablewithout the use of lasers to make the measurements. At the present time in the drugindustry, only a very small number of tablets are analysed, maybe 100 tablets permillion produced. Tests over the years have shown that on many production systemsthis is probably adequate. However, where tests show up errors, then large numbersof stock have to be destroyed. Also, time taken in testing with conventional analyticaltechniques means that stock has to be retained while analyses are being done, and thiscan be very expensive.

NIR may have applications in testing new materials under test since initially these arefrequently only available in limited quantities, and therefore requires a non-destructivesystem of analysis.

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Person(s) visited: J Reeves

Date: 13 March 2001

Address: Agricultural Research Service, Maryland



Overview of agricultural research in the USA

The previous (Clinton) administration placed greater emphasis on basic/fundamentalagricultural research, while Congress argued for more applied research. There aresigns that publicly funded agricultural research is now moving towards the appliedend, reflected in changes in organisation and structure, although there has been nooverall reduction in the agricultural research budget. However, there has been areduction in public funded research into NIRS and Dr Reeves is currently the onlyperson currently employed on NIRS in an animal science laboratory in the USDA.

Currently applications

Apart from the Grain Inspection Service, there is no state support or involvement in afeed analysis service but is provided entirely by the private sector. Developments areinitiated and funded by private companies including instrument manufacturers andanalytical laboratories. The feed analysis business in the USA (either by NIRS orconventional techniques) is fairly static. There are a large number of feed laboratoriesin the USA, offering NIRS analysis of feeds and forages. Accuracy of forage testingis monitored voluntarily by the Forage Testing Industry. The National Forage TestingAssociation (NFTA) is a non-profit making corporation dedicated to improving therepeatability and accuracy of forage testing laboratories. It was established in 1990(out of the National Hay Association, which had been established in 1976). Itsactivities include a proficiency testing program for forage testing laboratories which isused as a basis for certification of forage testing laboratories for dry matter (DM),crude protein (CP), acid detergent fibre (ADF) and amylase neutral detergent fibre(NDFA). As part of subscription paid service, they provide quarterly checks samplesof lucerne (alfalfa) and the results (for DM, CP, ADF, and NDFA) are reportedrelative to the median results of all the participating laboratories. Laboratories arethen certified based on accuracy of the determinations. Maize silage check samplesare also available.

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The NFTA evaluates approximately 150 laboratories within the USA and Canada foraccuracy of testing lucerne hay, lucerne-grass hay, grass hay, and maize (corn) silage.Rock River Laboratories (Illinois) is one of the largest laboratories in the USA and hasdeveloped small portable spectrometers, but apart from this there appears to have beenfew new developments or applications of NIRS in the animal feed business. DrReeves was of the view that there seems to be less interest in developing NIRS forfeed analysis in the USA than in Europe, where networks are being established. Thebig change that has occurred in the USA in the last five years has been the adoption ofNIRS by the pharmaceutical industry. This is the area that has seen the greatestdevelopment of NIRS technology, both in terms of hardware and data processing.NIRS is being used in all aspects including ingredient analysis and process control offinished products. Systems are now in place that are able to check every tabletthrough the blister packs, and provide analysis of the constituents, the coating etc.Bran+Lubbe have tended to lead the field in this area, but NIRSystems are now alsoactively involved in this area. The area that is likely to see the greatest application inthe future is in environmental management. Tight restrictions have been introduced ina number of States on waste, particularly due to concern over water quality (e.g.pathogens, nutrients etc.). Restrictions have been introduced that limit manureapplication to fields to the extent that crops are able to utilise the nutrients.Regulation enforcement implies that farmers know the nutrient value of their manure,and this raises problems with regards to obtaining representative samples from slurrylagoons, etc. This offers significant potential for small, portable instruments thatfarmers can use to analyse their organic manure. Current developments includesampling devises attached to output pipes from manure spreaders, linked to satellitesprogrammed with information on the nutrient status of the soil, crop type etc., therebyallowing controlled manure application. Whether NIRS will be capable of fulfillingthis role is still unknown. Dr Reeves has found with manure that the wavelengthsabove where the fibre-optic cables start to become ‘noisy’ (above about 1700 to 1800nm) are necessary to obtain good calibrations for ammonia. The only other methodthat looks promising is electrical conductivity. Cheaper instruments, down in thevisible and short wavelength range do not work for this application.

