胃蛋白酶预处理对大豆酸奶发酵过程的影响

The Influence of the Pretreatment by Pepsin in Fermentation of Soybean Yogurt

采用乳酸菌发酵经胃蛋白酶预水解后的豆浆,优化大豆酸奶的制作工艺参数。大豆经磨粉后制成6%的豆浆,在37℃下利用胃蛋白酶处理30 min,降解其中的蛋白质。随后添加玉米糖浆使糖浓度达到6%,接种豆浆量5%的乳酸菌种子,采用恒温发酵法,在38℃下,进行厌氧发酵并冷藏24 h。用占大豆干粉量0.5%的酶预处理30 min后,制备大豆酸奶所需恒温发酵时间比原来缩短,发酵液中总酸含量更高。经胃蛋白酶预处理的大豆与不经预处理的大豆相比,发酵时间明显缩短,发酵工艺得到改进。

To manufacture the soybean yogurt using lactic acid bacteria, soybean was ground to powder, mixed with water to make soybean milk and then pre-hydrolyzed by pepsin at 37 ℃ for 30 minutes. Then, high-fructose corn syrup was mixed with the pretreated soybean milk until the sugar degree reached 6%. 5% of lactic acid bacteria starter was inoculated to initiate the fermentation under anaerobic conditions at 38 ℃. The fermentation mixture was reserved at 4 ℃ for 24 h as secondary fermentation. The pre-hydrolysis of the soybean powder by 0.5% pepsin for 30 minutes could shorten the fermentation time and improve total acids in the soybean yogurt. Using pepsin to pre-treat soybean to manufacture the soybean yogurt can save the time of fermentation and produce a delicious soybean yogurt.