红茶通氧发酵过程中发酵叶相变化分析

Changes in Sensory and Physico-chemical Characteristics of Tea Leaves during Aerobic Fermentation for Black Tea

采用黔湄419、黔湄502、黔湄601、黔湄809和福鼎大白茶品种的茶青为原料,利用自制的通氧发酵装置进行通氧发酵,以自然发酵为对照;每15 min记录1次发酵叶感官品质变化情况,测定叶温及pH值。结果表明:通氧发酵处理前期叶面升温迅速且高于自然发酵叶温;明显加快发酵过程中叶面色泽的红变,促进特征香气的形成;发酵过程中,发酵叶pH值均呈降低趋势,通氧发酵处理降低速度更快;感官审评结果表明,通氧发酵样品品质整体不低于自然发酵样品。

Fresh tea leaves from different tea cultivars, Qianmei 419, Qianmei 502,Qianmei 601,Qianmei 809 and Fudingdabaicha were fermented in a laboratory-made aerobic fermentor to produce black tea in comparison to natural fermentation. Changes in sensory quality were recorded at 15-min intervals during the fermentation, and leaf temperature and pH were measured as well. The results showed that during the early stage of aerobic fermentation, the leaf temperature went up quickly to a level higher than that of natural fermentation. Aerobic fermentation accelerated the color alteration of tea leaves to red and facilitated the formation of characteristics aroma. During the fermentation process, the pH value of fermented tea leaves showed a downward trend under both conditions, but decreased faster under aerobic condition. The results of sensory evaluation showed that the overall quality of black tea from aerobic fermentation was as good as that from natural fermentation.