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The Formation of β-caseins During Cooling of Raw Milk
THE FORMATION AND STRUCTURE OF SOME PROTEOSE-PEPTONE COMPONENTS. A. T. Andrews National Institute for Research in Dairying, Reading, Great Britain Other fragments of proteolysis of j3-casein, which produces y-casein, were found in the proteose-peptone fractions. Their identity as the N-terminal fragment of j3-casein was confirmed for PP5 and PP8F fractions. THE FORMATION OF j3-CASEINS DURING COOLING OF RAW MILK. E. H. Reimerdes and E. Herlitz Die Bundesanstalt flir Milchforschung, Kiel, Germany Enzymatic reaction of j3-casein hydrolysis at 4°C was faster than at 26°C. MODEL PROTEOLYSIS OF j3-CASEIN BY IMMOBILIZED TRYPSIN AND ITS ANALYTICAL IMPORTANCE. E. H. Reimerdes Der Bundesanstalt flir Milchforschung, Kiel, Germany Three major y-caseins and two phosphoproteins were obtained. SESSION D. CASEIN MICELLES CASEIN MICELLES: THE COLLOID CHEMICAL APPROACH. T. A. 1. Payens Nederlands Instituut voor Zuivelonderzoek, Ede, The Netherlands In this main lecture of the session, model equations based on the DLVO theory were constructed for combined proteolysis and clotting of milk protein to explain rennet coagulation as well as the viscosity changes of concentrated milks during storage. THE ROLE OF CALCIUM, PHOSPHATE AND CITRATE IONS IN THE STABILIZATlON OF CASEIN MICELLES. 1. Visser et al. U nilever Research, Vlaardingen/Duivan, The Netherlands
SUBSTRUCTURE OF SYNTHETIC CASEIN MICELLES. A. M. Knoop et al. Die Bundesanstalt flir Milchforschung, Kiel, Germany Synthetic casein micelles electronmicroscopically similar to milk casein sub micelles were prepared by dropwise addition of CaCI" Na,HPO, and K, citrate into first-cycle casein solutions in a special manner and order of addition. SESSION E. APPLIED ASPECTS OF MILK PROTEIN RESEARCH THE USE OF MILK PROTEINS AS STARTING MATERIALS FOR OTHER FOODSTUFFS. C. V. Morr Texas Technical University, Lubbock, U.S.A. The molecular structure of milk protein and its implication in functionality of the protein was discussed in this main lecture. THEORY FOR THE HEAT-INDUCTED COAGULATION OF TYPE A MILK. T. G. Parker et al. Hanna Research Institute, Ayr, Great Britain The theory of branching processes with a concept of polyfunctional reaction was applied as 2-stage reactions. THE SYNERGETlC EFFECT OF UREA AND ALDEHYDES ON THE HEAT STABILITY OF CONCENTRATED SKIM MILK. D. D. Muir et al. H anna Research Institute, Ayr, Great Britain Increases in heat stability by adding the above compounds were compared between concentrated and nonconcentrated milks. HEAT STABILlLY IN CONCENTRATED AND NONCONCENTRATED MILKS: THE EFFECT OF UREA AND j3-LACTOGLOBULlN LEVELS AND THE INFLUENCE OF PREHEA T1NG. R. 1. Pearce, read by B. S. Harrap CSIRO, Highett, Australia This presentation was similar to the preceding one.
