Emulsifier peptides derived from seaweed, methanotrophic bacteria, and potato proteins identified by quantitative proteomics and bioinformatics

Betül Yesiltas,Simon Gregersen,Linea Lægsgaard,Maja L Brinch,Tobias H Olsen,Paolo Marcatili,Michael T Overgaard,Egon B Hansen,Charlotte Jacobsen,Pedro J García-Moreno

doi:10.1016/j.foodchem.2021.130217

Betül Yesiltas, Simon Gregersen + Show 8 more

Open Access

https://doi.org/10.1016/j.foodchem.2021.130217

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Abstract

Global focus on sustainability has accelerated research into alternative non-animal sources of food protein and functional food ingredients. Amphiphilic peptides represent a class of promising biomolecules to replace chemical emulsifiers in food emulsions. In contrast to traditional trial-and-error enzymatic hydrolysis, this study utilizes a bottom-up approach combining quantitative proteomics, bioinformatics prediction, and functional validation to identify novel emulsifier peptides from seaweed, methanotrophic bacteria, and potatoes. In vitro functional validation reveal that all protein sources contained embedded novel emulsifier peptides comparable to or better than sodium caseinate (CAS). Thus, peptides efficiently reduced oil–water interfacial tension and generated physically stable emulsions with higher net zeta potential and smaller droplet sizes than CAS. In silico structure modelling provided further insight on peptide structure and the link to emulsifying potential. This study clearly demonstrates the potential and broad applicability of the bottom-up approach for identification of abundant and potent emulsifier peptides.

Highlights

Due to growing consumer demand for clean label and sustainable food ingredients (Asioli et al, 2017), the search for potent, natural re placements for chemical additives, is rapidly devel oping
Some peptides may exhibit axial amphiphilicity by orienting their hydrophilic and lipophilic parts perpendicular to the oil–water inter face, independent of the secondary structure. Building on these physical prerequisites for peptide emulsification activity, we recently identified a range of emulsifier peptides embedded in potato proteins using a conceptually new bottom-up approach, which combines quantitative proteomics and bioinformatic prediction to identify potent emulsifier peptides releasable from abundant proteins in a given biomass (GarcíaMoreno, Gregersen et al, 2020; García-Moreno, Jacobsen et al, 2020)
Bottom-up shotgun proteomics analysis of the homogenized biomass resulted in identification of 1839 unique peptides distributed between 597 protein groups accounting for a total of 626 potential proteins (Table S1)

Summary

Introduction

Due to growing consumer demand for clean label and sustainable food ingredients (Asioli et al, 2017), the search for potent, natural re placements for chemical additives (e.g. emulsifiers), is rapidly devel oping. Interfacial properties play a key role in peptide interaction with biological membranes and relate to food preservation through antimicrobial activity (Findlay et al, 2010). These properties may coincide, when assessing the func tional properties of amphiphilic peptides (Dexter & Middelberg, 2008; Enser et al, 1990). Peptides, which may exhibit antioxidant activity, have been reported to show great potential for enhancing oxidative stability in oil-in-water emulsions (Cheng et al, 2010; García-Moreno, Gregersen et al, 2020; García-Moreno, Jacobsen et al, 2020)

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