Fast Atom Bombardment Mass Spectrometry of Chlorophylls

ment of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S IA4. Although the glucosinolate content of Canola meal is substantially lower than that of earlier varieties, the residual glucosinolate levels must be decreased by at least a further order of magnitude before the meal may be acceptable for incorporation into food products. Canola meal was extracted with lower aliphatic alcohols containing dissolved ammonia. Methanol containing 10% or more dissolved ammonia reduced the glucosinolate content of the meal from 1.5 to less than 0.2 mg/g. Results with ethanol were similar. Propanol and butanol were only partially effective in removing glucosinolates, but were somewhat more effective in the presence of water. The effect of methanol concentration, moisture content, solvent: seed ratio, and contact time were investigated. Methanol ammonia systems promise to be viable in removing and destroying all residual glucosinolates in the meal to the level of detectability attainable by the Youngs and Wetter spectrophotometric method.

A COMPOSITE REFERENCE STANDARD FOR THE IDENTIFICATION OF POTATO GLYCOALKALOIDS. Filadelfi, M.A., School of Food Science, Macdonald Campus of McGiII University, Ste. Anne de Bellevue, Quebec H9X ICO and A. Zitnak, Department of Horticultural Science, University of Guelph, Guelph, Ontario NIG 2WI. A simple reference standard had to be developed to facilitate positive identification of all degradation products of enzymatic hydrolysis in various potato tissue homogenates. This very simple reference standard was comprised of a mixture of all eight glycoalkaloid substances likely to occur in potato plant extracts and was obtained by simply terminating the stepwise degradation by mild acid hydrolysis (95% EtOH containing 1% HCI) of a-solanine and a-chaconine for 45 min. The products of this hydrolysis were combined and resolved during a single TLC run using the developing solvent of Osman et al. (1978). The resolution of the eight substances in the order of their solubility (Rr values) occurred as follows: a-S (.26), a-Ch (.34), f3..-S (.40), !3,-Ch (.44), !32-Ch (.55), y-S (.67), y-Ch (.71) and SD (.97).

DETECTION DE LA MAMMITE PAR LE DOSAGE DE LA CATALASE. Dubois, G., G. Normil, M. Gagnon, G. Roy et R. Charbonneau, Centre de recherches en sciences appliquees a I'alimentation (CRESALA R), Universite du Quebec, Montreal, Quebec H3C 3T8. Plusieurs auteurs mentionnent qu'i1 peut exister une relation Leucocytes-Catalase-Mammite. L'activite catalasique du lait a donc ete determinee apres la mise au point d'une methode et en utilisant un Catalasimetre R • Des analyses statistiques portant sur plusieurs centaines de donnees ont montre qu' il existait une correlation tres forte entre le nombre de leucocytes refletant I'etat de sante du pis et le taux de catalase presente dans le lait. Avec cette methode de mesure automatisee simple, rapide et precise, nous avons pu detecter la mammite a des degres divers in situ au niveau du pis de la vache et dans chacun des quartiers.

TASTE THRESHOLDS OF POTATO GLYCOALKALOID BITTERNESS. Filadelfi, M.A., School of Food Science, Macdonald Campus of McGill University, Ste. Anne de Bellevue, Quebec H9X ICO and A. Zitnak, Department of Horticultural Science, University of Guelph, Guelph, Ontario NIG 2WI. Glycoalkaloids are known to contribute to the bitter off-flavour of potato tubers. Taste differences and threshold concentrations were determined by tasting weak acidic solutions of a-solanine, a-chaconine and !32-chaconine in 0.02% lactic acid. These taste tests revealed two distinct taste perceptions; the first was a bitter sensation, coincidental with or followed by a peppery burning sensation. Detection thresholds for bitterness were 60 ppm for a-solanine and 15 ppm for both etchaconine and f3.2-chaconine. The burning sensation was noticed at 120 ppm for a-solanine and 30 ppm for both chaconines. In general, a-solanine was less bitter than either chaconine by a factor of four. From these observations it seems certain that the two chaconines are the major contributors to potato tuber bitterness.

