Honey Authenticity

PPP-Indien/Quality Control. QSI 2012 2

Honey Authenticity ©QSI 2013 2

1. Honey origin (floral & geographical)

2. Honey adulteration

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1. Honey origin

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•microscopical pollen count•test combined with examination of flavor and electrical conductivity

pro•information about geographical and botanical origin with one single test•furthermore overview about possible fermentation, adulteration, contamination etc.

con•only performable by staff with considerable experience•does not work for filtered honey (or mixtures of filtered and unfiltered honeys)

Honey origin determination of pollen spectrum

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•determination of trace elements with ICP-MS or AAS

pro•besides determination of origin additional information about toxic heavy metals

con•large databases are required for evaluation•at least 20 different elements necessary complex statistical evaluation•strong impact on the composition of elements by nearby industry•expensive test due to costly instrumentation

Honey origin trace elements

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•determination of different isotope ratios (e.g. hydrogen, oxygen, nitrogen, sulphur)

pro•-

con•large databases necessary (difficult to available)•expensive test due to costly instrumentation

Honey origin isotope ratios

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2. Honey adulteration

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•Addition of sugars to honey

•Feeding of sugars to bees

•Addition of pollen

•Addition of filtered honey

Honey adulteration

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•determination of carbon isotope ratios of honey and honey protein•detection of added sugars from C4-plants•Note: traces of bee feeding stuff is possibly not avoidable

pro•covers all sugars from C4-plants, e.g. corn ( high fructose corn syrup) and sugar cane•foreign sugars are quantified accurately (limit: 7 %)•AOAC Official Method 998.12, worldwide approved and accepted•sugars from C3-plants could be detected, too (example: rice syrup, beet sugar)

con•sugars from C3-plants detectable in higher amounts, but no quantification possible

Honey adulteration 13C/12C-Isotope Ratio-MS

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2007

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2012

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13C IRMS honey incl. protein 2007 to 2012

Honey adulteration QSI-statistics for 13C/12C-IRMS

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•Official AOAC interpretation: detection of sugars from C4-plants = negative differences between 13C-results of protein and honey

•research results by QSI: • high positive differences (> 1.2 ‰) indicate the presence

of sugars from C3-plants • evaluation of >1000 commercial honey samples• results largely confirmed by alternative tests• published at AOAC Annual Meetings in 2008 and 2011

•aim: modification of interpretation of AOAC Official Method 998.12

Honey adulteration 13C/12C-IRMS – positive differences

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•determination of carbon isotope ratios of single sugar fractions

•Use of e.g. inverted beet sugar syrup (=C3) to blend honey, and addition of C4-fructose to increase F/G-ratio > 13C-results of fructose and glucose differ from each other

pro•some syrups mixed of C3 and C4 can possibly be detected

con•determination of pure C4- or C3-sugars not possible

•Results honey study QSI: 13C-results of single sugar fractions differ considerably in freshly collected acacia nectars high natural variations possible

Honey adulteration LC-13C-IRMS

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•HPLC-RI determination of specific mono-, di- and trisaccharides•indications for adulteration:

• high amounts of sucrose (possible origin: beet or cane sugar)• high amounts of maltose and maltotriose (possible origin: starch-based syrup)• low F/G-ratio (possible origin: inverted sugar syrup)

pro•many information with one single test

con•all indications mentioned above can occur naturally in honey, depending on the type confirmation required•no quantification of foreign sugar

Honey adulteration sugar profile

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•HPLC-PAD determination of oligosaccharides in order to detect additions of starch-based sugar syrups•long experience: method developed and published by QSI 20 years ago

pro•covers all starch-based syrups, independent from carbon isotopes•sensitive test, detection limit about 0.1 - 1 % added syrup (BUT: such low amounts could possibly not be technically avoidable after feeding the bees)

con•no quantification possible due to high variations of oligosaccharides in different syrups, depending on the origin and the treatment of the syrup•Honeydew honeys contain oligosaccharides naturally, which need to be distinguished

Honey adulteration oligosaccharide profile

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Dextrin-standard (Dextrin from potatoes)

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Authentic honey sample

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Authentic honey sample intentionally adulterated with 50 % starch-based syrup

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Starch-based syrup

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Adulterated honey sample

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•NEW METHOD, offered by QSI since April 2013•determination of a specific marker substance for beet sugar with LC-MS/MS•mainly positive findings in honeys from China and Eastern Europe

pro•high specific test, substance only occurs in beet sugar syrup•positive findings even when inverted beet sugar is added to honey

con•no quantification possible due to high variations of the marker substance in different syrups, mainly depending on the treatment of the syrup

Honey adulteration beet sugar adulteration

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•determination of a specific marker substance for rice syrup (“SM-R“) with LC-MS/MS

pro•high specific test, substance only occurs in rice syrup

con•no quantification possible due to high variations of the marker substance in different syrups, mainly depending on the treatment of the syrup

Honey adulteration rice syrup adulteration

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•determination of arsenic•background: rice plants enrich arsenic from the ground. •findings in honey >0.01 mg/kg indicate addition of rice syrup•only recommended for confirmation of doubtful results with other analyses

pro•-

con•depending on the soil conditions and treatment of the syrup, the amounts of arsenic vary considerably unreliable results

Honey adulteration trace marker for rice syrup (“TM-R“)

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•determination of the activity of beta-fructofuranosidase:• enzyme which does not occur in honey naturally• used to invert sucrose to glucose and fructose

indirect proof for the addition of beet sugar syrup

pro•high specific test

con•no quantification of added sugar possible•if inversion is carried out in another way and/or if the enzyme is destroyed after inversion negative results in spite of adulteration with beet sugar

Honey adulteration foreign invertase

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•determination of the activities of beta- and gamma-amylase:• enzymes which do not occur in honey naturally• used to produce sugar syrup from starch

indirect proof for the addition of starch-based syrups

pro•-

con•no quantification of added sugar possible•same as foreign invertase: if inversion is carried out in another way and/or if the enzymes are destroyed after inversion negative results in spite of adulteration

Honey adulteration foreign amylase

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•pollen spectrum• as mentioned at the beginning: overview about possible

adulteration

•foreign dextrines• two alternative methods (“Fellenberg“, “Fiehe“) to detect

oligosaccharides in honey• only applicable for amounts >5 %

•proline• honey-typical amino acid• amounts < 180 mg/kg indicate addition of foreign sugar

Honey adulteration further tests

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Our recommendation to detect honey adulteration• pollen spectrum

• overview about irregularities

• 13C/12C-IRMS, Code 40260• covers all sugars from C4-plants (cane, corn etc.) and even

possibly from C3-plants

• oligosaccharide profile, Code 40290• covers all starch-based sugar syrups

• LC-MS/MS test for beet sugar, Code 40470• covers adulteration of (inverted) beet sugar

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Thank you for your attention!

Quality Services International GmbH

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D-28199 Bremen

Fon: +49 421 594770

info@qsi-q3.de

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