Comparative assessment of compositional components, antioxidant effects, and lignan extractions from Korean white and black sesame (Sesamum indicum L.) seeds for different crop years

The compositional components (lignan, protein, and oil) as well as antioxidant properties of white and black sesame seeds from different crop years were evaluated. Various solvent extracts of sesame seeds possessed two major peaks and their chemical structures were confirmed as sesamin (1) and sesamolin (2) using NMR spectroscopy and HPLC-DAD-ESI/MS technique. Moreover, their optimal extraction was achieved using 90% acetonitrile for 6 h at 25 °C. Lignans differed significantly with seed colours, cultivars, and crop years, whereas protein and oil contents exhibited slight variations. Interestingly, total average lignan of white cultivars (7.36 mg/g) was two times more than that of black sesasme (3.10 mg/g). Antioxidant effects of the 90% acetonitrile extracts of all cultivars also varied with black cultivars showing higher values than white seeds. Additionally, Kopoom (white) and Kangbaek (black) may be recommended as potential cultivars due to the highest lignan content (9.08 mg/g) and antioxidant capacity (DPPH: 81.5 and ABTS: 93.2% at 90 μg/ml: the concentration of the 90% acetonitrile extract on dried seed weight). Thus, antioxidant effects of sesame seeds may not well correlate with their contents of lignans.