Rapid microwave-assisted transesterification for the preparation of fatty acid methyl esters from the oil of yellow horn (Xanthoceras sorbifolia Bunge.)

Abstract

An efficient microwave-assisted transesterification (MAT) technique was developed to prepare fatty acid methyl esters (FAMEs) from yellow horn (Xanthoceras sorbifolia Bunge.) oil. To evaluate the applicability of this novel MAT method, the conversion yields of FAMEs and compositions were compared with those from the standard method of transesterification (AOAC Method 996.06). The results showed that MAT had obvious advantages to standard techniques in terms of short duration, high efficiency and stable composition. The parameters influencing the MAT procedure including microwave irradiation power, temperature, reaction time, molar ratio of methanol to oil and catalyst concentration were optimized. The maximum yield of FAMEs reached 96% under optimal MAT conditions of transesterification irradiation power 500 W, temperature 60 °C, 6 min, 1% wt catalyst and a molar ratio of methanol/oil 6:1 (v/v). Validation of the MAT method was performed in terms of repeatability and reproducibility; relative standard deviations for conversion yields were lower than 4.37 and 6.83%, respectively. These results revealed that the MAT method developed in the present investigation is suitable for the sample preparation of FAMEs from plant oils.