Lysozyme Separation From Egg White By Cation Exchange Chromatography

time and temperature treatments required to sequentially eliminate each transition. Longissimus dorsi and semimembraneosus muscles were removed from beef carcasses suspended by achilles tendon or pelvis. Samples, prepared by heating for 5 min at 57C (T 1), 70C (T 2) and 81C (T 3), were assessed by sensory panel for tenderness,juiciness and residual connective tissue. Weight loss, W-B shear and microstructure, using TEM, were also determined. The T, treatment showed significant difference for tenderness and residual connective tissue between muscles, but not between contraction states. Coagulation in the A-band is attributed to myosin denaturation. T 2 produced collagen shrinkage and a significant drop in W-B shear and residual connective tissue coupled with increased tenderness in semimembraneosus muscles. Sarcoplasmic proteins, myosin fragments and tropomyosin are the principal proteins implicated in this transition. The T 3 treatment resulted in the denaturation of all forms of actin and the troponins and actinins. BEEF MUSCLE CYTOSKELETON: THE INFLUENCE OF POST-MORTEM AGING, CALCIUM AND STORAGE TEMPERATURE. J.M. Russell* and D.W. Stanley, Department of Food Science, University of Guelph, Guelph, Ontario NIG 2WI. Sarcolemmal (muscle cell membrane) emptying was quantified with the assumption that this reaction is related to post-mortem degradation of the proteinaceous cytoskeleton in bovine muscle. A rotatable response surface design was employed with aging time (0.25 to 6.25 days), calcium concentration (0 to 50 mM) and storage temperature (3 to 28°C) as response variables. Time/calcium, time/temperature and temperature/calcium were significant interactions for psoas major; the time/temperature interaction was significant for semimembranosus. Sarcomere length and calcium activated neutral protease may account for increased emptying at low temperatures. EXTENDED SHELF LIFE OF FRANKFURTERS WITH ADDED PROTEIN HYDROL YSATE. Belinda Vallejo-Cordoba*, S. Nakai and W.D. Powrie, Dept. of Food Science, UBC, Vancouver, B.C. V6T 2A2 & T. Beveridge, Agr. Canada, Summerland, B.C. VOH IZO. Incorporation of a NaCI-free protein hydrolysate into a frankfurter batter significantly extended the shelf life of the finished product held at room and refrigeration temperatures. With hydrolysate-supplemented frankfurters having a water activity of 0.92, the aerobic bacterial counts were 5,000 times less than that of the control samples after 10 days at 25°C. Hydrolysatesupplemented frankfurters were stable during storage for 18 and 52 days, whereas the unsupplemented samples spoiled after 10 and 38 days at 25° and 16°C respectively. Differences in flavour and texture between the supplemented and unsupplemented sausages were nonsignificant by sensory analysis. PHYSICOCHEMICAL AND FUNCTIONAL PROPERTIES OF CHICKEN BREAST MUSCLE PROTEINS. E. Li-Chan*, L. Kwan and S. Nakai, Dept. of Food Science, Univ. of British Columbia, Vancouver, BC, V6T 2A2, and D.F. Wood, Food Research Institute, Agriculture Canada, Ottawa, ON, KIA OC6. Chicken breast muscle from broilers and laying hens was studied at 1-2h, 2 days and 7 days post-slaughter to determine changes in muscle pH, physicochemical properties of salt-extractable proteins and their effects on functionality. Generally functionality deteriorated from 0 to 2 days, then improved slightly at 7 days. Solubility decreased while surface hydrophobicity (So) and sulfhydryl content (SH) increased with time. Water binding and gelling properties were related to high muscle pH, low SH and low So before heating. Fat binding and emulsifying properties were related to high SH and parameters described by quadratic terms involving SH, solubility and So. LYSOZYME SEPARATION FROM EGG WHITE BY CATION EXCHANGE CHROMATOGRAPHY. E. Li-Chan* and S. Nakai, Dept. of Food Science, 1. Sim, Dept. of Poultry Science, and K. V. Lo, Dept. of Bio-Resource Engineering, University of British Columbia, Vancouver, BC, V6T 2A2. Lysozyme from egg white is in demand as a natural food preservative and therapeutic agent. Cation exchange chromatography was investigated for the separation of lysozyme as well as for recovery of lysozyme-free egg white retaining high functionality. A macro-

