In vitro assessment of the multifunctional bioactive potential of Alaska pollock skin collagen following simulated gastrointestinal digestion

BACKGROUND Dietary mineral deficiency, hypertension and diabetes have become serious human health problems. Dietary approaches are increasingly being investigated to address these issues. Identification of food‐derived biological peptides has become an important approach to control such diseases. Peptides generated from aquatic byproducts have been shown to possess biological activities. RESULTS Significantly higher copper‐chelating activity was observed on simulated hydrolysis of intact collagen. The collagen hydrolysate generated in the gastric stage exhibited moderate angiotensin‐converting enzyme (ACE)‐inhibitory activity with an IC50 value of 2.92 ± 0.22 mg mL−1, which significantly decreased to 0.49 ± 0.02 mg mL−1 after intestinal digestion. The dipeptidyl peptidase (DPP) IV‐inhibitory potency of the collagen hydrolysate generated directly following simulated gastrointestinal digestion (SGID) (IC50 2.59 ± 0.04 mg mL−1) was significantly lower than that of the collagen tryptic hydrolysate (CTH) (IC50 1.53 ± 0.01 mg mL−1). The antioxidant activities of collagen and CTH using the ferric‐reducing antioxidant power (FRAP) assay were 0.87 ± 0.10 and 1.27 ± 0.03 µmol Trolox equivalent (TE) g−1 respectively after SGID. CONCLUSION This study identifies collagen as a good and inexpensive substrate for the generation of biologically active peptides with potential applications as functional ingredients in the management of chronic illness and mineral deficiency problems. © 2014 Society of Chemical Industry