제주산 건조녹차를 에서 15분간 추출하여 여과한 다음 PET병에 밀봉하여 저온과 실내 및 실외에 각각 보관하면서 보존안정성을 측정하였다 저장기간에 따라 L값은 거의 변화가 없었지만 a값이 감소하고 b값이 증가하면서 전체적인 색깔이 짙어졌으며, 실내에서 저장한 경우가 실외저장이나 저온저장보다 저장기간이 길어질수록 더 짙어졌다. 녹차추출물 중의 주요 카테킨류로는(-)-epigallocatechin, (-)-epigallocatechin gallat
Preservation stability of the extract from dried green tea produced in Jeju, extracted at for 15 min and bottled in PET container after filtration and then settled at , indoor at room temperature and outdoor, respectively, was estimated. Color L-value was almost constant but color of the extract became darkened during storage, especially in indoor storage. Main catechins of green tea extract were (-)-epigallocatechin, (-)-epigallocatechin gallate, epicatechin, (+)-catechin, epicatechin gallate in order, and the content of epigallocatechin was 53.8%. Nevertheless total catechin content was not changed in cold storage, and of total catechins were reduced in outdoor or indoor storage after 14 weeks. Caffeine content were increased but total polyphenols were not changed largely during storage. Election donating abilities (EDA) showed more than 60% without influence of storage conditions and periods. Nitrite scavenging abilities (NSA) showed more than 90% at pH 1.2, but those were decreased gradually as pH increased, and then disappeared at pH 6.0. Color, polyphenols, antioxidant activities of extract were not so changed for more than 3 months. Microbial growth was not shown during same periods, due to heat treatment of the extracts at for 10 min.