EFFECTS ON BEEF MICROFLORA OF A THREE-STEP SOUS-VIDE METHOD

Abstract – The objective of this study was to determine the effect of a three-step sous-vide cooking method on the natural microflora present on beef at the time of cooking. Steaks were cooked in waterbath under three conditions: aerobically at 70°C to an internal temperature of 59°C (C1), single-step sous-vide at 59°C with a holding time of 4 h (C2), and three-step sous-vide in which steaks were cooked sequentially at 39°C for 1 h (C3), at 49°C for 1 h (C4) and at 59°C with a holding time of 4 h (C5). Seven groups, including total aerobes, lactic acid bacteria (LAB), Pseudomonads, Brochothrix thermosphacta, Enterobacteriaceae, coliforms and Escherichia coli were determined for raw and cooked steaks. The numbers of aerobes, LAB, Pseudomonads, B. thermosphacta, Enterobacteriaceae, and coliforms on C3 and C4 steaks were not significantly different (p>0.05) from raw steaks. All bacterial groups except aerobes and LAB on C2 and C5 steaks were not recoverable.