Effect of xanthan/enzyme-modified guar gum mixtures on the stability of whey protein isolate stabilized fish oil-in-water emulsions.

The effect of xanthan gum (XG) and enzyme-modified guar (EMG) gum mixtures on the physicochemical properties and oxidative stability of 2wt% whey protein isolate (WPI) stabilized oil-in-water (O/W) emulsions containing 20%v/v fish oil was investigated. EMG was obtained by hydrolyzing native guar gum using α-galactosidase enzyme. At higher gum concentrations (0.2 and 0.3wt%), the viscosity of the emulsions containing XG/EMG gum mixtures was significantly higher (P<0.05) of all emulsions. Increasing concentrations (0-0.3wt%) of XG/EMG gum mixtures did not affect the droplet size of emulsions. Microstructure images revealed decreased flocculation at higher concentrations. Primary and secondary lipid oxidation measurements indicated a slower rate of oxidation in emulsions containing XG/EMG gum mixtures, compared to XG, guar (GG), and XG/GG gum mixtures. These results indicate that XG/EMG gum mixtures can be used in O/W emulsions to increase physical and oxidative stabilities of polyunsaturated fatty acids in foods.