中文摘要：

【目的】建立米糠蛋白在较弱碱性和较低温下保持其特性的高效提取工艺并明确其理化特性。【方法】采用二次通用旋转正交组合设计优化米糠蛋白提取的最佳工艺条件;米糠蛋白特性分别考察其在不同pH、温度、离子强度下的溶解性、乳化性和起泡性,其中,溶解度的测定采用凯氏定氮法,乳化性的测定采用离心法,起泡性的测定采用体积法。【结果】建立米糠蛋白的最佳提取条件为：以pH11的弱碱性水溶液为溶剂,提取温度40℃,提取时间120min,在此条件下蛋白提取率可达80.93%。米糠蛋白的溶解度在等电点附近达到最低并随温度升高而增大,离子会降低其溶解度;pH、温度、离子强度对乳化性的影响与其对溶解性的影响表现一致性,蛋白浓度越高其乳化性越好;等电点附近米糠蛋白具有最低的起泡性和最强的泡沫稳定性,适当的热处理可以增强其起泡能力,且随着离子和蛋白浓度的升高起泡能力明显增强。【结论】在较弱碱性（pH11）和低温度（40℃）条件下提取米糠蛋白的得率可达80.93%,且所得米糠蛋白特性良好,显示出较好的应用前景。

英文摘要：

【Objective】To establish a highly efficient extraction technology for rice bran protein under low alkalinity and temperature, and determine its physicochemical properties.【Method】Quadratic general rotary unitized design was used to determine the optimal extraction process. The solubility, emulsibility and frothing capacity of rice bran protein at different pH, temperatures and ion concentrations were investigated. Kjeldahl’s method was used to measure the solubility, centrifugation method to measure the emulsibility, and volume method to measure the frothing capacity.【Result】The optimum extraction conditions were： pH 11, temperature 40℃, time 120 min, and the yield could reach up to 81.1% under such conditions. The solubility of rice bran protein was the lowest around isoelectric point, and the solubility increased with the increase of temperature, while it reduced due to ion presence. Effects of pH, temperature and ion concentration on emulsibility were similar to those effects on solubility. The higher the concentration pf rice bran protein the better of its emulsibility. Its frothing capacity was the lowest while foam stability was the highest around isoelectric point. Its frothing capacity was increased by suitable heating, and it was also significantly improved with the increase of ion concentration and protein concentration【.Conclusion】The yield of rice bran protein can reach up to 81.1% on low pH and temperature. The properties of rice bran protein obtained in this way are satisfying, indicating assuring potential for applications.