Changes in particle size, calcium and phosphate solubilization, and microstructure of rehydrated milk protein concentrates, prepared from partially acidified milk
Changes in particle size, calcium and phosphate solubilization, and microstructure of rehydrated milk protein concentrates, prepared from partially acidified milk
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由部分酸化的牛奶制备的复水牛奶浓缩蛋白的粒径、钙和磷酸盐溶解以及微观结构的变化
DOI：
10.1007/s13594-015-0270-1
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发表时间：
2016
影响因子：
--
通讯作者：
M. Corredig
中科院分区：
文献类型：
--
作者：
H. Eshpari;P. Tong;M. Corredig
目前的工作研究了使用超滤 (UF) 和渗滤 (DF) 制备的浓缩乳蛋白 (MPC) 的复水特性。在超滤之前，用葡萄糖酸-δ-内酯 (GDL) 将牛奶酸化至 pH 6，以改变最终浓缩物的矿物质成分。研究了重构 MPC 中酪蛋白胶束的粒径分布和微观结构，以及钙、磷酸盐和蛋白质在胶体相和可溶相之间的分配。通过电子显微镜分析的重构样品表明，即使在部分溶解的颗粒中，颗粒表面也是多孔的并且与其内部相似并且没有明显的表层。牛奶的部分酸化对微观结构没有任何显着影响；然而，它显着增加了 UF 和 DF 样品的酪蛋白胶束的平均直径，并降低了总钙和磷酸盐的浓度。对重构的 MPC 的离心上清液进行十二烷基硫酸钠 (SDS)-PAGE 分析表明，浓缩乳中可溶性酪蛋白的含量随着酸化而急剧增加，并且通过对牛奶进行透析恢复血清相的矿物质成分后进一步增加。这项工作有助于更好地理解加工条件，特别是浓缩前牛奶的部分酸化，如何改变复水后酪蛋白和 MPC 可溶相的组成和物理性质。这种改变可以显着影响重组 MPC 的技术特性。
The present work studied the rehydration properties of milk protein concentrates (MPCs), prepared using ultrafiltration (UF) and diafiltration (DF). Milk was acidified to pH 6 with glucono-δ-lactone (GDL) prior to UF to alter the mineral composition of the final concentrates. The particle size distribution and the microstructure of the casein micelles in reconstituted MPCs as well as the partitioning of calcium, phosphate, and proteins between the colloidal and soluble phases were investigated. Reconstituted samples analyzed by electron microscopy showed that, even in partially dissolved particles, the particle surface was porous and similar to its inner portion and had no distinct skin layer. Partial acidification of milk did not have any significant effects on the microstructure; however, it significantly increased the average diameter of the casein micelles for both UF and DF samples and decreased the concentration of total calcium and phosphate. Sodium dodecyl sulfate (SDS)-PAGE analysis of the centrifugal supernatants of reconstituted MPC demonstrated that the amount of soluble caseins present in milk concentrates dramatically increased with acidification, and it further increased after restoring the mineral composition of the serum phase through dialysis against milk. This work contributes to a better understanding of how processing conditions, particularly partial acidification of milk prior to concentration, can alter the composition and physical properties of the caseins and the soluble phase of MPC after rehydration. Such alterations can significantly impact the technological properties of the reconstituted MPC.