Inhibition of dipeptidyl peptidase IV (DPP-IV) was considered to be a crucial target for type 2 diabetes, and food-derived peptides were superior source of DPP-IV inhibitory peptides. The purpose of this investigation was to identify inhibitory peptides from salmon skin collagen using simulated digestion combined with Caco-2 cell monolayer membrane model. The analysis in silico showed that TKLPAVF and YLNF were potential inhibitory peptides. Determination of the inhibition activity showed that the IC 50 values of TKLPVAF and YLNF were 242.10 AE 3.40 and 146.90 AE 4.40 µM, respectively. Molecular docking results showed that seven hydrogen bonds were formed between YLNF and key residues of DPP-IV. YLNF may be considered a novel DPP-IV inhibitory peptide. In addition, YLNF could be transported by Caco-2 cell monolayer membrane in intact, and the apparent permeability coefficient value was (3.54 AE 0.34) × 10 -6 cm s −1 at 5 mM.

The objective of this study was to investigate the changes of the proteins in bovine milk serum after retort processing by label‐free quantification proteomics techniques. A total of 96 and 106 proteins were quantified in control group (CG) and retort group (RG), respectively. Hierarchical clustering analysis of the identified milk serum proteins showed a decrease in the abundance of most proteins, such as serum albumin, lactoperoxidase, lactotransferrin, and complement C3, and an increase in the abundance of other proteins such as κ‐casein, lipocalin 2, and Perilipin. Student's t‐test showed 21 proteins significantly differential abundance between CG and RG (p < .05), of which intensity‐based absolute quantification (iBAQ) of five proteins decreased and iBAQ of 16 proteins increased. Bioinformatics analysis demonstrated that retort processing increased the digestibility of proteins, but this improvement was offset by a decrease in the digestibility of proteins caused by protein modification. Our results provide insight into the proteome of retort sterilized milk for the first time. Given the extremely high security of retort sterilized milk, the proteome of bovine milk serum changes after retort sterilization exposed in this study will contribute to the formula design of retort sterilized milk products.