Effects of Sorbic Acid-Chitosan Microcapsules as Antimicrobial Agent on the Properties of Ethylene Vinyl Alcohol Copolymer Film for Food Packaging.

Abstract

This paper discusses the possibility of using sorbic acid-chitosan microcapsules (S-MPs) as an antibacterial component of active ethylene vinyl alcohol copolymer (EVOH) film. S-MPs with a diameter of approximately 1 to 4 μm showed a sorbic acid loading capacity of 46.5%. Addition of S-MPs (3%, w/w) increased the tensile strength, haze, oxygen, and water vapor barrier properties, as well as reduced the elongations at break and transmittance of S-MPs-EVOH (S-MP-EVOH) film. Antibacterial tests showed that the inhibitory capacity of S-MP-EVOH film against Salmonella Enteritidis and Escherichia coli was higher than that against Listeria monocytogenes. Moreover, the antibacterial effect of sorbic acid-EVOH (S-EVOH) film was stronger than that of S-MP-EVOH film. However, S-MP-EVOH film demonstrated a longer effective time than S-EVOH film. Using the total viable counts and total volatile base nitrogen as the judgment standard, S-MP-EVOH/polyethylene terephthalate (PET) composite film could extend the shelf life of fish fillets by 4 d at 4 °C, compared with EVOH/PET film. For this reason, S-MP could be a potential antibacterial component of active films.