Assembling soy protein-propylene glycol alginate binary nanocomposite particles via transacylation reaction to stabilize high-oil-phase curcumin-loaded emulsions: Influence of gel network

To make the emulsion more stable under complex environments, a novel emulsifier, soy protein isolates (SPI)-propylene glycol alginate (PGA) binary nanocomposite particles (SPIP_n), was synthesized using a transacylation reaction. The findings revealed that SPIP_n formed when the carboxyl groups in PGA and the amino groups in SPI were covalently bonded, facilitated by various forces. SPIP_n-2:3 was identified as the most suitable emulsifier for the subsequent preparation of curcumin-loaded emulsions and could emulsify emulsions with an φ as low as 0.5 to form emulsion gels. Moreover, an increase in the φ value strengthened the gel network structure, leading to enhanced macroscopic viscosity, elasticity strength, and creaming stability. Furthermore, the emulsion with an φ of 0.6 retained up to 96 % and 99 % of curcumin after storage for 30 days and irradiation for 720 min, respectively. This study could provide a simple and convenient method to improve food product stability.