Storage life at 2° C or -1.5° C of beef steaks cooked by a three-step sous-vide method

The effect of a three-step sous-vide cooking method on the storage life of beef steaks at 2°C or -1.5°C were assessed for their microbiological and organoleptic properties. 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, at 49°C for 1 h and at 59°C with a holding time of 4 h (C3). After cooking, aerobic C1 steaks and vacuum-packed C2 and C3 steaks were stored for 7, 14, 21, or 28 days at 2°C or -1.5°C. At each sampling time, total aerobes, lactic acid bacteria (LAB), Pseudomonads, Brochothrix thermosphacta, Enterobacteriaceae, coliforms, and Escherichia coli were enumerated, and colour and odor of the steaks were assessed. All sous-vide C2 and C3 steaks had acceptable odours and also retained the color at both temperatures for up to 28 days. Regardless of storage temperature, at the end of the storage duration, C1 steaks had significantly higher (P < 0.05) numbers of aerobes, LAB and Pseudomonads than C2 and C3 steaks. No E. coli was recovered from any of the steaks cooked by any of three methods throughout the storage. Coliforms and Enterobacteriaceae were sporadically recovered from C1 and C2, but not from C3 steaks. Overall, C3 steaks had superior microbiological quality than C1 and C2 steaks and notably longer storage life at both temperatures than C1 steaks.