Journal of Tea Science Research, 2024, Vol.14, No.1, 57-63 http://hortherbpublisher.com/index.php/jtsr 57 Invited Review Open Access Caffeine Degradation Pathways Mediated by Microbial Communities in Tea Fermentation JieZhang1 , Baofu Huang2, Guangman Xu2 1 Institute of Life Sciences, Jiyang Colloge of Zhejiang A&F University, Zhuji, 311800, Zhejiang, China 2 Chinese Traditional Medicine Center, Cuixi Academy of Biotechnology, Zhuji, 311800, Zhejiang, China Corresponding email: jessizhang0701@gmail.com Journal of Tea Science Research, 2024, Vol.14, No.1 doi: 10.5376/jtsr.2024.14.0006 Received: 07 Jan., 2024 Accepted: 11 Feb., 2024 Published: 26 Feb., 2024 Copyright © 2024 Zhang et al., This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Preferred citation for this article: Zhang J., Huang B.F., and Xu G.M., 2024, Caffeine degradation pathways mediated by microbial communities in tea fermentation, Journal of Tea Science Research, 14(1): 57-63 (doi: 10.5376/jtsr.2024.14.0006) Abstract The fermentation of tea is a complex biochemical process significantly influenced by the microbial communities present. This study focuses on the caffeine degradation pathways mediated by these microbial communities during tea fermentation. Understanding the mechanisms behind caffeine degradation is essential for optimizing tea processing to cater to varying consumer demands regarding caffeine content. This review comprehensively covers the role of microbial communities identified in different types of tea, such as Pu-erh, Oolong, and Black tea, and their specific interactions that lead to caffeine degradation. We discuss the involvement of key microorganisms, including various fungi and bacteria, and the enzymatic processes they facilitate. Special attention is given to the metabolic pathways of caffeine transformation, highlighting how specific microbes like Aspergillus sydowii and Lactobacillus casei contribute to these processes. Additionally, the paper examines environmental and processing factors that influence microbial activity and caffeine degradation. By synthesizing current research, this review aims to shed light on the potential of microbial engineering to develop tea products with controlled caffeine levels, thereby enhancing their health benefits and flavor profiles. Future research directions are suggested, focusing on the genetic and metabolic engineering of microbes to refine the caffeine degradation process further. Keywords Caffeine degradation; Tea fermentation; Microbial communities; Microbial engineering; Enzymatic pathways Introduction Tea, an infusion of the leaves of the Camellia sinensis plant, is one of the most widely consumed beverages in the world, second only to water. Its popularity is owed not only to its distinctive flavors and cultural significance but also to its numerous health benefits. Among the various bioactive compounds present in tea, caffeine is particularly notable for its stimulating effects on the human central nervous system, enhancing alertness and cognitive performance. However, the impact of caffeine on human health is complex, with studies indicating both beneficial and adverse effects depending on the context and level of consumption (Prasanth et al., 2019). The process of tea fermentation, which is crucial in determining the flavor profile and chemical composition of the final product, involves a complex interplay between tea polyphenols and microbial communities. Microbial fermentation can significantly alter the levels of key metabolites in tea, such as catechins and caffeine, thereby influencing the sensory qualities and health properties of the beverage (Wang et al., 2023). The role of specific microbes, such as the "golden flower" fungi Eurotium cristatum and the fungus Aspergillus sydowii, has been highlighted in the fermentation process, with implications for both the flavor and health benefits of the tea (Zhou et al., 2020a; Wang et al., 2023). Understanding the pathways of caffeine degradation during tea fermentation is of particular interest, as it can lead to the production of metabolites with distinct health implications. For instance, the fungus Colletotrichum camelliae has been shown to metabolize caffeine through the degradation of uric acid, which may have applications in managing caffeine-contaminated environments and producing low-purine foods to prevent diseases like hyperuricemia and gout (He et al., 2023). Moreover, the microbial conversion of tea polyphenols and caffeine
RkJQdWJsaXNoZXIy MjQ4ODYzNA==