Oxygen Radical Absorbance Capacity and Tocopherol Content in Pressed Oils Made from Sesame (Sesamum indicum L.) Cultivar "Maruhime" and Rapeseed (Brassica napus L.) Cultivar "Nanaharuka"

This study aimed to evaluate both the lipophilic and hydrophilic oxygen radical absorbance capacities (ORAC) in pressed oils made from sesame (Sesamum indicum L.) cultivar "Maruhime" and rapeseed (Brassica napus L.) cultivar "Nanaharuka." For this reason, we slightly modified the extraction method for antioxidant compounds using an accelerated solvent extractor system, and the multi-laboratory validated lipophilic ORAC method previously reported. Acceptable recovery was observed when four matrices of oils and fats fortified with a-tocopherol and gallic acid were subjected to the modified extraction method. Moreover, it was confirmed that the lipophilic ORAC value of a-tocopherol, as determined by the modified method, was within the range of the mean reproducibility standard deviation in the multi-laboratory comparison study. In the pressed oil from sesame cultivar "Maruhime," L-ORAC value was 12.6 to 33.8 times higher than H-ORAC, and the mean L-ORAC and H-ORAC values were 2 926 and 130 mu mol-Trolox equivalent/100 g, respectively. Also, L-ORAC value in the pressed oil from rapeseed cultivar "Nanaharuka" was 2.2 to 13.1 times higher than H-ORAC, and the mean L-ORAC and H-ORAC values were 552 and 87 mu mol-Trolox equivalent/100 g, respectively. The contribution of tocopherols to L-ORAC value of the pressed oil from rapeseed cultivar "Nanaharuka" ranged from 24 to 55 %; however, the contribution was smaller, ranging from 7 to 22 %, in the pressed oil from sesame cultivar "Maruhime."