A deeper insight into the characteristics of double-layer oil-in-water emulsions stabilized by Persian gum and whey protein isolate

Whey protein isolate (WPI) is an excellent emulsifier. However, WPI-stabilized emulsions tend to flocculate at pH values close to their isoelectric point. In this work, a layer by layer (LBL) technique was used to develop double layer oil in water emulsions using a mixture of WPI and water-soluble fraction of Persian gum (WSPG). Polysaccharide concentration and pH were found to have a major impact on the stability of the final system. At a constant total biopolymer concentration, increasing the amount of WSPG significantly (p E″), at the interface especially at pH 5.0. The results showed that WSPG is an appropriate candidate for improving the physical stability of WPI-stabilized emulsions at pH values close to isoelectric point.