Primary Analysis Of The Main Enzymes In Daqu Of Special-flavor Liquor

Daqu is an important material in the liquor production process regarding as a saccharification agent, a fermentation agent, and a aroma agent,. It has a great effect on the yield and quality of the liquor. A solid-state fermentation is taken for Daqu by using raw material as daqu bricks, inoculating with the environmental microorganisms in a culture room. Various microbes and enzymes were enriched in the Daqu starter by incubating different natural microorganisms at the Daqu bricks composing of starch materials during Daqu making processing.In this study, different enzymes were detected by the methods of titration and spectrophotometer including saccharifying enzyme, liquefying amylase, acid protease, cellulase, xylanase and esterifying enzymes, and the quantities of bacteria, yeast and mould were counted by standard plate count for Daqu starters among different culture stages and different storage stages of special-flavor liquor. The relationship was preliminary explained between enzymes activity and different microbial group. So we could get the following results.(1) The saccharifying enzyme vigor and acid protease vigor is the highest, liquefying amylase vigor, cellulase vigor, xylanase vigor and esterifying enzyme are following.(2) During the culture stage, all the enzyme activity except saccharifying enzyme and esterified enzyme increased rapidly in the earlier stage of culture and the enzyme activity reached the maximum after 15 days. The enzyme activity began to decline and had a slight rise after 20 days.(3) In the storage phase, the enzyme activity is reduced with increasing storage time. But among 3 or 4 months storage, the enzyme activity decreased more slowly, while still maintaining a high level of vitality. The enzyme activity decreased significantly after 5 or 6 months. The resulting:the storage period is 3 or 4 months. The longer storage, the greater the enzymes vitality loss.(4) The trend of changes of the number of various types of microorganisms and various types of enzyme activity are same during the Daqu culture stage. It maintained an upward trend before the 15d and the maximum was got about 15d. From 15d to 25d, the number of microorganisms and enzymes activity began to decline. The micro-organisms is declining faster and enzymes in the rate of decline is slower. The number of microorganisms was a significant reduction when the finished Daqu storage 1-2 months. After three to four months, the number of bacteria and mold decline slower than the first two months, yeast almost can not be detected. The number of microorganisms changes slightly than the first two months after storage 5 to 6months. The various enzymes of the finished Daqu had a slight movements in the 0 to 4 months of storage period, but remained relatively stable state. The enzyme activity decreased to a large range when the Daqu storage five to six months. The results show that enzyme activity who affected by the declining number of microorganisms was declining in the early and mid of storage period. Later the decrease of enzyme activity is mainly affected by the environment.