THE EFFICACY OF NATURAL PLANT ANTIMICROBIALS AGAINST ESCHERICHIA COLI

Abstract

The number of foodborne disease outbreaks related to fresh produce has increased in recent years. This has coincided with a growing public demand for minimally processed fruits and vegetables. Effective produce sanitizers are therefore needed that are at least as effective as chlorine, currently the most commonly used sanitizer. Natural antimicrobials from plant extracts and essential oils are a possible alternative. These are highly effective and may also be used in situations in which chlorine is not advantageous; for instance, in situations in which chlorine has limited efficacy or because of concerns over the production of harmful by-products resulting from chlorine use. Plant derived essential oils have been shown to be antibacterial, antiviral, and antifungal. In this study we examined the use of natural antimicrobials from plant extracts and essential oils as possible alternative sanitizers. We examined these antimicrobials for their efficacy against Escherichia coli. In addition, since many of these natural compounds are believed to be membrane active, silver ions were added to some of the tests to assess the potential for synergy between the antimicrobials. Silver ions, although slow-acting on their own, often exhibit a synergistic antimicrobial effect when combined with other membrane active antimicrobials such as oxidizing agents. These studies reveal that plant derived antimicrobials are effective sanitizers with the potential to replace commonly used chlorine