The influence of different emulsifiers on dotted gizzard Shad (Konosirus punctatus) oil emulsions

This study investigates the effects of chitosan quaternary ammonium salt (HACC), carrageenan (CA), and lecithin (LC) on soy protein isolate (SPI). SPI is a widely used natural emulsifier but is highly susceptible to environmental perturbations; the incorporation of additional bioactive components can modulate its structural integrity and functional stability. For the first time, the physicochemical properties, microstructure, and in vitro digestibility of previously reported SPI complexes were compared. The results indicated that the introduction of polysaccharides and phospholipids endowed SPI with additional hydrogen bonds and electrostatic interactions, leading to pronounced alterations in its properties and conformation. Notably, the SPI-HACC fish oil emulsion exhibited superior physicochemical characteristics and enhanced structural stability. Moreover, during storage, the peroxide values of the SPI-HACC fish oil emulsion remained below industry thresholds, effectively extending the product's shelf life. This study demonstrates that SPI-HACC complexes hold considerable potential for application in fish oil encapsulation and delivery systems.