Study of Solid–Liquid Extraction Kinetics of Oil from Dried Avocado (Persea Americana) Flesh Using Hexane as A Solvent.

In the present study, solid–liquid extraction of dried avocado flesh was investigated using hexane as a solvent for three pre-treatment methods (uncooked, cooked with CaCO₃, and cooked with water) and two material sizes (8 mm × 5 mm × 5 mm and ≤1.19 mm). Based on the highest yield of avocado oil obtained, the kinetics of oil extraction for a material size of ≤1.19 mm for the various pre-treatment methods was studied. Two stages, namely rapid oil extraction and slow oil extraction, were observed. Three kinetics models (Peleg, power law, and unsteady-state diffusion model) were used to describe the extraction of avocado oil. At conditions with the highest oil yield, the Arrhenius equation was used to calculate the activation energy at three different temperatures (25, 40, and 50°C). Based on the R² value obtained, the unsteady-state diffusion model (R² = 0.6236– 0.8752) is most suitable to describe the avocado oil extraction process. A positive value of the activation energy (47.51 kJ/mol) confirmed that the avocado oil extraction process is endothermic. [ABSTRACT FROM AUTHOR]