Property Modification of Edible Wheat, Gluten-Based Films

Procedures were developed to produce edible wheat, gluten-based films. A film was produced as a standard. Five additional films were then produced by modifying the initial film-forming solution. Modifications included changing the plasticizer, partially substituting wheat gluten with soy protein isolate and corn zein, and incorporating two acetylated monoglyceride products. All films were characterized by measuring selected mechanical properties, and permeabilities to water vapor and to oxygen. Comparison of the films, in terms of their measured properties, indicates ways to improve the overall performance of the standard film as a potential packaging material. A main limitation of all of the films was their poor water vapor barrier characteristics. On the other hand, they were very good oxygen barriers. All modified films were stronger than the standard in terms of tensile and bursting strength. The film containing soy protein was the strongest and the most uniform. Significant differences in measured properties were observed when the plasticizer was changed from glycerin to triethylene glycol.