Analysis of Sensory Qualities and Microbial Community Structure in the Fermented Grains by Low-Temperature Daqu from Different Regions of China

Area of Science:

• Food Science and Microbiology
• Fermentation Technology
• Biotechnology

Background:

• Low-temperature Daqu (LTD) is a crucial starter culture for fermented grains (FG) in Light-amora Baijiu production.
• The specific influence of LTD on the sensory characteristics and microbial ecosystem of FG requires detailed investigation.

Purpose of the Study:

• To investigate the impact of LTD from different regions on the sensory profiles and microbial community structures of fermented grains (FG).
• To elucidate the differences in microbial composition and functional gene expression between LTD and FG.

Main Methods:

• Utilized electronic sensing for sensory attribute analysis (odor and taste).
• Employed MiSeq high-throughput sequencing to analyze microbial community structures (bacteria and fungi).
• Analyzed bacterial gene functions related to metabolic pathways.

Main Results:

• Significant differences in odor and taste were observed between FG groups fermented by different LTD (P < 0.05).
• Dominant bacteria in FG were Lactobacillus, while dominant fungi were Saccharomycopsis and Saccharomyces.
• LTD exhibited distinct microbial communities and gene functions compared to FG, with LTD favoring anaerobes and FG favoring facultative anaerobes.
• A significant portion (71.77%) of endemic bacteria were unique to FG and absent in LTD.

Conclusions:

• Regional variations in LTD significantly affect the sensory qualities and microbial composition of fermented grains (FG).
• The distinct microbial and functional profiles of LTD and FG highlight their different roles in the fermentation process.
• This study enhances understanding of LTD's critical role in shaping FG characteristics and fermentation outcomes.