O'Connell J E, Fox P F
Department of Food Chemistry, University College, Cork, Ireland.
J Dairy Sci. 2000 Mar;83(3):378-86. doi: 10.3168/jds.S0022-0302(00)74892-2.
Milks with casein micelles larger or smaller than control milk were prepared by differential centrifugation. The heat stability of these modified milks increased markedly throughout the pH range 6.4 to 7.1 with decreasing casein micelle size. Within the region of the minimum in the heat coagulation time-pH profile, the control milk coagulated by a two-stage process, but the modified milks, because of their narrower casein micelle size distribution, coagulated by a single-stage process at the pH of minimum stability. The content of kappa-CN and protein hydration increased as the size of the casein micelles decreased, and the level of glycosylation of kappa-CN and protein surface hydrophobicity increased as a function of micelle size. The effect of casein micelle size on the heat stability of milk is likely to be related to changes in the above physico-chemical properties.
通过差速离心法制备了酪蛋白胶粒比对照乳大或小的乳。在pH值6.4至7.1的整个范围内，随着酪蛋白胶粒尺寸减小，这些改性乳的热稳定性显著提高。在热凝固时间-pH曲线的最小值区域内，对照乳通过两阶段过程凝固，但改性乳由于其酪蛋白胶粒尺寸分布较窄，在最低稳定性pH值下通过单阶段过程凝固。随着酪蛋白胶粒尺寸减小，κ-酪蛋白含量和蛋白质水合作用增加，κ-酪蛋白糖基化水平和蛋白质表面疏水性随胶粒尺寸而增加。酪蛋白胶粒尺寸对乳热稳定性的影响可能与上述物理化学性质的变化有关。
