红茶发酵过程生理生化变化及调控技术研究进展

Research Progress of Physiological and Biochemical Changes and New Techniques in Fermentation of Black Tea

发酵是形成红茶品质特征的关键工序,其实质是在特定温湿度和供氧条件下,以多酚类酶促氧化形成茶黄素(TFs)、茶红素(TRs)、茶褐素(TBs)等高聚物为核心,同时芳香物质、糖类、蛋白质等品质成分发生剧烈变化。笔者综述了多酚氧化酶、过氧化物酶、β-葡萄糖苷酶和脂肪氧合酶等酶类在红茶发酵过程中主要发挥的功效,以及多酚类、蛋白质、氨基酸、芳香物质和糖类等生化成分在发酵期间的变化规律,概括了液态悬浮发酵、通氧发酵、添加外源物发酵等新型发酵技术,以及温湿度、光照、供氧量等参数的调控和一些辅助工艺在红茶发酵过程中应用的研究进展。通过这些理论研究展望了未来红茶发酵机理的研究内容和发酵设备,为红茶发酵的进一步研究提供基础和借鉴。

In manufacture of black tea, one of the most important steps is fermentation which significantlyinfluences the sensory quality of tea. Under the condition of certain temperature, humidity and oxygenconcentration, tea polyphenols presented in macerated leaves get oxidized to form TFs, TRs, TBs and otherpolymers, and aromatic substances, carbohydrate and protein change dramatically during the fermentationstage of black tea processing. The main functions of important enzymes in black tea fermentation, includingpolyphenol oxidase, peroxidase, β-glycosidase and lipoxygenase, and change rules of the main biochemicalcompositions including polyphenols, proteins, sugars, amino acids and aromatic substances were summarizedin this paper. Besides, the author focused on the auxiliary techniques and new fermentation techniques such assuspension fermentation, oxygen supply fermentation and exogenous additive fermentation. The control offermentation environment parameters were reviewed as well, such as temperature, humidity, light and oxygenconcentration. Based on these theoretical researches, the main mechanism of fermentation and the development of new fermentation equipment were prospected for further study of fermentation of black tea.