RESUMEN
This manuscript reports for the first time a heterogenous catalytic route to monoglycerides (MAGs) from microalgal oil. Microalgae is an important biomass source with high-value applications, such as food ingredients with essential fatty acids. To date, the glycerolysis of microalgae has only been investigated for a microbial oil (Schizochytrium sp.) using enzyme catalysis. However, the use of enzymes on a large scale is currently economically impeditive and requires highly selective lipases. In this study, metal oxides were screened and the reaction conditions optimized for rapeseed oil. The optimized conditions were then used to investigate the production of MAGs from Scenedesmus sp. microalga. The most promising catalyst was found to be MgO/KOH, which gave a 44 % yield. Comparing two reaction systems (low temperature 70 °C/atmospheric pressure and high temperature at 200 °C/20â bar), it was found that the latter has a superior performance. Due to the stability of the product in air, the presence of an inert atmosphere is essential to achieve high yields.
RESUMEN
This study investigated the glycerolysis of babassu oil by Burkholderia cepacia lipase immobilized on SiO2-PVA particles in a continuous packed bed reactor. Experiments were conducted in a solvent-free system at 273.15 K either in an inert atmosphere or in the presence of cocoa butter to prevent lipid oxidation. The reactor (15 × 55 mm) was run at a fixed space time of 9.8 h using different molar ratios of babassu oil to glycerol (1:3, 1:6, 1:9, 1:12, and 1:15) to assess the effects of reactant molar ratio on monoacylglycerol productivity and selectivity. Nitrogen atmosphere and cocoa butter were equally effective in inhibiting lipid oxidation, indicating that addition of cocoa butter to glycerolysis reactions may be an interesting cost-reduction strategy. An oil/glycerol molar ratio of 1:9 resulted in the highest productivity (52.3 ± 2.9 mg g-1 h-1) and selectivity (31.5 ± 1.8%). Residence time distribution data were fitted to an axial dispersion model for closed-vessel boundary conditions, giving a mass transfer coefficient (kc) of 3.4229 × 10-6 m s-1. A kinetic model based on elementary steps of the studied reaction was written in Scilab and compared with experimental data, providing standard deviations in the range of 5.5-7.5%.
Asunto(s)
Arecaceae/metabolismo , Reactores Biológicos , Burkholderia cepacia/enzimología , Enzimas Inmovilizadas/metabolismo , Glicerol/metabolismo , Lipasa/metabolismo , Monoglicéridos/metabolismo , Aceites de Plantas/metabolismo , Antioxidantes/metabolismo , Grasas de la Dieta/metabolismo , Hidrólisis , Cinética , ViscosidadRESUMEN
In this work, the free lipase Eversa® Transform 2.0 was used as a catalyst for enzymatic glycerolysis reaction in a solvent-free system. The product was evaluated by nuclear magnetic resonance (1H NMR) and showed high conversion related to hydroxyl groups. In sequence, the product of the glycerolysis was used as stabilizer and biopolyol for the synthesis of poly(urea-urethane) nanoparticles (PUU NPs) aqueous dispersion by the miniemulsion polymerization technique, without the use of a further surfactant in the system. Reactions resulted in stable dispersions of PUU NPs with an average diameter of 190 nm. After, the formation of the PUU NPs in the presence of concentrated lipase Eversa® Transform 2.0 was studied, aiming the lipase immobilization on the NP surface, and a stable enzymatic derivative with diameters around 231 nm was obtained. The hydrolytic enzymatic activity was determined using ρ-nitrophenyl palmitate (ρ-NPP) and the immobilization was confirmed by morphological analysis using transmission electron microscopy and fluorescence microscopy.