Convective drying of Moringa oleifera seeds: kinetics modelling and effects on oil yield from different extraction techniques

This work shows the convective drying kinetics of moringa seeds (Moringa oleifera L) at different drying temperatures 40, 50, 60, 70, and 80 °C and the effect drying on the extracted oil yield. Four simplified models were fitted to the kinetics data, and a phenomenological mathematical model (PMM) was developed to describe the process. The simplified model that better represented the experimental data was Verma, with a global relative mean error of 1.31%. The PMM with the use of an equilibrium boundary condition at the surface produced better results than those obtained when considering the convective condition, indicating that the effects of external mass transfer resistance are neglected. The moringa oil was extracted from all dried seeds conditions using different extraction techniques, such as Soxhlet technique, ultrasound-assisted, and mechanical extraction; and the maximum oil yield obtained for dry seeds was 43.06%, 31.53%, and 24.93% respectively. All drying temperatures of the moringa seed do not show influence the oil yield obtained in each extraction method used.