A "PNMR study to elucidate the function of Ca, P and citrate in the stabilization of casein micelles was presented. PHYSICO-CHEMICAL CHARACTERISTICS OF CASEIN MICELLES IN DILUTE AQUEOUS MEDIA. P. F. Fox and B. M. Nash University College, Cork, Ireland Using dialysis tests, a tight association of Ca in casein micelles was demonstrated. THE EQUILIBRIA OF CALCIUM AND PHOSPHATE IONS WITH THE MICELLAR CALCIUM PHOSPHATE OF COW'S MILK. R. L. 1. Lyster National Institute for Research in Dairying Reading, Great Britain A calorimetric heat of solution was determined to investigate the equilibrium. The presence in milk of hydroxyapatite at pH 5.7 and above and tricalcium citrate at pH below 5.7 was demonstrated. THE VOLUMINOSITY OF CASEIN MICELLES AND SOME OF ITS IMPLICATIONS. P. Walstra Agricultural University, Wageningen, The Netherlands Voluminosity values of 2 to 4 mllg casein seemed to be reasonable. Can. Inst. Food Sci. Techno!. J. Vo!. 12, No. I, January 1979
EFFECTS OF PROCESSING AND PROTEIN COMPOSITION OF MILK ON THE HEAT STABILITY OF EVAPORATED MILK. D. F. Newstead New Zealand Dairy Research Institute, Palmerston North, New Zealand Processing operations discussed were preheating, evaporation, homogenization and sterilization and the protein composition variables were casein, whey proteins and nonprotein solids (lactose and salts). HYDRATION OF CASEIN MICELLES: KINETICS AND ISOTHERMS OF WATER VAPOUR SORPTION OF MICELLAR CASEIN ISOLATED FROM FRESH AND HEAT TREATED MILKS. M. Riiegg et al. Federal Dairy Research Institute, Liebefeld~Berne, Switzerland Results were consistent with the finding that an association of hydrophobic whey proteins with caseins occurs upon heating of milk. Casein hydration appears to occur stepwise by formation of layers or zones of differently bound water. OTHER PAPERS THE PROTEOLYTIC ACTIVITY IN UHT STERILIZED MILK. C. Corradini Universita Cattolica del Sacro Cuore, Piacenza, Italy
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SUBSTRUCTURE OF SYNTHETIC CASEIN MICELLES. A. M. Knoop et al. Die Bundesanstalt flir Milchforschung, Kiel, Germany Synthetic casein micelles electronmicroscopically similar to milk casein sub micelles were prepared by dropwise addition of CaCI" Na,HPO, and K, citrate into first-cycle casein solutions in a special manner and order of addition. SESSION E. APPLIED ASPECTS OF MILK PROTEIN RESEARCH THE USE OF MILK PROTEINS AS STARTING MATERIALS FOR OTHER FOODSTUFFS. C. V. Morr Texas Technical University, Lubbock, U.S.A. The molecular structure of milk protein and its implication in functionality of the protein was discussed in this main lecture. THEORY FOR THE HEAT-INDUCTED COAGULATION OF TYPE A MILK. T. G. Parker et al. Hanna Research Institute, Ayr, Great Britain The theory of branching processes with a concept of polyfunctional reaction was applied as 2-stage reactions. THE SYNERGETlC EFFECT OF UREA AND ALDEHYDES ON THE HEAT STABILITY OF CONCENTRATED SKIM MILK. D. D. Muir et al. H anna Research Institute, Ayr, Great Britain Increases in heat stability by adding the above compounds were compared between concentrated and nonconcentrated milks. HEAT STABILlLY IN CONCENTRATED AND NONCONCENTRATED MILKS: THE EFFECT OF UREA AND j3-LACTOGLOBULlN LEVELS AND THE INFLUENCE OF PREHEA T1NG. R. 1. Pearce, read by B. S. Harrap CSIRO, Highett, Australia This presentation was similar to the preceding one.
A "PNMR study to elucidate the function of Ca, P and citrate in the stabilization of casein micelles was presented. PHYSICO-CHEMICAL CHARACTERISTICS OF CASEIN MICELLES IN DILUTE AQUEOUS MEDIA. P. F. Fox and B. M. Nash University College, Cork, Ireland Using dialysis tests, a tight association of Ca in casein micelles was demonstrated. THE EQUILIBRIA OF CALCIUM AND PHOSPHATE IONS WITH THE MICELLAR CALCIUM PHOSPHATE OF COW'S MILK. R. L. 1. Lyster National Institute for Research in Dairying Reading, Great Britain A calorimetric heat of solution was determined to investigate the equilibrium. The presence in milk of hydroxyapatite at pH 5.7 and above and tricalcium citrate at pH below 5.7 was demonstrated. THE VOLUMINOSITY OF CASEIN MICELLES AND SOME OF ITS IMPLICATIONS. P. Walstra Agricultural University, Wageningen, The Netherlands Voluminosity values of 2 to 4 mllg casein seemed to be reasonable. Can. Inst. Food Sci. Techno!. J. Vo!. 12, No. I, January 1979
EFFECTS OF PROCESSING AND PROTEIN COMPOSITION OF MILK ON THE HEAT STABILITY OF EVAPORATED MILK. D. F. Newstead New Zealand Dairy Research Institute, Palmerston North, New Zealand Processing operations discussed were preheating, evaporation, homogenization and sterilization and the protein composition variables were casein, whey proteins and nonprotein solids (lactose and salts). HYDRATION OF CASEIN MICELLES: KINETICS AND ISOTHERMS OF WATER VAPOUR SORPTION OF MICELLAR CASEIN ISOLATED FROM FRESH AND HEAT TREATED MILKS. M. Riiegg et al. Federal Dairy Research Institute, Liebefeld~Berne, Switzerland Results were consistent with the finding that an association of hydrophobic whey proteins with caseins occurs upon heating of milk. Casein hydration appears to occur stepwise by formation of layers or zones of differently bound water. OTHER PAPERS THE PROTEOLYTIC ACTIVITY IN UHT STERILIZED MILK. C. Corradini Universita Cattolica del Sacro Cuore, Piacenza, Italy
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