Purpose: The objective of this study was to determine the microbiological quality including incidence of Salmonella spp. on cherry tomatoes at points of sale.
Methods: Samples of cherry tomatoes were collected from four supermarkets (157) and four local markets (83) from Querétaro, México. Fruit (50 g) were analyzed to quantify aerobic plate counts (APC), coliforms, molds/yeasts, and Escherichia coli; Salmonella presence was also investigated in 50 g samples. All microbiological analysis was done using Bacteriological Analytic Manual (BAM) methods. Nonparametric comparisons of microbial populations were carried out using the Wilcoxon-Kruskal-Wallis test.
Results: Populations of microbial indicator were higher in samples collected from local markets (P<0.05). Median values of APC, coliforms and molds/yeasts on tomatoes from supermarkets and local markets were 3.58 and 5.10, 1.02 and 1.52, 3.21 and 4.76 log CFU/g, respectively. Escherichia coli was present on samples from supermarkets (4.5%) and local markets (16.9%) at low levels (0.09 to 0.69 log MPN/g). Salmonella spp. was also detected in 16.6% (26 of 157) and in 8.4% (7 of 83) of the tested samples from supermarkets and local markets, respectively.
Significance: The presence of Salmonella was higher in tomatoes from supermarkets despite the fact that E. coli, an indicator of fecal contamination, did not reflect the same trend. This data set could be helpful to understand the risk for consumer’s health associated with Salmonella and cherry tomatoes.