Chemical Free Sanitizers to Prevent E. Coli Contamination and Reduce Food Waste

Background

Avoiding E. coli contamination in beef packing plants is essential not only from a food safety standpoint but also to prevent food waste. E. coli contamination can result in beef products being thrown out, massive recalls, decreased consumer confidence in the beef industry, and a lower demand for beef products. Although current food safety practices are highly effective at preventing E. coli contamination researchers have found that some bacteria can form biofilms that enable them to survive even the most rigorous cleaning procedures. Biofilms are a collection of bacteria that build up and bond together, making them harder to remove. Biofilms aren’t just a problem in the beef industry; for example, dental plaque is a common biofilm.

Objectives

• To evaluate the potential of atmospheric cold plasma (ACP) activated air, ACP activated water nano-mist, and light emitting diode (LED) technologies as alternative sanitizers for inactivating E. coli on surfaces and in biofilms.

What They did

Researchers developed biofilms of bacteria (Escherichia coli) on food grade stainless steel and high density polystyrene to mimic commercial packing plant surfaces, personal equipment surfaces and conveyers and tested 4 different technologies to determine how effective they are at inactivating bacteria in biofilms. Atmospheric cold plasma is a gas (can be anything from helium to just regular air) that is ionized (activated) to give it antimicrobial properties and allows it to break up biofilms without the use of additional chemicals. Both ACP activated air and water mist have been tested. Since the ACP activated water is applied as a mist it has the potential to greatly reduce the amount of water plants use to clean surfaces. Researchers have also tested UV light pulses (Ultraviolet (UV-C) light and blue light) emitted from LEDs to inactivate biofilms.

What They learned

Overall, this study shows the huge potential of all the four technologies i.e., UV light pulses emitted from LED, ACP and ACP water mist treatments on the inactivation of bacterial biofilm on food contact surfaces. The UV-C light treatment was more effective than the blue light treatment in inactivating the biofilms. For example, the UV-C light treatment reduced the biofilm on polystyrene surfaces by more than 99.9% after 2 min of treatment compared to more than 90% after 2 min of blue light treatment. The biofilm inactivation efficacy of ACP water mist treatment was more than the ACP treatment. For example, the ACP water mist treatment reduced the biofilm on food contact surfaces by more than 99% after 1 min of treatment compared to more than 90% after 1 min of ACP treatment. These tested novel technologies have commercialization potential and future studies may focus on the scale-up of these technologies.

What it means

This study provided an understanding of the potential of 4 technologies (ACP, ACP activated water mist, and LED (UV-C and blue light pulses)) in reducing biofilm on the surfaces of meat packing facilities, as green sanitizers. Future studies are required to scale-up these technologies for commercial application.