Changes occurring in nutritional components (phytochemicals and free amino acid) of raw and sprouted seeds of white and black sesame (Sesamum indicum L.) and screening of their antioxidant activities

The present study is the first to investigate the germination properties regarding phytochemicals, amino acids, total phenolics, and antioxidant capacities of white and black sesame seeds. Nutritional components and antioxidant effects showed considerable differences. Sesamine and sesamolin composition decreased (white: 4.21→1.72, 3.57→1.57 mg/g; black: 2.43→0.58, 1.36→0.45 mg/g) during germination. Moreover, catechin displayed the predominant composition in sprouted seeds with values of 13.50 mg/g (white) and 19.09 (black) mg/g followed by (-)-epicatechin and sinapic acid. Total phenolics increased by approximately 4 times upon germination, i.e., 503.1±27.1→ 2085.0±56.7 (white) and 645.8±31.5→2480.1±49.5 (black), mg GAE/g. Amino acids also remarkably increased in sprouted white (7.04→31.69mg/g) and black (6.55→26.97mg/g) seeds, with individual composition occurring in the following order: asparagine>arginine>tryptophan>leucine>alanine. In particular, arginine and tryptophan exhibited the greatest variations. The antioxidant effects against DPPH radical were stronger in sprouted seeds depending on the phytochemicals. Therefore, sprouted sesame can be utilized as an excellent source for functional foods.