Coupling nanofiltration and osmotic evaporation for the recovery of a natural flavouring concentrate from shrimp cooking juice
Résumé
A new combination of membrane-based processes was studied in order to produce a natural flavouring concentrate from shrimp cooking juice. The process associates a pre-concentration step by nanofiltration (NF) until a Volume Reduction Ratio (VRR) of 10 and a final concentration by osmotic evaporation (OE). Thanks to NF, the juice was partially concentrated and desalinated, allowing the further OE step to be run in optimal conditions: reduction of the quantity of water to be evaporated and of the production of brine, limitation of the loss of volatile compounds and improvement of sensory acceptability. During OE step run at pilot-scale, a 52% dry matter concentrate was obtained with aroma loss lower than 35%. Products were characterised by sensory and chemical analyses all along the process. With sensorial characteristics matching the expectancies, the concentrate could be incorporated at 2.5% in food preparations.