Research is also being done on soils to determine natural mineralisation by infraredspectroscopy. Current models using NIRS are poor, but are better using mid infrared(MIR) spectra. Following Kyoto accord, there is considerable interest in determiningthe carbon status of soils, and IR spectroscopy offers potential for rapid soil analyses.Studies are currently being done using both NIR and MIR, and early studies show thatthese have considerable potential. But the question still remains regarding the regionof the spectra, which gives the best results. To date, evidence seems to suggest that asthe sample sets get bigger NIR seems to do much better than MIR. On a large data setrecently obtained, prediction of carbon was achieved with MIR (r2 0.92; error 0.14%carbon) and NIR (r2 was 0.98; error 0.07% carbon), but MIR seemed to deal moreeffectively with ouliers. The US Department of energy are also interested in thepotential of MIR as a means of monitoring carbon change in soils, but whether NIR orMIR are going to be good enough is still debatable. Very high specifications arerequired to monitor carbon change in the soil (one tenth of one gram of carbon percubic metre change per year), nevertheless, this remains an area of considerableinterest in Government research. Dr Reeves is currently analysing several thousandsof samples of soil form the Soil Conservation Department in order to build a database

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principally of carbon, but also for nitrogen, minerals, and pH. MIR often seems todetermine pH better than NIR but it is not certain whether it also results on over-fitting in some cases.

Dr Reeves’ group is the only one to have undertaken NIR vs. MIR comparisons withforages, but the results suggest that MIR works just as well as NIR. On one set ofsamples (fescue) the MIR seemed to over-fit. It may be that there is more informationin the MIR range, but the problems of over-fitting and outliers disappears withincreasing size of sample sets. In forage analyses with mid-IR, the errors were usuallylower and r2 usually higher with mid-IR, but only slightly. However, with soils thisgroup are seeing some real differences between the two techniques, with MIRshowing significantly higher r2 values. Instrument manufacturers do not seeminterested in developing MIR instruments, however, this may change, when thepotential of MIR for soil analyses is confirmed by studies in the USA and Australia(the only other country apart from the USA that appears to be undertaking studies onthe use of MIR for soil analyses).

Instrumentation

Dr Reeves has worked on the FT-IR and seems to be as good as the scanningmonochromator, but not better. According to Dr Reeves, the main problem with FT-IR is that the spot size is very small; therefore, care is needed to prevent damage to thesample. There is currently no available transport device, no rotating sample deviseetc., for either FT-IR or FT-NIR. He has built his own sample carrier, which allowshim to scan a sample 50 mm long by 5 mm wide. While this seems to help, it is stillpossible to damage the sample. In discussion with instrument manufacturers, anumber have expressed an interest in developing instruments with larger spot sizes,but Dr Reeves is not aware that any have done so.

Since Dr Reeves is now mainly working with slurry and manure, samples are usuallydried prior to scanning. When scanning large numbers of samples, samples areanalysed in bags. Earlier work with silages compared bags with dried and groundsamples. On wet feeds, the bags did not appear to have any real effect; although theremay have been wavelengths, which were obscured, but this did not appear to have anyadverse effects, and both techniques gave similar results. Similar comparisons havenot been made with manure, but with soils, the bag is having a deleterious effect. Thereasons for this are not clear; but it may be because the soils have so much lessorganic matter. This study also looked at dried samples (in bags) and the results werenot as good as those obtained using the closed scanning cup. The advantage of usingbags is that they are so convenient, particularly when working with material such asslurry or manure.

Fibre optics

Dr Reeves has done a number of studies comparing fibre optic probes with scanningsamples in sealed bags. To-date his general impression is that fibre optic probes donot work quite as well as bags and the longer the probe the noisier it is (do not workabove 2300 nm). In their work, Reeves used every wavelength up to 1900 nm andthen averaged every 20 wavelengths between 1900 and 2300 nm. This approach

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smoothed out the data but they were able to retain the ammonia peak (at around 2100nm). It is not clear how legislation will be implemented, but it there is a requirementto sample every tank, or even the slurry/manure as it is being applied to the soil inorder to get a representative analysis of the material being applied, then there arelikely to be significant developments in fibre optic probes.

Diode arrays

Dr Reeves has not had direct experience with the use of diode arrays butacknowledges their potential, particularly in terms of speed. Their cost and theproblems of matching could be overcome by selecting specific wavelengths andhaving a relatively few number of diodes. For example, only five or six diodes wouldbe needed for ammonia in manure. These machines are fast, stable, and thereforeoffer considerable potential.

