Microbiological Quality of Fresh Fruit and Vegetable Products in Catalonia

Microbiological quality of fresh fruit and vegetable products in Catalonia (Spain) using normalised plate-counting methods and real time polymerase chain reaction (QPCR)

Journal of the Science of Food and Agriculture
Volume 88, Issue 4, Date: March 2008, Pages: 605-611

Esther Badosa, Rosalia Trias, Dolors Parés, Maria Pla, Emilio Montesinos ^*

Institut de Tecnologia Agroalimentària-CeRTA-CIDSAV, Universitat de Girona, Campus de Montilivi, E-17071 Girona, Spain

Abstract

BACKGROUND: Commercially available fruits and raw and ready-to-eat vegetables (n = 445) were examined for aerobic, coliform, and yeast and mould counts using normalised methods. Listeria spp., Listeria monocytogenes and Salmonella spp. were detected by real time polymerase chain reaction (QPCR) after enrichment.

RESULTS: Aerobic plate counts ranged from < 10 to > 10⁹ colony-forming units (CFU) g^-1, with the lowest and highest counts recorded for fruits and sprouts respectively. The highest incidence level of coliforms was found in ready-to-eat vegetables, with up to 65.7% of samples containing from 5 to 9 log₁₀CFU g^-1. Yeasts and moulds showed their highest incidence level between 5 and 6 log₁₀ CFU g^-1, with an overall range from < 2 to 9 log₁₀ CFU g^-1. Salmonella spp., Listeria spp. and L. monocytogenes were detected in 0.67, 2.7 and 0.9% respectively of the total samples examined.

CONCLUSION: The samples analysed can be gathered into two main groups, one showing low microbial counts (fruits) and a second group (raw whole leaves and roots and packed ready-to-eat vegetables) with higher microbial contamination. Although incidence levels of pathogenic bacteria reported here are in the lower range of those reported elsewhere, positive detections highlight the importance of good hygienic measures throughout the whole food chain.