Optimization of Oleofoam and Protein-Polysaccharide Ratios for Enhanced Physicochemical Characteristics of A/O/W Double Emulsion: Potential Applications in the Food Industry

Preparing air-in-oil-in-water (A/O/W) double emulsion involves two key steps: oleofoam formation and dispersion of the oleofoam in an aqueous solution containing protein as an emulsifier and hydrocolloid as a thickening agent. This study aimed to investigate the effect of oleofoam level and varying concentrations of protein-polysaccharide ratios on the thermal stability, encapsulation yield and rheological properties of A/O/W double emulsion. An oleofoam was obtained using a lipophilic emulsifier (distilled monoglyceride MG) and sunflower oil at 5°C with maximum stability. Two levels of oleofoam (20% and 25 wt %) were added to an aqueous solution containing different concentrations of sodium caseinate (SC) (5, 8, and 10 wt %) and kappa carrageenan (KC) (0.4 and 0.8 wt %). Results indicate that oleofoam level did not significantly affect air encapsulation efficiency and particle size, while protein-polysaccharide ratios could significantly impact all properties of A/O/W double emulsion. Increasing the concentration of sodium caseinate and kappa carrageenan improved thermal stability and encapsulation yield while simultaneously reducing particle size. All A/O/W emulsions exhibited shear thinning behavior among the range of shear rates studied, indicating significant potential for food applications.