COMPARISON OF OXYGEN AND WATER-VAPOR PERMEABILITIES OF WHEY-PROTEIN ISOLATE AND BETA-LACTOGLOBULIN EDIBLE FILMS

Oxygen permeability (OF) and water vapor permeability (WVP) of whey pr otein isolate (WPI) and beta-lactoglobulin (beta-Lg) edible films were studied at three different levels of glycerol content. WVP and OP of WPI films were not statistically different from WVP and OP of beta-Lg films. Although the presence of glycerol as plasticizer could have mas ked some differences between beta-Lg and WPI films, beta-Lg appears to contribute to the barrier properties of the protein matrix of WPI in a manner similar to the other whey protein fractions. Temperature had an exponential effect on the OP of WPI and beta-Lg films. Results fitt ed the Arrhenius model with activation energies in the 10.5-13.5 kcal/ mol range.