Experts have identified steps food firms can take to reduce the risk of Listeria contamination of frozen vegetables.
The European Food Safety Authority (EFSA) assessment focused on vegetables that are blanched – scalded in hot water or steam for a short time – before they are frozen. Companies blanch vegetables before freezing because it stops enzyme actions which can cause loss of flavor, color and texture.
Mitigation measures range from cleaning and disinfection of the food producing environment to water, time and temperature control at different processing steps, and accurate labelling. It is also important to monitor the production environment for Listeria monocytogenes as it can persist in this setting and then contaminate food, according to the report.