主要研究了盐诱导大豆分离蛋白(soy protein isolate,SPI)形成的冷凝胶对乳酸菌在胃酸pH下的保护作用。用CaCl2作为凝胶剂诱导大豆分离蛋白成胶,以30 min时乳酸菌在胃酸pH下的存活率作为评价指标,来评价冷凝胶对细菌的抗酸保护作用。变性温度为85℃、SPI浓度为9%以及CaCl2浓度为20 mmol/L时所形成的冷凝胶,在pH1.2的胃酸环境下对乳酸菌的保护性最好,活菌落的数量级由初始的107变为102,下降了5个数量级。说明大豆分离蛋白冷凝胶对乳酸菌有良好的保护性,并为益生菌在食品中的开发和应用提供了非常好的前景。

This study mainly investigated the protection of salt-induced soy protein isolate(SPI) gels on lactic acid bacteria in gastric acid.SPI was induced by CaCl2 to form the cold-set gel.The protection on lactic acid bacteria was determined by the survival rate of 30 minute in gastric acid.From the orthogonal experiment analysis,we can obtain the optimal experimental solution: A3B3C2.The solution show that the cold-set gel of 9% SPI induced at 85 ℃ by 20 mmol/L CaCl2 can give the best protection on lactic acid bacteria in the gastric acid condition of pH 1.2,and the order of lactic acid bacteria treated with the acid condition of pH 1.2 for 30 minute from 107 by the initial down to 102,dropped five orders.This suggested that this cold-set gels can provide better protection on lactic acid bacteria,and can be a prospect in the development and application of probiotics in food.