热处理对浓缩乳清蛋白起泡性的影响及其在咖啡奶盖中的应用

Effect of heat treatment on the foaming properties of whey protein concentrate and its application in coffee milk cover

乳清蛋白是一种优质的蛋白补充剂,因其优良的泡沫特性而广泛应用于咖啡奶盖等泡沫食品。通过热处理对乳清蛋白进行改性,测定溶解度、浊度、巯基含量、粒径、电泳、泡沫微观结构来研究乳清蛋白在不同热处理温度下的理化性质和起泡性。结果表明在50~90℃条件下,热处理对乳清蛋白溶液的溶解性、巯基含量、浊度等产生显著影响(P<0.05)。SDS-PAGE电泳结果表明,当温度大于70℃时,乳球蛋白的条带明显的变浅,在电泳凝胶的上层形成大分子的聚集物。随着温度的升高,起泡性逐渐增加,在60℃时起泡能力达到最大值为102.13%,在70℃时泡沫稳定性达到最大值为61.36%。与对照组相比,70℃热处理后咖啡上的乳清蛋白奶盖泡沫更加细密且具有较好的稳定性。为热处理提升乳清蛋白起泡性提供了理论依据和技术支撑。

Whey protein is a high-quality protein supplement that is widely used in foam foods such as coffee and milk cover due to its excellent foam properties.In this study,the physical ochemical properties and blistering of whey proteins at different heat treatment temperatures were studied by modifying their solubility,turbidity,sulfhydryl content,particle size,electrophoresis,and foam microstructure.The results showed that the solubility,sulfcontent and turbidity of whey protein solution were significantly affected at 50-90℃(P<0.05).SDS-PAGE electrophoresis showed that the bands of milk globulin became significantly shallow at a temperature greater than 70℃,and that aggregates of macromolecules were formed in the upper layer of the electrophoretic gel.Increasing temperature achieved a maximum foaming capacity of 102.13%at 60℃and a maximum foam stability of 61.36%at 70℃.The whey protein milk cap foam on the coffee after70℃heat treatment was thinner and more stable compared with the control group.This study provides a theoretical basis and technical support for heat treatment to enhance the blistability of whey protein.