18B-22 |
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J. LEE, Y. Yoon, and E. Choe. Dept. of Food & Nutrition, Inha Univ., 253 Younghyundong Namgu, Incheon, 402-751, South Korea Roasted sesame oil is famous for high oxidative stability mainly due to the antioxidant activity of sesamol. Other lignan compounds, sesamin and sesamolin, are also present in roasted sesame oil. Despite higher concentrations of sesamin and sesamolin, systematic study on the effects of these lignan compounds has not been reported. Therefore, this research was performed to investigate the effects of lignan compounds present in roasted sesame oil on the oil oxidation during storage in the dark. Sesamol, sesamin, or sesamolin was added to tocopherol-stripped sunflower oil (TSSO) at 0, 50, 100, and 200 ppm of oil. The oil samples were stored at 60oC in the dark for 7 days. Oxidation of TSSO was determined by conjugated dienoic acid contents (CDA), p-anisidine value (PAV), and fatty acid composition. Concentrations of lignan compounds in the oil during storage were also determined by high performance liquid chromatography. CDA contents and PAV of TSSO increased with storage time due to the oil oxidation during storage in the dark. TSSO added with sesamol, sesamin, and sesamolin showed lower CDA formation and PAV than TSSO without lignan compounds, which suggests that lignan compounds acted as antioxidants in the autoxidation of TSSO. Kinds and concentration of lignan compounds in the oil and storage time affected the oil oxidation individually and interactively. Sesamol showed higher antioxidant activity than sesamin and sesamolin. The higher the concentration of the lignan compounds in the oil and the longer the storage time, the higher the antioxidant activity of lignan compounds in the TSSO oxidation in the dark. Addition of lignan compounds and their addition levels did not significantly affect fatty acid compositions of TSSO during storage in the dark. Lignan compounds contents in TSSO decreased with storage time and sesamol was decomposed faster than sesamin or sesamolin.
Session 18B, Food Chemistry: Antioxidant and bioactive agents
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |