Microbiological and nutritional quality of sous vide or traditionally processed fish: influence of fat content.

Resumen

Sous vide technology, which implies vacuum packaging, pasteurization and storage at a chill temperature, also implies a challenge to obtain a balance between an extended shelf life and microbiological safety of the product with a fresh-like appearance and a high nutritional value. The aim of this work was to determine the effect of fat content of two fish species (salmon and trout) on survival of mesophilic, psychrotrophic, Enterobacteriaceae, Micrococaceae and anaerobes during sous vide cooking and their control during chilled storage for 3, 20 and 45 days. Proximate and fatty acid composition was also determined using a traditional cooking method. Analyses were undertaken comparatively with the same culinary technique for sous vide and traditionally cooked fish. Higher fat levels in all products resulted in fewer microbial reductions. In order to establish adequate pasteurization (temperature/time) combinations for the assurance of microbial quality and shelf life of sous vide processed fish, fat content and fatty acid composition of food should be considered.