How can the risk of Listeria be reduced in cold storage areas in industrial settings?
Microbiological and chemical air decontamination in cheese-making facilities and other food industries is a particularly sensitive issue. The products being processed, as well as the conditions during cooking, production, and packaging, create an environment conducive to food contamination. PhotoClean, an expert in industrial air treatment in France, explains how to reduce the risk of Listeria in cold storage areas.
What is Listeria, and in what environments does it thrive?
Known by its full name, Listeria monocytogenes, this bacterium poses a serious threat to the food industry because it multiplies at low temperatures, around 0°C. It is even resistant to freezing and deep-freezing. This microorganism is therefore a recurring source of contamination in refrigerated environments: cold storage rooms, and areas where fresh foods are processed or packaged. Furthermore, the bacterium can survive for long periods on contaminated surfaces.
Industrial cheese factories are particularly at risk of Listeria contamination, as the temperature and humidity conditions there promote bacterial growth.
Various categories of food can be contaminated:
- cheese and raw milk (soft cheeses are particularly susceptible);
- cream- or milk-based fillings in commercially produced pastries;
- cured meats (including tongue, pâté, and rillettes);
- delicatessen products and raw foods;
- smoked fish;
- raw or undercooked meats;
- certain fresh vegetables and herbs…
What are the risks associated with Listeria infection?
This microorganism causes listeriosis, a potentially fatal disease in vulnerable individuals. It can start as a simple case of gastroenteritis but progress to meningitis or sepsis. Reducing the risk of Listeria is therefore a major public health issue.
In addition, any food contamination has serious economic consequences and damages the brand image of the companies involved.
How can Listeria contamination be prevented in the food industry?
This bacterium grows rapidly under certain conditions: high ambient humidity, condensation, or standing water; insufficient or irregular cleaning and disinfection; and the formation of biofilms on surfaces. Preventing Listeria in industrial cold storage areas therefore involves addressing these growth factors.
In refrigerated environments, there are three main sources of bacterial contamination that must be addressed:
- floors and drainage systems (drains, traps, etc.);
- cold rooms, refrigerators, and freezers;
- ambient air.
Preventing Listeria risk in cold storage areas requires proper design of industrial facilities, strict and frequent hygiene procedures, and staff awareness. The effectiveness of ventilation and air treatment also directly impacts the risk of contamination.
The food industry often uses HEPA filters and laminar flow to purify the air in processing areas. This system maintains purified air flowing in a single direction at a constant speed without turbulence, which limits the spread of microorganisms and airborne contaminants. However, these systems are energy-intensive, bulky, and limited in their processing capacity.
Why choose the PhotoClean industrial air treatment solution?
The effectiveness of PhotoClean technology relies on the biocidal properties of UV-C rays, combined with a proprietary filter medium that increases the contact surface area and reduces the required exposure time. The result: high-performance, continuous air treatment with very little pressure drop, delivered by compact, energy-efficient equipment.
Thanks to Photoclean’s air treatment modules, it is now possible to treat the entire production environment, including hard-to-reach areas. This comprehensive treatment reduces the presence of Listeria and other pathogenic microorganisms, thereby contributing to food safety.
Request information and an audit of your facilities in the food industry from Photoclean.