An assessment of the microbiological safety of fresh whole-leaf herbs from retail premises in the United Kingdom with a focus on Salmonella spp

J Appl Microbiol. 2015 Sep;119(3):827-33. doi: 10.1111/jam.12855. Epub 2015 Jun 25.

Abstract

Aims: Fresh herbs have been associated with a number of outbreaks in recent years, in the United Kingdom and elsewhere. A study of fresh herbs was carried out to assess their microbiological safety in relation to Salmonella contamination and levels of Escherichia coli.

Methods and results: Between January and March 2014, 774 samples of ready-to-eat, fresh, whole-leaf herbs were collected from retail premises in the United Kingdom. Overall, Salmonella was detected in nine samples (1·2%). Of these, five were curry leaves. Other herbs contaminated with Salmonella were basil (two samples), walleria (1) and coriander (1). Escherichia coli was detected in 13% of samples, with 11% containing unsatisfactory levels (≥10(2) g(-1)).

Conclusions: Whilst 88% of samples in this study were of an acceptable microbiological quality, the presence of Salmonella and/or elevated E. coli levels in 12% is a cause for concern. Curry leaves, in particular, had significantly higher rates of contamination with both Salmonella and E. coli than other herbs.

Significance and impact of the study: This study highlights the potential public health risk associated with the consumption of certain ready-to-eat fresh herbs, and the need for good hygiene practices and effective decontamination procedures during the growth, harvesting and subsequent handling of these products.

Keywords: Salmonella; curry leaves; food safety; fresh herbs; survey.

MeSH terms

  • Consumer Product Safety
  • Escherichia coli / genetics
  • Escherichia coli / isolation & purification*
  • Food Contamination / analysis*
  • Food Handling / methods
  • Humans
  • Plant Leaves / microbiology*
  • Plants, Medicinal / microbiology*
  • Salmonella / genetics
  • Salmonella / isolation & purification*
  • United Kingdom