不同因素对酶诱导乳清蛋白凝胶性质的影响及其结构研究

Effects of Different Factors on the Properties of Protease-induced Whey Protein Gel and Elucidation of Its Microstructure

采用蛋白酶诱导乳清浓缩蛋白(WPC)成胶,对影响凝胶性质的乳清浓缩蛋白质量浓度、酶与底物比(E/S)、pH值、温度以及钙离子浓度分别进行研究。结果表明:乳清蛋白质量浓度、反应pH值、温度和钙离子浓度均会不同程度地影响乳清蛋白凝胶的质构性质和保水性,且当乳清蛋白质量浓度为10g/100mL,E/S为0.5%,pH值为7.0,酶解温度为50℃,钙离子浓度为2.5mmol/L时制得的乳清蛋白凝胶具有类似于脂肪的质地和口感,具有很好的模拟脂肪特性。透射电镜分析表明此凝胶为一种结构较为松散的颗粒聚集状凝胶。

This study focused on the forming process of protease-induced whey protein gel and its affecting factors such as protein concentration, enzyme-to-substrate ratio （E/S）, pH, temperature and calcium concentration, which can provide some experimental data for the production of fat substitutes based on enzyme modified whey protein. Results showed that all these factors had influences on the textural properties and water holding capacity of enzyme-induced whey protein gel to different extents. Gels prepared under the conditions of 10g/100mL whey protein concentration, 0.5% enzyme-to-substrate ratio, pH 7.0, 50 ℃ and 2.5 mmol/L calcium concentration had fat-like textural and mouth-feeling properties. Transmission electron micrographic observation showed the gel had a loose aggregated structure.