植物蛋白乳酸菌饮品储存过程中乳酸菌的变化规律

以嗜热链球菌FJAT-7928、干酪乳杆菌FJAT-7929为菌株,以黄豆为基质,发酵得到植物蛋白乳酸菌饮品,研究其在4℃保存条件下菌落数以及酸度和pH值的变化。结果表明,保存30d内,两菌种混合发酵植物蛋白乳酸菌饮品的乳酸菌可高达到3.5×109 cfu.mL-1,高于单独发酵的植物蛋白乳酸菌饮品中的活菌数。混合发酵植物蛋白乳酸菌饮品的最终酸度为109.0°T,pH值为3.58;FJAT-7929单独发酵植物蛋白乳酸菌饮品最终酸度为114.0°T,pH值为3.65;FJAT-7928植物蛋白乳酸菌饮品酸度为60.0°T,pH值4.09。4℃保存3种发酵处理的植物蛋白乳酸菌饮品,30d内乳酸菌活菌数和酸奶的理化性质基本稳定。

Lactobacillus Population and Properties of Soy Yoghurt in Cold Storage

Using soybean as the protein basis,yoghurt was made by inoculating FJAT-7928(Streptococcus thermophilus)and FJAT-7929(Lactobacillus bulgaricus).The lactic acid bacteria population,acidity and pH of the yoghurt stored at 4℃ were determined.The result showed that the soy yoghurt prepared by the co-fermentation had a maximum number of the bacteria of 3.5×109 cfu·mL-1,which was more than those in the soy yoghurt inoculated with either FJAT-7928 or FJAT-7929 alone.After 30 days of the cold storage,the acidity of the co-fermented yoghurt was 109.0°T,which was in between 114.0°T for FJAT-7929 yoghurt and 60.0°T for FJAT-7928 yoghurt.The final pH of the co-fermented yoghurt was 3.58,which was lower than 3.65 for FJAT-7929 yoghurt or 4.09 for FJAT-7928 yoghurt.At 4℃,the Lactobacillus population,acidity and pH of all three yoghurt products remained constant after 30 days in storage.