关键词: 氮代谢, 氮代谢

Abstract: In this paper, the effects of drying process of primary processing on the quality of Keemun black tea were studied. The one-bud-two-leave fresh leaves, which were withered, curled and fermented at the same level, belonging to the breed of ‘Qimen zhuye’ were picked as raw materials. During the drying process, the interaction effects (3×3) on the fermented leaves’ contents of major biochemical ingredients and sensory qualities were researched, using the randomized blocks design method, at three levels of the velocity of first drying, which were quick (9 min), medium (12 min) and slow (15 min), and three levels of the temperature of final drying, which were high (90℃), medium (75℃), and low (60℃). Every treatment was replicated twice. All of the dried leaves’ major biochemical ingredients and sensory qualities were respectively detected and evaluated. The results showed that, the contents of amino acid, soluble sugar, thearubigins, theaflavins and theabrownins in the dried leaves were all highly significantly affected (P<0.01) by the velocity of first drying, and so do their sensory qualities (colour, aroma, taste and the brewed leaves). The contents of soluble sugar(P<0.01), theabrownins (P<0.01), caffeine (P<0.05), thearubigins (P<0.05) and theaflavins (P<0.05) were significantly affected by the temperature of final drying. The contents of thearubigins, theabrownins, theaflavins and sensory qualities (color, aroma, taste and the brewed leaves) were highly significantly affected by the interaction effects (P<0.01); and the contents of amino acid and soluble sugar were significantly affected by the interaction effects (P<0.05). The score of color and taste, and the total score of the dried leaves, treated with the quick level of the velocity of first drying, in the sensory evaluations was slightly lower than the others. The dimmer brewed dried leaves, treated with slow level and had the medium aroma, were evaluated than the others. The total score of dried leaves, treated with the low level of the temperature of final drying, was lower than the leaves treated with the medium and the high level. In conclusion, the experimental combination of the medium (12 min) level of the first drying’s velocity and the medium (75℃) level of the final drying’s temperature and the one of the medium (12min) level of the first drying’s velocity and the high (90℃) level of the final drying’s temperature, were better than the others, and the former was the best.