Effect of sous vide cooking, with freezing, on selected quality parameters of seven fish species in a range of sauces

As quotas and the supply of conventional species continue to tighten, there is a need to test the acceptability of many fish species. Seven fish species (albacore tuna, cardinal fish, orange roughy, blue ling, red-fish, roundnose grenadier and Greenland halibut) were cooked by the sous vide process (Barriquand Steriflow retort; 20 min/90 degrees C) in 12 savoury sauces. Sensory results showed that sous-vide-cooked albacore tuna, cardinal fish and blue ling were the most acceptable species and tikka, tomato-and-pesto, arrabbiata and hollandaise the preferred sauces. Greenland halibut and roundnose grenadier were too soft after sous vide cooking. Freezing post sous vide cooking did not influence product quality and gave additional benefits over chilling of an extended shelf life and more flexibility in relation to product safety. The pH of the sauces was in the range 3.96 (cajun) to 5.42 (bearnaise) and mean pH values fell from 4.66 before sous vide cooking to 4.38 after cooking. Sauce colour also became lighter during sous vide cooking of fish portions, as indicated by Hunter Lab colour values. The results of the research have been disseminated to seafood companies and scale-up trials are in progress.