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Isolation and characterization of vicilin from vicia faba
EFFECTIVENESS OF SODIUM CHLORIDE AS A CRYOPROTECTANT FOR CHUM SALMON EGGS UTILIZED IN THE PROCESSING OF CAVIAR. Craig, C.* and W. D. Powrie, Department of Food Science, University of British Columbia, Vancouver, British Columbia, V6T 2A2. The efficiency of NaCI as a cryoprotectant for salmon eggs, sp. O. keta, was evaluated on the basis of a comparison of membrane strength, yolk viscosity and brining time for caviar produced from fresh eggs, eggs previously frozen for 7 d/-lOoC, and eggs first subjected to a 30 min immersion in 2.5 M NaCI, then frozen. The cryoprotected eggs differed from those either fresh, or untreated and frozen, by requiring a shorter brining time to produce the 4-5070 chloride content required for salmon caviar. Caviar from cryoprotected eggs possessed a yolk of lower apparent viscosity, but a membrane strength comparable to that produced from fresh eggs. QUALITY OF MEAT FROM OYSTERS SHUCKED WITH THE AID OF A CHEMICAL. Whyte, John N.C.* and Barron L. Carswell, Fisheries and Oceans Canada, Fisheries Research Branch, Vancouver, British Columbia, V6T IX2. Magnesium chloride, 0.327M. proved 90% effective in gaping oysters within 12 hours. Infusion of magnesium, approx. 0.3% wet weight of meat and displacement of calcium by 91 % was responsible for inhibition of muscle contraction. Brine treatment was more effective than fresh-water leaching in removal of infused magnesium and retention of constituent carbohydrate in oyster meat. Overall sensory evaluations indicated use of magnesium chloride as an aid to shucking oysters would provide fresh meat with barely acceptable taste characteristics but would provide fresh brine-washed meat, smoked and pickled products with readily acceptable sensory properties. PSYCHOPHYSICAL ANALYSIS OF APPLE JUICE FOR PREFERENCE OPTIMIZATION. Sharma*, D.D. and M.B. McConnell, Department of Food Science, University of Manitoba, Winnipeg, Manitoba R3T 2N2. An optimization equation for preference (Y) including aroma intensity (Xl)' sugar content (X 2) and acid-phenolic balance (X 3) was developed by maximum r 2 improvement technique. The equation is Y = -8.11 + 16.99X 1 + 1.28X2 + 0.76X 3 (r2 = 0.999). Chemical properties (sugar, acid and phenolic contents) were analysed by standard methods, sensory properties (perceived sweetness, sourness, bitter-astringent taste and aroma) by magnitude estimation and preference of apple juice by hedonic scaling. Relationships of preference with chemical, chemical balance and sensory properties were established by curvilinear regression. The above combination of independent variables was found to be a most practical combination for estimating preference of apple juice. A METHOD FOR THE ISOLATION, SPECIATlON AND BIOTYPING OF CAMPYLOBACTER JEJUNI AND CAMPYLOBACTER COLI FROM FRESH PORK AND POULTRY CARCASSES. Lammerding*, A.M., Agriculture Canada, Animal Pathology Laboratory, Guelph, Ont., NIG lY4; M.M. Garcia, Agriculture Canada, Animal Diseases Research Institute, Nepan, Ontario, K2H 8P9; E.D. Mann, Agriculture Canada, Animal Pathology Laboratory, Winnipeg, Manitoba, R3G IB2 and H. Lior, National Enteric Centre, Bureau of Microbiology, Laboratory Centre for Disease Control, Ottawa, Ontario KIA OL2. A laboratory procedure to detect contamination of fresh pork and poultry carcasses with Campylobacter jejuni and C. coli was developed. The method involves enrichment in a selective peptonebased broth and plating onto Mueller-Hinton agar containing sheep's blood, antibiotics and growth supplements. Suspect colonies are confirmed by morphological examination and 6 metabolic tests. Biotyping, based on hippurate hydrolysis, a modified rapid H2S test and DNA hydrolysis, differentiates 8 biotypes representing C. jejuni, C. coli and C. laridis (formerly NARTC-nalidixic acid resistant thermophilic campylobacters). The method has demonstrated effective recovery of the thermophilic campylobacters and can be easily incorporated as a routine procedure in food microbiology laboratories. Biotyping may provide additional information to elucidate sources of contamination of meats and poultry.
