OPTIMIZATION OF MICROWAVE ASSISTED HYDRODISTILLATION OF LEMONGRASS (CYMBOPOGON CITRATUS) USING RESPONSE SURFACE METHODOLOGY

This research deals with the optimization of microwave assisted hydrodistillation (MAHD) of Lemongrass (cymbopogon citratus) by using response surface methodology. The constituents of extracted oil using MAHD was compared with the one obtained by conventional hydrodistillation (HD). The major constituent found in both extracts was citral, however with more abundant amount in MAHD. Central composite design (CCD) has been employed for evaluate the effect of water to plant material ratio, microwave power level and extraction time. The design model predicted the optimum yield of 1.4612 % at water to plant material ratio of 8:1, 250 W microwave power level and 90 min of extraction time. ANOVA results show the model was significant as indication from R 2 and F-value of 0.95 and 29.78, respectively. The yield obtained under the proposed economic condition in the laboratory (1.4635%) was very close with the predicted one, proved the reliability of the employed model, as well as the success of the RSM in optimizing the extraction conditions