Complementary and efficient methods for di- and tri-peptide analysis and amino acid quantification from simulated gastrointestinal digestion of collagen hydrolysate

• Published in: Food science & technology Vol. 155; p. 112880
• Main Authors: Larder, Christina E., Iskandar, Michèle M., Sabally, Kebba, Kubow, Stan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2022
• Subjects: Amino acids; blood; Capillary electrophoresis; cattle; collagen; Collagen hydrolysate; cost effectiveness; derivatization; digestion; hydrolysates; hydrophilic interaction chromatography; Hydrophilic interaction liquid chromatography (HILIC); in vitro digestion; Peptides; collagen hydrolysates; Peptides; Amino acids; electrospray ionization; gas chromatography; capillary electrophoresis; method detection limit; Hydrophilic interaction liquid chromatography (HILIC); angiotensin converting enzyme; hydrophilic interaction liquid chromatography; ultra-performance liquid chromatography; ion trap; relative standard deviation; high-performance liquid chromatography; external standard; internal standard; multiple reaction monitoring; liquid chromatography-mass spectrometry; capillary zone electrophoresis; instrument detection limit; molecular weight; Collagen hydrolysate; nuclear magnetic resonance; gastrointestinal; bioactive peptides; small intestine; standard error of the mean; standard deviation
• ISSN: 0023-6438; 1096-1127
• DOI: 10.1016/j.lwt.2021.112880

Collagen hydrolysates (CHs) are composed of bioactive peptides (BAPs) and amino acids (AAs), which contribute to their health enhancing properties. Post digestion profiling of CHs typically evaluates either BAP or AA content in blood but not within digests. Existing methods for peptide analysis are optimized for blood samples and rely on costly methods that require substantial sample preparation and data interpretation. A capillary electrophoresis (CE) method was developed as a rapid, cost effective, and reliable method for analysis of BAPs (Ala-Hyp, Pro-Hyp, Pro-Hyp-Gly, Gly-Pro-Hyp) within digests. Coupled to LC-MS, a hydrophilic interaction liquid chromatography (HILIC) column was used to quantify 19 AAs in digests, without derivatization. Two bovine CHs (CH-GL and CH-OPT) underwent in vitro digestion and their BAP and AA content was assessed. The Gly-Pro-Hyp and Pro-Hyp-Gly content was greater in CH-GL versus CH-OPT with values of 19.82 ± 4.25 and 8.969 ± 2.742 μg/mL respectively. The two CHs had distinct peptide profiles; 13 unidentified peptide peaks from each CH were not found in the other. No differences in AA content were observed. The present work describes sensitive and rapid methodology for concurrent analysis of BAPs and AAs after digestion of CHs, which can support further understanding of the bioactive components of CHs. •Concurrent peptide and amino acid analysis of collagen hydrolysate digests was done.•A novel capillary electrophoresis method was described for peptide analysis.•Amino acids were measured without the need for derivatization.•Bovine collagen hydrolysates differed in peptide profiles.