Abstract
Interrelation between the antioxidative activities of 70% ethanol extracts from bran fraction of 23 kinds of colored rice and chuchung as a control were examined. Antioxidative activities were evaluated by assaying reducing power, electron-donation ability to DPPH free radical, scavenging activity of hydroxy radical $({\cdot}OH)$ generated through Fenton reaction and inhibitory activity on lipid peroxidation using linoleic acid autoxidation system, respectively. Among 24 varieties of colored rice LK 1-3-6-12-1-1 had the strongest reducing power followed by Elwee, DZ 78, Jumlalocal-1 and SC-45 in decreasing order. The electron-donating ability to DPPH radical was higher in order of HP 883-1-1-1-B-1-1, HP 833-1-3-1-1-1, LK 2-7-12-1-1 and DZ 78. The hydroxy radical scavenging activity was higher in order of DK-1, IR 1544-38-2-2-1-2-2, SC-5 and SC-45 but LK 2-7-12-1-1 had oxidative effect. In the liaoleic acid autoxidation model system, RGS No 336, LK 1B-2-1-1, LK 1B-4-12-1-1, LK 1A-2-12-1-1, LK 2-7-12-1-1 and HP 883-1-1-1-B-1-1 exhibited strong antioxidative activities but Elwee, Jumlalocal-l and SC-45 showed to have oxidative effects. The rice variety of highest pigment content was Elwee and the next were RGS-No 336, IR 1544-38-2-2-1-2-2 and SC-5 with the order of higher content. The reducing power was correlated with the quantity of the pigment in the ethanolic extract of rice bran and SC-5 showed relatively high antioxidative activity in every results of antioxidative activity tests.
갈색에서부터 흑자색까지의 색상을 가지는 국.내외에서 수집한 23종류 유색미의 항산화 활성, 색소체 함량의 변기 및 상관성을 검정하였다. 유색미 에탄올 추출물 시료가 나타내는 환원력은 일반미 품종인 추청에 비해서 거의 모든 품종에서 높게 나타났으며, 환원력이 특히 높은 품종은 LK 1-3-6-12-1-1, Elwee, DZ 78, Jumlalocal-1, SC-45 등이었다. 전자공여능이 높은 품종은 HP 883-1-1-1-B-1-1, HP 833-1-3-1-1-1, LK-2-7-12-1-1, DZ 78 등이었고 hydroxy radical 소거활성이 큰 품종은 DK-1, IR 1544-38-2-2-1-2-2, SC-5, SC-45 등이었으며, LK 2-7-12-1-1은 오히려 산화촉진효과를 나타내는 품종이었다. 자동산화에 의한 지질 과산화물 형성을 강하게 억제하는 품종들은 RGS No. 336, LK IB-2-1-1, LK 1B-4-12-1-1, LK 1A-2-12-1-1, LK 2-7-12-1-1, HP 833-1-1-1-B-1-1등이었고 Elwee, Jumlalocal-1, SC-45 등의 품종은 산화적인 활성을 나타내고 있었다. 23품종의 유색미 중에서 색소체의 함량이 가장 많은 품종은 Elwee이었으며, 색소체 함량은 환원력과 정의 상관성이 있었고, 추출물이 고농도로 처리되었을 때 높은 환원력을 보인 유색미 품종은 linoleic acid 자동산화반응에서 지질 과산화를 촉진하는 경향이 있었다. 유색미 23품종 중에서 SC-5는 모든 반응계에서 비교적 높은 항산화 활성을 나타내었다.
