Multi-objective optimization of pervaporation process for food products

Pervaporation identifies a nonthermal and nondestructive membrane-based process whose objective is to extract a substance from a defined liquid solution. If applied to food products, it is possible to drive out and preserve organoleptic and nutritional properties and food flavors. Through certain packaging devices it is possible, after the treatment of the food matrix, to reintroduce the flavor and obtain innovative and value-added products, closer and closer to fresh ones. This paper describes a multi-objective optimization model applied to the process of flavors recovery from spices, adopting pervaporation technology. Aim of this work is to realize a model that determines all the possible configurations of the system, performing a multi objective optimization in order to find the best configuration possible. The whole flavors recovery process is characterized by four phases: drying, sterilization, Volatile Organic Compound extraction through PDMS membrane and aroma reintroduction. An Excel sheet was initially created, modelling the physical relations between the process variables. At this point modeFRONTIER™ software, a multi-objective optimization and process integration tool based on the Pareto-optimal frontier of the objectives space was used. It was set, as input variables, the total flow exiting from the dryer, the percentage of aroma in weight, pressure ratio, membrane selectivity, total permeate pressure, membrane permeability and thickness. Output variables are permeate concentration and feed pressure. A couple of constraints for each output of the model were considered. Final step was performed with the aim to determine the optimal solution between all the Paretooptimal ones obtained by the optimization process previously described. This phase was carried out using Multi Criteria Decision Making (MCDM) tool included in modeFRONTIER™ software.