A systemic review on Liubao tea: A time‐honored dark tea with distinctive raw materials, process techniques, chemical profiles, and biological activities

Abstract

Liubao tea (LBT) is a unique microbial‐fermented tea that boasts a long consumption history spanning 1500 years. Through a specific post‐fermentation process, LBT crafted from local tea cultivars in Liubao town Guangxi acquires four distinct traits, namely, vibrant redness, thickness, aging aroma, and purity. The intricate transformations that occur during post‐fermentation involve oxidation, degradation, methylation, glycosylation, and so forth, laying the substance foundation for the distinctive sensory traits. Additionally, LBT contains multitudinous bioactive compounds, such as ellagic acid, catechins, polysaccharides, and theabrownins, which contributes to the diverse modulation abilities on oxidative stress, metabolic syndromes, organic damage, and microbiota flora. However, research on LBT is currently scattered, and there is an urgent need for a systematical recapitulation of the manufacturing process, the dominant microorganisms during fermentation, the dynamic chemical alterations, the sensory traits, and the underlying health benefits. In this review, current research progresses on the peculiar tea varieties, the traditional and modern process technologies, the substance basis of sensory traits, and the latent bioactivities of LBT were comprehensively summarized. Furthermore, the present challenges and deficiencies that hinder the development of LBT, and the possible orientations and future perspectives were thoroughly discussed. By far, the productivity and quality of LBT remain restricted due to the reliance on labor and experience, as well as the incomplete understanding of the intricate interactions and underlying mechanisms involved in processing, organoleptic quality, and bioactivities. Consequently, further research is urgently warranted to address these gaps.

Influence of Various Tea Utensils on Sensory and Chemical Quality of Different Teas

“…Dark tea is a post-fermented tea. The processing of white tea, which is a micro-fermented tea, mainly uses sunlight for withering [ 4 ]. The key step in the processing of oolong tea is the rotation course (Zuo-Qing), which controls the degree of fragmentation of tea cells in order to achieve the purpose of controlling the degree of fermentation.…”

Determination of the variations in the metabolic profiles and bacterial communities during traditional craftsmanship Liupao tea processing

“…Presently, it has been regarded as a Chinese geographical indication product and gained increasing attention, owing to its unparalleled sensory characteristics of vibrant redness, thickness, aging aroma, and purity, significantly different from black tea and green tea ( Huang et al, 2023 ). Moreover, Liupao tea has been reported to have multitudinous bioactive compounds, which lay the substance foundation for its various health benefits, such as antioxidant, anti-obesity, anti-diabetes, antihy-perlipidemic effect, antiaging effects, improvements inmetabolic syndrome-related diseases, protection againstorganic damage, and regulation of intestinal microbiotaflora ( Feng et al, 2023 ).…”

“…According to the difference in post-fermentation method, Liupao tea could be classified as traditional craftsmanship Liupao tea (TC-Liupao tea) and modern craftsmanship Liupao tea (MC-Liupao tea) ( Feng et al, 2023 ). Traditional craftsmanship is an indispensable method in the development process of Liupao tea, which is of great significance.…”