Interfacial properties of potato peptides identified by bioinformatics: application in omega-3 delivery emulsions

Bioinformatics was used to identify emulsifying peptides embedded within the structure of potato protein. This reduced time and cost of extensive screening hydrolysis processes. Up to 40 synthetic peptides having between 10 and 29 amino acids, different net charge and potential different conformation at the interface (e.g. a-helix, b-sheet and unordered) were tested in this study. First, interfacial tension measurements and evaluation of the physical stability of 5wt.% fish oil-in-water emulsions (e.g. zeta potential, droplet size during storage) were carried out in order to select the best performing peptides. Secondly, Synchrotron Radiation Circular Dichroism (SRCD) was used to study the conformation at the oil/water interface of the selected peptides. Finally, the oxidative stability of fish oil-in-water emulsions stabilized with the selected peptides was evaluated by using Electron Spin Resonance (ESR) and determination of hydroperoxides and secondary volatile oxidation products. The results indicated that up to five peptides showed similar or superior emulsifying activity when compared to sodium caseinate (e.g. based on interfacial tension measurements and droplet size of the emulsions). Thus, this work shows the feasibility of using bioinformatics to identify plant-based emulsifiers embedded in potato protein, which could be employed to stabilize omega-3 delivery emulsions.