Optimization of extraction of lemongrass leaves (Cymhopogon citratus) with microwave-assisted hydrodistillation using Box-Behnken design

Abstract

Lemongrass (Cymbopogon citratus) is one of the plants as source of essential oils, which are widely used as food and beverage flavors and aromatherapy. This plant has great potential to be developed due to low prices and high planting power. The extraction of essential oils from lemongrass generally still uses conventional methods of water distillation or steam distillation, which requires a long distillation time (about 6 hours) to get good quality oil. However, extraction with water using a microwave as a heating method, known as Microwave Assisted Hydro distillation (MAHD) is considered to be able to shorten the extraction time. This research aims to extract lemongrass oil through microwave-assisted hydro distillation method by studying the effect of extraction time, microwave power, and water ratio to feed ingredients, as well as searching for optimal operating conditions using the Response Surface Methodology Method Box. Behnken Design (BBD). The experiments were carried out under atmospheric pressure using operating variables: extraction time, microwave strength and feed to solvent ratio, respectively. Before the experiment starts, the response surface methodology using Box Behnken Design (3 factors and 2 levels) is planned to minimize the number of experiments. The maximum yield using the Micro Auxiliary Hydro distillation method requires a much faster time compared to conventional methods. The results obtained by studying the effects of the parameters show that the results increase with the extraction time and microwave power. The prediction value generated from the response surface methodology with the Box-Behnken design shows that there is conformity with the results obtained from the experiment, this shows that the optimization methodology carried out has made the experiment more effective and efficient and can find out which parameters significantly influence or not, and get the optimum conditions for the highest yield. Then the next experiment can be focused on increasing the results in terms of quality and quantity.