Process evaluation of solvent‐free lipase‐catalyzed esterification schemes in the synthesis of structured triglycerides from oleic and palmitic acids

Abstract

AbstractDifferent schemes in the production of structured triglycerides based on solvent‐free esterification of oleic acid and palmitic acid with glycerol were evaluated in terms of reactant conversion, product composition, and yield. Two‐step processes, with or without glycerol dosing, were compared with one‐step versions carried out at temperature conditions within 40°C–60°C to a final oleic acid/palmitic acid/glycerol ratio of 2:1:1, the stoichiometric ratio in 1,3‐dioleoyl‐2‐palmitoyl glycerol (OPO). Substantial amounts of C52 triglycerides, including OPO, were produced in all schemes at 34.98–39.55 wt.% of the total triglycerides and triglyceride yields of 50.10–56.56 wt.% based on the raw materials. The two‐step process with glycerol dosing at 60°C showed the highest palmitic acid incorporation at the sn‐2 position of 46.46%, but the same process carried out with a step increase in temperature from 40°C to 60°C gave the highest OPO yield at 19.30 wt.%. These results demonstrate the possibility of manipulating regioselectivity and triglyceride specificity by varying reactant feeding schemes without the use of solvents and sn‐1,3‐specific lipases common in conventional acidolysis‐based processes.