본 연구는 다류원료 식물류의 물 추출물에 대해 항산화성을 검토하고 그 항산화 물질(페놀성 화합물, 비타민 C, 셀레늄)을 분석하였다. 대두유에 식물류의 물 추출물을 0.02%(추출고형분 함량, w/w) 첨가하여 $55^{circ}C$ 공기순환식 인큐베이터에서 36일 저장기간 동안 과산화물가 측정과 $110^{circ}C$에서 Rancimat 방법에 의해 항산화성을 검토하였으며 첨가제가 들어있지 않은 대두유를 대조구에 사용했고 0.02% BHT 첨가한 대두유는 비교구로 사용하였다. 대조구와 BHT 첨가구에 비해 산화 유도기간이 $55^{circ}C$에서는 구기자, 우롱차, 귤껍질(진피), 유자, 매실 물 추출물 등이 길었으며 $110^{circ}C$에서는 우롱차, 인스탄트커피, 유자, 구기자, 오미자, 매실 물 추출물 등이 길었다. 추출고형분 g당 총페놀성 물질 함량은 우롱차, 녹차, 홍차, 커피, 계피, 결명자 물 추출물 등에서 높았고 비타민 C 함량은 커피, 두충, 홍차, 영지, 계피, 감잎, 치커리, 녹차, 우롱차 물 추출물 등에서 높았으며 셀레늄은 모든 물 추출물에서 검출되지 않았다. 이들의 항산화성은 단일 항산화성 물질의 효과에 기인하기 보다는 페놀성 화합물, 비타민 C 등 복합적 효과에 의한 것으로 사료된다.
The water-soluble extracts of plants used as tea materials were investigated for their antioxidant activities and active components(total phenolics, ascorbate and selenium). Antioxidant activities of the plant extracts were determined by measuring the changes in both peroxide values(POV method) during storage(36 day, $55^{circ}C$) and conductivity of soybean oil at $110^{circ}C$(Rancimat method). Soybean oil without any additive was used as a control. Soybean oil treated with 0.02% BHT was used as a positive control. The test samples were prepared by mixing the plant extracts with soybean oil in 0.02% concentration by weight. The water-soluble extracts of lycii fructus(23 d), oolong tea(23 d), orange peel(23 d), citron(22 d), and apricot(22 d) showed longer induction periods, compared to control(21 d) and BHT(21 d) by POV method. Also water-soluble extracts of oolong tea(12 h), instant coffee(11 h), citron(10 h), cinnamomi cortex(10 h), schizandrae fructus(10 h), lycii fructus(10 h) and apricot(10 h) demonstrated longer induction periods, compared to control(8 h) and BHT(8 h) by Rancimat method. The contents of total phenolic compounds were observed to be high in water-soluble extracts of oolong tea, green tea, black tea, coffee, cinnamomi cortex, and cassiae semen. Ascorbate contents were found to be high in coffee, eucommiae cortex, black tea, ganoderma, cinnamomi cortex, persimmon leaf, chicory, green tea and oolong tea extracts. The selenium contents were not detected in all the extracts. The antioxidative effects of some plant extacts were seemed to be the combined effects of various antioxidant components such as phenolics and ascorbate.
