富含游离态异黄酮豆豉的制曲工艺优化

Koji-making Technolgy Optimization of Douchi in Free Isoflavones

为了制备富含游离态异黄酮的豆豉,以前期筛选出的一株高产β-葡萄糖苷酶的菌株为菌种进行制曲。在研究接种量、发酵温度、发酵时间三种单因素对豆曲中蛋白酶和β-葡萄糖苷酶的活力影响基础上,采用三元二次正交旋转组合实验设计对制曲工艺进行优化,确定了最佳的制曲工艺条件为接种量(105.4个孢子·g-1大豆)、制曲温度26.5℃、制曲时间4 d,在此条件下,β-葡萄糖苷酶酶活力为245.24 U·g-1,蛋白酶酶活力为623.17 U·g-1。

In order to make Douchi in free isoflavones,the pre-screened higher product β-glucosidase was used as strain in koji-making process. Based on the three single factors of inoculation amount,Koji-making temperature and time,the activity effects of proteinase and β-glucosidase were researched,and koji-making process was optimized by three factors quadratic regression orthogonal rotational combination design. The optimal condition was as follows： inoculation amount 105.4spores·g^-1soybean,koji-making temperature 26.5 ℃,koji-making time of 4 d. Under these conditions,the activities of β-glucosidase and proteinase reached up to 245.24 U·g^-1and 623.17 U·g^-1.