Interfacial effects of gallate alkyl esters on physical and oxidative stability of high fat fish oil-in-water emulsions stabilized with sodium caseinate and OSA-modified starch

Effects of sodium caseinate (SC) and its combination with OSA-modified starch (SC-OS; 1:1) alone and with n-alkyl gallates (C0-C18) on the physical and oxidative stability of high-fat fish oil-in-water emulsion were evaluated. SC emulsion contained the smallest droplets and highest viscosity due to the fast adsorption at droplet surfaces. Both emulsions had non-Newtonian and shear-thinning behavior. A lower accumulation of lipid hydroperoxides and volatile compounds was found in SC emulsion due to its better Fe2+ chelating activity. The incorporated short-chain gallates (G1 > G0 similar to G3) in SC emulsion had a strong synergistic effect against lipid oxidation compared to that of SC-OS emulsion. The better antioxidant efficiency of G1 can be related to its higher partition at the oil-water interface, while G0 and G3 had a higher partition into the aqueous phase. In contrast, G8, G12, and G16 added emulsions indicated higher lipid oxidation due to their internalization inside the oil droplets.

Automated summary

The effects of sodium caseinate (SC) and its combination with OSA-modified starch (SC-OS; 1:1) on the physical and oxidative stability of high-fat fish oil-in-water emulsion were studied. The SC emulsion had smaller droplets and higher viscosity due to fast adsorption. Both emulsions exhibited non-Newtonian and shear-thinning behavior. SC emulsion showed lower lipid oxidation due to better Fe2+ chelating activity. Short-chain gallates (G1 > G0 similar to G3) in SC emulsion had a synergistic effect against lipid oxidation, while G8, G12, and G16 added emulsions showed higher lipid oxidation due to internalization.