ANTIOXIDANT AND ANTIMICROBIAL EFFECTIVENESS OF CATECHIN-IMPREGNATED PVA-STARCH FILM ON RED MEAT

A biodegradable polyvinyl alcohol (PVA)-starch film was fabricated for use as a packaging film with added antioxidant and antimicrobial properties. PVA-starch films were impregnated with catechins extracted from green tea. The catechins were identified and quantified by HPLC, and the antioxidant and antimicrobial characteristics of the packaging film were examined using thiobarbituric acid-reactive substance values and cell count methods. The results showed that tensile strength and elongation decreased with increasing amounts of incorporated constituents. In a model study, the inclusion of catechins at a level of 1,000 ppm inhibited the growth of airborne microorganisms, and antioxidant capacity in cooking oil was clearly reached when 500 ppm catechins were incorporated into the film. In a feasibility test, a level of 1,000 ppm was found to be sufficient for effective antioxidant and antimicrobial activities of raw beef at refrigeration temperatures. The results suggest that a PVA-starch film with catechins incorporated may be beneficial for maintaining food quality through its antioxidant and antimicrobial activities. PRACTICAL APPLICATIONS Certain phytochemicals have both antioxidant and antimicrobial activities, and could be incorporated into packaging films for quality retention. Therefore, the use of catechin into a biodegradable film composed of polyvinyl alcohol and starch should be beneficial to assure quality and to be environment friendly. The active film developed in this study can be used as a home-use wrap for fresh meat products, such as red meat, poultry or seafood, as these products are very susceptible to oxidation and microbial growth.