| Summary: | 碩士 === 國立中興大學 === 食品暨應用生物科技學系所 === 99 === Green tea is one of the most popular beverage all over the world. People are attracted to its aroma and interested in health benefit. The objectives of this study were to evaluation aroma quality and antioxidant ability of green tea industrial use modified by β-glucosidase. The tea study useing is Longjung green tea which is famous in China. The aroma quality was evaluated using enzyme in different modified times from 1 to 4 hours at 40℃. After enzyme added, the aroma consisted of volatile flavour compound（VFC） identified different in tea infusions. The green and roasty note relative ratio showed in oder: control 0.71＜treated 1hr 0.94＜treated 4hrs 1.11＜treated 2hrs 1.36＜treated 3hrs 1.38. Four green note, one fermented note and one fruity note of VFC identified relative content increased after enzyme treated. The result is similar to sensory analysis. Otherwise, green note had positive correlation with some sensory properties such as fresh, clean and negative correlation with stunt.
No significant was found between individual catechins, gallic acid and caffeine in tea infusions after enzyme modified（p＞0.05）. The antioxidant ability was evaluated by using assays of TPP, TEAC, and DPPH. No different was found on antioxidant ability in tea infusions after enzyme modified. However, the green note increasing was the positive contribution for aroma quality in industrial Longjung tea modified by β-glucosidase.
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