Portable analysers

It is now possible to purchase small, hand-held spectrometers. On such instrument,currently being sold for about $500, has a light source and uses a film to filter specificspectra. Currently can identify the range from visible to about 1100 nm, althoughthere is no theoretical reason why they could not go all the way out to the MIR region.There has been a great deal of interest in these, having throw-away sensors which canbe used, e.g., to detect pollution in streams. The problem is that for the MIR region,the detectors get more expensive. Whether portable machines that are capable ofdetecting to the MIR region will be developed will depend on the market. At presentReeves does not foresee a sufficient demand for these to justify the additionalmanufacturing costs associated with extending to the MIR region. Small portablespectrometers are now being used in supermarkets and grocery stores in Japan toallow shopkeepers to check the quality of produce. They are able to detect, forexample, sugar levels as well as detect internal blemishes, e.g. bruising in fruit.Portable NIR spectrometers are also now widely used in hospitals to test blood oxygenlevels and consist of small devices strapped to the hand or arm. Developments are atan advanced stage to develop similar instruments to detect blood glucose andcholesterol levels (important topics in health management).

The future of NIRS will be in the development of small, portable and perhapsdisposable spectrophotometers with specific purposes.

MIR vs. NIR

MIR can be useful for understanding and interpreting NIR spectra, but how importantthis is has been questioned by some. Little research appears to have been done oncombining the two regions, although Reeves has done some work with forages, butfound no advantage from combining the whole spectral region compared to NIRregion alone. This is probably due to the fact that within the IR spectra the sameinformation is repeated at decreasing levels of intensity from the MIR to NIR regions.Derivitisation is just as important for MIR as for NIR and surprisingly the samederivatives apply to both regions.

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In general, MIR is superior to NIR for carbon, nitrogen, minerals and metalcontamination of soils. In forages, NIR is better for protein and digestibility, but MIRgenerally out-performs NIR for ADF and NDF analyses. The main disadvantage ofMIR is the presence of strong absorption bands and thus the potential for spectraldistortions when analysing material in the fresh state. In a recent publication (Reevesand Zapf, 1999. Applied Spectroscopy, 53:836-844) it was shown that by usingvarious spectral regions and search algorithms using either NIR or MIR couldsuccessfully match unknown food ingredients to products of a similar nature, althoughthe extent to which this could be successfully achieved depended on the searchalgorithms used. This method, they suggested, appears to be a suitable alternative todiscriminant analysis.

In another recent study (Reeves, 1999. Near Infrared spectroscopy, 7:89-100), MIRwas compared with NIR analysis of 325 diversely treated feedstuffs. All sampleswere scanned using a Pacific Scientific 6250 scanning monochromator and FT-MIRspectrometer equipped with a diffuse reflectance attachment. The results showed thatwhile visual determination of likely compositional or spectral outliers was not feasibleusing either approach, changes in spectra due to treatment were much more easilyattributed to compositional components using MIR rather than NIR spectra. In otherwords, spectral interpretation of treated forages and by-products was much simplerand easier in the MIR than the NIR, but the MIR spectral interpretation does notappear to offer any additional benefits with respect to improving calibrations fordetermining composition.

Software developments

Although not available in most of the software currently available, Dr Reeves felt thata number of people are working with ‘genetic outruns’ for wavelength selection. Inhis experience, software developers are generally unwilling to discuss their latesttopics of research or development until they appear in commercial software.However, an area that is likely to be given attention will be improvements in signalprocessing and processing speed. Having attended many of the NIR meetings in theUSA in the last few years, he has not seen anything radically different in softwarepackages, other than modifications of partial least squares (PLS).

Artificial Neural Networks

In collaboration with Mark Westerhouse, Reeves found for 10 data sets that artificialneural networks (ANN) was better in seven cases, PLS better in two and stepwiseregression better in one, however the differences were not dramatic. The main riskwhen using ANN is that of over-fitting. Reeves referred to the fact that there are somecentres in Europe where everything is done by ANN, including calibration transfer,but he was not aware of something similar in the USA.

