茶白星病对茶鲜叶主要化学成分的影响

于茶白星病严重发生期,采集不同感病程度的病叶进行茶多酚、咖啡碱、氨基酸和水浸出物等主要化学成分的测定.结果表明,病情指数为17.6,27.5,64.5的茶鲜叶中,茶多酚含量分别比健叶低1.8%,7.7%,11.4%,咖啡碱含量分别比健叶低3.7%,15.3%,26.7%,水浸出物含量分别比健叶低7.7%,9.4%,14.4%,说明感病鲜叶中构成成茶品质的主要化学成分含量降低;游离氨基酸的含量分别比健叶高65.8%,106.8%,115.7%,这可能与感病组织内蛋白水解酶活性提高,蛋白质降解有关.

Effect of tea white scab on main chemical composition in tea leaves

Previous studies on the protections of tea are mainly focused on the influence of the diseases to the tea growth and the productivity,rather than the qualities of the infected tea leaves.The author collected healthy leaves and sick leaves of various statuses during the period of serious tea white stab diseases,and then determined some main chemical compositions,such as tea polyphenols,coffee alkali,amino acids and water soluble matter.It shows showed that,with illness index as 17.6,27.5,64.5 separately of the fresh tea leaves,the content of teak polyphenols is 1.8%,7.7% and 11.4% lower separately than that in healthy leaves while the coffee alkali is 3.7%,15.3% and 26.7% lower and the water soluble matter is 7.7%,9.4%,14.4% lower.It is indicated that the essential components to the tea quality are being decreased.At the same time,the content of free amino acid is 65.8%,106.8% and 115.7% higher respectively,which may be related to the increasing activities of proteolytic enzymes and the degradation of the protein.