Protein nativity explains emulsifying properties of aqueous extracted protein components from yellow pea

In this paper, the emulsifying properties of a protein-enriched fraction from pea are unravelled. The emulsifying properties of mildly fractionated protein fractions from yellow pea and compared to those of commercial pea protein isolate. The emulsion stability of an oil-in-water emulsions were determined under acidic pH, under acceleration forces and a freeze-thaw treatment. It was found that the emulsions stabilized by the mildly fractionated proteins were less prone to flocculation and coalescence. Those differences were related to the interfacial properties, which indicated that the mildly fractioned proteins were able to form a strong and viscoelastic layer on the interface, providing protection against disruption and high compressive forces. The native state of the mildly fractionated protein was used to explain those results. Denatured protein as obtained after conventional fractionation or after applying an additional heating step resulted in an altered interface characteristics, which could explained increased flocculation and droplet coalescence. Overall, the results indicated the relevance of using mild conditions during fractionation. Mild fractionation, thereby shifting the focus from purity to functionality, could be a route to make novel ingredients, with more natural character in a sustainable manner.