Recovery of key components from real flavor concentrates by pervaporation

Experimental study was conducted on pervaporation processes for recovering key flavor compounds from aqueous flavor systems for three real flavor systems (apple essence, orange aroma, and black tea distillate). Both continuous and batch operations were carried out. Key flavor compounds were identified and successfully recovered from the real flavor systems that were tested. Mass transfer equations for pervaporation were derived based on the nonequilibrium thermodynamics principles [L. Onsager, Reciprocal relations in irreversible process I, Phys. Rev. 37 (1931) 405; L. Onsager, Reciprocal relations in irreversible process II, Phys. Rev. 38 (1931) 2265]. Mathematical models for process simulation were developed. A material balance was applied to calculate recovery and loss percentages of flavor compounds. Flavor loss rate due to evaporation leakage was determined by fitting experimental data into a developed batch operation model. Separation performance for long-term operation was predicted based on the process simulation model. Significant flavor loss was observed in the pervaporation recovery process. Pervaporation design with better sealing and collection methods was highly recommended for process scale-up.