Supercritical carbon dioxide extraction of lycopene from tomato processing by-products: Mathematical modeling and optimization

Supercritical carbon dioxide (SC-CO2) extraction of lycopene from tomato processing byproducts, namely, tomato peel and seed, was mathematically modeled. Mathematical modeling of the SC-CO2 extraction data was implemented using the mass conservation law that resulted in two partial differential equations for solvent and solid phases. The model was then employed to investigate the effects of temperature (40-80 degrees C), pressure (30-50 MPa), and peel to seeds ratio (30/70 to 70/30) on the lycopene yield. The maximum lycopene yield of 1.32 mg/kg of raw material was obtained at 80 degrees C, 50 MPa, and peel/seeds ratio of 70/30. The lycopene yield had a direct relationship with external mass transfer coefficient, but inverse relationship with the partition coefficient of the solute between the solid and the fluid phase and particle diameter; however, the amount of oleoresin was only a function of the initial mass fraction of extractable solute in the solid phase and mass of feed.