REPORT ON THE INTERNATIONAL DAIRY FEDERATION. Emmons, D.B., Food Research Institute, Research Branch, Agriculture Canada, Ottawa, Ontario KIA OC6 and L. Rodgers, SecretaryTreasurer, FIL-IDF Canada, c/o Animal Products Division, Agriculture Canada, Ottawa, Ontario KIA OC5. The major event in 1982 is the XXI International Dairy Congress, Moscow, July 12-16. Participating Canadians will be: Mr. Savage as President of IDF, Mr. Hurd, Session Chairman, and six invited speakers. Important meetings were the Seminar on Recombined Milk and Milk Products (Singapore, October 1980), Seminar on Dairy Education (Rome, May 1980), Seminar on Dairy Ingredients in the Food Industry (Luxembourg, May 1981) and Symposium on Bacteriological Quality of Raw Milk (Kiel, September 1981). Planned meetings are: Seminar on Cow of the Future (Warsaw, August 1982), Workshop on Computer Application in Milk Transport (Toronto, September 1983), Symposium on Role of Milk Proteins in Human Nutrition (Kiel, March 1983), Second Seminar on Dairy Effluents (Killamey, April 1983), Symposium on Physico-Chemical Aspects of Dried Protein-Rich Milk Products (Denmark, May 1983) and a Seminar on Fermented Milks (France, 1984). IDF continues to publish about one dozen documents each year and various standards and methods of analysis, e.g., a revised Monograph on UHT Milk (available from the Secretary). DETECTION OF GLUCOSE OXIDATION PRODUCTS IN CHILLED FRESH MEATS UNDERGOING SPOILAGE. Farber, J.M. and E.S. Idziak, Macdonald Campus of McGiII University, 21, III Lakeshore Road, Ste. Anne de Bellevue, Quebec H9X ICO. The fate of nutrients during storage of longissimus dorsi muscle at 4°C was examined. Glucose concentrations in meat were shown to decrease with time concommitant with an approximately fourfold increase in the activity of glucose dehydrogenase. Using an enzyme assay, gluconate concentrations in meat were determined and shown to increase from 2.3-39.8 !Jog/g upon storage of the meat from day 0 to day 6. At day 12, gluconate concentrations had decreased to 10.6 !Jog/g. Dark firm dry meat, which contains little or no glucose, did not exhibit the same rise and fall in gluconate concentration. Thin layer chromatographic analysis confirmed the presence of 2-keto-gluconate in 6 and 12 day old longissimus dorsi muscle that had been stored at 4°C. It appears that glucose, at 4°C, is being converted to gluconate and/or 2-keto-gluconate extracellularly, by one of the main meat spoilage organisms, most likely the Pseudomonads.

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THE MECHANICAL PROPERTIES OF SCALLOP MUSCLE. Fmdlay, C.J. and D.W. Stanley, Department of Food Science, University of Guelph, Guelph, Ontario NIG 2WI. The hardness of scallop muscle, as measured by Instron compression, increases as a function of heating. Heating in boiling water results in a linear response with respect to time. Equilibration in circulating water to temperatures of 25,40,50,55,60,65,70,75 and 80°C gives a step function that is linear below 60°C and above 65°C. The first linear change reflects the increase in hardness due to dehydration. Room temperature dehydration produced a similar linear increase in hardness. The second linear portion has a greater slope, probably due to thermal shrinkage of connective tissue as well as dehydration. The transition reflects the denaturation of myofibrillar proteins and the average hardness increases by 4.38 N/scallop. THE MICROSTRUCTURAL SCORING OF MUSCLE TEXTURE. Findlay, C.J. and D. W. Stanley, Department of Food Science, University of Guelph, Guelph, Ontario NIG 2WI. Food texture is a consequence of microstructure. Quantitative evaluation of microstructure should relate directly to texture measurement. Scallop adductor muscle is an excellent model system to study the behaviour of myofibrillar protein. Previously frozen samples were equilibrated in a circulating water bath to temperatures of 25,40, 50, 55, 60, 65, 70, 75 and 80°C. Each sample was blind coded and examined by SEM to determine a percentage of irregular fibres. This figure was about 30% for uncooked muscle. Samples below 50°C gave damage results under 45%, while those over 65°C were above 60%. The response parallels the Instron compression step function that reflects denaturation of myofibrillar proteins between 60 and 65°C. Linear regression of damage vs. hardness gave an R2 of 0.86 at P = .004. FAST ATOM BOMBARDMENT MASS SPECTROMETRY OF CHLOROPHYLLS. Fisher, R.W. and H. Daun, Department of Food Science, Cook College, Rutgers University, New Brunswick, New Jersey 08903. Naturally occurring pigments, such as the cWorophylls, are thermally labile, nonvolatile compounds. These pigments have not been previously identified without chemical alteration or the formation of derivatives of these compounds. The development of fast atom bombardment (FAB) J. tnst. Can. Sci. Tec/mo/. Aliment. Vol. IS. No. 3. 1982

