Pervaporative recovery of volatile aroma compounds from fruit juices

During fruit juice concentration, many components of aroma are lost due to their high volatility in aqueous solutions. These compounds are rather important for the sensorial quality of juices and must therefore be recovered and then added back to the concentrated juice. Despite their importance, these compounds are present at very low concentrations in juices and their recovery using traditional techniques, such as distillation and partial condensation, is somewhat complex. Pervaporation constitutes a promising alternative for substituting these techniques. In this paper, the literature on the application of this membrane process for recovering aroma compounds is reviewed. Both experimental studies and modeling efforts are considered, covering issues like organic aroma compounds which are often investigated, membrane materials and their performance, operating parameters and their effects, concentration polarization, available models and their limitations. In addition, for easier comprehension, an overview of theoretical concepts in pervaporation is presented.