大米蛋白乳化性质研究

本文研究了大米分离蛋白(RPI)、酶法大米分离蛋白(E-RPI)、谷蛋白等在不同pH和Na2SO3存在条件下的乳化性能及其表现特点，并与大豆分离蛋白(SPI)的乳化性能进行了比较，结果表明，增加大米蛋白溶解性的措施均有利于改善大米蛋白的乳化性能。谷蛋白一旦溶解其乳化能力与大豆蛋白相当。RPI、E-RPI经Na2SO3处理后，乳化性能明显提高，说明通过解除大米蛋白分子中亚基的聚合，可以改善大米蛋白的物化功能性。

Emulsifying Properties of Rice Protein Isolate

Rice protein isolate could be used as food ingredients with its hypoallergenic and high nutritive quality. In this paper, emulsion properties of several kinds of rice protein isolate made by different methods were investigated. Emulsifying activities (EA) expressed by turbidity of diluted emulsion of glutelin (extracted by alkaline), rice protein isolate (RPI, by non-alkaline), E- RPI(by amylase) were 0.392, 0.121, 0.180 respectively, and that of soy protein isolates (SPI) was 0.372. However emulsifying stabilities (ES) of all samples were 19.0min, 40.3min, 35.0min, 10.6min, respectively. By adding NaOH in emulsions, the EA of all samples increased but the changes of ES were not significant. After emulsions were treated with Na2SO3, the increase in EA and decrease in ES of RPI and E-RPI were apparent. The Results showed that the mechanisms of changes caused by pH and Na2SO3 in RPI and E-RPI were different.