Preparation and Evaluation of Physico-Mechanical Gluten Film and its Comparison with Low Density Poly Ethylene Film

The packaging and food industries are now more than ever joining efforts to reduce the amount of food packaging and to use biodegradable materials as an environmentally-friendly alternative to the synthetic polymers for cost effectiveness as well as environmental reasons. The aim of this research is to compare the physical and mechanical properties of gluten edible films to the low density poly ethylene films (LDPE).
Gluten edible films containing different concentrations of glycerol (1.5, 3 and 5 % wt) were prepared by the ordinary mixing as well as the ultra-sound system. The films were evaluated for the elongation at break and tensile strength and compared with LDPE films.
The application of ultrasound for preparation of the samples did not have significant effect on the mechanical and barrier properties of them. The effect of freezing on the mechanical properties of gluten film revealed that freezing led to an increase in the tensile strength and elongation at break up to 75 and 300%, respectively. The results of mechanical tests of gluten films, when compared to the LDPE film, indicated that gluten films characteristics were comparable to the petroleum source films, especially at 3% weight of glycerol content.
The oxygen permeability of the gluten films showed that because of having low oxygen permeability as compared to LDPE film, gluten film can be used as a strong oxygen barrier for packaging industries. Moreover, being edible and environmentally friendly film, it can be applied as effectively controlled-permeation packaging in order to prevent the decay of food products.