淀粉原料焙炒对酱油制曲的影响

Effect of Roasted Starch on Soy Sauce Koji-making

本研究以小麦、面粉为淀粉原料,采用焙炒技术,在最佳焙炒时间下分别比较经焙炒处理的小麦、面粉与未经处理的小麦、面粉对酱油成曲的蛋白酶活、氨肽酶活、淀粉酶活、纤维素酶活和氮溶指数(NSI)等理化指标的影响。同时,通过测定酱油大曲酶解液的总糖转化率和蛋白回收率,筛选最佳焙炒时间。实验表明,小麦、面粉的最佳焙炒时间均为20 min,在此条件下,焙炒处理对酱油成曲酶系及理化指标的影响较大。经焙炒的小麦所制成曲较生小麦成曲在中性蛋白酶活、氨肽酶活、纤维素酶活、孢子数和NSI分别提高了13.06%、12.58%、9.92%、37.04%和10.46%;经焙炒的面粉所制成曲较生面粉成曲在中性蛋白酶活、氨肽酶、纤维素酶活、孢子数和NSI分别提高了32.88%、28.17%、18.07%、13.04%和10.79%;但小麦、面粉焙炒后,酱油成曲淀粉酶活略有降低。综上,小麦和面粉的焙炒处理均对成曲的酶系增强及理化指标的提高有一定的促进作用。

In this study, wheat and flour were chosen as raw starch materials to investigate the effect of roasting on soy sauce koji-making. Indexes including activities ofprotease, aminopeptidase, amylaseand cellulose enzyme, NSI and other physiochemical indexes were compared between kojis of the roasted wheat and original wheat, as well as between that of the roasted flour and original flour. All the compassions were conducted trader the optimum roasting time, which was determined by conversion rate of total sugars and protein recovery of kojis hydrolyzates. The optimum roasting time for both wheat and flour was 20 min, under which the enzyme systems and physiochemical indexes of kojis were well influenced. The activities ofprotease, aminopeptidase and cellulose enzyme, spore and NSI ofkoji gained from roasted wheat increased by 13.06%, 12.58%, 9.92%, 37.04% and10.46%, respectively when compared with that from original wheat. The activities of protease, aminopeptidase, cellulose enzyme, spore and NSI of koji gained from roasted flour were increased by 32.88%, 28.17%, 18.07%, 13.04% and 10.79%, respectively. The amylase activities of kojis cultivated with roasted wheat and flour both decreased a little. In conclusion, the use of both the roasted wheat and flour can improve the quality of kojis, thus starch material roasting can be an alternative way to improve the enzyme systems and physiochemical indexes ofkojis.