从自然发酵小麦酱中筛选曲霉及制曲工艺研究

从自然发酵的小麦酱中分离得到4株黄曲霉（Aspergillus flavus）和2株黑曲霉（Aspergillus niger），对其进行生理效价分析，结果表明，黄曲霉4号产糖化型淀粉酶和蛋白酶能力最强，且具有较强的产α-淀粉酶和酯化酶的能力，适合作为小麦酱制曲的发酵菌株。对其制曲工艺进行优化，结果表明，在接种量为4%，制曲温度为32 ℃，制曲时间为70 h的条件下，小麦曲的蛋白酶酶活力为549 U/g，较自然发酵制曲的481 U/g有较大提高。

Screening of Aspergillus from natural fermented wheat paste and the koji making technology

Four Aspergillus flavus strains and two Aspergillus niger strains were isolated from natural fermented wheat paste, and the physiological value of the strains were analyzed. Results showed that A. flavus 4 had the strongest ability to produce saccharifying amylase and protease, and strong ability to produce α-amylase and ester enzyme, which was suitable for fermenting wheat paste. The optimum fermentation conditions were strain inoculum 4%, starter-making temperature 32 ℃ and time 70 h. Under this condition, the wheat starter protease activity was 549 U/g, which was much higher than that in the natural fermented koji (481 U/g).