JAPAN – A recent study in Japan on Environmental Monitoring Programs (EMPs) has unveiled the persistent presence of Listeria monocytogenes in food production facilities, emphasizing the significance of these monitoring programs.
The research, conducted between 2021 and 2022, aimed to tailor EMPs to the specific needs of Japanese food businesses and promote the widespread adoption of these crucial monitoring strategies.
In their meticulous study, researchers delved into the intricacies of food safety by examining two side dish manufacturing plants and a meat processing facility.
To effectively tackle the challenge of Listeria contamination, they meticulously divided these facilities into three critical areas.
The “Dirty Area” where raw materials were handled, the “Semi-Clean Area” designated for the mixing of raw ingredients and semi-finished products, and finally, the “Clean Area” where post-cooking processes took place.
Within this framework, the sampling locations were further categorized into four distinct zones.
“Zone 1” represented areas in direct contact with food, while “Zone 2” encompassed spaces in close proximity to food or food contact surfaces.
“Zone 3” was characterized by its removal from food or food contact surfaces within the food processing area, and “Zone 4” included areas not in direct contact with food, typically located outside the confines of the food processing area.
This systematic zoning allowed for a comprehensive assessment of Listeria contamination risks throughout the facilities.
Findings and remediation strategies
At Facility A, a critical discovery was made when L. monocytogenes was detected in Zone 3 of the clean area.
Closer inspection revealed potential contamination pathways from the dirty area to the clean area.
Effective intervention was achieved by employing normal cleaning practices coupled with disinfection using carbonated hypochlorite water with a chlorine concentration of 150 parts per million (ppm).
Facility B, specializing in ready-to-eat salad products, encountered suspected contamination in 15 food samples.
Investigation honed in on the slicer and the surrounding area. It was found that contamination with L. monocytogenes serotype 3b increased after slicer use. A rigorous regimen of disassembly, thorough cleaning, and disinfection was subsequently implemented.
Facility C, which processes raw meat through multiple stages, detected L. monocytogenes serotype 4b (4e) throughout various areas, even on the wheels of a smoking cart transporting goods across zones.
To combat this pervasive presence, diligent cleaning and disinfection efforts for the cart were intensified.
Overall, EMPs have unveiled the persistent presence of Listeria monocytogenes in each facility, emphasizing the significance of these monitoring programs.
They have also identified cleaning and workflow challenges, allowing for the swift implementation of corrective measures.
The study recommends that the facilities maintain a “Plan-Do-Check-Act” cycle, ensuring ongoing vigilance in food safety protocols.
This research underscores the importance of tailoring food safety practices to the unique needs of each facility and the power of EMPs in fortifying the safety of food production.
As Japan takes proactive measures to enhance food safety, these findings have the potential to serve as a valuable blueprint for facilities worldwide seeking to protect consumers and uphold the highest standards of food safety.