Effects of quinoa addition on physicochemical properties, microbiome profiles, and volatile organic compounds in...

The selection of raw materials plays a pivotal role in shaping the microbial ecology and metabolic functions of Daqu, a fermentation starter widely used in Baijiu production. Quinoa (Chenopodium quinoa Willd.), a pseudocereal rich in proteins, polyphenols, and bioactive compounds, has recently gained attention as a functional food ingredient. In this study, Quinoa was used to replace a certain proportion of wheat and incorporated into the making process of medium-temperature Daqu (MTD), and its effects on the physicochemical properties, microbial community dynamics, and volatile organic compound (VOC) were investigated. Compared with traditional MTD, quinoa-supplemented Daqu (L-MTD) exhibited significantly higher starch (increased by 8.4 %), reducing sugar (increased by 12.7 %), and acidity (increased by 15.3 %) levels (p < 0.05), along with enhanced esterification and fermentation power of its central part (increased by 10.2 % and 9.5 %, respectively, p < 0.05). High-throughput sequencing revealed that quinoa addition reshaped the microbial community by enriching beneficial lactic acid bacteria (e.g., Lactobacillus and Weissella) and reducing potential spoilage fungi (e.g., Aspergillus and Rhizopus). In addition, Lactobacillus and Saccharomycopsis showed strong correlations with the accumulation of esters and aromatic compounds, including ethyl lactate, phenethyl acetate, DL-(-)-pantoyl lactone, and benzyl alcohol. Redundancy analysis (RDA) indicated strong correlations between Lactobacillus and Saccharomycopsis with the accumulation of esters (such as ethyl acetate and ethyl lactate) and aromatic compounds (such as benzyl alcohol and phenethyl acetate), providing a research basis for identifying functional microbial strains in MTD and conducting subsequent micro-fermentation experiments. These findings highlight the potential of quinoa as a functional additive that modulates the microbial ecology and enhances the aroma complexity of Daqu, thereby offering a novel strategy for improving the quality and potential health value of traditional fermented products.