Abstract
These studies were carried out to investigate the quality of green tea processed by different 1st-pan-firing time and to select the best conditions of green tea processing. The results were as follows. At harvesting tea plant leaf, tea plants had 4 leaves, each leaf size was $6.4cm\;{\times}\;2.4cm$, and weight of 100 buds was 40.2g. The content of moisture of green tea was decreased with the prolongation of 1st-pan-firing time, and the yield of green tea at 10 min. pan-firing time was the highest value of 20.12%. After processing green tea, 1st 10 min. pan-fired one had much more contents of total nitrogen(TN 5.41%) and total amino acid(T.A.A; 3,282mg/100g) and less content of tannin(13.22%) and caffeine(1.64%) than the other treatments. The content of chlorophyll and vitamin C went down with the extension of 1st pan-firing period. Sixteen kinds of free amino acid including theanine as a good taste component of green tea were isolated and measured by HPLC. T.A.A contents were in the range of $2,447{\sim}3,192mg/100g$ and among various pan-firing methods, 10 min. 1st pan-fired one had the highest content of T.A.A. The taste-determinants such as theanine, aspartic acid, serine, glutamic acid and arginine in green tea liquor, occupied as much as $89.4{\sim}90.0%$ of T.A.A.s. Among these, theanine was more than 50%, Lightness and yellowness of green tea were increased with delay of pan-firing time, while green color appeared to be more distinct at 10 min. 1st pan -firing time than other treatments. Besides, it gained the highest score of sensory evaluation among them. These above results suggested that 10 min. pan-fired green tea was considered to be the best level as pan-firing time of green tea processing.
덖음차 제조공정중 첫 덖음시간에 따른 최적 제다조건을 구명한 실험결과는 다음과 같다. 채엽시 엽수는 4매, 엽장 및 엽폭은 $6.4cm\;{\times}\;2.4cm$, 백아중(白芽重)은 40.2g이었다. 첫 덖음시간이 길어질수록 수분함량은 감소하여 6분 덖음시 6.0%에서 14분 덖음시 4.6%로 되었고, 제품수율은 10분에서 20.12%로 가장 높았다. 덖음시간에 따라 전질소는 $5.14{\sim}5.41%$, 총아미노산은 $2,531{\sim}3,282mg/100g$의 변이를 보였으며, 그 중에서 첫 덖음시간이 10분일 때 가장 함량이 높았던 반면, 탄닌은 $13.22{\sim}13.86%$로 10분 처리에서 함량이 가장 낮았다. 카페인 $1.64{\sim}2.01%$로 첫덖음시간에 별로 영향을 받지 않았으며, 엽록소($319.1{\sim}380.3mg/100g$)와 비타민 C ($158.9{\sim}208.8mg/100g$)는 덖음시간이 길어질수록 함량이 감소하는 경향을 보였다. 16종의 유리아미노산 및 질소화합물 분석 결과 총 함량은 $2,447{\sim}3,192mg/100g$이었으며 10분 첫 덖음이 가장 높은 함량을 나타냈다. 이들 중에서 theanine이 50% 이상이었고 aspartic acid, serine, glutamic acid 및 arginine을 합치면 $89.4{\sim}90.0%$였다. 차의 색깔은 덖음시간이 길어질수록 황색이 증가하였고 녹색은 10분 덖음에서 가장 진한 색을 나타냈다. 또한 관능검사 결과도 10분 덖음이 가장 높은 평가를 받았다. 이상의 결과로 보아 첫 덖음 시간의 경우 10분이 적당하리라 생각된다.