Pathogenic microorganism survival in dulce de leche

In order to evaluate the survival of Salmonella typhimurium, Listeria monocytogenes, Escherichia coli O157:H7 and Staphylococcus aureus in dulce de leche, aliquots of this sweet were experimentally contaminated with these pathogenic microorganisms at 103 (C1) and 101 (C2) bacterial cells per gram, and later analysed to evaluate microorganism viability after storage for 0, 1, 2, 3, 5, 10, 20 and 30 days. Salmonella and L. monocytogenes were recovered from all aliquots. E. coli O157:H7 and S. aureus were recovered from all aliquots at C1 concentration, and up to the 5th and 10th day, respectively, at C2 concentration. Relevant public-health danger pathogenic microorganisms were found to survive up to 30 days in dulce de leche.