Study of the Encapsulation Efficiency and Controlled Release Property of Whey Protein Isolate--Polysaccharide Complexes in W1/O/W2 Double Emulsions

The complexes of whey protein isolate (WPI) with guar gum (GG) or gum arabic (GA) were used to prepare water-oil-water double emulsions. Lipid-soluble vitamin E (VE) and water-soluble vitamin B2 (VB2) were encapsulated together in these two systems. The abilities of these complexes to control the release rates were compared. When the ratio of WPI/polysaccharides increased from 5:0.1 to 5:0.5, the encapsulation efficiency (EE) of VE increased from 73 to 88 percent, and EEVB2 from 61 to 68 percent in WPI-GG system; whereas only minor changes were in both EEVE and EEVB2 in WPI-GA system. In the controlled release study, WPI-GG complexes showed better resistance to the attack of the enzymes than WPI-GA complexes did. These phenomena were attributed to the formation of compact aggregates promoted by electrostatic effects.