Antioxidant Effects of Ulmus davidiana Extracts on Various Oil
Fish oil에 대한 유근피 및 유백피 추출물의 과산화물가를 측정한 결과 유근피는 모든 용매의 추출물에 대해 항산화 작용이 높게 나타났다. 0.1% 추출물 첨가구 모두 저장 6시간에는 30 meq/Kg을 보인 후 최종 18시간까지 40 meq/Kg이하의 과산화물가를 보여 저장 시간이 증가해도 산화 억제효과가 높게 나타났다. 0.05%의 경우 부탄올과 메탄올 추출물은 상업용 항산화제와 비교할 때 유사한 항산화 효과를 나타내었다. 유백피는 0.1%
We prepared extracts from Ulmus davidiana (root, Korean source; URK) and Ulmus davidiana (bark, Korean source; UBK). URK extracts obtained with all tested solvents showed the highest antioxidant effects on fish oils. Both treatments containing 0.1% (v/v) extract from URK and UBK each showed that peroxide values of 30 meq/kg were maintained for 6 h and levels of 40 meq/kg were apparent for up to 18 h, indicating that antioxidative activity seemed to sustain during all tested time periods. Compared with commercial antioxidants, butanol and methanol extracts diluted to 0.05% (v/v) had similar antioxidative effects. Water and butanol UBK extracts diluted to 0.1% (v/v) both showed the highest antioxidative activities. After addition of metal ions, methanol and butanol URK extracts diluted to 0.1% (v/v) showed enhanced antioxidative activity. UBK ethanol extracts displayed superior antioxidative activity and a constant peroxide value throughout storage. However, in the case of Perilla oil, -tocopherol which is known as a natural antioxidant did not show any antioxidative activity except in the BHT. Methanol and butanol URK extracts diluted to 0.2% (v/v) showed superior antioxidative activities throughout the experiment. A methanolic UBK extract (0.2%, v/v) also had a similarly increased antioxidative effect. In tests involving addition of metal ions to all extracts, the methanolic UBK extract (0.2%, v/v) showed excellent antioxidative activity. When lard was tested, antioxidant levels did not differ significantly among extracts prepared using four different solvents at either 0.05% or 0.1% concentrations (both v/v). Addition of metal ions at levels of 0.05% or 0.1% (w/v) to these extracts had no significant additive effect on oxidation.