Software ownership and Intellectual property rights

Similar problems are being faced with the development of universal calibrations forsoils as with feeds and forages. John Shenk has developed calibration software forsoils based on ‘LOCAL’ facility within the Infrasoft International (ISI) software. This

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LOCAL approach identifies a number of samples from a large data set which matchthe samples to be analysed and then develops a ‘local’ calibration, but this software ispatented. It is not clear to what extent the underlying principles of this approach arepatented, or how logical it would be to do this in a slightly different way. Forexample, if a set of 50 spectra were identified as being similar to the sample set,would this be a patent violation? If it is, then it means that approach could not beused if trying to develop a portable, PC-based, instrument. Reeves was of the viewthat software developers were unlikely to make available the ‘LOCAL’ software foruse on portable instruments. Development of a universal calibration for soils isunlikely, at least not with the level of accuracy that will be required for carbonsequestration, but it was clear that sub-calibrations were necessary to get the level ofaccuracy required for carbon sequestration.

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DISCUSSION

The information contained within the individual fact finding reports represents a wide

range of views, and of past and current experiences of NIRS technology. While some

may hold the belief that NIRS has progressed beyond the stage of research into the

stage of application and implementation, it is clear from the review that there is a

significant amount of NIRS related research still on-going across the world. Much of

the research is taking place using current NIRS technology (e.g. NIR scanning

monochromators). However, it is also clear that the newly emerging technologies, in

particular the new diode array instruments, will present an important opportunity in

the future to extend the scope of the application of NIRS in both feed and food

industries. Without doubt the newly emerging technologies are at the stage of

considerable development and will require research in order for their potential to be

fully realised.

The application of NIRS has largely been based on a predictive approach and

generally involving the analysis of samples within a laboratory environment. The

evidence from the review highlights that the technology will continue to be applied to

the prediction of specified parameters. What does emerge, however, is that

increasingly there will be departure from the current approach on how the predictive

analysis will be carried out. This will include analysis of samples in their fresh-state

(e.g. fresh forages, whole cereal grains and seed legumes, complete diets and whole

fruits), greater in-line monitoring of feed and food manufacturing processes through

the use of fibre-optic probes and a move away from laboratory-based analysis. The

potential for NIRS to be used at the site of application will largely be achieved

through the very important developments taking place with NIRS instrumentation

including, the new diode array instruments and the increased minaturisation of

instruments. It is also likely that the range of parameters to be predicted will increase

and will include, animal based measurements (in vivo digestibility, intake, feed

preference), quality and sensory attributes of foods etc. The results highlight that

important information on the nutritional characteristics of animal feeds may be gained

from the NIR spectra of faeces. Early evidence suggests that faeces-based calibrations

may be independent of diet composition or animal species. It is also clear that NIRS

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is seen as being able to play a number of important predictive roles, with various

applications having different requirements of NIRS. While some analytical

approaches may require a high level of precision (e.g. prediction of feed quality), other

applications may use the technique as a screening tool (e.g. analysis of breeding lines)

and therefore demand a lower level of precision.

Since NIR spectra contain all the information relating to the complex interaction of

NIR radiation with the molecular bonds within a sample, there is a widely held view

that the spectra can be used directly to provide information about specific samples

(without the need for calibration). This has been widely demonstrated through the

ability of NIRS to authenticate or discriminate between sample types or between

different variants of a particular sample (e.g. rice grain authentication; non-genetically

modified from genetically modified). The spectra of samples will also allow

important developments to be made in understanding important processes through

monitoring changes at specific points within a series of spectra. Certainly a number of

the reports highlight that further work is required in order to maximise the potential

use of NIR spectra and will certainly be an area of continued development.

The progress made in the application of NIRS technology has been due largely to the

developments in chemometrics and computer capabilities. While many expressed the

need for further developments in the field of chemometrics, there was clearly a view

that the development of large databases and the use of artificial neural networks had

great potential. The development of databases, possibly utilising the benefits of the

Internet, may lead to an increased level of co-ordination between laboratories both

within and between different countries. This approach may also lead to a greater

degree of co-ordination between different scientific disciplines in

nationally/internationally important research topics. The important developments in

crop tissue testing (e.g. rice, wheat and barley) highlights the benefits of the co-

ordinated approach undertaken by cereal chemists, spectroscopists and soil scientists.

This work has had considerable impact on the management of these crops, thereby

reducing the impact of these systems on the environment.

