Purification, identification, and synthesis of five novel antioxidant peptides from Chinese chestnut (Castanea mollissima Blume) protein hydrolysates

This study was done to isolate novel antioxidant peptides from Chinese chestnut protein (CCP) hydrolysed with alcalase. A series of purification steps including ultrafiltration, gel filtration chromatography, anion exchange chromatography, and reverse-phase high-performance liquid chromatography were used to purify the CCP. ABTS radical scavenging capacity was assessed to evaluate antioxidant activity. Five antioxidant peptides, VYTE, TKGQ, MMLQK, TPAIS, and VSAFLA, with molecular weights of 590.20, 592.17, 745.29, 647.20, and 606.34 Da, respectively, were obtained from the most active fractions and characterized using nano-liquid chromatography electrospray ionisation-tandem mass spectrometry. VYTE and VSAFLA showed the highest ABTS radical scavenging capacity with IC50 values of 0.13 +/- 0.01 and 0.28 +/- 0.04 mg/mL, respectively (P < .05). Moreover, the five novel antioxidant peptides had good antioxidant activity after synthesis and simulated digestion. These novel peptides may have potential applications as functional foods or nutraceutical compounds.