Abstract:
To understand the functional characteristics and compositional differences among different types of high-temperature Daqu, the physicochemical properties, enzyme activities, sensory characteristics, and compositional differences of high-temperature black Daqu, white Daqu, and yellow Daqu were comprehensively analyzed by means of instrumental analysis, sensory evaluation and multivariate statistics. The results showed that black Daqu was characterized by higher acidity and moisture content but lower enzyme activity. The free amino acid content was measured at 7.69±1.21 g/kg, and 104 volatile components were identified, including various furan and aldehyde ketone compounds, contributing to prominent baking and sauce aromas. White Daqu was observed to have lower acidity and moisture content but higher enzyme activity. The free amino acid content was determined to be 12.00±2.62 g/kg, and 115 volatile components were detected, with a high abundance of pyrazines and esters, resulting in a rich aroma featuring fruity and grainy notes. Yellow Daqu was found to exhibit physicochemical properties and enzyme activity similar to those of white Daqu. The free amino acid content was quantified at 9.90±0.78 g/kg, and 110 volatile components were identified, including numerous acids and heterocyclic compounds, leading to a distinct aroma dominated by Qu and Douchi notes. Through multivariate statistical analysis, clear clustering among different Daqu types was revealed, with 28 volatile components and 10 amino acids (VIP > 1) identified as key differential markers. The findings of this study provide theoretical support for the differentiated use of various high-temperature Daqu.