Glycerolysis of Buriti Oil (Mauritia flexuosa) by Magnesium Oxide and Immobilized Lipase Catalysts: Reaction Yield and Carotenoids Degradation

Buriti (Mauritia flexuosa) is a palm tree widely distributed in South America. The oil extracted from its fruit is an added value product for its high carotenoids content. The aim of this work was to evaluate the alkaline (magnesium oxide—MgO) and enzymatic (lipase B from Candida antarctica immobilized on macroporous acrylic resin) glycerolysis of buriti oil to obtain non-ionic emulsifiers and evaluate the carotenoids degradation during this process. Alkaline glycerolysis was carried out using a 3:1 glycerol/oil molar ratio, temperatures of 170 and 210 °C, and MgO contents of 0.5 and 1%wt. Enzymatic glycerolysis reactions were performed using 3%wt. of a lipase catalyst and varying the following parameters: glycerol: oil molar ratio (3:1, 6:1, and 9:1), solvent (tert-butyl alcohol) concentration (50%, 150%, and 250%, vol./substrate mass), and temperature (40, 55 and 70 °C). The products were analyzed by liquid chromatography and UV–visible spectroscopy (370–520 nm). Enzymatic glycerolysis was superior in terms of conversion and selectivity to monoacylglycerols (MAG). MAG yields were close to 80% or higher for most conditions tested for enzymatic glycerolysis, while the maximum yield for alkaline glycerolysis was of 58%. UV–Vis data showed that carotenoids were severally degraded in alkaline glycerolysis, while the enzymatic product exhibited high preservation of carotenoids and color and odor similar to those of the pure buriti oil. Based on the final composition of the non-ionic emulsifiers obtained from buriti oil by enzymatic glycerolysis, they can be considered potential raw materials for cosmetic and food industries.