보문 : 시판 녹차, 홍차, 오룡차의 항산화 및 상승효과

The antioxidative effect of tea extracts from green tea, oolong tea and black tea was investigated. The extraction yields of crude catechin were green tea 5.4%, oolong tea 3.5`%, and black tea 2.5%. Green tea, oolong tea and black tea of crude catechin showed antioxident activity at concentrations of 200ppm, and the oolong tea showed highest antioxidant effect. The browning intensities (at 420 nm) of green, oolong and black tea were 0.140, 0.582 and 0.915, respectively and green tea showed highest hydrogen donating ability (HDA) and than followed by oolong or black tea. Also, When the crude catechin (100 ppm) was used in combination with α-tocopherol(50 ppm) and ascorbyl palmitate (50 ppm), the crude cathechin showed very strong synergistic effect, comparable to that of crude catechin (200 ppm).