xxxii / Affaires de l'Institut
ISOLATION AND CHARACTERIZATION OF VICILIN FROM VICIA FABA. Arntfield*, S.D., M.A.H. Ismond, and E.D. Murray, Department of Food Science, University of Manitoba, Winnipeg, Manitoba, R3T 2N2. The purpose of this investigation was to isolate the storage proteins (particularly vicilin) from Vicia jaba retaining as much of the conformational integrity of the proteins as possible. Initial attempts to separate the proteins with gel filtration were unsatisfactory due to the apparent association of the two major structural proteins. Upon further investigation it was found that the vicilin fraction was preferentially soluble in 0.2 M sodium acetate, pH 7.5. Gel filtration of this extract was required to remove contaminating phenolics. The isolated fraction was then characterized with respect to molecular weight, subunit composition and amino acid composition. THE QUANTITATIVE ANALYSIS OF FAT AND PROTEIN IN MEAT BY TRANSMISSION INFRARED ANALYSIS. Mills, Bernice L., Dept. of Nutrition, Universite de Montreal, P.O. Box 6128, Mtl, P.Q. H3C 317, and F.R. van de Voort, School of Food Sc., McGill University, Ste-Anne de Bellevue, P.Q. H9X lCO. Transmission infrared analysis, which has been successfully applied to milk analysis, was assessed for the quantitative analysis of fat and protein in meat products. Meats of varying fat and protein content were converted into milk-like emulsions, which were in turn analyzed by standard chemical methods and by a Multispec M infrared analyser. The performance of the instrument for meat analysis using a standard milk calibration was also assessed and compared to the instrument set with a meat calibration. Both approaches provided a good estimate of the fat and protein content for a range of meat products, the meat calibration being more accurate than the milk calibration. The infrared method allowed for rapid and accurate analysis of meat and has future potential in the meat industry for quality control purposes. INVESTIGATION OF THE FUNCTIONAL PROPERTIES OF SURIMI PROCESSED FROM PARASITIZED AND NONPARASITIZED WHITEFISH (Coregonus c1upeajormis) AND TULLIBEE (Coregonus artedil). York, R.K.* and D.G. Iredale, Department of Fisheries and Oceans, Freshwater Institute, Winnipeg, Manitoba, R3T 2N6 and M.B. McConnell, L. Malcolmson, A. Hydamaka, D. Ryland and P. Stephen, Department of Food Science, University of Manitoba. Certain stocks of the coregonids, whitefish and tullibee, serve as an intermediate host for a harmless but aesthetically objectionable parasite, Triaenophorous crassus. This severely decreases the economic value of these fisheries. The processes in surimi production were investigated to evaluate their effectiveness in removing any residue of the parasite and in producing a protein base material with the required functional properties. Texture evaluation indicated a superior quality surimi could be manufactured from these species from fish sampled from a variety of sources and held for varying times prior to processing. Product composition data was also consistent with this result. OBJECTIVE FIELD TEST FOR SQUID QUALITY. LeBlanc, Raynald J.,* OceanChem Ltd., and Tom A. Gill, Canadian Institute of Fisheries Technology, TUNS, Halifax, Nova Scotia. A rapid color test has been developed for the' field testing of squid quality. The test is based on the measurement of ammonia which is generated in spoiling squid. The ammonia in squid extracts is converted to glutamate in the presence of glutamate dehydrogenase and a-ketoglutarate. The electrons generated in this reaction due to the oxidation of the cofactor NADH, are transferred to either piodonitrotetrazolium violet or 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, resulting in the formation of colored formazans. The formazans are subsequently partitioned into isobutanol and compared with ammonia standards. The color test was found to be semi-quantitative and accurate to within ± Img% mantle ammonia nitrogen. The test procedure takes ca.20 minutes to complete and can be performed in the field without the use of any elaborate laboratory equipment. The results of the ammonia tests were found to correlate well with degree of spoilage of the Atlantic short-finned squid (//lex iIIecebrosus). J. Inst. Can. Sci. Technol. Aliment. Vol. 17, No. 3, 1984
