Antimicrobial activity and mechanism of ferulic acid in combination with UV-A light against Escherichia coli and its application on chicken preservation

More attention has been paid to developing new antibacterial drugs from natural products due to antibacterial resistance. Ferulic acid (FA) is a natural phenolic acid with demonstrated antimicrobial effects. However, its bactericidal activity is insufficient to achieve a rapid bacteria reduction in a short time. This study demonstrates the antimicrobial activity and synergistic interaction of FA in combination with ultraviolet A (UV-A) against Escherichia coli (E. coli) . The synergistic activity against E. coli was concentration and time-dependent. A set of associated changes in cellular functions of E. coli including membrane integrity, cell membrane permeability and DNA damages were measured. Morphologically, the treated cells exhibited a bacterial membrane and DNA dysfunction. Furthermore, the photostability and photochemical pathway of FA upon UV-A exposure was investigated. A rapid photochemical degradation of FA upon UV-A irradiation was observed due to the photoisomerization process of FA. Type II reaction was assumed as the main photochemical pathway as evidenced by the actions of different quenching agents. Antibacterial activity of FA + UV-A was also tested on chicken breast meat. A reduction of the loads of E. coli bacteria on chicken and good maintenance of its quality was achieved. This combination of methods helps to reduce the use of chemical food preservatives and provide new ways to control pathogenic microorganisms in food industry.