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

Abstract

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. 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)). 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. 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.