以新鲜大豆和成品牛乳为原料,研究了发酵工艺对酸豆乳酸度、黏度和乳酸菌活力等指标的影响。结果显示,以传统酸奶发酵剂乳酸菌为菌种,大豆浆液为主要原料,经发酵获得酸豆乳工艺可行。在单因素实验的基础上,经正交实验确定酸豆乳发酵的最佳工艺条件为:豆浆和牛奶体积比为5∶5,发酵9 h,按0.5 g/L发酵液添加驯化后乳酸菌液作为发酵剂,经发酵得到的产品酸度达到70°T以上,黏度2025 mPa.s,凝乳性较好,美兰褪色时间为50 min,乳酸菌活力提高,无豆腥味。

In this research,we studied the effect of the fermentation conditions on the acidity,viscosity and the viability of Lactobacillus of soya-yogurt using fresh soybean and finished milk as raw material.The results showed it was feasible to produce soya-yogurt from soy-bean milk using traditional yogurt starter.Experimental factors and levels were determined by single-factor experiments.The orthogonal experimental design was used to optimize the fermentation conditions.The results showed that the optimal fermentation conditions were as followes: ratio of soy-bean milk to milk was 5∶ 5,fermentation time was 9h,inoculation volume of taming lactobacillus was 0.5 g/L.In these fermentation conditions,products obtained good acidity value of more than 70°T and moderate viscosity value of 2025 mPa·s.The yoghurt had good texture and fermented flavor,and had no soybean pungent taste.