Determination of Antioxidants Contents in Various Plants Used as Tea Materials

Forty plants used as tea materials were chosen for determining the contents of total phenolics, selenium (Se), , and ascorbate. Total phenolics and ascorbate contents were analyzed colorimetrically. The Se contents were measured by hydride-atomic absorption spectrometry. The contents of and were simultaneously determined by high performance liquid chromatography using separate detectors, UV for and FL for analyses. The contents of these antioxidants were as follows (per 100 g dry plant); Contents of total phenolics in green tea leaf, black tea leaf, oolong tea leaf and instant coffee were about 7 g and the Se contents in corni fructus and arrowroot were found to be about , which were the highest among all plants used. Contents of in eucommiae cortex, persimmon leaf and green tea leaf were 8587, 6222 and respectively. The persimon leaf contained the highest content (33 mg) and then followed by eucommiae cortex (26 mg), green tea leaf (16 mg) and black tea leaf (13 mg) in order. Ascorbate contents were found to be high in green tea leaf (199 mg) and black tea leaf (117 mg).