Physicochemical properties of fish oil in water multilayer emulsions prepared by a mixture of whey protein isolate and water-soluble fraction of Farsi gum

Physicochemical properties and storage stability of fish oil (FO) in water multilayer emulsions, stabilized with different mixtures of whey protein isolate (WPI) and water-soluble fraction of Farsi gum (WSFG), were studied under the effects of total biopolymer concentration (TBC), WSFG:WPI mixing ratio (MR) and pH for 1 month. pH reduction decreased the surface potential of dispersed droplets; however, an increase in the WSFG:WPI MR (at constant pH values corresponding to electrostatic interactions) significantly increased the absolute values of surface potential and hence the physical stability of emulsions. An increase in TBC increased droplet size and emulsion viscosity. The emulsion viscosity was also positively correlated with WSFG:WPI MR. During storage, higher values of TBC and WSFG:WPI MRs led to lower absorbance values. An increase in the WSFG:WPI MR and TBC significantly retarded the oxidation of emulsified FO. •Formation of physically stable emulsions at pH values close to the pI of protein•An increase in the WSFG:WPI MR increased the physical stability of emulsions.•Lipid oxidation decreased by increasing WSFG:WPI MR and TBC.