Characterization and antimicrobial properties of food packaging methylcellulose films containing stem extract of Ginja cherry

BACKGROUND: Food contamination and spoilage is a problem causing growing concern. To avoid it, the use of food packaging with appropriate characteristics is essential; ideally, the packaging should protect food from external contamination and exhibit antibacterial properties. With this aim, methylcellulose (MC) films containing natural extracts from the stems of Ginja cherry, an agricultural by-product, were developed and characterized. RESULTS: The antibacterial activity of films was screened by the disc diffusion method and quantified using the viable cell count assay. The films inhibited the growth of both Gram-positive and Gram-negative strains (Listeria innocua, methicillin-sensitive Staphylococcus aureus, methicillin-resistant S. aureus, Salmonella Enteritidis, Escherichia coli). For the films with lower extract content, effectiveness against the microorganisms depended on the inoculum concentration. Scanning electron microscope images of the films showed that those containing the extracts had a smooth and continuous structure. UV-visible spectroscopy showed that these materials do not transmit light in the UV. CONCLUSION: This study shows that MC films containing agricultural by-products, in this case Ginja cherry stem extract, could be used to prevent food contamination by relevant bacterial strains and degradation by UV light. Using such materials in food packaging, the shelf life of food products could be extended while utilizing an otherwise wasted by-product. © 2013 Society of Chemical Industry.