초록 열기/닫기 버튼
This study examined the factors affecting the tea quality by analyzing the quality characteristics of different shoot parts in different tea cultivars and tea seasons in Jeju, Korea. New growing shoots were plucked from 'Saemidori' (early-maturing), 'Yabukita' (mid-maturing), and 'Hushun' (late-maturing) at each tea season, and separated into seven parts bud, 1st leaf, 2nd leaf, 3rd leaf, 4th leaf, 5th leaf, and stem to analyze the quality components. The tea quality components including the total free amino acids, theanine, catechins, caffeine, tannin, vitamin C, and fiber were determined by NIR analysis. The changes in the total free amino acids and theanine content in the different shoot parts were similar in the three cultivars and three different tea seasons. These contents decreased gradually in the lower leaves and were slightly higher at the stem than at the 4th and 5th leaf. The changes in thetotal cathechins and tannin contents showed a similar tendency to decline gradually in leaves and decrease rapidly in the stem. The EC, ECG and EGCG content in the individual cathechins were similar to the total cathechins. The caffeine content in the different shoot parts showed a similar tendency to those of the total amino acids and theanine at the three cultivars and three tea seasons. The caffeine content decreased gradually at the lower leaves and was higher at the stem than at the 3th and 4th leaf. The Vitamin C content was relatively constant at different leaf positions, but was slightly low in the stem with a higher tendency at the 1st crop than at the 2nd and 3rdcrop in all three cultivars. The crude fiber content was similar at the different cultivars and tea seasons, whereas it increased gradually at the lower shoot parts, and was similar at the stem to that of the 5th leaf. These results suggest that the shoot parts at different tea cultivars and tea seasons can be major factors affecting the tea quality.
