日照白毫乌龙茶初制过程主要生化成分的变化

以日照白毫乌龙茶为研究对象,研究其初制过程中主要生化成分如茶多酚、儿茶素总量、游离氨基酸、咖啡碱以及儿茶素组分(EGC、C、EGCG、EC、ECG),儿茶素氧化产物(茶黄素、茶红素、茶褐素)含量的变化。结果表明,水浸出物含量高于国家标准;茶多酚、儿茶素总量明显下降;游离氨基酸含量在整个初制过程中总体呈上升趋势;咖啡碱与可溶性糖含量在整个初制过程中总体呈下降趋势;儿茶素组分以酯型儿茶素EGCG和ECG变化剧烈;儿茶素氧化产物TF、TR和TB含量呈上升趋势,毛茶的TR/TF比值约为12.10。此外,还对日照白毫乌龙茶与红茶、闽台乌龙茶主要生化成分进行了比较分析,以研究日照白毫乌龙茶的特点。

Variations of main biochemical components during the primary processing of Rizhao Pekoe Oolong tea

Variations of main biochemical components, such as tea polyphenol, total catechins, free amino acid, caffeine, five catechins (EGC, C, EGCG, EC, ECG), and catechin oxidation products (TF, TR and TB) during the primary processing of Pekoe Oolong tea were investigated. The results showed that the water extract content was higher than the national standard. The contents of tea polyphenol and total catechins obviously decreased. The free amino acid contents were increasing in the primary processing. The contents of caffeine and?soluble?sugar decreased. In five catechins investigated, EGCG and ECG varied acutely. The contents of TF, TR and TB increased in the primary processing and the TR/TF ratio in the raw tea was 12.10 approximately. In addition, the main biochemical components in Rizhao Pekoe Oolong tea and black tea and the components in Oolong tea from Fujian and Taiwan were compared to study the characteristics of Rizhao Pekoe Oolong tea.