Stability of conventional vs. Pickering emulsions using ovalbumin-anionic starch complexes for spray-dried lipid microcapsules

The utilization of oils rich in polyunsaturated fatty acids can be enhanced by transforming them into spray-dried powdered microcapsules to inhibit oxidation. The functional characteristics of biopolymers, such as proteins and modified starch, may be combined to generate superior protective matrices in the form of stable emulsions. In this study, polyelectrolyte complexes of anionic starch (AS) and ovalbumin (OVA) at varying OVA/AS ratios (1:0, 0:1, 1:0.5, 1:1, 2:1, 3:1) were used to spray-dry and microencapsulate chia seed oil. AS and OVA interaction created viable polyelectrolyte complexes when turbidity was measured at varying OVA/AS ratios across pH 1-10. Higher AS to OVA ratios improved antioxidant properties, wettability (74.9°-84.1°), hydrophobicity (288.67 ± 6.06 μg/g-1980 ± 8.78 μg/g), and emulsification. Moreover, the microcapsules showed the highest encapsulation efficiency (83.94 ± 1.05 %), total oil contents (68.90 ± 0.50 %), and the lowest surface oil (11.06 ± 1.37 % at 1:1 OVA) using complexes for Pickering emulsions through homogenization and spray drying. These microcapsules demonstrated reduced peroxide values after 30 d of storage at 50 °C (56.27 ± 0.68 meqO₂/kg), 80 % humidity (84.37 ± 0.68 meqO₂/kg), or light (54.84 ± 0.71meqO₂/kg) compared to OVA-stabilized emulsion microcapsules. OVA/AS polyelectrolyte complex-stabilized Pickering emulsions may facilitate the production of stable oil microcapsules for food applications.