Bayati* A.A.K., andA.M.A. Salih, Food Science Department, College of Agriculture, Abu-Ghraib, Baghdad, Iraq. Cows, buffaloes and sheep milks were compared with regard to levels of lipolysis, lipoprotein lipase (LPL) activities in milk and whey, % fat, fat globule size and somatic cell count. The effect of homogenization, heparin and different types and concentrations of blood serum on the activity of LPL in their milks and its relative activation and inhibition by the intrinsic activator and inhibitor, respectively were also studied. It was concluded that milks from different animal species vary markedly in their susceptibility to lipolysis, with cows milk being the most susceptible, sheep the least and buffaloes milk having intermediate susceptibility. Important factors contributing to this difference are fat globule size, LPL activity (especially in whey) and the relative concentration of activators and inhibitors. HPLC CHROMATOGRAPHY OF WATER EXTRACT OF CHEDDAR CHEESE. Pham*, A.-M., G.F. Amantea and S. Nakai, Department of Food Science, University of British Columbia, Vancouver, British Columbia V6T 2A2. Water-soluble fractions were prepared from mild, medium and aged cheddar cheese. Sensory analysis revealed that the freeze-dried water extracts exhibited typical cheddar flavour of different ages. HPLC pattern from the Adsorbosphere RP C8 showed better resolution than the Vydac RP C l8 and the patterns confirmed the difference in flavour. Computer programs for multi-variate analysis were compared for performance and it was found that the factor analysis (P4M-principal component mode) and regression on principal component (P4R) of the BMDP program were suitable for grading. Stepwise linear discriminant analysis (BD07M) was useful for this distinction. UTILIZATION OF RESIN NEUTRALIZED WHEY AS FOOD INGREDIENT. Helbig*, N.B. and S. Nakai, Department of Food Science, University of British Columbia, Vancouver, British Columbia V6T 2A2. Anion exchanged whey was used as an ingredient in a variety of food products. As much as 10% whey solids was added to beverages and 20% to dry instant mashed potatoes without impairing the acceptability. Up to 12 and 18% whey solids could be incorporated into soups and complete nutrition breakfast drinks, respectively. 100% replacement of milk in dough and batter formulations gave acceptable breads and cakes. Meat balls, cheese sauce and fried chicken batter containing whey were also tested, no significant difference in acceptability (P <0.05) being obtained when milk in the formulations was completely replaced with resin neutralized whey. PREPARATION OF EGG WHITE SUBSTITUTE FROM WHEY PROTEIN CONCENTRATION. To*, B., N.B. Helbig and S. Nakai, Department of Food Science, University of British Columbia, Vancouver, B.C. V6T 2A2. A new simplex optimization with a mapping technique facilitating visualization of the optimum location was applied to find the treatment conditions for obtaining the maximum overrun value. The largest overrun value (with the limit dilution value for gelling) obtained after 17 experiments was 183% (2.5) when cysteine (1.0% of protein) and pepsin, (2.5% of protein) were added to a 10% whey protein solution and incubated for 52 lOin at 35° C, pH 2.0, then held at 41 ° C for 5 min. The overrun of egg white was 176% (3.0) which could be reproduced by incubating the whey protein solution at pH 2.5 with 3% pepsin. INTERACTION OF BETACYANINE AND BETAXANTHINE PIGMENTS ISOLATED FROM RED BEET. LeeWing*, P.,J.F. Richards and V. Karunartne, Department of Food Science, University of British Columbia, Vancouver, British Columbia. Betacyanins and betaxanthins were isolated from red beets using a fractionization procedure based on extraction with acidified ethanol. Interaction between betacyanins and betaxanthins were determined for varying proportions of the mixed components. The visible spectra of all sample fractions were recorded prior to further analyses. Hunterlab colour values as well as high performance liquid chromatography were used to determine the relationship between pigment colour and the interaction of the mixed components. Interaction between the pigment types were further verified by the I H NMR spectroscopy. Results show that both physical and chemical interaction occur in the mixed pigment types. I H NMR spectra revealed the formation of unknown components.
