Pea flour as stabilizer of oil-in-water emulsions: Protein purification unnecessary

Abstract

Plant proteins have recently gained considerable attention as stabilizers of food-grade oil-in-water emulsions. However, the separation of plant proteins from their native matrix can be cumbersome due to the molecular complexity of plants. This issue could be alleviated by avoiding the protein purification step. In this work, we show that native pea flour containing 50 wt% starch and 20 wt% protein has similar interfacial properties compared to concentrated pea protein systems (~55 wt% protein). Interfacial tension profile of pea flour was similar to that of concentrated pea protein, indicating that proteins are the primary stabilizing agents of the interface. The fabricated oil-in-water emulsions (10.0 wt% oil) made with pea flour or pea protein concentrate containing 0.2 and 0.3 wt% protein showed a similar monomodal droplet size distribution. Moreover, both emulsions stabilized by the pea flour and the pea protein concentrate had similar rheological properties, showing that starch granules did not have any impact on the physical properties. This work clearly showed that stable oil-in-water emulsions can be produced with pea flour and further purification of pea proteins is not necessary.