响应面试验优化酪蛋白-魔芋葡甘聚糖共混溶胶制备工艺及其稳定性

Optimization of Preparation Process for Casein-Konjac Glucomannan Blend Sol and Its Stability

为提高蛋白-多糖共混物的稳定性及拓宽其在食品领域的应用,以酪蛋白(casein,CS)-魔芋葡甘聚糖(konjac glucomannan,KGM)为研究对象,探究了共混溶胶制备过程中CS-KGM总质量浓度、共混比例、p H值、反应温度对CS-KGM共混溶胶流变特性的影响,并以黏度为指标,用响应面法对共混比例、p H值、反应温度进行共混工艺优化。在总质量浓度为1.2 g/100 m L的基础上,响应面优化结果表明3个因素对共混溶胶均有显著的影响,其最佳优化工艺参数为:共混比例(KGM-CS质量比)6∶4、反应温度60℃、p H 6.5;在此条件下,CS-KGM共混溶胶黏度的验证值为33.63 Pa·s,与理论预测值35.12 Pa·s相近。同时,将优化前和优化后共混溶胶进行贮藏稳定性对比实验,显示优化前与优化后共混溶胶出现相分离现象时间分别为4 d和5 d,优化后稳定性显著高于优化前共混溶胶。

With the aim to improve the stability of protein-polysaccharide blends and to broaden their application in the food industry, we investigated the effects of the preparation parameters （substrate concentration, blending proportion, pH and temperature） on rheological characteristics of casein-konjac glucomannan （CS-KGM） blend sol and optimized blending proportion, pH and temperature based on sol viscosity by using response surface analysis. The results of response surface analysis showed that when the total substrate concentration was 1.2 g/100 mL, all three selected parameters had significant effects on sol viscosity and were optimized as follows： a KGM-CS ratio of 6：4, 60 ℃ and pH 6.5. Experiments conducted under these conditions gave a viscosity value of 33.63 Pa-s, which was closed to the predictive value （35.12 Pa.s）. In addition, a comparative study of storage stability was also carded out, and the results showed that the phase separation times of the optimized and original samples were 4 and 5 days, respectively. This study indicated that the stability of optimized sol was significantly higher than that of the original one.