During the last decades, food safety became a major concern for producers, consumers, and governments. Food safety implies that food products need to be safe in a chemical, physical, and microbiological way. With respect to microbiological safety, the occurrence of foodborne pathogens in food products can be a real threat for human health. Contamination of food products can occur at different stages of the production process; e.g., during cultivation/breeding, harvesting/slaughtering, processing, and storage. In the processing plant, food contact surfaces are a primary area of concern as contamination sources.

Currently, disinfection processes involve rinsing with (hot) water and antimicrobial agents, together with a mechanical action. However, this has some important drawbacks. First of all, it has become clear that human pathogens, i.e., Salmonella spp., and Listeria monocytogenes, grow predominantly as biofilms on a variety of biotic and abiotic surfaces, rather than in planktonic forms or as colonies. Biofilm-associated cells exhibit higher resistance to antimicrobial agents due to different defence mechanisms. One of those mechanisms is the production of extracellular polymeric substances (EPS), forming a physical barrier that limits the diffusion of antimicrobial agents. Since most of the implemented disinfection processes are based upon their potential to inactivate planktonic cells, they can be highly ineffective when applied to inactivate biofilms. Secondly, the residues of antimicrobial agents can be toxic and alter the sensory values of food products.

Since the current inactivation methods are not efficient, new methods need to be investigated for the inactivation of biofilms grown on biotic and abiotic surfaces. Cold atmospheric plasma and light at different intensities and wavelengths are nonthermal, emerging antimicrobial decontamination technologies. These technologies have a great potential for application in the food industry; for decontamination of surfaces and pieces of equipment, as well as for fresh vegetables and fruits, juices, and several processed foods.

Presentations