Interesterification of Soybean Oil and Methyl Stearate Catalyzed by Guanidine-Functionalized SBA-15 Silica

The main purpose of this study was to develop a heterogeneous interesterification catalyst for the modification of edible oils to enhance their physicochemical and functional performances. To achieve this, 1,3-dicyclohexyl-2-octylguanidine was covalently immobilized on the SBA-15 (Santa Barbara Amorphous 15) material and then used as solid catalysts for the interesterification between soybean oil and methyl stearate. The characterization of the guanidine-functionalized SBA-15 material included Fourier transform infrared spectra, scanning electron microscopy, elemental analysis, and nitrogen adsorption-desorption techniques. It was shown that the solid base catalyst could efficiently catalyze the interesterification reaction. After the interesterification, the fatty acid profiles and triacylglycerol compositions of interesterified products were substantially varied. The influence of interesterification parameters, such as the substrate ratio, reaction time, reaction temperature and catalyst loading, on the interesterification reaction was investigated regarding the percentage of stearic acid in interesterified triacylglycerols. The stearic acid percentage of 27.9 % was achieved at 100 A degrees C within 4 h when the methyl stearate/soybean oil molar ratio of 6:1 was employed. The catalyst could be recovered easily by filtration and reused without significant loss of activity.