ScholarWorks@중앙대학교

초록

This study aimed to develop alternative packaging materials by coating polyethylene terephthalate (PET) with antimicrobial substances (glucose oxidase and potassium sorbate) and confirming antimicrobial and antibiofilm activity of the coated PET. Before examining the antimicrobial activity of coated PET, attenuated total reflectance–Fourier-transform infrared spectroscopy was conducted to ensure that glucose oxidase and potassium sorbate were present and generously coated on the PET samples. The graph peaks indicated the conjugated interaction of glucose oxidase with potassium sorbate on the chitosan-based PET surface. At 4 × MIC, glucose oxidase–coated PET reduced E. coli biofilm on shrimp by 2.9 log CFU/g at 10 °C and 3.1 log CFU/g at 25 °C, and on beef by 2.6 log CFU/g at 10 °C and 1.5 log CFU/g at 25 °C, relative to untreated controls. Potassium sorbate–coated PET achieved reductions of 2.9 and 3.1 log CFU/g on shrimp, and 2.9 and 1.9 log CFU/g on beef at 10 and 25 °C, respectively. Notably, the combination-coated PET exhibited the greatest antibiofilm efficacy, reducing E. coli by 2.9 and 3.1 log CFU/g on shrimp and 3.7 and 3.8 log CFU/g on beef at 10 and 25 °C, respectively. The inhibitory effect of combination treatment with glucose oxidase and potassium sorbate against E. coli biofilm was visually confirmed using confocal laser scanning microscopy and field-emission scanning electron microscopy. Moreover, reverse transcription polymerase chain reaction analysis revealed that glucose oxidase and potassium sorbate could inhibit quorum sensing- and virulence-related gene (luxS, pdfs, and rpoS) expression in E. coli. Therefore, this study confirmed that combination treatment with glucose oxidase and potassium sorbate effectively reduces E. coli biofilms, thus increasing food safety.

키워드