xxxii / Affaires de l'Institut
ISOLATION AND CHARACTERIZATION OF VICILIN FROM VICIA FABA. Arntfield*, S.D., M.A.H. Ismond, and E.D. Murray, Department of Food Science, University of Manitoba, Winnipeg, Manitoba, R3T 2N2. The purpose of this investigation was to isolate the storage proteins (particularly vicilin) from Vicia jaba retaining as much of the conformational integrity of the proteins as possible. Initial attempts to separate the proteins with gel filtration were unsatisfactory due to the apparent association of the two major structural proteins. Upon further investigation it was found that the vicilin fraction was preferentially soluble in 0.2 M sodium acetate, pH 7.5. Gel filtration of this extract was required to remove contaminating phenolics. The isolated fraction was then characterized with respect to molecular weight, subunit composition and amino acid composition. THE QUANTITATIVE ANALYSIS OF FAT AND PROTEIN IN MEAT BY TRANSMISSION INFRARED ANALYSIS. Mills, Bernice L., Dept. of Nutrition, Universite de Montreal, P.O. Box 6128, Mtl, P.Q. H3C 317, and F.R. van de Voort, School of Food Sc., McGill University, Ste-Anne de Bellevue, P.Q. H9X lCO. Transmission infrared analysis, which has been successfully applied to milk analysis, was assessed for the quantitative analysis of fat and protein in meat products. Meats of varying fat and protein content were converted into milk-like emulsions, which were in turn analyzed by standard chemical methods and by a Multispec M infrared analyser. The performance of the instrument for meat analysis using a standard milk calibration was also assessed and compared to the instrument set with a meat calibration. Both approaches provided a good estimate of the fat and protein content for a range of meat products, the meat calibration being more accurate than the milk calibration. The infrared method allowed for rapid and accurate analysis of meat and has future potential in the meat industry for quality control purposes. INVESTIGATION OF THE FUNCTIONAL PROPERTIES OF SURIMI PROCESSED FROM PARASITIZED AND NONPARASITIZED WHITEFISH (Coregonus c1upeajormis) AND TULLIBEE (Coregonus artedil). York, R.K.* and D.G. Iredale, Department of Fisheries and Oceans, Freshwater Institute, Winnipeg, Manitoba, R3T 2N6 and M.B. McConnell, L. Malcolmson, A. Hydamaka, D. Ryland and P. Stephen, Department of Food Science, University of Manitoba. Certain stocks of the coregonids, whitefish and tullibee, serve as an intermediate host for a harmless but aesthetically objectionable parasite, Triaenophorous crassus. This severely decreases the economic value of these fisheries. The processes in surimi production were investigated to evaluate their effectiveness in removing any residue of the parasite and in producing a protein base material with the required functional properties. Texture evaluation indicated a superior quality surimi could be manufactured from these species from fish sampled from a variety of sources and held for varying times prior to processing. Product composition data was also consistent with this result. OBJECTIVE FIELD TEST FOR SQUID QUALITY. LeBlanc, Raynald J.,* OceanChem Ltd., and Tom A. Gill, Canadian Institute of Fisheries Technology, TUNS, Halifax, Nova Scotia. A rapid color test has been developed for the' field testing of squid quality. The test is based on the measurement of ammonia which is generated in spoiling squid. The ammonia in squid extracts is converted to glutamate in the presence of glutamate dehydrogenase and a-ketoglutarate. The electrons generated in this reaction due to the oxidation of the cofactor NADH, are transferred to either piodonitrotetrazolium violet or 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, resulting in the formation of colored formazans. The formazans are subsequently partitioned into isobutanol and compared with ammonia standards. The color test was found to be semi-quantitative and accurate to within ± Img% mantle ammonia nitrogen. The test procedure takes ca.20 minutes to complete and can be performed in the field without the use of any elaborate laboratory equipment. The results of the ammonia tests were found to correlate well with degree of spoilage of the Atlantic short-finned squid (//lex iIIecebrosus). J. Inst. Can. Sci. Technol. Aliment. Vol. 17, No. 3, 1984