Modulation of the emulsifying properties of pea globulin soluble aggregates by dynamic high-pressure fluidization

The effects of thermal aggregation and microfluidization on pea (Pisum sativum L.) globulin characteristics and emulsifying properties were investigated. The thermal treatment of native pea globulins (NPs) induced the formation of aggregates (< 150 nm) that were partially stabilized by disulphide bonds and characterized by higher surface hydrophobicity and lower surface charge vs NPs. These modified characteristics facilitated the development of 0/W interfaces and smaller droplets by aggregates. Nevertheless, coalescence and flocculation were favoured in aggregate-based vs NP-based emulsions. The microfluidization process (70, 130 MPa) led to structure rearrangements within globulin aggregates, resulting in decreased protein particle size and hydrophobicity. The positive action of the new characteristics of microfluidized aggregates on emulsion stability, by reducing the flocculation and creaming phenomena, was more pronounced at the highest microfluidization pressure. Because of these enhanced inter-droplet interactions, the gel-like structure of the aggregate-stabilized emulsion was supposed to play a key role in this stability. Industrial relevance: Microfluidization or dynamic high pressure is a novel technology that could improve techno-functional properties of pea proteins after thermal aggregation. Microfluidization process at 70 MPA or 130 MPa broke large aggregates previously induced by the protein aggregation, and lead to new protein conformations. The new characteristics of microfluidized aggregates partly hinder the negative effect of thermal aggregation on the emulsion stability of aggregated proteins, especially when high microfluidization pressures were used (130 MPa). These findings will be of crucial importance for the development of pea protein-based oily formulations.