Preparation and process optimization of Fuqu made by distiller's grains of strong-flavor Baijiu

In this study, using wheat bran as raw materials, Fuqu was prepared by addition of distiller's grains from strong-flavor (Nongxiangxing) Baijiu production. With starch liquor yield, saccharification enzyme activity of Fuqu and bacteria and yeasts counts as evaluation indexes, the effects of distiller's grains addition, water addition, culture temperature and Daqu inoculum on the evaluation indexes were determined by single factor tests, and the Qu-making process conditions were optimized by orthogonal tests. The results showed that adding distiller's grains could increase glucoamylase activity, microbial quantity and liquor yield of starch, the optimum Qu-making process conditions were as follows: distiller's grains addition 10%, water addition 55%, culture temperature 30 ℃, Daqu inoculum 7%. Under the optimized Qu-making process conditions, the liquor yield of starch reached 51.4%, which was 38.91% higher than that before optimization.