Risk Assessment and Management of Listeria Monocytogenes in Ready‐to‐Eat Lettuce Salads

Abstract

Foodborne diseases constitute a major concern in societies, and their causes are aimed to be identified and minimized. Only in the last few years, this is encouraged by the application of risk assessment, management, and communication. This work presents a probabilistic quantitative microbiological risk assessment and management of Listeria monocytogenes in ready-to-eat lettuce salads in Spain. For risk assessment, a guideline provided by Codex Alimentarius was followed. Food chain was modeled from processing of raw material at the factory up to consumption. Different assumptions were made to describe the variables of the model by probability distributions or mathematical models. Monte Carlo simulations of the model were run to estimate the number of cases in low-risk and high-risk populations. Although results deviated from the number of cases observed in Spain, given an ideal situation of 100% compliance of the microbiological criterion ≤100 cfu/g throughout the shelf-life of the product, the resulting number of cases was near the real situation. From the 4 risk management measures simulated, the injection of a mixture of gases into packages at manufacture (CO 2 about 5.5%, O 2 about 3%, and N 2 for the balance) was the most effective in reducing the number of cases, followed by 4 d of storage at home and prevention of high-risk consumers from consumption of ready-to-eat lettuce salads. More research and cooperation between different stakeholder organizations are needed in order to progressively improve the model. With this work, a breakthrough has been made with regards to risk assessment and management procedures and implementation.

Thermophysical properties and thermal behavior of leafy vegetables packaged in clamshells

“…These products are popular because they offer freshness, high nutritional value and convenience to consumers. Unfortunately, several outbreaks of food borne illness have been associated with fresh-cut lettuce in recent years (Carrasco et al, 2010;Delaquis et al, 2007;Luo et al, 2010;Harris et al 2003). Outbreaks caused by contamination with the verotoxigenic bacterium Escherichia coli O157:H7 are a significant concern given the severity of illness and potential long term sequela that may result from infection.…”

A quantitative exposure model simulating human norovirus transmission during preparation of deli sandwiches

“…in ready-to-eat food products, but most studies have been focused on bacterial pathogens such as Salmonella spp. (Sant'Ana et al, 2014;Franz et al, 2010), Listeria monocytogenes (Mataragas et al, 2010;Carrasco et al, 2010) and Escherichia coli 0157 (Strachan et al, 2006). Regarding HuNoV, a number of QMRA models have been developed to evaluate the risk of HuNoV in drinking water (Aström et al, 2007) and recreation water Soller et al, 2010).…”

Food Safety Risk Management

“…The risk output indicated that processed meats could be responsible for up to ~40% of cases of listeriosis in Australia, a level that could be in line with the available epidemiological data. Application of risk management measures for L. monocytogenes in ready-to-eat lettuce salads was made by Carrasco et al (2010). They showed that the most effective measures to reduce the risk of listeriosis were the use of specific mixture of gases in packages, the reduction of shelf-life to four days and the prevention of high-risk population from consuming ready-to-eat lettuce salads.…”