The utilization of natural deep eutectic solvent composition in tocotrienol and tocopherol extraction from crude palm oil and its acylglycerol products

Abstract

Vitamin E is the largest phytonutrient in crude palm oil (CPO) which comprises isomers, tocopherols and tocotrienols. In this study, natural deep eutectic solvent (NADES), an alternative to organic solvent in the extraction of various bioactive compounds, was used to extract vitamin E from CPO. Three types of CPO, including CPO, CPO-rich diacylglycerol (CPO-DAG), and monoacylglycerol (CPO-MAG), were used to analyze the effect of acylglycerol composition in this extraction. The modified CPOs were obtained through a lipase-catalyzed glycerolysis reaction. The extraction used choline chloride-based NADES combined with acetic acid (ChCl-AA), oxalic acid (ChCl-OA), and citric acid (ChCl-CA) by creating a two-phase system between NADES and oils. The result shows that CPO: ChCl-AA yielded the highest vitamin E concentration (4439 mg/kg) and extraction efficiency (74.98%). Furthermore, CPO: ChCl-AA selectively separated tocotrienols, producing the tocotrienol-rich fraction (TRF). The ChCl-AA was then chosen to be used in CPO-DAG and CPO-MAG. The TRF concentrations in CPO-DAG and CPO-MAG were 3539.87 and 627.22 mg/kg, respectively. The ChCl-AA was the best combination for TRF extraction in CPO because CPO-DAG and CPO-MAG have free hydroxyl groups that hinder the hydrogen bond formation between NADES and tocotrienol molecules.