Microbial Community Affects Daqu Quality and the Production of Ethanol and Flavor Compounds in Baijiu Fermentation
Pei‐Jie Han, Lu-Jun Luo, Ying Han, Liang Song, Pan Zhen, Dayong Han +5 more
Foods
Abstract
Daqu is a traditional starter for Baijiu fermentation and is produced by spontaneous fermentation of ground and moistened barley or wheat. The quality of Daqu is traditionally evaluated based on physicochemical and subjective sensory parameters without microbiological analysis. Here, we compared the physicochemical characteristics of qualified (QD) and inferior (ID) Daqu, their microbial communities based on plate counting and PacBio SMRT sequencing of rRNA gene libraries, and their impacts on Baijiu fermentation. The results showed that the glucoamylase and α-amylase activities of QD were significantly higher than those of ID. The counts of yeasts and relative abundances of functional microbes, especially the amylolytic bacterium <i>Bacillus licheniformis</i> and fungi <i>Saccharomycopsis fibuligera</i> and <i>Lichtheimia ramosa</i>, were significantly higher in QD than in ID. The laboratory-scale Baijiu fermentation tests showed that the relative abundances of the amylolytic microbes were higher in the QD than the ID fermentation set, resulting in more efficient fermentation, as indicated by more weight loss and higher moisture content in the former. Consequently, more glycerol, acetic acid, ethanol, and other volatile compounds were produced in the QD than in the ID fermentation set. The results suggest that Daqu quality is determined by, and can be evaluated based on, its microbial community.
Extracted Claims
4 claims extracted from this paper into the knowledge graph
glucoamylase and α-amylase activities were significantly higher qualified Daqu (QD) compared to inferior Daqu (ID)
“The glucoamylase and α-amylase activities of QD were significantly higher than those of ID.”
amylolytic microbes were higher QD fermentation set compared to ID fermentation set
“The relative abundances of the amylolytic microbes were higher in the QD than the ID fermentation set, resulting in more efficient fermentation, as indicated by more weight loss and higher moisture co...”
yeast counts and relative abundances of functional microbes were significantly higher qualified Daqu (QD) compared to inferior Daqu (ID)
“The counts of yeasts and relative abundances of functional microbes, especially the amylolytic bacterium <i>Bacillus licheniformis</i> and fungi <i>Saccharomycopsis fibuligera</i> and <i>Lichtheimia r...”