混合溶剂醇洗芝麻浓缩蛋白的加热改性研究

Heating modification of sesame protein concentrate extracted by ethanol leaching with mixed solvents

对60%乙醇-正己烷混合溶剂浸提的醇洗芝麻浓缩蛋白进行碱性条件下的水浴加热改性。通过单因素实验和响应面实验,确定的最佳工艺条件为:加热温度78℃,加热时间31 min,pH 9.5,料液比1∶12。改性后芝麻浓缩蛋白的NSI(氮溶解指数)由3.61%提高到23.89%,吸油性提高1.83倍,吸水性提高1.34倍,乳化性提高1.13倍,乳化稳定性提高1.24倍,起泡性提高1.02倍。

Sesame protein concentrate extracted from cold pressed sesame cake by n hexane and 60% of ethanol was modified by water bath heating under alkaline condition. The optimal modification condi tions were obtained by single factor experiment and response surface methodology as follows： heating tem perature 78℃, heating time 31 min, pH 9.5, solid liquid ratio 1 ： 12. The nitrogen soluble index （NSI） of sesame protein concentrate after modification increased from 3.61% to 23.89%. With the in crease of NSI, the oil absorption capability, water absorption ability, emulsification, emulsion stability and foamability of modified sesame protein concentrate increased by 1.83, 1.34, 1.13, 1.24, 1.02 times respectively comparing with the sesame protein concentrate