• Open Access

Scientific Opinion on the risk posed by pathogens in food of non-animal origin. Part 2 (Salmonella and Norovirus in leafy greens eaten raw as salads)

Authors

  • EFSA Panel on Biological Hazards (BIOHAZ)


  • Panel members: Olivier Andreoletti, Dorte Lau Baggesen, Declan Bolton, Patrick Butaye, Paul Cook, Robert Davies, Pablo S. Fernandez Escamez, John Griffin, Tine Hald, Arie Havelaar, Kostas Koutsoumanis, Roland Lindqvist, James McLauchlin, Truls Nesbakken, Miguel Prieto Maradona, Antonia Ricci, Giuseppe Ru, Moez Sanaa, Marion Simmons, John Sofos and John Threlfall.
  • Correspondence: biohaz@efsa.europa.eu
  • Acknowledgement: The Panel wishes to thank the members of the Working Group on risk posed by pathogens in food of non-animal origin Part 2: Ana Allende, Nigel Cook, Paul Cook, James McLauchlin, Christophe Nguyen-The, Birgit Nørrung and Mieke Uyttendaele for the preparatory work on this scientific opinion and EFSA staff: Maria Teresa da Silva Felicio, Ernesto Liebana Criado, Mariano Lopez Romano and Liese van Gompel for the support provided to this scientific opinion.
  • Adoption date: 6 March 2014
  • Published date: 27 March 2014
  • Question number: EFSA-Q-2012-00238
  • On request from: European Commission

Abstract

Leafy greens eaten raw as salads are minimally processed and widely consumed foods. Risk factors for leafy greens contamination by Salmonella spp. and Norovirus were considered in the context of the whole food chain including agricultural production and processing. Available estimates of the prevalence of these pathogens (together with the use of Escherichia coli as an indicator organism) in leafy greens were evaluated. Specific mitigation options relating to contamination of leafy greens were considered and qualitatively assessed. It was concluded that each farm environment represents a unique combination of numerous characteristics that can influence occurrence and persistence of pathogens in leafy greens production. Appropriate implementation of food safety management systems, including Good Agricultural Practices (GAP), Good Hygiene Practices (GHP) and Good Manufacturing Practices (GMP), should be primary objectives of leafy green producers. The relevance of microbiological criteria applicable to production, processing and at retail/catering were considered. The current legal framework does not include microbiological criteria applicable at primary production which will validate and verify GAP and GHP. It is proposed to define a criterion at primary production of leafy greens which is designated as Hygiene Criterion, and E. coli was identified as suitable for this purpose. A Process Hygiene Criterion for E. coli in leafy green packaging plants or fresh cutting plants was considered and will also give an indication of the degree to which GAP, GHP, GMP or HACCP programs have been implemented. A Food Safety Criterion for Salmonella in leafy greens could be used as a tool to communicate to producers and processors that Salmonella should not be present in the product. Studies on the prevalence and infectivity of Norovirus are limited, and quantitative data on viral load are scarce making establishment of microbiological criteria for Norovirus on leafy greens difficult.

Ancillary