Preparation and Investigation of Antimicrobial Biodegradable Edible Film Based on Corn Starch

Edible, biodegradable films, by acting as barriers to control the transfer of moisture, oxygen, lipids, and flavours, can prevent quality deterioration and increase the shelf life of food products. On the other hand, regarding edible film capacity in transferring food additives, extending shelf-life of food products could be considered. So by adding antimicrobial-antioxidants compounds, the possibility of prevention of pathogenic microorganisms will be provided. Composite edible films based on corn starch different concentrations of Zataria multiflora Boiss and Mentha pulegium (1,2,3%) were prepared by emulsification with the aim of improving the mechanical, water barrier and microbial properties. Data were analyzed using the SAS for Windows program. The mechanical properties were influenced by adding essential oils as tensile strength decreased and elongation increased significantly. This was more evident in case of Zataria multiflora essential oil. The properties of these film in relation to their structure were observed by scanning electron microscopy (SEM). SEM observation confirmed the presence of essential oil in both the internal and surface parts of the films which explained decreasing water barrier properties of films containing lipidic compounds. Results show that essential oil can have important role in application of these film for food technology. Therefore, essential oil could be incorporated into these films for some food-technology applications that need a low affinity toward water.