Characterization of carvacrol incorporated antimicrobial film based on agar/konjac glucomannan and its application in chicken preservation

The objective of this study was to fabricate and characterize antimicrobial films based on Agar/Konjac glucomannan (KA) incorporated with carvacrol (CV) (1%, 1.5% and 2%). The physical, structural and antimicrobial properties were studied to evaluate the effects of carvacrol on the composite films. Results indicated that the addition of 2% CV markedly enhanced the tensile strength (36.72 MPa), elongation at break (100.19%), hydrophobic properties and UV barrier properties compared with KA film. X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy indicated good compatibility and the formation of intermolecular hydrogen bonds. Additionally, the addition of 2% CV showed strong antimicrobial activities against the most common food spoiling bacteria, Staphylococcus aureus and Escherichia coli. Finally, the potential application of the films was evaluated by the packing test of chicken, where KA-2% CV was able to prolong the shelf life of refrigerated chicken breast from 5 days to 9 days. Overall, the composite films incorporating 2% carvacrol was a promising antimicrobial packing material to displace petrochemical-based plastics to extend the shelf life of foods.