POSITION AVAILABLE

Closing date for applications is November 3D, 1986.

SUbject to final budgetry approval.

Egg Quality

Insights

Consumer concern over egg qualityhas prompted a crackdown on Agricul­ture Canada.

In a co-operative program withprovincial departments of agriculture,provincial egg marketing boards andgrading stations, federal inspectors arenow examining eggs from suspect­quality birds prior to grading.

If they don't meet the required stand­ards, they won't qualify as table-qualityGrade A eggs. Watery whites andincreased breakage at the retail levelbecause of thin shells, have becomemore common in recent years and eggsthat should have been used forprocessed foods were getting to thetable egg market, giving rise to con­sumer complaints.

New technology is partly to blame.Today's high-speed egg grading sys­tems can quickly size eggs, but are notprecise in judging shell quality.

1986-87 Executive as follows:President: Ernie ReimerVice-President: Chinnia V. ChandraSecretary: Maureen NewmanMembership: R. BearnsDirectors: R. Whitaker

T.R. PatelThose elected who are not members

have indicated their willingness to jointhe Institute. Dr. A.M. Martin will sub­stitute for Dr. N. F. Haard as theRegional Communicator.

UNIVERSITY OF GUELPH EGG PRODUCERS' CHAIR

Endowed Chair in Egg Products

The University of Guelph is seeking an Associate Professor or Professor in the area of EggProducts Utilization and Egg Technology. The position is funded by an Endowment fromthe Ontario Egg Producers' Marketing Board. In addition to supplying an appropriate salary,funds will be provided for technical assistance and research. The Chair has been estab­lished by the egg producers of Ontario to develop new and further uses of eggs and eggproducts.

The applicant should be an innovative researcher with the expertise to investigate egg com­position and use from a chemical, physical and/or nutritional standpoint. This person mustbe able to interact with faculty, staff and graduate students in various disciplines therebyserving as a catalyst to increase research activity in the area of egg products.

The Chair is essentially aresearch position and the incumbent will be expected to develop aprogram that includes the supervision of graduate students, technical help and post-doctor­al fellows. In addition to research funds provided by the endowment, the incumbent will beexpected to seek other outside funding to strengthen and expand the research program.

The position will be housed in the Department of Animal and Poultry Science and will re­port to the Chairman of the department. Excellent facilities are available in the Departmentof Animal and Poultry Science and, in addition, the incumbent will have access to facilitiesin other university units as the program requires. There are excellent opportunities to liaisewith all on-campus departments allied to this area as well as with the industry. Applicationsshould include a complete resume and the names of four people to whom we may write forreference.

Send to: Or. G.K. Macleod, ChairmanDepartment of Animal and Poultry ScienceUniversity of GuelphGuelph, Ontario, N1 G 2W1

Award Recipients, Donors, Program parti­cipants. ClFST Alberta Section StudentNight held in February at Labatts Brewery.

.S(!ction lJpdate0\ . \~~~

knqwledge in various aspects of foodtechnology, including food chemistry,food microbiology and food processing.Students also have the opportunity toupgrade or acquire new skills in relatedareas of science and technology, orexpand into new areas, includingmanagment and business. The tradi­tional research thesis of most graduateprograms is not required. In its placestudents take more courses and com­plete a special project which involves in­depth study of a topic of personalinterest to the student. Each student'sprograms is tailored to his/her needsand background.

The program is a demanding one,especially designed for highly moti­vated persons who wish to preparethemselves for senior positions in thefood industry or government. It shouldbe especially appealing to individualswho wish to upgrade their knowledgein food science and add to it skills inrelated scientific areas such as computertechnology, toxicology, microbiology,statistics or analytical chemistry. Alter­natively, candidates may wish to com­bine courses in the food science areawith management studies, economicsor marketing. Graduates from the pro­gram will be well prepared to assumesenior technical or managerial positionsin science-based food and related com­panies, government regulatory agen­cies, and a variety of other professionalroles.

Preference for admission to the pro­gram is given to students with at leasttwo years of relevant experience in thefood industry or government.

Students normally will enter the pro­gram in early September and completetheir program by Christmas of the fol­lowing year. The time required to com­plete the program is tailored to theneeds and background of the individualstudent involved. Courses takeninclude graduate and senior under­graduate courses in the Department ofFood Science and in other relevantareas of instruction. At least eight of thecourses taken by each student must beat the graduate level. The needs andbackground of the student are takeninto account in decisions on courserequirements. In addition, each studentis required to complete a special project,on a topic of particular interest to thestudent and acceptable to his/her super­visory committee.

The Newfoundland and Labrador Sectionof the Canadian Institute of FoodScience and Technology has elected its

Can. Insf. Food Sci. Technol. J. Vol. 19, No.4, 1986 Institute Affairs / v

What is Protein Quality?

As noted above, proteins are made upof some 23 amino acids. Of these, thehuman body is incapable of synthesiz­ing 9 - they are known as the essen­tial amino acids and must be suppliedin the diet. (See Table 1)Table 1. Essential Amino Acids (Humans)

PartlyRe-

General Sub- placed'Amino Acid Class class By

, It has been established that part of thebody's requirement for methionine andphenylalanine can be met by cystine andtyrosme respectively.

