Study on the Changes of Tocopherols and Lignans and the Oxidative Properties of Roasted Sesame Oil during Manufacturing and Storage

摘要

This study investigated the antioxidant content and oxidative properties of roasted sesame oil during manufacturing and storage at 25 deg C in the dark for 18 months. The manufacturing steps included pressing of the roasted sesame seeds, and then three filtering steps. Filtering decreased the oil viscosity, but increased free fatty acid content. The peroxide value (POV) was not affected by filtering. Sesamin, sesamolin, and tocopherol levels were significantly higher in the 3rd filtered oil as compared to the other oils; however, sesamol content was reduced. The roasted sesame oil oxidized slowly during storage at 25 deg C in the dark, and there was no POV change up to 9 months of storage. The levels of sesamol, sesamin, sesamolin, and tocopherols in the oil decreased with storage time, and the tocopherol decomposition rate (-3.04%/month) was higher than that of total lignan compounds (-1.06%/month). Therefore, these results suggest that tocopherols have priority over lignan compounds in performingas antioxidants in roasted sesame oil during storage.