热稳定米糠粕和米糠低温浸出粕制备米糠蛋白的对比研究

Comparison of rice bran proteins extracted from heat-stabilized defatted rice bran and low temperature solvent defatted rice bran

为探讨热稳定米糠粕和米糠低温浸出粕制备米糠蛋白的差异,测定了两种原料所得米糠蛋白的乳化性、乳化稳定性、起泡性和泡沫稳定性,分析了热稳定米糠粕制得的米糠蛋白和米糠低温浸出粕制得的米糠蛋白的溶解性能差异和氨基酸组成变化,并利用差示扫描量热仪(DSC)研究了其蛋白质结构的差异。结果表明:两种原料制得的米糠蛋白的功能特性差别不大,但以热稳定米糠粕为原料制得的米糠蛋白的蛋白质含量低于以米糠低温浸出粕为原料制得的米糠蛋白的;热稳定米糠粕制得的米糠蛋白的溶解性比米糠低温浸出粕制得的米糠蛋白的溶解性差,胱氨酸含量的提高和蛋白质结构的变化可能是热稳定米糠粕溶解性相对较差的原因。

In order to explore the differences between the rice bran proteins extracted from low temperature solvent defatted rice bran and heat-stabilized defatted rice bran,the emulsifying activity,emulsion stability,foaming capacity and foam stability of the proteins obtained from two different raw materials were tested,and the solubility and amino acid composition of the proteins obtained from two different raw mate-rials were analyzed,at the same time, the differences of their structures were researched by differential scanning calorimeter （ DSC） . The results showed that two kinds of rice bran proteins had similar functional characteristics. However,the solubility and protein content of the protein obtained from the heat-stabilized defatted rice bran were obviously poorer than that extracted from low temperature solvent defatted rice bran. The improvement of cystine content and the changes of protein structure might be the causes of the poor solubility of the protein obtained from heat-stabilized defatted rice bran.