Increasing the microbial inactivation of Staphylococcus aureus in sauces by a combination of enterocin AS-48 and 2-nitropropanol, and mild heat treatments.

摘要

Staphylococcus aureus was challenged with the cyclic bacteriocin AS-48 in four commercial sauces singly and in combination with sublethal heat treatments (50-60 degrees C, for 5 min) and with 2-nitro-1-propanol (2NPOH). Heating at 60 degrees C in combination with AS-48 (25 mug/ml) reduced initial counts (4.1-4.5 log CFU/ml) below detection limit (1.0 log CFU/ml), while a combined treatment at 55 degrees C inhibited proliferation of staphylococci in sauces for 24 h at 22 degrees C. In BHI broth, enterocin AS-48 (0-15 mug/ml) acted synergistically with 2NPOH (0-220 mM), reducing the concentrations of both antimicrobials required for inactivation of S. aureus. In sauces, enterocin AS-48 (25 mug/ml) plus 2NPOH (25 mM) reduced initial cell concentrations (4.1-5.0 log CFU/ml) below detectable levels within 8-24 h, depending on the sauce. The combinations of enterocin AS-48 and 2NPOH or sublethal heat are interesting for testing as part of hurdle technology aimed at reducing the risks for proliferation of S. aureus in sauces. All rights reserved, Elsevier.