Quantitative assessment of the impact of cross-contamination during the washing step of ready-to-eat leafy greens on the risk of illness caused by Salmonella

Author(s)

Maffei, Daniele F. ; Sant'Ana, Anderson S. ; Franco, Bernadette D. G. M. ; Schaffner, Donald W.

• Document type: Journal article
• Source: Food Research International; v. 92, p. 106-112, FEB 2017.
• Web of Science Citations: 10

Abstract

The aim of this study was to develop a quantitative microbial risk assessment (QMRA) model to estimate the risk of illness caused by Salmonella in ready-to-eat (RTE) leafy greens, based on common practices in Brazilian processing plants. The risk assessment model considered five modules: in field, washing step, retail storage, home storage and dose-response. Fifty thousand iterations of a @Risk model built in Excel were run for each of sixty scenarios. These scenarios considered different initial pathogen concentrations, fractions of contaminated produce and chlorine concentrations. For chlorine, seven pre-set concentrations (0, 5, 10, 25, 50, 150 and 250 mg/L) and three triangular distributions were considered {[}RiskTriang(0,5,10 mg/L), RiskTriang(0,80,250 mg/L) and RiskTriang(10,120,250 mg/L)]. The outputs were risk of infection, estimated numbet of illnesses and estimated percent of illnesses arising from cross-contamination. The QMRA model indicated quantitatively that higher chlorine concentrations resulted in lower risk of illness. When simulation was done with <5 mg/L of chlorine, most (>96%) of the illnesses arose from cross-contamination, but when a triangular distribution with 10, 120 and 250 mg/L of chlorine was simulated, no illnesses arising from cross-contamination were predicted. Proper control of the sanitizer in the washing step is essential to reduce initial contamination and avoid cross-contamination. (C) 2016 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 14/17017-6 - Quantitative assessment of the impacts of cross-contamination during vegetable washing on the microbial risk of infection by Salmonella in ready-to-eat vegetables
• Grantee: Daniele Fernanda Maffei
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 12/03471-1 - Minimal processing of vegetables: influence of washing-disinfection conditions on Salmonella inactivation, on the occurrence and extent of cross-contamination and impacts on microbiological safety of ready-to-eat vegetables
• Grantee: Daniele Fernanda Maffei
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 13/07914-8 - FoRC - Food Research Center
• Grantee: Bernadette Dora Gombossy de Melo Franco
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC