Correlation Analysis between Physicochemical Properties of Daqu and Flavor of Liquor Products

Daqu with different technic under high temperature,medium high temperature and medium temperature and Daqu under different storage periods(one year,half a year and no storage) were selected to carry out laboratory solid state fermentation experiments. The differences of flavor of liquor fermented by different technology and storage Daqu and Daqu enzyme activity(saccharification power,liquefaction power,fermentation power,esterification force) were analyzed. The results showed that different Daqu technology had significant effects on the main higher alcohols and aldehydes,and the storage period of Daqu had no significant effect on them. The total acids(767.39 mg/L) and total esters(3493.21 mg/L) of high temperature Daqu liquor samples were significantly higher than those of the other two,and the total ester content of stored Daqu liquor samples was higher than that of unstored Daqu liquor(one-year Daqu and half-year Daqu were higher than 43.6% and 46.1%,respectively). There was a significant positive correlation between Daqu fermentation power and normal propyl alcohol,a significant negative correlation between esterification power and β-phenylethanol and acetaldehyde,and a significant negative correlation between liquefaction power and the total acids and total esters. Among the physicochemical indexes of Daqu,esterification power had a great effect on the overall liquor flavor. Therefore,the technology and storage period of Daqu have effects on the flavor of liquor. This study would be conducive to a deeper understanding and control of liquor flavor from Daqu factors,and have a certain reference significance for the establishment of Daqu standards and enterprise liquor-making production.