Fate of Heavy Metals in Sesame Seeds during Heat Pressure Process.

Sesame (Sesamum indicum L.) is one of the important oil crops and has been remarkably used as a natural seasoning in Korea. In oil seeds and seed products, the heavy metal contents are of concern and hence, an important decisive factor for the assessment of their quality. Therefore, in this study, we conducted an experiment to confirm the fate of heavy metals in sesame seeds (SS) to two types of sesame by-products, the sesame defatted flour (SDF) and sesame oil (SO) during heat pressure process. The results indicated that cadmium (Cd) contents transferred at a higher rate from SS to SO, and with a little transfer to SDF. Similarly, lead (Pb) and arsenic (As) contents in SS were highly transferred to SO than SDF. In addition, all transfer ratios of Cd, Pb and As from SS to two sesame by-products, except for transfer ratio of Cd from SS to SDF, inversely decreased in a dose-dependent manner as the heavy metal contents in SS increased. Therefore, we suggest that Cd, Pb and As may be more likely to be transferred to edible sesame oil rather than the remnant of seeds during heat pressure process. As the heavy metal contents in sesame seeds increases, the transfer ratio decreases to sesame oil. This study will be helpful for predicting the heavy metal content in edible sesame oil through heat pressure process of metal-contaminated sesame seeds.