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Overall, the review highlights a significant number of opportunities for the application

of NIRS. These include:

• The rapid prediction of all the chemical and nutritional properties of fresh forages

at the point of harvest (e.g. use of forage maize parameters as indicators of maize

silage quality). Also, the prediction of the nutritional value of whole cereal grain

prior to processing. These applications may also involve the use of newly

emerging technologies where analysis can be completed at the site of application

(e.g. instruments mounted to forage and grain harvesters).

• Prediction of rumen parameters from animal diets/dietary ingredients and the

parameters required by the new feed evaluation systems/models being developed

(including nutrient degradation, microbial protein production).

• Analysis of faeces to support feed analysis, health status (e.g. worm burden,

nutrient deficiency) and animal behaviour (e.g. feed selection and feed preference).

The analysis of faeces has important implications to both intensive and extensive

animal systems (e.g. hill and upland situations).

• Use of NIRS as a whole farm management monitoring tool (e.g. dairy production)

through the analysis of feeds/whole diet, milk (e.g. urea content), urine (e.g.

nitrogen, purine derivatives), blood, and faeces.

• Prediction of carcass composition and quality (in-line), distinction between fresh

and previously frozen meat, between animal breeds and between meats from

animals of different ages.

• Prediction of sensory attributes of foods including taste, flavour etc..

• Development of crop tissue testing in order to match nutrient applications to crop

requirements throughout its development. Also to assess soil nutrient status (e.g.

nitrogen, carbon) and sewage sludge, manure and compost composition.

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• Prediction using plant canopies to a lesser or greater extent (e.g. nitrogen content of

leaves, pesticide/fungicide treatment of single, whole cereal grains, detecting

vegetation change in species-rich grasslands, weed competition in standing crops).

• Opportunity for the development of large spectral databases or libraries and for the

opportunity to expand the use of networks including the use of the Internet for on-

line retrieval of sample spectra for calibration development.

• Greater scope for the direct use of spectral information for sample identification

(e.g. geographical origin, food and feed type and classification, organic vs. non-

organic standards).

• Expansion of in-line NIRS analysis (e.g. manufacturing processes) and the

possibility to alter process conditions based on the predicted analysis.

The potential for the continued development of NIRS in the feed and food industries

appears enormous. At present, NIRS appears to be at an important stage of

development particularly with respect to the development of diode array technology.

However, further work is required particularly with respect to the transfer of

calibrations between instruments when using fresh (undried) samples and for the

transfer of calibrations to and between diode arrays. The scope for developing large

databases of NIRS spectra is also limited at present by the low number of

institutes/organisations with suitable databases of sample NIR spectra. NIRS is also

likely to be limited to the analysis of macro-nutrients although in itself this may not be

a limitation but a realisation of the scope of the technology. Greater consideration is

therefore required to understand how other complementary technologies can be used

together with NIRS in order to provide the full range of parameters required in any

given situation.

CONCLUSIONS

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The results of the Project confirm that NIRS is a relevant and indeed vital technology

to the feed and food industries. Considerable opportunities are available for the

technology transfer of work on-going elsewhere to situations in the UK. It is also

concluded that NIRS is at an extremely important stage of development and the newly

emerging technologies, such as diode arrays, offer considerable scope for the further

development of NIRS applications. At such an important stage in the development of

NIRS it is essential that the UK develops a greater understanding of the potential of

this technique and to ensure a greater degree of co-ordination and co-operation in the

research and development of this technology. It is clear from the visits made that both

within the EU and the world at large, the UK lags behind in fully researching and

exploiting the value of this technology.

REFERENCES

Baker, C. W., Givens, D. I. and Deaville, E. R. (1994). Prediction of organic matter

digestibility in vivo of grass silage by near infrared reflectance spectroscopy: effect of

calibration method, residual moisture and particle size. Animal Feed Science and

Technology, 50: 17-26.

Deaville, E. R. and Givens, D. I. (1998) Regions of normalised near infrared

reflectance difference spectra related to the rumen degradation of fresh grass, grass

silage and maize silage. Animal Feed Science and Technology, 72: 41-52.

Givens, D. I., De Boever, J. L. and Deaville, E. R. (1997). The principles, practices

and some future applications of near infrared reflectance spectroscopy for predicting

the nutritive value of foods for animals and humans. Nutrition Research Reviews, 10:

83-114.

Office of Science and Technology, 1998. Foresight for Agriculture, Horticulture &

Forestry. DTI, London, 17pp.

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