Recovery by nanofiltration and reverse osmosis of marine flavours from seafood cooking waters

Cooking waters from buckies, shrimps and tuna have a high level of polluting load (Chemical Oxygen Demand - COD - comprised between 5 and 40 gO(2)/L) and have to be treated before being rejected in the environment. However, these juices seem to contain interesting flavour compounds. This recovery would allow the industrialists to diminish the waste water treatment cost and to recover high added value molecules. In this work, a membrane process system consisting in ultrafiltration (UF) followed by uanofiltration (NF) or reverse osmosis (RO) was used to reduce the pollution load and to concentrate flavour compounds of seafood cooking juices (buckies, shrimps and tuna). The first ultrafiltration step (cut-off: 0.02 mum) consisted in clarifying the cooking waters in order to increase fluxes of the following filtrations. NF (cut-off: 300 Da) did not seem to be efficient enough for flavour recovery, whereas RO was, for shrimps and buckies cooking juices. At the opposite, aromas contained in the tuna cooking juice were not perfectly retained by the RO membrane used. Nevertheless, the polluting load was considerably decreased after RO (COD reduced by 95% for shrimps and buckies and 85% for tuna).