PDF(Pubmed)
Abstract：
Elevating the flavor profile of strong flavors Baijiu has always been a focal point in the industry, and pit mud (PM) serves as a crucial flavor contributor in the fermentation process of the fermented grains (FG). This study investigated the influence of wheat flour and bran (MC and FC) as PM culture enrichment media on the microbiota and metabolites of FG, aiming to inform strategies for improving strong-flavor Baijiu flavor. Results showed that adding PM cultures to FG significantly altered its properties: FC enhanced starch degradation to 51.46% and elevated reducing sugar content to 1.60%, while MC increased acidity to 2.11 mmol/10 g. PM cultures also elevated FG\'s ester content, with increases of 0.36 times for MC-FG60d and 1.48 times for FC-FG60d compared to controls, and ethyl hexanoate rising by 0.91 times and 1.39 times, respectively. Microbial analysis revealed that Lactobacillus constituted over 95% of the Abundant bacteria community, with Kroppenstedtia or Bacillus being predominant among Rare bacteria. Abundant fungi included Rasamsonia, Pichia, and Thermomyces, while Rare fungi consisted of Rhizopus and Malassezia. Metagenomic analysis revealed bacterial dominance, primarily consisting of Lactobacillus and Acetilactobacillus (98.80-99.40%), with metabolic function predictions highlighting genes related to metabolism, especially in MC-FG60d. Predictions from PICRUSt2 suggested control over starch, cellulose degradation, and the TCA cycle by fungal subgroups, while Abundant fungi and bacteria regulated ethanol and lactic acid production. This study highlights the importance of PM cultures in the fermentation process of FG, which is significant for brewing high-quality, strong-flavor Baijiu.
摘要：
提升浓香型白酒的风味特征一直是业内关注的焦点,和坑泥（PM）是发酵谷物（FG）发酵过程中的关键风味因素。这项研究调查了小麦粉和麸皮（MC和FC）作为PM培养富集培养基对FG的微生物群和代谢产物的影响，旨在为改善浓香白酒风味提供策略。结果表明，向FG中添加PM培养物可显着改变其性质：FC将淀粉降解提高到51.46％，将还原糖含量提高到1.60％，而MC将酸度增加至2.11mmol/10g。PM培养物也提高了FG的酯含量，与对照组相比，MC-FG60d增加了0.36倍，FC-FG60d增加了1.48倍，己酸乙酯分别上升0.91倍和1.39倍，分别。微生物分析显示，乳酸菌占丰富细菌群落的95％以上，Kroppenstedtia或芽孢杆菌在稀有细菌中占主导地位。丰富的真菌包括Rasamsonia，Pichia,和热细菌，而稀有真菌由根霉和马拉色菌组成。宏基因组分析显示细菌优势，主要由乳杆菌和脂乳杆菌(98.80-99.40%)组成，代谢功能预测突出与代谢相关的基因，尤其是MC-FG60D。PICRUSt2的预测表明对淀粉的控制，纤维素降解，和真菌亚组的TCA周期，丰富的真菌和细菌调节乙醇和乳酸的生产。这项研究强调了PM培养物在FG发酵过程中的重要性，这对于酿造高质量的啤酒很重要，浓郁风味的白酒。
