Fabrication of Quercetin-Loaded Biopolymer Films as Functional Packaging Materials

Three functional packaging films were prepared by adding quercetin into three different polymers, carboxymethyl cellulose (CMC), gelatin, and poly(lactic acid) (PLA). Quercetin was more compatible with CMC compared to gelatin and PLA. The mechanical strength of the CMC film improved while it decreased for the gelatin and PLA films on the incorporation of quercetin. The addition of quercetin completely blocked the UV transmission of the biopolymer films while reducing some transparency. The release of quercetin depended on the food simulant solution, polymer type, and temperature, and it was highest for the gelatin/quercetin film in 50% ethanol at 25 °C. The quercetin-added films showed antioxidant and antibacterial activities subject to the release rate of quercetin. The CMC/quercetin and gelatin/quercetin films showed significant inhibition function on Listeria monocytogenes and Escherichia coli.