Production of dipeptidyl peptidase IV inhibitory peptides from defatted rice bran

► DPP-IV inhibitory protein hydrolysate was produced from defatted rice bran. ► Its IC50 value was 2.3 ± 0.1 mg/mL against DPP-IV. ► Leu-Pro and Ile-Pro were identified as the inhibitory peptides from the peptides. ► Ile-Pro was the strongest inhibitor among the 15 Xaa-Pro dipeptides and Pro-Ile. ► Ile-Pro competitively inhibited DPP-IV (Ki = 0.11 mM).