Ultrasound assisted esterification of Moringa oleifera oil and its optimization by central composite design

Abstract

The present work describes the esterification of Moringa oleifera oil (MOO) using ultrasound treatment at a frequency of 60 kHz. The influence of process parameters of esterification such as methanol to oil ratio, catalyst concentration and reaction time on acid value reduction have been analyzed by central composite design (CCD) of Response surface methodology (RSM). ANOVA table indicate the significance of methanol to oil ratio and interaction between catalyst concentration and ultrasonication time. Using Numerical optimization tool, the acid value is reduced to 3mg KOH/g of oil using 2 vol% conc. H2SO4, 0.4:1 volumetric ratio of methanol to oil in 60 min at 60°C. Meanwhile, the conversion of free fatty acid (FFA) into methyl ester is further confirmed with the Fourier Transform Infrared Spectroscopy (FTIR) analysis.