|Title:||不同茶樹品種多酚酶活性及其在製茶過程中之變化||Other Titles:||Varietal Difference in Tea Polyphenol Oxidase Activities and Its Changes During Tea Manufacturing Process||Authors:||陳英玲
|Keywords:||多酚酶;茶;製茶過程;Polyphenol oxidase;Tea;Manufacturing process||Issue Date:||Dec-1995||Publisher:||農業試驗所||Start page/Pages:||111-119||Source:||農業試驗所特刊;第56號||Conference:||農特產品加工研討會專刊
Proceeding of A Symposium on Processing of Agricultural Products
The investigation of the main tea varieties (clones) in Taiwan has shown that activities of polyphenol oxidase in the varieties (clones) suitable for semifermented tea manufacture are evidently lower than those for black tea manufacture. This enzyme was found to show a Km of 2.0×10-3M(at 30℃) for(+) catechin. The activities of polyphenol oxidase can be promoted by shaking the fermentation process of Paochung tea manufacture. The activities of this enzyme were found to fluctuate with the shakings. Oxidation of catechins (about 6%-l0% oxidation) increased with times and physical strength of shakings. Little change in the activities of polyphenol oxidase was observed in the check treatment because of lack of shaking suggesting that the oxidation of catechins was not evident. This indicated that obvious fermentation of tea did not take place during the processing.
It can be inferred from the results that the times and physical strength of shakings were closely related with the activation of polyphenol oxidase and oxidation of catechins in tea fermentation.
The enzyme activity during the process of black tea manufacturing in tea leaves was found to increase continually in the withering period and reached the highest point by rolling, about 2 times more than that in the fresh leaves and decrease along with the fermentation process after rolling, then disappear after drying.
|Appears in Collections:||農業化學組|
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