Evaluation of microbial quality and yeast diversity in fresh-cut apple.

The present work's aim was to study the microbial quality of minimally processed apples commercialized in Portugal. Sixty eight samples of fresh-cut apple were analyzed before their best-before date in 2011 and 2012 for aerobic mesophilic and psychrotrophic microorganisms, total coliforms, lactic-acid bacteria (LAB), coagulase-positive staphylococci and fungi. The parameters of food safety studied were Cronobacter sakazakii , Salmonella spp. and Listeria sp. Samples were analyzed according to standard methodologies and using Chromocult Agar for coliforms and Escherichia coli . The yeasts were identified by restriction analysis of the ITS-5.8S rDNA-region and 26S rDNA partial sequencing. The mesophilic and psychrotrophic microorganisms ranged from 3.3 to 8.9 and from 4.9 to 8.4 log CFU/g, respectively. Coliforms were detected in all the samples and staphylococci in 5.8% of them. LAB numbers varied from 2.8 to 8.7 and fungi (yeast and molds) from 3.6 to 7.1 log CFU/g. The most common yeasts were Candida sake and Pichia fermentans followed by Hanseniaspora spp., Candida spp., Meyerozyma guilliermondii , Metschnikowia pulcherrima , Cryptococcus spp. and the psychrotrophic Cystofilobasidium infirmominiatum . Foodborne bacteria and opportunistic pathogenic yeasts were not detected in the apples studied. The results obtained respected the European Commission regulation regarding criteria of food hygiene and safety. [ABSTRACT FROM AUTHOR]