Healthy oils by glycerolysis of triglycerides on basic catalysts

C.A. FERRETTI; J.I. DI COSIMO; M.L. SPOTTI

Rio de Janeiro

Simposio; 8th Inter. Symposium on Acid-Base Catalysis; 2017

9th International Symposium on Acid-Base Catalysis

Vegetable oils are mainly composed of triglycerides (TG). Diglycerides (DG) are esters of glycerol containing two acyl chains. There are different forms: the asymmetrical sn-1,2-DG and the symmetrical sn-1,3-DG isomers.Recently, several studies have shown that compared with TG, the regular intake of oil diglycerides (DG), in particular the 1,3-DG isomer, has a positive effect in preventing bodyweight gain and obesity-related diseases [ , ]. These beneficial effects are related to its distinct metabolic pathway compared to TG or 1,2-DG rather than to a reduced energy content [2]. The metabolism of the 1,3-DG isomer in the small intestine avoids re-synthesis of TG and the consequent fat deposit in the body tissues. In this work we present our results on the synthesis of DG-rich vegetable oils under heterogeneously catalyzed conditions using MgO as a solid catalyst. The process comprises the glycerolysis of the oil triglycerides, according to Eq. (1):2 TG+Gly ↔3 DG (1)where Gly stands for glycerol. We studied the reaction conditions that favor the synthesis of the 1,3-DG isomer so that the product is a diglyceride-rich healthy edible oil. We investigated the complex reaction pathways leading to the different glycerides and the effect of the experimental variables such as temperature and Gly/TG ratio on the shift of the reaction pathways and therefore, on the glycerolysis product composition. Furthermore, we studied the conditions (temperature, inert gas flow rate and presence of free fatty acids) that affect both, the stability and quality of the glycerolysis product mixture, and the interconversion of the DG isomers.