Optimization of Palmitic Acid Extraction from Palm Oil with Betaine-Based Natural Deep Eutectic Solvent Using Response Surface Methodology

Deacidification is one of many steps in the palm oil refining process which aims to separate free fatty acids from the oil. The deacidification process was using green solvent, known as deep eutectic solvent (DES), that consisted of betaine anhydrous and hydrogen bonding donor of 1,2-propanediol (DES-1) and 1,4-butanediol (DES-2) at a molar ratio of 1:5 and 1:4, respectively. In this study, the process condition was optimized using response surface methodology (RSM) through central composite design to predict the maximum palmitic acid content in DES extract. The independent variables were extraction temperature (40, 60, 80 degrees C) and mass ratio of DES to oil (1:2, 1:1, 2:1). The p-values obtained from the ANOVA of the extraction yield data indicates that the dependence of the extraction yield of palmitic acid on DES to palm oil mass ratio and extraction temperature were linear and quadratic, respectively. The result shows that betaine anhydrous and 1,4-butanediol DES in molar ratio of 1:4 could extract palmitic acid up to 49.9% at temperatureof 42.8 degrees C and DES to oil mass ratio of 2:1.