EFFECT OF LAURIC ACID AND WHEAT GLUTEN ON CHEMO-PHYSICAL AND MECHANICAL PROPERTIES OF ZEIN-BASED EDIBLE FILMS

In this study, the effect of lauric acid and wheat gluten on physico-chemical and mechanical properties of zein-based edible films was studied. Edible films based on thermoplastic zein containing different amount of lauric acid and wheat gluten were obtained through two step procedures: melt mixing and subsequent compression molding. Results highlighted that the addition of lauric acid brought about an increase in tensile modulus and maximum stress and a decrease of water vapor permeability of zein-based edible films. This behavior can be attributed to the increase of the hydrophobic character of the produced films. On the other hand, the addition of wheat gluten induced a reduction of water vapor permeability without affecting their mechanical properties. The best compromise between barrier and mechanical properties was observed for the thermoplastic zein-based films containing 11% and 15% of lauric acid and wheat gluten, respectively.