Valorization of Olive Pomace Oil with Enzymatic Synthesis of 2-Monoacylglycerol.

2-Monoacylglycerols (2-MAG) with a high content of oleic acid at sn-2 position was synthesized by enzymatic ethanolysis of refined olive pomace oil, which is a byproduct of olive oil processing. Six lipases from different microbial sources were used in the synthesis of 2-MAG. Immobilized lipase from Candida antarctica gave the highest product yield among the selected lipases. Response surface methodology was applied to optimize reaction conditions; time (4 to 10 h), temperature (45 to 60 °C), enzyme load (10 to 18 wt%), and ethanol:oil molar ratio (30:1 to 60:1). The predicted highest 2-MAG yield (84.83%) was obtained at 45 °C using 10 (wt%) enzyme load and 50:1 ethanol:oil molar ratio for 5 h reaction time. Experiments to confirm the predicted results at optimum conditions presented a 2-MAG yield of 82.54%. The purification yield (g 2-MAG extracted/100 g of total product) was 80.10 and 69.00 for solvent extraction and low-temperature crystallization, respectively. The purity of the synthesized 2-MAG was found to be higher than 96%.