Enriching antimicrobial peptides from milk hydrolysates using pectin/alginate food-gels

• Published in: Food chemistry 2021-08, Vol.352, p.129220-129220, Article 129220
• Main Authors: Um, Jounghyun, Manguy, Jean, Anes, João, Jacquier, Jean-Christophe, Hurley, Daniel, Dillon, Eugene T., Wynne, Kieran, Fanning, Séamus, O'Sullivan, Michael, Shields, Denis C.
• Format: Article
• Language: English
• Subjects: Alginate; Alginates - chemistry; Amino Acid Sequence; Animals; Antimicrobial Cationic Peptides - chemistry; Antimicrobial Cationic Peptides - pharmacology; Antimicrobial peptide; Bioinformatics; Casein; Gel enrichment; Gels; Hydrolysate; Microbial Sensitivity Tests; Milk - chemistry; Pectin; Pectins - chemistry; Peptidomics; Protein Hydrolysates - chemistry
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2021.129220

[Display omitted] •Pectin-alginate gels can enrich for antimicrobial peptides.•Pectin-alginate enriched peptides showed broad range antimicrobial activity.•Separation capabilities largely reflect selection based on charge and length. Cationic antimicrobial peptides have raised interest as attractive alternatives to classical antibiotics, and also have utility in preventing food spoilage. We set out to enrich cationic antimicrobial peptides from milk hydrolysates using gels containing various ratios of anionic pectin/alginate. All processes were carried out with food-grade materials in order to suggest food-safe methods suited for producing food ingredients or supplements. Hydrolysed caseinate peptides retained in the gel fraction, identified by mass spectrometry, were enriched for potential antimicrobial peptides, as judged by a computational predictor of antimicrobial activity. Peptides retained in a 60:40 pectin:alginate gel fraction had a strong antimicrobial effect against 8 tested bacterial strains with a minimal inhibitory concentration of 1.5–5 mg/mL, while the unfractionated hydrolysate only had a detectable effect in one of the eight strains. Among 110 predicted antimicrobial peptides in the gel fraction, four are known antimicrobial peptides, HKEMPFPK, TTMPLW, YYQQKPVA and AVPYPQR. These results highlight the potential of pectin/alginate food-gels based processes as safe, fast, cost-effective methods to separate and enrich for antimicrobial peptides from complex food protein hydrolysates.