Microbial dynamics in tea processing: Implications for endophytes, phytochemistry, and sustainable contamination mitigation

Tea is one of the most preferred beverage after water, globally valued for its characteristic aroma, flavor, and known health benefits. Derived from leaves of Camellia sinensis L. Kuntze, its multiple health benefits are attributed by catechins which are dominating polyphenols, and contributes to its rich antioxidant, antimicrobial, anti-carcinogenic properties. However, there is a persistent challenge in maintaining the tea hygiene, safety, and overall quality due to microbial contamination encountered at multiple steps of tea processing including cultivation, harvesting, packaging, storage, and transportation. The current study provides a comprehensive review of microbial dynamics across the tea production chain, addressing the research gap concerning sources of microbial contamination, associated perturbations on beneficial tea endophytes, and their implication for tea quality. This review further discusses role of biocontrol agents, good manufacturing practices, and sustainable agricultural approaches which could be useful in strategically mitigating harmful microbial population, and promoting tea quality.