**Required only by infants.

The remaining amino acids can besynthesized by the body providing asuitable source of amino groups (e.g.other amino acids) is available - theseare known as the dispensable aminoacids. It should be kept in mind thatthese amino acids are merely dispens­able as dietary components - they arenot dispensable to the body.

Proteins differ in quality dependingon their amino acid composition andtheir digestibility. The more completethe amino acid profile and the morenearly this profile approaches the phys­iological needs of a species forindividual amino acids, the higher the

ment for protein per se. Rather, dietaryprotein serves as a source of aminoacids which are required for the build­ing up of body parts or systems that arepredominantly protein in composition(e.g. muscle, organs, enzymes, hor­mones, antibodies). Thus, in the grow­ing individual these amino acids areneeded for the synthesis of all tissueproteins, and in all individuals, grow­ing or mature, for the replacement ofbody proteins that are normally brokendown in the body's dynamic state. Inthe pregnant individual, amino acidsare required for the building of fetal tis­sues, while the lactating female requiresamino acids for the synthesis of milkproteins. Amino acids in excess of thebody's needs for tissue synthesis areused as a source of energy - a sourcethat is less efficient than either carbo­hydrates or fats (Health & WelfareCanada, 1983).

Weight of protein coI!sumed in gramsPER = Weight gain in grams

quality of protein in that food. In addi­tion, the more biologically available theamino acids in a food, the higher itsprotein quality (National Academy ofSciences - National Research Council,1980).

In order to be accurate and applicableto a wide range of foods, any methodof assessing the protein quality of a foodmust take into account all the basicparameters that determine the qualityof that protein - i.e. quantities ofessential amino acids, digestibility ofthe protein itself and the bioavailabil­ity of its amino acids.

A large number of methods forexpressing protein quality may befound in the scientific literature, but itis not within the scope of this paper todescribe all of these various methodsnor to discuss their relative success inthe evaluation of proteins (The UnitedNations University, 1980). However,two methods will be mentioned inorder to provide a basis for the proteinratings of various foods.

The protein efficiency ratio (PER) isthe official method of evaluating proteinquality of foods in Canada and theUnited States. This method involves thefeeding of each test protein to a groupof growing rats, measuring the averagegain in weight of the animals over afour-week period and dividing thevalue by the average protein intake ofthe animals over that period of time.

Because individual dietary proteinsvary in composition, an amino acid thatmay be in low concentration in one isfrequently complemented by a higherlevel in another when the mixedsources of protein are consumedtogether. Thus a vegetarian diet cansuccessfully meet the body's amino acidneeds through the judicious combina­tion of "complementary" plant proteinsources.

Measurement of Protein Quality

RPER = PER of test animals x 100PER of reference animals

In each test, a reference standardgroup of rats are fed the basal diet con­taining casein as the only source of pro­tein. A relative protein efficiency ratio(RPER) is calculated as follows:-

The PER method has been criticizedfor not adequately crediting proteinused for maintenance, for lack of pre-

HydroxySulfur- Cystine

contain-ing

Aromatic Tyrosine

Neutral Branched­chain

LeucineValineThreonineMethionine

Histidine"LysineIsoleucine

PhenylalanineTryptophan

Protein Quality

The Nature of Protein and its Functionin the Body

Proteins are made up of one or morechains of amino acids called polypep­tides. These chains are so called becausethe amino acids are linked together byamide bonds, known as peptide link­ages. The particular way in which the23 or so known amino acids are com­bined in each protein determines itsbiochemical characteristics, but theamounts of the various amino acidspresent in a protein determines itsnutritional value (Lloyd et al., 1978).

The body does not have a require-

During recent years, much emphasishas been placed by the scientific com­munity and by the media upon certaincharacteristics of animal products thatare claimed to have negative implica­tions in human health. We are wellaware of the publicity given to the totalfat, the saturated fatty acids and thecholesterol contributions to the humandiet of such animal products as eggs,milk, and red meats.

Unfortunately, this emphasis hastended to obscure in the minds of con­sumers the many excellent nutritionalqualities of these same products. Usingbut one example, it is well known thatred meats constitute a major source ofmost of the B-complex vitamins, as wellas being an excellent source of suchmacro-elements as potassium andphosphorus and of such trace elementsas zinc, copper and iron, the latter ina highly available form. In a similarvein, specific nutritional advantagesmay be attributed to eggs and milk.Moreover, all of these animal productsshare a major nutritional advantage,that being a high level of protein whosequality is of the highest order.

Poorer-quality eggs usually comefrom flocks that are more than ninemonths old. Since profits can be slight,some producers put off slaughteringtheir flocks for as long as possible to getas many eggs as they can from eachbird, even though the quality hasslipped.

Earlier this year, Agriculture Canadainspectors at grading stations begansampling ungraded eggs from pro­ducers whose flocks are at least ninemonths of age.

1£ their eggs are not up to standards,producers are visited by a field repre­sentative of the provincial marketingboard and are given three weeks tocome up with a plan for correctiveaction.

viii / Affaires de l'Institut J. Inst. Can. Sci. Technol. Aliment. Vol. 19. No.4. 1986