Bioactive β-Carbolines Harman and Norharman in Sesame Seed Oils in China

The beta-carbolines in our diet, mainly including harman and norharman, are a group of biologically active, naturally occurring plant-derived alkaloids. Fragrant sesame seed oil is one of the most popular flavor edible oils in China. Considering that sesame seeds are roasted at 200-240 & DEG;C during the processing of flavor sesame seed oils, it is meaningful to investigate the levels of beta-carboline compounds in various sesame seed oils. In this work, the levels of beta-carbolines (harman and norharman) in different types of sesame seed oils in China (e.g., pressed fragrant sesame oil, ground fragrant sesame oil) have been determined systematically. The results showed that the levels of total beta-carbolines in pressed fragrant sesame oils (700.5~2423.2 mu g/kg) were higher than that in ground fragrant sesame oils (660.4~1171.7 mu g/kg). Roasting sesame seeds at high temperatures (200-240 & DEG;C) led to higher levels of beta-carbolines (660~2400 mu g/kg) in fragrant sesame seed oils. In addition, the loss of tryptophan might be attributed to the formation of beta-carbolines in sesame seeds during the roasting process. In general, fragrant sesame seed oils (pressed fragrant sesame oils, ground fragrant sesame oils) contain higher levels of beta-carbolines due to the formation of harman and norharman during the roasting sesame seed process.