Effects of Different Wheat Varieties on the Quality, Microbial Community Structure, and Metabolites of Strong Aroma-Type Daqu

In this study, physicochemical analyses, sensory evaluation, amplicon sequencing, and non-targeted metabolomics were employed to analyze the quality traits of 12 new wheat varieties, as well as the sensory quality, bacterial and fungal community structures and metabolites in Daqu made from these varieties. The quality trait analysis indicated that wheat varieties with lower grain hardness, protein content, and wet gluten content were more suitable for producing high-quality Daqu. Amplicon sequencing revealed that the dominant bacteria in Daqu produced from these wheat varieties were Leuconostoc, Pantoea, Thermoactinomyces, Lactococcus, and Saccharopolyspora, and the predominant fungi were Thermomyces, Thermoascus, Aspergillus, Saccharomycopsis, and Trichosporon. Correlation analysis showed that Thermomyces, Saccharomycopsis, Kosakonia, Rhizopus, and Rhizomucor were significantly positively correlated with certain sensory quality indicators of Daqu (P < 0.05), whereas Leuconostoc was significantly negatively correlated with certain sensory quality indicators of Daqu (P < 0.05), suggesting that fungi might contribute more to Daqu quality. Metabolomics analysis indicated that metabolites such as xylitol and glycolic acid were not only key components influencing the quality of Daqu but also served as potential biomarkers for distinguishing Daqu produced from different wheat varieties. This study reveals key quality parameters for superior Daqu-making wheat, providing a theoretical basis for the breeding of new wheat varieties dedicated to Daqu production and for high-quality Daqu fermentation.