Jiao Yan, Zhao Yuntai, Chang Ying, Ma Zhaoxiang, Kobayashi Isao, Nakajima Mitsutoshi, Neves Marcos A
Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan.
College of Food and Biological Engineering, Qiqihar University, Qiqihar, China.
Front Nutr. 2022 May 27;9:822053. doi: 10.3389/fnut.2022.822053. eCollection 2022.
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.
尽管天然乳化剂单独使用时往往存在许多缺点，但它们在组合使用时，乳化能力和稳定性通常会意外提高。在本研究中，使用微通道（MC）乳化法制备了由两种天然蛋白质乳化剂即乳清分离蛋白（WPI）和酪蛋白酸钠（SC）以不同比例组合稳定的单分散乳液。研究了温度、pH值、离子强度和储存时间对乳液微观结构和稳定性的影响。对微观结构和液滴尺寸分布的分析表明，WPI、SC和混合蛋白稳定的乳液呈现出均匀的液滴分布。混合蛋白乳化剂稳定的MC乳液的液滴尺寸和ξ电位高于单独由WPI或SC稳定的乳液。两种蛋白质和混合乳化剂稳定的乳液在高盐浓度下比合成乳化剂吐温20具有更好的稳定性。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，这归因于两种蛋白质乳化剂层提供了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是满足MC乳液要求的潜在稳定剂。本研究为单分散和稳定的天然乳液体系的配方提供了依据。
