Mean temperature of 534 surveyed domestic refrigerators in the Netherlands at the bottom shelf was 5.7 °C.

The mean temperature of the upper shelf was 7.7 °C and significantly warmer.

Growth rates (μmax) of pâté and cooked ham were modelled using the square root model.

Domestic storage for either <7 days or below 7 °C reduced the cases by >80 %.

Reduction of cases may be achieved by targeted communication to especially the elderly.

Inadequate domestic refrigeration is frequently cited as a factor that contributes to foodborne poisoning and infection, and consumer behaviour in this regard can vary largely. This study provides insight into the temperature profiles of domestic refrigerators in the Netherlands and the impact on the number of listeriosis cases related to ready-to-eat (RTE) cooked meat products. A survey was conducted among Dutch consumers (n = 1020) to assess their knowledge and behaviour related to refrigerators. Out of these participants, 534 measured their refrigerator's temperature, revealing an average temperature of 5.7 °C (standard deviation (SD) of 2.2 °C) with a maximum of 17 °C. Elderly people (65 years and older) had refrigerators with temperatures that were on average 0.6 °C higher than those of younger people (35 years or younger). The 24-hour temperature profiles of an additional set of actively surveyed refrigerators (n = 50) showed that the temperature measured on the upper shelf was significantly higher (mean 7.7 °C, SD 2.7 °C) than the temperature measured on the bottom shelf (5.7 °C, SD 2.1 °C). Quantitative Microbiological Risk Assessment (QMRA) predicted that the primary factors contributing to the risk of listeriosis were the initial concentration and the time and temperature during household storage. Scenario analysis revealed that storing opened RTE cooked meat products at home for either <7 days or at temperatures <7 °C resulted in a significant reduction of over 80 % in predicted illness cases. Among all illness cases, the elderly represented nearly 90 %. When assessing the impact of the disease in terms of Years of Life Lost (YLL), the contribution of the elderly was 59 %. Targeted communication, particularly directed towards the elderly, on the importance of storing RTE cooked meat products at the recommended temperature on the bottom or middle shelf as well as consuming within two to three days after opening, holds the potential to significantly reduce the number of cases.

Storage temperature

Storage time

Food safety

Risk assessment

QMRA

Deli meat

Ham

Pâté

Listeria monocytogenes

The used QMRA model, along with the outcomes of one simulation with 10,000 iterations and another simulation with 1,000,000 iterations, is available at https://doi.org/10.4121/98b4d5dd-7b07-48c0-bbc7-62a2f10944b1.

© 2023 The Authors. Published by Elsevier B.V.