Pervaporation as a deodorization process applied to food industry effluents: recovery and valorisation of aroma compounds from cauliflower blanching water

In the food industry, unit operations of stabilisation (such as blanching) produce aqueous effluents generally nonpolluting but often odorous. The objective of this study was to apply the pervaporation process to the deodorization of a cauliflower blanching effluent in order to reduce its volatile organic compounds content and to try to recover a valuable food flavouring fraction. A systematic study of pervaporation has been performed on three sulfur compounds identified as typical compounds of the cauliflower odour. Then, the separation performances obtained on an industrial effluent were evaluated through physico-chemical and sensorial analysis. They showed that pervaporation was an efficient process for deodorization and offers a real potential for valorisation of the permeate.

Pervaporation was applied to an industrial effluent in order to be deodorised and to recover a valuable aromatic fraction. Sulfur compounds were identified as key components of the effluent odour. On a model solution containing three sulfur compounds, operative conditions of pervaporation were determined. A 100 µm PEBA membrane was selected. On this membrane, the sorption step of the sulfur compounds was the limiting step. The highest flux was obtained with the DMTS which has the lowest diffusion coefficient but the highest sorption coefficient in PEBA. Lastly, the pervaporation was applied to the effluent and demonstrated that the deodorization is possible. Moreover, the odour quality of the permeate was completely modified, compared to the cauliflower blanching water, due to the membrane selectivity and seems to have a real potential of valorisation.