xxxviii I Affaires de l'Institut

porous weak acid resin was chosen from various possible strong and weak acid exchangers based on its relatively low cost, high lysozyme recovery and potential for continuous use. Polyacrylamide gel electrophoresis yielded a lysozyme fraction of high purity, except for possible co-elution of avidin, a protein valued for analytical applications. The lysozyme-free egg white possessed superior whipping, gelling and emulsifying properties. POTENTIAL USE OF THE COLUMBIAN OCEANS AND ITS FOOD DEVELOPMENT. G.D.l. Acevedo*, Faculty of Marine Sciences and Food Engineering, Universidad de Bogota 10rge Tadeo Lazano, Bogota, Columbia. During the course of the last five years, government of Colombia in collaboration with the United Nations was successful in exploring for new species of fish in the territorial waters of the Pacific Ocean that would greatly benefit the economic development of this area. Our efforts in the utilization of these fish for local consumption and export markets will be discussed. FROZEN STORAGE OF NOVA SCOTIAN MUSSELS (MYT!LUS EDULISj. D.W. McPeak* and R.G. Ackman, Canadian Institute of Fisheries Technology, Technical University of Nova Scotia, P.O. Box 1000, Halifax N.S. B31 2X4. Cultivated mussels of commercial size were evaluated by both sensory and chemical tests for their acceptability during frozen storage. Samples of freshly cooked mussel meats in lots of 150-200 g were stored at either -12°C or -30°C over a period of five months. The frozen mussels were thawed and ranked by taste by a semi-trained taste panel. After as little as fifteen weeks of storage the taste panels showed a preference for the mussels stored at -30°C. A representative sample of mussels was homogenized for determination of moisture, protein nitrogen, fat and ash. The neutral and polar Iipids were separated and quantified by latroscan TLC/FID. Lipid hydroysis products (monoglycerides, Iysophosphatidylcholine, lysophosphatidylethanolamine) accompanied major lipids such as triglyceride, sterol etc. These artifacts are possible indicators of future storage quality. ETUDE DU PROCEDE DE FABRICATION DE LA MO RUE LEGE REM ENT SALEE. Pomerleau* L., G. Picard, C. VilIeneuve et 1. Lapointe. Universite Laval, Quebec, P.Q. GIK 7P4; Peches et Oceans Canada, Quebec, P.Q. GIK 419. L'objectif de cette etude est de definir la marge de variation des caracteristiques physico-chimiques et biochimiques de la morue, lors des diverses etapes de la transformation en produit legerement salee. L'approche experimentale consiste a mesurer certains parametres i.e. eau, sel, texture etc., sur des poissons qui sont transformes selon la methode traditionnelle et/ou assistes d'un sechage mecanique. Les resultats obtenus revelent une difference appreciable entre les produits selon I'option choisie. Dans I'ensemble, une meilleure connaissance des principales etapes de la transformation i.e. saumurage, pilage et la vitesse de sechage, serait de nature a ameliorer l'uniformite et la qualite du produit fini. EFFECT OF A CITRIC ACID-CACL 2-ASCORBIC ACID DIP AND CO 2 MODIFIED ATMOSPHERE PACKAGING ON THE STORAGE LIFE OF SALMON FILLETS AT -1°C. W.D. Powrie, B.l. Skura*, C.H. Wu, and C. Craig. Department of Food Science, University of British Columbia, Vancouver, B6T 2A2 and T.l. Beveridge, Agriculture Canada, Summerland, B·.C. VOH IZO. Salmon fillets, untreated and treated by dipping in a I fJ70 citric acid - 0.5fJ7o CaCl 2 - I fJ70 ascorbic acid solution were placed in barrier bags that were backflushed with CO 2 prior to sealing. Packages were stored at 4°C and -1°C. Storage at -I °C extended the time before off-odours were detected by about 21 days over that at 4°C. Off-flavours were detected in salmon stored at _1°C by 5 weeks storage. Acid dipping, although decreasing the aerobic psychrotrophic microflora by 1.2 10glO compared to untreated salmon, did not increase storage life at _1°C. Sensory evaluation and shear values showed that acid treatment decreased the tenderness of salmon fillets. INFRARED AS A MECHANISM FOR DETERMINING NITROGEN LEVELS IN K1ELDHAL DIGESTS. E.K. Grunfeld* and F.R. van de Voort. Department of Food Science and Agricultural

J. Inst. Can. Sei. reehnol. Aliment. Vol. 18, No. 3, 1985