Catechins are present in green tea

Catechins are present in green tea leaves in relatively
high amounts (up to 30% of dry matter). These compounds
are mainly responsible for the characteristic
astringent and bitter taste of black tea brews (Zhang
et al., 1992; Kiehne, 1996). Recently the catechins have
attracted much attention in relation to their antimutagenic
and antitumorigenic activities (Wang et al.,
1989; Zhu and Xiao, 1991). In contrast, Bu-Abbas (1997)
stated that the contribution of flavanols to the antimutagenic
activity of green tea is limited. The catechins
have strong antioxidative properties as illustrated by
their ability to scavenge oxygen radicals and chelate
metal ions (Shahidi et al., 1993; Wanasundara and
Shahidi, 1994; Chen and Ho, 1995). It has been stated
that (-)-epigallocatechin gallate (EGCG) and (-)-epicatechin
gallate (ECG) possess the strongest antioxidative
effect in meat lipids and marine oils (Wanasundara
and Shahidi, 1996). Epidemiological studies
have also shown that tea polyphenols are effective in
the chemoprevention of colon cancer (Kim et al., 1994).
The health properties of tea flavonoids have been
recently extensively reviewed (Tijburg et al., 1997;
Hollman et al., 1997).

Results (Indonesian) 2:

Katekin yang hadir dalam daun teh hijau di relatif
jumlah tinggi (hingga 30% dari bahan kering). Senyawa ini
terutama bertanggung jawab untuk karakteristik
rasa zat dan pahit brews teh hitam (Zhang
et al, 1992;. Kiehne, 1996). Baru-baru ini katekin telah
menarik banyak perhatian dalam kaitannya dengan antimutagenik mereka
kegiatan dan antitumorigenic (Wang et al,.
1989; Zhu dan Xiao, 1991). Sebaliknya, Bu-Abbas (1997)
menyatakan bahwa kontribusi flavanol ke antimutagenik
aktivitas teh hijau terbatas. Katekin
memiliki sifat antioksidan yang kuat seperti yang digambarkan oleh
kemampuan mereka untuk mengikat radikal oksigen dan kelat
ion logam (Shahidi et al, 1993;. Wanasundara dan
Shahidi, 1994; Chen dan Ho, 1995). Telah dinyatakan
bahwa (-) - epigallocatechin gallate (EGCG) dan (-) - epicatechin
gallate (ECG) memiliki antioksidan yang kuat
efek lipid daging dan minyak laut (Wanasundara
dan Shahidi, 1996). Studi epidemiologis
juga menunjukkan bahwa polifenol teh yang efektif dalam
satu kemoprevensi kanker usus besar (Kim et al, 1994.).
Sifat kesehatan flavonoid teh telah
baru-baru ini secara luas Ulasan (Tijburg et al, 1997;.
Hollman et al, 1997. ).