Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/21/2010
Publication Date: 3/3/2011
Citation: Du, W., Olsen, C.W., Avena Bustillos, R.D., Friedman, M., Mchugh, T.H. 2011. Physical and antibacterial properties of edible films formulated with apple skin polyphenols. Journal of Food Science. 76(2):149-155. doi: 10.1111/j.1750-3841.2010.02012.x.
Interpretive Summary: The results of the present study show that apple skin extracts can be used to prepare apple-based antimicrobial edible films with good water barrier and stretch strength properties for food applications by direct contact.
Technical Abstract: Fruit and vegetable skins have polyphenolic compounds, terpenes, and phenols with antimicrobial and antioxidant activity. These flavoring plant essential oil components are generally regarded as safe (GRAS). Edible films made from fruits or vegetables containing apple skin polyphenols have the potential to be used commercially to protect food against contamination by pathogenic bacteria. The main objective of this study was to evaluate physical properties as well as antimicrobial activities against Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella enterica of apple skin polyphenols at 0-10% (w/w) concentrations in apple puree film forming solutions (APFFS) formulated into edible films. Commercial apple skin polyphenol powder had a water activity of 0.44 and high total soluble phenolic compounds and antioxidant capacity (995.3 mg chlorogenic acid/100 g and 14.4 mg Trolox/g, respectively). Antimicrobial activities of edible film containing apple skin polyphenols were determined by the overlay method. Apple edible film with apple skin polyphenols was highly effective against Listeria monocytogenes. The minimum concentration need to inactive Listeria monocytogenes was 1.5%. However, apple skin polyphenols did not show any antimicrobial effect against E. coli O157:H7 and Salmonella enterica even at 10% level. The presence of apple skin polyphenols reduced water vapor permeability of films. Apple skin polyphenols increased elongation of films and darkened the color of films. The results of the present study show that apple skin polyphenols can be used to prepare apple-based antimicrobial edible films with good physical properties for food applications by direct contact.