大豆蛋白乳化性的研究

以低温脱脂大豆粉为原料制备大豆蛋白液,采用酸条件热改性处理,考察不同加热温度、pH、加热时间对乳化性影响。通过正交实验确定最优乳化性的改性条件:加热温度50℃,pH=6.0,加热时间60min,此条件下改性的大豆蛋白乳化性较未处理样提高了31.3%;同时实验表明,改性大豆蛋白中Na+浓度为1.0%（质量分数）时,其乳化性比未处理样提高了41.7%。对对照样和不同条件改性的大豆蛋白进行内源性荧光扫描,结果显示在280nm处激发产生的发射荧光最大峰位（λm）和强度发生了改变,说明蛋白质结构改变对其乳化性有着重要影响。 

Study on emulsifying properties of isolated soy protein

Low temperature defatted soybean protein was treated by thermal modification in the acid condition, and the influence of different heating temperature, pH and heating time on the emulsification was studied. The best modified conditions was obtained through the orthogonal test:the best heating temperature was 50℃, pH was 6.0, and the heating time was 60min, emulsification of the modified sample was increased by 31.3% , even reached 41.7% , when the concentration of Na + (mass fraction) was 1.0% . And structure of the modified soy protein was verified to have changed by endogenous fluorescence scan at 280nm. It showed that the change of protein structure had an important impact on the emulsification.