Influence of Oil Content and Different Stabilizers on Microstructure and Rheological Characteristics of Food Emulsions Based on Beans Aquafaba

In this study, beans aquafaba was used as the emulsifying agent for oil-in-water (o/w) emulsions with sunflower oil concentrations of 30% and 60%. The primary approach to stabilizing such emulsions is by increasing their viscosity through the incorporation of selected polysaccharides. For this purpose, xanthan gum or pregelatinized corn starch were added as stabilizers. The effects of oil content and different stabilizers on the microstructure and rheological properties were evaluated using laser diffraction and rotational viscometry. A pre-optimized seed-to-water ratio of 1:1.5 yielded beans aquafaba with a protein concentration of 0.5%. Further evaporation was used to increase the protein content to 0.8%. The aquafaba-based emulsion samples exhibited a bimodal particle size distribution. An increase in both oil and xanthan gum content had minimal impact on the mean volume diameter of emulsion particles, whereas the addition of pregelatinized corn starch significantly increased this value. All emulsions exhibited pseudoplastic flow behavior. The flow curves were approximated using the power-law and Herschel–Bulkley models. The calculated dynamic yield shear stresses consistently increased with increasing content of both oil and stabilizer in the range from 0.3 to 5.0 Pa. It is worth noting that in emulsions with an oil content of 30%, the addition of xanthan gum had a significant impact on this indicator, while in emulsions with an oil content of 60%, the addition of pregelatinized corn starch had a greater impact. Consequently, higher concentrations of the selected polysaccharides led to the formation of more viscous systems exhibiting enhanced stability. The developed food emulsions based on beans aquafaba are a promising technology in the development of vegetarian products.