Characterizing and decoding the effects of co-culture fermentation on dark tea infusion flavor development: elucidating microbial succession and metabolic dynamics mediated by Eurotium cristatum and water kefir

作者：Yao Gao, Rui Zhuo, Hong Luo, Chi‐Tang Ho, Yulian Chen, Hui Zhou, Zhe Qu, Huanyu Chen, Youjin Yi, Yuanliang Wang, Xiaozhen Peng, Mingzhi Zhu, Zhonghua Liu, Yu Xiao · 发表于：Food Chemistry X · 年份：2025 · DOI：10.1016/j.fochx.2025.102876 · 被引用次数：26 · 研究领域：Tea Polyphenols and Effects、Fermentation and Sensory Analysis、Food Quality and Safety Studies

Water kefir (a probiotic-rich culture) and Eurotium cristatum (a key fungus in Fu brick tea) were co-fermented with dark tea infusion to investigate dynamic changes in volatile organic compounds (VOCs), microbial communities, and biochemical components. Co-fermentation dramatically altered microbial composition, enriching beneficial lactic acid bacteria ( Liquorilactobacillus , Lacticaseibacillus ) while inhibiting undesirable microbes (e.g., Saccharomyces ). A total of 65 VOCs were identified, with co-fermentation promoting floral, fruity, minty, and stale aromas (e.g., linalool, methyl salicylate, acetophenone) while reducing off-flavors (e.g., 3-methylbutanoic acid). Multivariate analysis revealed core functional microbiota ( Gluconobacter , Acetobacter , Eurotium , etc.) strongly associated with flavor formation. Additionally, co-fermentation modulated organic acids, free amino acids, and catechins, improving sensory attributes. Sensory evaluation confirmed superior aroma complexity (enhanced minty/fungal floral notes) and balanced taste (reduced sourness/bitter/astringency characteristics). These findings demonstrate that water kefir and E. cristatum co-fermentation synergistically improves dark tea flavor characteristics, offering a promising strategy for industrial-scale probiotic tea beverage development.