Contribution of microorganisms from pit mud to volatile flavor compound synthesis in fermented grains for Nongxiangxing Baijiu brewing.

Abstract

Nongxiangxing Baijiu (NB) is known for its distinct flavor profile which is attributed to key aroma compounds. The exposed fermentation technique, utilizing Daqu and solid-state fermentation in pit muds, plays a crucial role in flavor development. While previous studies have investigated the impact of microorganisms from pit mud and fermented grains on flavor compound production, a comprehensive understanding of microbial functions in the entire pit fermentation system is lacking. Herein, we aimed to explore the role of pit mud-derived microorganisms in shaping the microbial community and flavor compound synthesis in NB. There are 76 volatile flavor compounds were identified in fermented grains during Nongxiangxing Baijiu fermentation. Main flavor compounds in Nongxiangxing Baijiu clustered within the same network module. And 27.27% of microorganisms in the core modules of the fermented grain co-occurrence network originated from pit mud. The relationship between pit mud microorganisms and flavor compounds revealed a significant positive correlation (92%). Notably, Prevotella and Sarocladium were identified as the main contributors to this effect on flavor. Microorganisms originating from pit mud influenced the composition and activity of microorganisms in fermented grains and facilitated the production of flavor compounds in NB. This article is protected by copyright. All rights reserved.