Comparative quality analysis of Luzhou single-layer and double-layer Daqu
ZHANG Man1, XIE Jun2, WEI Chun-hui2, WANG Hong1,Li Zi-jian1, LUO Hui-bo1,2*
1(College of Bioengineering, Sichuan University of Science and Engineering, Zigong 643000,China) 2(Liquor Making Bio-Technology and Application of Key Laboratory of Sichuan Province, Zigong 643000, China)
Abstract: In order to improve the quality evaluation system of Daqu and mechanical starter-making, the physicochemical, biochemical and microbial biomass of single-layer and double-layer Daqu were measured. The quality differences between two kinds of Daqus and the interrelationships between the Daqu′s indicators were analyzed. An evaluation system was established to directly analyze the quality of single-layer and double-layer Daqu. The results showed that the physicochemical properties of single-layer and double-layer Daqu were similar, but the fermentation force, liquefaction force, saccharification power, esterification power and protease activity of single-layer Daqu were higher than that of double-layer Daqu. The microbial biomass of single-layer Daqu was also higher than that of double-layer Daqu. The quality of single-layer Daqu was significantly better than that of double-layer Daqu. The products had the highest overall score of S2M (0.89 points) and the lowest score of the D2M (0.21 points) and the score size was S2M>S1M>D1M>D2M.