The effect of edible films and coatings with differentcomponents on microbial inactivation

Edible films and coatings are effective against microbiological degradation caused by food-borne microorganisms. Edible films and coatings have some advantages over normal packaging materials. Edible films are organic biopolymer based materials. These fine materials are used as a coating on the surface of the food and used to protect the food against external influences. In this study, the antimicrobial effects of edible cellulosic films prepared with β-carotene, hesperidin and propolis against Staphylococcus aureus and Escherichia coli, which are important food pathogens, were evaluated directly under artificial storage conditions with artificial contaminated food samples. Fresh white cheese samples from semi-hard traditional Turkish cheeses were used for artificial contamination. Antimicrobial activity of β-carotene, hesperedin and propolis was measured by the paper disc method. The antimicrobial activity of cellulose-based edible films containing antimicrobial agent was measured by the modified agar diffusion method. The antioxidant determination with the DPPH radical and the total amount of phenolic substance were tested. The reduction capacities of the different film compositions formed in the coating processes on E. coli and S. aureus levels were similar. However, it was determined that hesperidin sprayed films showed E.coli growth and carotene sprayed films showed antimicrobial effects on S. aureus growth. The growth of both bacterial species has been high in the presence of 20% propolis (> %50). Cellulosic based edible antimicrobial films have shown more antimicrobial effects and more bacterial growth inhibition than potassium sorbate, which is used today as a preservative. With this advanced packaging technology, food safety can be ensured, shelf life of the product can be extended and food losses in this sector can be reduced. Keywords: Edible cellulosic based film, ß-carotene, Hesperidin, Propolis, Antimicrobial activity, Fenolic compound.