嗜热链球菌发酵改良纳豆工艺优化

采用嗜热链球菌为改良菌种,通过二次发酵改良纳豆。熟制灭菌后的大豆在纳豆菌接种量2%、发酵温度37℃、发酵时间24 h条件下进行一次发酵。以嗜热链球菌的发酵温度、发酵时间、接种量为因素,以感官评分、纳豆激酶酶活为指标,通过单因素和响应面实验,研究嗜热链球菌二次发酵改良纳豆的最佳工艺条件。结果表明:在发酵温度42℃、发酵时间18.6 h、接种量1.5%时改良效果最佳,得到的感官评分为8.0分,纳豆激酶酶活为1964 U/g。改良效果较好,纳豆臭味下降,纳豆激酶酶活提高。

Optimization of Fermentation Process for Streptococcus thermophilus Improved Natto

Streptococcus thermophiles was used as a modified strain to improve natto by secondary fermentation.The sterilized soybeans were inoculated with 2% natto inoculum and fermented 24 h at 37℃.Through single factor and response surface experiments,based on the fermentation temperature,fermentation time and inoculum of Streptococcus thermophilus,with sensory score and nattokinase activity as indicators,the most effective conditions for secondary fermentation of Streptococcus thermophilus was studied.The results showed that the best improvement was obtained when the fermentation temperature was 42℃,the fermentation time was 18.6 h,and the inoculum volume was 1.5%. The sensory score was 8.0 score and the nattokinase activity was 1964 U/g. The improvement effect was good,the bad odor of natto decreased,and the activity of nattokinase increased.