Effect of Different Formulations on Mechanical and Physical Properties of Calcium Alginate Edible Films

Background: Environmental problems of the plastic materials used in food packaging and the demand for food quality improvements lead to the development of packaging in natural materials. Edible films such as calcium alginate extend the shelf life by acting as a selective barrier against moisture and oxygen. The main objective of this study was to explore a calcium alginate based edible film to improve the quality and extend the shelf life of food products.  Methods: Tests of physical properties including water vapor permeability (WVP) and oxygen transmission rate (OTR) and mechanical properties including tensile strength (TS) and elongation at break (E) of two calcium alginate based formulations (dextrose monohydrate based and maltodextrin based) were done in triplicate. Data were investigated using SPSS (16.0). Significant differences in the results were detected by the Mann-Whitney U test.  Results: There was no significant difference in mechanical properties and WVP of these two formulations, though WVP values related to the dextrose monohydrate based formulation were slightly higher than those of the maltodextrin based formulation. A significant decrease was observed in OTR of the maltodextrin based formulation compared to the dextrose monohydrate based formulation.  Conclusion: There was no significant difference in mechanical properties (TS and E) and WVP between these two formulations however, a significant reduction was observed in OTR of the maltodextrin based formulation compared to the dextrose monohydrate based formulation. Therefore, the last was more suitable as a barrier to oxygen.