Microbiological safety and sensory characteristics of salmon slices processed by the sous vide method

The aim of this work is to evaluated the microbiological quality and the sensory characteristics of salmon slices processed by the sous vide method under different conditions of time-temperature when stored at 2 and 10 degreesC. Three different combinations of time-temperature were studied (5 min/65 degreesC, 10 min/90 degreesC and 15 min/90 degreesC). The product stored at 2 or 10 degreesC was evaluated periodically to study its sensory quality, microbiological condition and proximate composition. Batches stored at 2 degreesC had lower growth rates of mesophiles and psychrotrophs. Staphylococcus aureus, Bacillus cereus, Clostridium perfringens and Listeria monocytogenes were not found in any of the samples. Neither aerobic nor anaerobic sporeforming bacteria were detected in the salmon processed at 90 degreesC for 15 min and stored at 2 degreesC after 45 days. The heat treatment of 90 degreesC for 15 min was the most effective for extending the shelf life of fish (>45 days). However, under these conditions the sensory characteristics were not optimal. It can be conclude that the treatment at 90 degreesC for 15 min was the most effective one to ensure the safety and to extend the shelf life of sous vide salmon. However, under these conditions the sensory characteristics were not optimal immediately after processing. This study emphasizes the importance of heat treatment and storage temperature in order to ensure the safety particularly in a fat fish, since fat can acts as a protecting agent in the heat resistance of microorganisms. (C) 2003 Elsevier Ltd. All rights reserved.