• Amino acids composition;
  • antioxidant activity;
  • DNA damage;
  • molecular weight distribution;
  • sweet potato protein hydrolysates


In this study, sweet potato protein (SPP) hydrolysates were prepared by six enzymes (alcalase, proleather FG-F, AS1.398, neutrase, papain and pepsin). The antioxidant activities and protective effect against oxidative DNA damage of SPP hydrolysates were investigated. Alcalase hydrolysates exhibited the highest hydroxyl radical-scavenging activity (IC50 1.74 mg mL−1) and Fe2+-chelating ability (IC50 1.54 mg mL−1) (< 0.05). Compared with other five hydrolysates, the hydrolysates obtained by alcalase had the most abundant <3-kDa fractions. In addition, below 3-kDa fractions of alcalase hydrolysates showed the highest antioxidant activities and protective effects against DNA damage through both scavenging hydroxyl radicals and chelating Fe2+, which was probably because of the increase in several antioxidant amino acids, such as His, Met, Cys, Tyr and Phe, as well as the hydrophobic amino acids. The results suggested that enzymatic hydrolysis could be used as an effective technique to produce high value-added peptides products from SPP.