Microbiological quality and safety of non-treated fresh and squeezed juices from supermarkets in Lleida, Spain

Abstract

The growing consumption of untreated juices has increased the outbreaks related to Salmonella spp., Escherichia coli O157:H7 and Listeria monocytogenes. Although these pathogens are not in favourable conditions in fruit juices, cases of survival in acidic environments have been reported in fruit and vegetable juices. Thus, this study has evaluated the microbiological quality (total aerobic mesophilic microorganisms (TAM), moulds and yeasts, total coliforms (TC) and E. coli populations) and investigated the occurrence of foodborne pathogens (Salmonella spp. and L. monocytogenes) in 100 fresh (blended) and self-service (monovarietal) untreated juices. Concerning the obtained results, pH was higher for fresh juices than for self-service juices. The results showed great variability in TAM, moulds and yeasts and TC populations. For TAM, the results ranged from 1.7 to 7.4 log cfu mL−1. Values for moulds and yeasts, ranged from below detection limit (<10 cfu mL−1) to 5.9 log cfu mL−1. And for TC, results went from below detection limit (<1 cfu mL−1) to 4.4 log cfu mL−1. However, significant differences were only observed between the two types of samples in TC, being higher in fresh juices than in self-service juices. For E. coli enumeration, all the samples were below the detection limit (1 cfu mL−1). Finally, no Salmonella spp. or L. monocytogenes were detected in 25 mL of sample. All analysed samples complied the requirements from European regulation.