Kinetic study of canola oil and tocopherol extraction: Parameter comparison of nonlinear models

Abstract

In this work a statistical method of comparison was used in order to compare the parameters of a modified diffusion model representing the kinetics of canola oil and tocopherol extraction. The model takes into account an initial stage where solvent removes the oil from the surface of the ground seed by washing. Kinetic tests were carried out in a batch extractor at different temperatures (from 25 to 60°C) using hexane as solvent. Tocopherol concentration in the extracted oil was determined by HPLC. The parameter comparison showed that the portion extracted during the washing stage was only temperature-dependent in the case of tocopherol extraction, whereas the effective diffusion coefficients were temperature-dependent in oil and tocopherol extraction. The diffusivities ranged from 1.3 10-12 to 3.0 10-12 m2.s-1 and from 1.6 10-12 to 2.3 10-12 m2.s-1 for oil and tocopherol extraction, respectively. The oil and tocopherol extraction activation energy was 19.1 kJ.mol-1 and 8.1 kJ.mol-1, respectively.