Edible Wax-Based Nanoparticles as Novel Stabilizers for Oil-in-Water Pickering Emulsion

Abstract

Edible solid lipid nanoparticles (SLNs) made of beeswax (BW) and propolis wax (PW) were applied to stabilize oil-in-water (O/W) emulsion. To produce emulsions, the optimum levels of SLNs-to-oil ratio (SOR), oil content, and homogenization speed were obtained based on minimum mean droplet size (D-4,D-3), span, and creaming index (CI). The influence of thermal treatment, pH, and ionic strength were investigated on the physical properties of optimal formulations in comparison with polysorbate 80 stabilized emulsion. The microscopic images demonstrated the presence of wax-based nanoparticles on the oil droplets surface. The long-term storage had no significant effect on D-4,D-3 of all produced emulsions. The conventional emulsion had the maximum CI (4.5), while PW and BW stabilized emulsions depicted a CI of 4.1 and 3.3 after 60-day storage, respectively. The conventional stabilized emulsion showed the highest peroxide value (2.7 meq O-2/kg oil) compared to Pickering ones (ca. 1.8 meq O-2/kg oil) at the end of 30-day storage.