PDF(Pubmed)
Abstract：
Although natural emulsifiers often have many drawbacks when used alone, their emulsifying ability and stability can usually be improved unexpectedly when used in combination. In this study, monodisperse emulsions stabilized by combining two natural protein emulsifiers, i.e., whey protein isolate (WPI) and sodium caseinate (SC), in different proportions were prepared using microchannel (MC) emulsification. The influences of temperature, pH, ionic strength, and storage time on the microstructure and stability of the emulsions were examined. Analysis of the microstructure and droplet size distribution revealed that the WPI-, SC-, and mixed protein-stabilized emulsions exhibited uniform droplet distribution. The droplet size and ξ-potential of the MC emulsions stabilized by mixed protein emulsifiers were higher than those of the emulsions stabilized by WPI or SC separately. The emulsions stabilized by the two types of proteins and mixed emulsifiers had better stability under high salt concentrations than the synthetic emulsifier Tween 20. WPI-SC-stabilized emulsions were more resistant to high temperatures (70-90°C) and exhibited excellent stabilization than those stabilized by WPI and SC, which was attributed to the more sufficient coverage provided by the two types of protein emulsifier layers and better protein adsorption at the oil-water interface. These results indicate that WPI-SC is a potential stabilizer for MC emulsion requirements. This study provides a basis for the formulation of monodisperse and stable natural emulsion systems.
摘要：
虽然天然乳化剂在单独使用时通常有许多缺点，组合使用时，它们的乳化能力和稳定性通常会出乎意料地提高。在这项研究中,通过结合两种天然蛋白质乳化剂稳定的单分散乳液，即，乳清分离蛋白（WPI）和酪蛋白酸钠（SC），使用微通道(MC)乳化以不同比例制备。温度的影响，pH值,离子强度,和储存时间对乳液的微观结构和稳定性进行了考察。微观结构和液滴尺寸分布的分析表明，SC-,和混合蛋白质稳定的乳液表现出均匀的液滴分布。通过混合蛋白质乳化剂稳定的MC乳液的液滴尺寸和电势高于分别通过WPI或SC稳定的乳液的液滴尺寸和电势。两种蛋白质和混合乳化剂稳定的乳液在高盐浓度下的稳定性优于合成乳化剂Tween20。WPI-SC稳定的乳液比WPI和SC稳定的乳液更耐高温（70-90°C），并表现出优异的稳定性，这归因于两种类型的蛋白质乳化剂层提供的更充分的覆盖以及在油-水界面处更好的蛋白质吸附。这些结果表明WPI-SC是MC乳液要求的潜在稳定剂。本研究为制备单分散稳定的天然乳液体系提供了依据。
