RESUMO
Monoglyceride MG has a wide function in the food industry, in particular as a natural emulsifier, pharmaceuticals, cosmetics, antioxidant, and antibacterial. Therefore, the production of polyol ester from esterification of acid (OA) and glycerol was investigated. The process optimization was performed using a Box-Behnken design, examining the effects of temperature, molar ratio, and catalyst amount. For predicting the optimal point, a second-order polynomial model was fitted to correlate the relationship between independent variables and response (% MG). The effects of temperature (100, 150, and 200 °C); catalyst amount (4, 10, and 16% w/w); and glycerol/oleic acid ratio (1:1, 1:2, and 1:3) were investigated and found to deeply affect the reaction outcome. At the optimal reaction conditions: 200 °C, 0.2% w/w KSF, and a glycerol/oleic acid ratio (3:1), more than 71.8% monoglycerides with selectivity of 80% were obtained. Confirmation experiments were performed to demonstrate the effectiveness of this approach, and the characterization of monoglycerides was performed using high-performance liquid chromatography (HPLC).
RESUMO
The production of fatty acid esters from stearic, oleic, and palmitic acids and polyols (ethylene glycol and glycerol) was investigated in this work. A series of montmorillonite-based clays catalysts (KSF, KSF/0, KP10, and K10), having different physicochemical properties, were used as acidic catalysts. The influence of the specific surface area and the acidity of the catalysts on the esterification rate were explored. The best catalytic activities were obtained with KSF catalyst. The optimization of various factors on the reaction was also studied, including catalyst concentration, reaction temperature and molar ratio (polyol / fatty acid). The yield rate reached 94% under the optimum conditions and the recovery rate maintained more than 96% after 5 batches.