mass spectroscopy has enabled researchers to obtain molecular Ions and fragment ions directly from the unaltered pigments. The FAB mass spectra of the natural colourants chlorophyll a and b will be presented. EFFECT OF STORAGE ON BITTERNESS DEVELOPMENT, PROTEOLYSIS AND VISCOSITY IN UHT MILK. Froehlich, D.A. and R.C. McKellar, Food Research Institute, Agriculture Canada, Ottawa, Ontario KIA OC6. The effect of storage on bitterness development, proteolysis and viscosity of ultra high temperature (UHT) milk was examined. UHT milk from four producers (two direct and two indirect sterilization methods) were kept at 25°C and evaluated every 2 weeks during a 20 week storage period. Bitterness, as evaluated by a thirteen member trained panel, using an unstructured 15 cm scale for intensity of bitterness, showed a progressive increase over time. Proteolysis, measured as the increase in trichloroacetic acid soluble free amino groups, and viscosity also increased during storage. UHT milk sterilized by the direct method was particularly susceptible to spoilage due to proteolytic enzymes and coagulation. The correlation between perceived bitterness and proteolysis was good, indicating the possibility in predicting UHT milk shelf life from proteolysis measurements. EFFICACITE DE HUIT DESINFECTANTS SUR DIFFERENTS TYPES DE SURFACE. Gelinas, P. and J. Goulet, Departement de sciences et technologie des aliments, Universit6 Laval, Quebec, Quebec GIK 7P4. A partir de la methode de dilution d'emploi de I' AOAC (1980), nous avons etudie I'influence de trois types de surfaces communement rencontres en industrie alimentaire sur I' activite desinfectante de huit produits commerciaux. Apres avoir inocule des anneaux d'acier inoxydable, de polypropylene et d'aluminium au moyen d'une suspension de Pseudomonas aeruginosa ATCC 15442, ces derniers furent seches et desinfectes par immersion dans chacune des solutions sous etude. Pour la grande majorite des produits testes, des concentrations dix fois superieures it celles efficaces sur I' acier etaient requises pour desinfecter le polypropylene et I'aluminium. L'examen au microscope electronique it balayage demontre que I'adhesion des bacteries serait etroitement reliee it la nature des surfaces. THE MANIPULATION OF THE THERMAL GELATION PROPERTIES OF VEGETABLE PROTEIN ISOLATES USING CONDITIONS OF pH AND NaCl CONCENTRATION. Grealy, J.M., T.J. Maurice and C.D. Myers, General Foods, 520 William Street, Cobourg, Ontario K9A 4L4. The thermal gelation properties of vegetable protein isolates, produced via a novel process, can be manipulated by altering the conditions of pH and NaCI concentration. Isolates from sources such as fababean, soybean and rapeseed can be used to achieve thermal gels similar to those produced with egg albumen. ROLE OF INDUSTRIAL GASES IN THE FOOD INDUSTRY. Hayek, J., Canadian Liquid Air Ltd., 1I55 Sherbrooke Street West, Montreal, Quebec H3A IH8. Applications of gases in the food industry have been in use for some 15 years. Gaseous or liquid Nz and CO z are used worldwide and in Canada usage volume currently exceeds 100,000 tons/year. Industrial gases are introduced in many food sectors where their neutral and cold properties are needed most. Applications such as freezing, chilling, inerting and sparging use gases to prevent deterioration in many foods. Trends for the future in the use of industrial gases and cryogenics will be discussed. A NEW CONTINUOUS ANION EXCHANGE PROCESS FOR DESALTING CHEESE WHEY. Helbig, N.B., K. Eugster and S. Nakai, Department of Food Science, University of British Columbia, Vancouver, British Columbia V6T 2A2. An anion exchange resin was packed in a loop of cotton knit tubing which was cycled continuously around rollers. During cycling, the resin belt was dipped successively in tanks containing cottage cheese whey and 1 N KOH. The whey thus neutralized had a pleasant, mildly sweet taste suitable as an ingredient for food processing. This new system is simpler in construction than the fluidized bed system and also reduced the resin disintegration since no resin pumping is required. The system is also easily adaptable to small or large processing size. Factors affecting the desalting efficiency have been investigated. Can. Inst. Food Sci. T.chnol. J. Vol. IS, No. 3, t982

