Spanish researchers assess shelf life and Listeria risk

Scientists in Spain have assessed the shelf life safety of certain ready-to-eat foods and the risk from Listeria monocytogenes.

The Barcelona Public Health Agency (ASPB) asked for an opinion on the safe shelf life of Listeria monocytogenes in products such as cheeses, cooked meats, including pâtés, and cured meats sliced and prepackaged before retail sale. It was published recently in the Food Risk Assess Europe journal.

In 2019, 72 listeriosis cases were reported in Catalonia. ASPB provided 90 samples (32 in 2020 and 58 in 2021) from four categories of ready-to-eat foods. Food was sliced or cut into portions in retail establishments in Barcelona and packaged in different formats: vacuum-packed, in a heat-sealed or shrink-wrapped tray, or wrapped in film.

The prevalence of Listeria monocytogenes was 6.75 percent, and positive samples were from all food categories. Shiga toxin-producing E. coli (STEC) was also detected in two samples of cheese made from raw milk; one of these was E. coli O145.

Setting a safe shelf life

95 percent of the product display equipment was at temperatures equal to or below 5 degrees C (41 degrees F). Scientists found 44 samples did not include any date on the packaging.