Development and characterization of water-in-water emulsion using pea protein and different gums

Water-in-water (W/W) emulsions are gaining attention for their potential applications in food and nutrition due to their unique properties, including biocompatibility and stability. However, achieving stable W/W emulsions remains challenging, requiring a careful combination of biopolymers. The present study aimed to formulate W/W emulsion using a combination of protein and polysaccharide phases. Pea protein (P) was considered for the protein phase, and locust bean gum (LBG), guar gum (GG), xanthan gum (XG) were considered for the polysaccharide phase. The protein-polysaccharide phases were mixed in 10:90, 20:80, 80:20, and 90:10 ratios to create nine W/W emulsion combinations for Pea protein-Locust bean gum (PL), Pea protein-Guar gum (PG), and Pea protein-Xanthan gum (PX) each. These 27 emulsion combinations were then characterized based on their particle size, interfacial tension, phase separation, microstructure, and rheological properties. PL-6 (60:40 ratio) exhibited the smallest particle size (0.1891 ± 0.0113 μm), lowest interfacial tensions (1.78 ± 0.071 mN/m), and superior rheological properties. The emulsion phase separation study showed that the process followed the Exponential decay model, with PL-6 having the lowest decay rate constants (k = 17.640 s⁻¹). The microstructure of the emulsions was revealed through Confocal laser scanning microscopy analysis. The results concluded that PL-6 emulsion proved highly effective for formulating a stable W/W emulsion. This research opens new possibilities for using such emulsions in various applications, particularly in food and nutritional security.