Skip to main content
SLU publication database (SLUpub)

Review article2017Peer reviewedOpen access

Is your lunch salad safe to eat? Occurrence of bacterial pathogens and potential for pathogen growth in pre-packed ready-to-eat mixed-ingredient salads

Söderqvist, Karin


As part of a trend toward healthy convenience foods, ready-to-eat (RTE) mixed-ingredient salads have become popular products among consumers. A mixed-ingredient salad contains combinations of raw (e.g. leafy vegetables and tomatoes) and processed (e.g. chicken, salmon, ham, pasta and couscous) ingredients. Contamination of leafy vegetables can occur during any step in the production chain and, since there is no step that kills pathogens, a completely safe final product can never be guaranteed. Meat ingredients, for example poultry meat and ham, are generally heat-treated before preparation, but may be contaminated after this treatment, e.g. when diced or sliced. When several ingredients are mixed together, cross-contamination may occur. Preparation of mixed-ingredient salads requires human handling, which presents an additional risk of bacterial contamination. With high-protein ingredients, e.g. cooked meat, the mixed-ingredient salad represents an excellent substrate for bacterial growth. This article reviews current knowledge regarding human bacterial pathogen prevalence in mixed-ingredient salads and the potential for pathogen growth in this product during storage.


Deli salad; Listeria monocytogenes; pathogenic Yersinia enterocolitica; Salmonella enterica; shiga toxin-producing Escherichia; colitemperature abuse

Published in

Infection Ecology & Epidemiology
2017, Volume: 7, number: 1, article number: 1407216

    UKÄ Subject classification


    Publication identifier


    Permanent link to this page (URI)