Characterization of soy albumin based water-in-water emulsion and its application for entrapment of quercetin from onion peel waste

This study characterizes water-in-water (W/W) emulsions, consisting of two immiscible water phases formulated using soy albumin with locust bean gum, guar gum, or xanthan gum as sustainable alternatives to traditional emulsions reliant on synthetic stabilizers. The emulsions were tested at varying protein-polysaccharide ratios, the 60:40 ratio of soy albumin and LBG (SL-6) exhibited optimal properties, including the smallest particle size (0.250 ± 0.015 μm), lowest interfacial tension (1.531 ± 0.061 mN/m), and superior rheological behavior. Stability was observed over 0-52 h, with SL-6 showing the lowest decay rate constant (k = 15.120 s⁻¹). The Power Law model was applied to characterize the emulsions' non-Newtonian flow behavior, analyzing the consistency index (K) and flow behavior index (n). Emulsions exhibited higher R² values confirmed the model's accuracy in describing rheological properties. Microstructural analysis was conducted using confocal laser scanning microscopy. Further in this study, SL-6 was applied as a green solvent for entrapping quercetin from onion peel waste, showing equivalent entrapment and better bioavailability compared to conventional solvent-Ethanol. Thushighlighting the SL-6 emulsion's potential as an effective green solvent for quercetin entrapment, addressing the environmental and health risks associated with conventional solvent-based methods.