Abstract

1,3-Diacylglycerols (1,3-DAG) are minor components in edible oils with potential for the management of overweight and obesity. In this work, 1,3-DAG containing stearidonic acid (SDA), gamma-linolenic acid (GLA), and alpha-linolenic acid (ALA), were synthesized by lipase-mediated catalysis following a Taguchi experimental design. SDA, GLA, and ALA are polyunsaturated fatty acids (PUFA) able to act as precursors of anti-inflammatory lipid mediators in the human body and may help with prevention or relief of inflammatory diseases. Solvent-free synthesis of 1,3-DAG was successfully performed by esterifying glycerol with free fatty acids (FFA) obtained from Echium plantagineum seed oil. Crude reaction products were further purified by saponification. Two lipases (Lipozyme (R) RM-IM and Lipozyme (R) 435) and three variables (substrate molar ratio, lipase load and reaction time) were used to optimize the reaction conditions. At the optimal conditions, 88.7 mol% of DAG was produced (68.0 mol% 1,3-DAG and 20.7 mol% 1,2-DAG) using Lipozyme (R) 435 at 60 degrees C, a glycerol:FFA molar ratio of 1:3, a lipase load of 2.0 wt%, and 4 h reaction time. Proportions of SDA, GLA and ALA in the 1,3-DAG were 32.7, 32.3 and 22.0% respectively. The synthesized 1,3-DAG have potential as functional ingredients in foods for weight and obesity management.