Microwave-assisted hydrodistillation (HAPM) of lemongrass (Cymbopogon citratus) essential oil

Abstract

Microwave Assisted Hydrodistillation (HAPM) is an advanced hydrodistillation (HD) technique that uses a microwave oven in the extraction process. The effect of different water to raw material ratios of 6:1, 8:1 and 10:1 on the essential oil yield of Cymbopogon citratus was determined using HAPM (250W). It is observed that by decreasing the ratio of water to plant material from 10:1 to 8:1, the highest extracted oil yield (w/w) increased from 1.29% to 1.48%. However, the yield of extracted oil (w/w) decreased to 0.90% when the ratio is reduced to 6:1. It was found that the main variables affecting the extraction process are the ratio between water and plant material, followed by the extraction time and microwave power level. The condition predicted by the design model for the optimal yield obtained of 1,461% was 8:1 water / plant material ratio, microwave power level of 250 W and 30 minutes of extraction time.