xiv / Affaires de I'Institut
VARIATIONS IN DRY MATTER AND CARBOHYDRATE CONTENTS OF COMMERCIALLY GROWN AND STORED POTATOES. Mazza*, G., Agriculture Canada, Research Station, Morden, Manitoba. Variations in dry matter, sucrose and reducing sugars of commercially grown and stored Russet Burbank, Norchip and Kennebec potato cultivars were studied. Dry matter content increased with tuber maturing, decreased during the curing period and remained practically constant during storage. Sucrose concentrations of tubers were high in early harvests and decreased rapidly with later dates of sampling reaching minimum levels at maturity. Production and storage site, growing sea-. son and storage temperature had little effect on sucrose and dry matter contents of most cultivars. Norchip potatoes contained less sucrose, less dry matter and less reducing sugars than either Kennebec or Russet Burbank tubers. Dry matter levels of growing tubers correlated negatively with sucrose and reducing sugar contents. However, correlations of dry matter with sucrose and reducing sugars of stored potatoes were very low, and with a few exceptions nonsignificant. SEASONAL VARIATION OF IODINE VALUE, SOFfENINO' POINT, SOLID FAT INDEX AND FATTY ACID COMPOSITION OF BUTIER. Chia*, A.C., Gay Lea Foods Co-op, Ltd., Guelph, Ontario NIH 6J6. This study presents the results of monthly sampling of butters produced by Gay Lea Foods, Guelph, Ontario, for one year, 1979 to 1980. Range and mean iodine value, softening point, trans fatty acid (TFA) plus the solid fat index and the fatty acid composition of the butters are tabulated. Statistical analysis shows that a highly significant positive or negative correlation is found in the following comparisons: IV vs SP (r = 0.8613), vs TFA (r = 0.9533), vs C4 to C20 (r = -0.9818), vs CI8:1,2,3 +C20:1 (r = -0.8192)andtotalSFlvsCI8:1,2,3 +C20:1 (r = -0.9644). STUDY OF THE SAPONIFICATION REACTION OF VITAMIN A IN FORTIFIED MILK POWDER AND MARGARINE COMPARING HPLC AND SPECTROPHOTOMETRY. Chia*, A.C., C.M. Martin and D.M. Sorci, Gay Lea Foods Co-op Ltd., Guelph, Ontario NIH 6J6. A modified cleanup procedure was used for the determination of Vitamin A in fortified milk powder and margarine. The completeness of the saponification reaction of Vitamin A indicates a dependence upon the concentration of the base and the heat treatment used. The method is quantitative and studies of Vitamin A palmitate indicate recoveries greater than 90%. A comparison of data obtained by high pressure liquid chromatography and spectrophotometry is present. EFFECT OF TIME AND STORAGE CONDITIONS ON VITAMIN A LEVELS IN SKIMMILK POWDER. De Boer*, M., L. de Man, G.C. Ashton and J.M. de Man, Department of Food Science, University of Guelph, Guelph, Ontario NIG 2WI. Skimmilk powder was obtained directly from the manufacturer and stored at 21,26 and 32° C in the dark and at 21° C under fluorescent light with an intensity of 3760 Ix. The samples were packaged in transparent plastic bags and analyzed by the fluorometric method for Vitamin A at two week intervals for up to 16 weeks. Statsitical analysis of the data involved significant loss of Vitamin A which levelled off after 10-12 weeks. The percent of Vitamin A remaining after 10 weeks in the dark was 80% at 21° C, 72% at 26° C and 62% at 32°C. The greatest breakdown of Vitamin A occurred under fluorescent light with only 30% remaining after 10 weeks. Random samples of skimmilk powder were obtained from local supermarkets and analyzed for vitamin A content and met Government requirements for Vitamin A content. CHARACTERIZATION AND UTILIZATION OF BY-PRODUCTS FROM ETHANOL FERMENTATION OF FODDER BEETS. Bottner, M.I., A. Wieczorek and N. Kosaric, Biochemical and Food Engineering, The University of Western Ontario, London, Ontario N6A 5B9. Three by-products are produced when fodder beets are used as the raw material for ethanol production: the pulp remaining after extraction of the juice, the yeast and the stillage. The quantity and composition of each of these components have been determined and evaluated. They can be combined and further treated aerobically to metabolize the residual sugars and produce a high-protein, vitamin-rich biomass suitable for animal feed. The parameters for the fermentation and the quality of the subsequent product have been investigated and evaluated.
J. Inst. Can. Sei. Teehnol. Aliment. Vol. 16. No. 3, 1983