浓缩乳蛋白的离子交换脱钙及其对酪蛋白胶束的影响

Effects of ion exchange decalcification on casein micelles

研究了浓缩乳蛋白的离子脱钙技术,以及部分脱钙对截留液中酪蛋白存在形式及酪蛋白胶束水合率的影响。研究确定了离子交换树脂的平衡脱钙时间为2 h,并通过改变树脂添加量得到了0、5%.5%、10.5%、19.6%、29.6%、38.7%、49.9%、63.8%和83.6%系列脱钙程度的截留液。随着脱钙程度的增加,截留液超离心上清中游离酪蛋白的含量逐渐增加,而超离心沉淀的胶束酪蛋白减少,说明酪蛋白逐渐从酪蛋白胶束中游离出来。当脱钙程度为0~29.6%时,酪蛋白胶束的水合率从2.6 g/g（干基）增加到4.1 g/g（干基）,而脱钙程度从29.6%进一步增加到83.6%时,酪蛋白胶束水合率则变小至3.3 g/g（干基）。浓缩乳蛋白的钙离子含量以及酪蛋白的存在状态决定了其在应用时的功能特性,研究对开发新型的浓缩乳蛋白配料具有重要的指导意义。

This study investigated the technology of ion exchange decalcification of milk protein concentrate（ MPC）,and also the effects of partial decalcification on casein micelle and its hydration property. A series of decalcified MPC retentates（ decalcification ratios of 0,5. 5%,10. 5%,19. 6%,29. 6%,38. 7%,49. 9%,63. 8%,83. 6%） were produced after 2 hours of ion exchange with adding corresponding amounts of resins. Casein components dissociated from casein micelles regarding the increase of decalcified MPC retentates; the contents of micellar casein decreased,while the concentrations of dissociated casein in the supernantants increased. The hydration properties of casein micelles increased from 2. 6 g / g dry basis to 4. 1 g / g dry basis（ 0-29. 6% decalcification）,and then decreased to 3. 3 g / g dry basis（ 29. 6%-83. 6% decalcification）. The content of calcium ions and the state of casein micelles in MPCs may affect the functionalities of MPCs in application. This study offered the potential of new MPCs with different functionalities and also will broaden the applications of new MPCs into food industry.