Identification and characterization of two novel α-glucosidase inhibitory peptides from almond (Armeniaca sibirica) oil manufacture residue

• Published in: Food science & technology 2020-12, Vol.134, p.110215, Article 110215
• Main Authors: Gu, Xin, Gao, Tao, Hou, Yakun, Li, Di, Fu, Le
• Format: Article
• Language: English
• Subjects: Almond (Armeniaca sibirica); Isolation and structure characterization; Stimulated digestion; α-Glucosidase inhibitory peptides
• ISSN: 0023-6438; 1096-1127
• DOI: 10.1016/j.lwt.2020.110215

Almond consumption is associated with ameliorating type 2 diabetes mellitus (T2DM). The purpose of this study is to isolate peptides with high α-glucosidase inhibitory activity from almond (Armeniaca sibirica) oil manufactured residue hydrolysate by ultrafiltration, gel chromatography and reversed-phase high-performance liquid chromatography (RP-HPLC) and to characterize their structures. The results indicated that the nutritional values of Var, Met+Cys, Ile, and Leu were high in almond oil residue, and the first limiting amino acid was Lys. Two peptides recovered from hydrolysed products of Prote Ax and Protease M were Trp-His and Trp-Ser, respectively, which showed higher α-glucosidase inhibitory activity compared with other peptides. These two peptides were relatively stable under simulated digestion conditions. The α-glucosidase inhibitory activity IC50 of Trp-His was 17.03 ± 0.05 μmol/L for both before and after digestion, whereas the IC50 of Trp-Ser significantly increased after simulated digestion, from 24.71 ± 0.02 μmol/L to 44.63 ± 0.03 μmol/L. These results indicated the potential use of residue from almond oil processing for treating T2DM. •Protein from almond oil manufacture residue was evaluated.•Peptide A and B were isolated from protein of almond oil manufacture residue.•The structure of A and B were characterized.•Peptide A and B showed excellent α-glucosidase inhibitory activity.•The changes in structure and activity were investigated after simulated digestion.