Kinetics, thermodynamics and isotherm modelling of cloud point extraction of lycopene

Abstract

Present work investigates kinetics, thermodynamics and solubilization isotherm of cloud point extraction of lycopene (CPEL) using non-ionic surfactant L62. The kinetics of CPEL has been found to follow pseudo second order with a regression coefficient of 0.99. The experimental data have been fitted to Langmuir adsorption isotherm (R² = 0.97) and Freundlich adsorption isotherm (R² = 0.96). Surfactant concentration required to extract a given amount of lycopene predicted using Langmuir isotherm is comparable with experimental results (R² = 0.96). Thermodynamic parameters obtained for CPEL are: ΔH°= 86.22 kJ/mol and ΔS° = 0.290 kJ/mol K. ΔG° is negative for the investigated temperature range (65-85 °C). Lycopene stability data in coacervate phase suggests that the rate of lycopene degradation is best described by a second order kinetic model. Thus, the storage medium found to have influence on lycopene degradation/isomerisation in the surfactant phase.