Enzymatic synthesis of partial glycerol caprate in solvent-free media

Enzymatic synthesis of partial glycerol caprate from capric acid and glycerol was investigated by using lipase from Candida antarctica (CAL) in a solvent-free microaqueous media. In a closed reactor, equilibrium conversion reached 65.6% in 9 h under optimal reaction conditions which were: temperature, 60 °C; initial water content in glycerol, 12% (w/w); lipase dosage, 100 U/g of capric acid; molar ratio of glycerol:capric acid, 1:1. Initial reaction mixture phase states were investigated by using a flat plate cooling-quenching method with a micrograph system. Regional capric acid concentration surrounding the immobilized lipase surface is higher than that in the bulk phase. CAL did not express 1,3-position specificity in the final product. Mechanical fray partly denatured CAL in batch reactor. Capric acid conversion as high as 96.9% was obtained in 6 h with several modified reaction procedures in a batch reactor.