Plant protein microgels as novel stabilizers for oil-in-water emulsions

Plant-based protein alternatives have attracted great attention due to their health and environmental benefits; however, compared to animal proteins, plant proteins generally have poor surface activities. This work demonstrated that microgels from lentil, soy and fava bean protein have strong capacity to stabilize emulsions.

The plant microgels were prepared by the biopolymer phase separation mechanism by heating the protein-polysaccharide mixture. This method, characterized by low energy requirements, absence of toxic organic solvents, and simplicity in equipment, presents a promising avenue for the large-scale production of plant protein microgels.

Additionally, plant protein microgels with different sizes had been studied to stabilize the emulsion with varying protein and oil concentrations. Compared to the untreated proteins, microgels exhibited a significant enhancement in emulsion stability at the same protein concentrations. Confocal laser scanning microscopy images illustrated that the microgels could absorb at the oil-water interface, forming Pickering emulsions and effectively stabilize emulsions with 10%-50% oil over a long period of time. In addition, some microgels were dispersed in the continuous phase, stabilizing the emulsions by gelling effects. Moreover, the microgels demonstrated to improve emulsion texture by replacing fat globules in model food systems. This research has provided a strategy to improve emulsifying properties of plant proteins for their wide applications in food formulations to create stable and healthy low-fat food products.