金花白茶加工过程中主要滋味物质的动态变化

以2017年福建寿眉散茶为原料,按照渥堆、汽蒸、压制定型、发花、干燥等加工工艺制成金花白茶。通过对加工过程中8个有代表性的工艺节点取样检测,以探明金花白茶加工过程中茶多酚、儿茶素、咖啡碱、氨基酸、水浸出物、可溶性糖、黄酮、茶三素等主要滋味物质含量的动态变化,并探究各类滋味物质的动态变化对其滋味品质的影响。结果表明,金花白茶加工过程中,茶多酚、儿茶素、游离氨基酸、可溶性糖、茶黄素及茶红素含量均逐渐降低,金花白茶较原料降幅分别为24.26%、52.89%、27.44%、9.38%、48.83%及30.96%。黄酮总量、没食子酸及茶褐素含量逐渐增加,金花白茶较原料增幅分别为20.46%、10.92%及77.31%。水浸出物、咖啡碱、茶氨酸含量略有增加,增幅为2.89%、7.70%、8.63%。这些变化有利于金花白茶滋味浓醇厚不苦涩,汤色红浓明亮品质的形成。同时结合感官审评发现,茶多酚、茶黄素、咖啡碱、游离氨基酸及茶褐素均与金花白茶滋味品质显著或极显著相关。

Dynamic Changes of Main Quality Components in Jinhua White Tea Processing

Jinhua white tea was made from Fujian Shoumei loose tea in 2017 by pile fermentation, steaming, pressing, shapping, fungal fermentation and drying. This study aimed to explore the dynamic changes of the main taste quality components during Jinhua white tea processing. Thecontents of catechins, caffeine, amino acids, water extracts, soluble sugars, flavonoids, theathree were detected in samples from 8 representative processing points. This study alsoevaluatedthe impact of the dynamic changes in taste substances during Jinhua white tea processing on its taste quality. The results showed that during the processing of Jinhua white tea, the contents of tea polyphenols, catechins, free amino acids, soluble sugars, theaflavins and thearubigins decreased gradually. Compared with the raw materials, the decreases of Jinhua white tea were 24.26%, 52.89%, 27.44%, 9.38%, 48.83% and 30.96% respectively. The total flavonoids, gallic acid and theabrownin contents increased gradually, and the increases of Jinhua white tea compared with raw materials were 20.46%, 10.92% and 77.31% respectively. The contents of water extract, caffeine and theanine increased slightly by 2.89%, 7.70% and 8.63%. All these changes are beneficial to the formation of Jinhua white tea with thick and mellow taste, red and bright soup color. At the same time, combined with sensory evaluation, it was found that tea polyphenols, theaflavins, caffeine, free amino acids and theabrownin were significantly or extremely significantly related to the taste quality of Jinhua white tea.