THE ENZYMIC RELEASE OF FATTY ACIDS FROM PHOSPHATIDYLCHOLINE IN PEAS. Henderson, H.M., J. Kanhai and N.A.M. Eskin, Department of Food Science, University of Manitoba, Winnipeg, Manitoba R3T 2N2. Deterioration in the flavour of fresh or unblanched frozen peas during postharvest storage may be partly due to the activity of lipid degrading enzymes. While the enzymes lipoxygenase, lipase and phospholipase D have been demonstrated in peas by other workers, this study describes the enzymic release of fatty acids from phosphatidylcholine, suggesting the presence in peas of phospholipase A and/or B activities. The biochemical properties of this enzymic activity will be described. The objective is a greater understanding of the role of lipid degrading enzymes in the postharvest degradation of endogenous lipids in peas. STORAGE OF JERUSALEM ARTICHOKE TUBERS FOR HIGH FRUCTOSE SYRUP PRODUCTION. Hoehn, E., R.W. Kolesar and J.W. Rogers, Department of Food Science, University of Manitoba, Winnipeg, Manitoba R3T 2N2. Currently we are evaluating the potential of Jerusalem artichoke as a source of high fructose syrup. Manufacturing based on a year round rather than seasonal operation appears more viable, but would require year round storage of tubers. Tubers were submitted to cold, frozen and dehydrated storage. Total sugar loss, change of fructose/glucose ratio and spoilage were monitored. Changes observed in cold stored tubers included a slight decrease of total sugars, a decrease of the fructose/ glucose ratio and substantial spoilage (50%) occurring after 8 weeks in storage. Treatment of cold stored tubers with mold inhibitor reduced spoilage, and no spoilage occurred in frozen or dehydrated samples. Since none of the treatments affected extractability of the sugars from the tubers, it may be feasible to use frozen storage for winter and dehydrated storage for balance of year processing. MICROWAVE HEATING OR MOISTURE ADJUSTMENT TO ELIMINATE NEMATOSPORA FROM MUSTARD SEED. Holley, R.A., Food Research Institute and G.E. Timbers, Engineering and Statistical Research Institute, Research Branch, Agriculture Canada, Ottawa, Ontario KIA OC6. In 1979, 50% of the North American crop of Brassica juncea was highly contaminated with Nematospora. A continuous flow microwave system was used successfully to destroy the yeast without affecting the desirable bitter principle of mustard. At the natural moisture level of 6.8%, a temperature of 87.2°C was needed to kill the yeast, whereas in seed adjusted to 9.74% moisture, a temperature of 70.8°C was adequate. Coincidently it was found that sublethally heated yeast died off in the moisture amended seed during storage. Simple adjustment of seed moisture to > 10% yielded Nematospora-free seed if stored 13 days at 37°C or 37 days at 23°C. At 4°C and 14.9% moisture there was no effect on Nematospora viability up to 77 days. EVALUATION OF METAL FOOD CANS - A CURRENT PERSPECTIVE. Hotchner, S.J., Manager, Evaluation & Specifications, Metal Container Research, American Can Company, 433 N. Northwest Highway, Barrington, Illinois 60010. Both the can manufacturer and the food packer need accurate knowledge of the effect foods have on the can, and vice versa. An understanding of food can performance is achieved through blending the recognized scientific disciplines of statistics, food science, sensory testing, analytical chemistry and electrochemistry with metal can technologies. The resulting empirical evaluation approach is described, with examples of how all these disciplines are jointly applied to the current challenges arising from the availability of new materials and alternate can manufacturing processes. IN-PLANT RECYCLING OF FOOD PROCESS WATERS. Hydamaka, A.W., R.A. Gallop and J. Yau, Department of Food Science, University of Manitoba, Winnipeg, Manitoba R3T 2N2. The food industry uses large quantities of potable water, usually inefficiently, to create corresponding effluent/environmental problems. By contrast, the authors have shown that appropriate grades of water can be efficiently used at each food processing operation, under excellent quality control of both phases, for extended periods. Small in-plant purifier modules (especially using activated carbon) can permit rapid purification and intensive recycling of major process waters, such as in vegetable, fish and poultry processing. Major possibilities exist for

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