Antioxidant Activity of Solvent Extracts from Korean Fermented Tea

Major components and antioxidant activity of fermented tea were investigated. Contents of total flavonoid and total phenol showed the highest score in ethanol extract ($481.4\;{\mu}g/g$ and 33.5 g/100g), respectively. Their contents in hot water extract ($405.7\;{\mu}g/g$ and 23.6 g/100g) were lower than those of the others extracts. However, their contents of ethyl acetate extract($495.2\;{\mu}g/g$, 39.5 g/100g) from fermented tea stored for 1 year had the highest amount among all tested samples. Catechins of fermented tea were found to be EGC, GC, catechin, catechol and EGCG. However, they were not detected in hot water extract. Scavenging activities of DPPH free radical of all extracts from fermented tea were increased in proportion to their concentration and were $72.4\%$ for fermented tea and $80.9\%$ for fermented tea stored for 1 year. Reducing power of ethanol extract at $500\;{\mu}g/mL$ were 0.78 as OD value of 700 nm for fermented tea and 0.88 for fermented tea stored for 1 year, respectively. Antioxidant activities of ethyl acetate extracts at $3000\;{\mu}g/mL$ were $86.6\%$ for fermented tea and $73.7\%$ for fermented tea stored for 1 year, respectively.

용매별 후발효차 추출물의 항산화 효과

자연 유래의 미생물 효소를 이용하여 제조되는 후발효차의 주요성분과 항산화능을 조사하였다. 후발효차의 총 플라보노이드와 총 페놀 함량에서 각각 ethanol 추출물($481.4\;{\mu}g/g$, 33.5 g/100g)이 가장 높았으나, 1년 저장한 시료에서는 ethyl acetate 추출물($495.2\;{\mu}g/g$, 39.5 g/100g)이 다른 모든 추출물보다 가장 높았다. 후발효차의 catechin류는 EGC, GC, catechin, catechol 및 EGCG가 검출되었으며, 열수 추출물에서는 EGCG가 검출되지 않았다. DPPH free radical 소거능은 모든 추출물에서 그 농도가 증가할수록 활성이 증가하였는데, 저장하지 않은 후발효차와 1년간 저장한 것의 ethanol 추출물에서는 각각 $72.4\%$ 및 $80.9\%$였다. 금속 화합물 형성에 대한 환원력의 효과는 에탄올 추출물 $500\;{\mu}g/mL$에서 0.78과 0.88(1년 저장)의 환원력을 나타났고, ${\beta}$-carotene-linoleate system에서 ethyl acetate 추출물 $3000\;{\mu}g/mL$의 항산화능은 $86.6\%$와 $73.7\%$(1년 저장)를 나타내었다.