Study on the pretreatment methods for extraction of essential oil from lemongrass (Cymbopogon citratus), Basil (Ocimum basilicum) and coriander (Coriandrum sativum) leaves

The extraction process of essential oils are becoming very expensive with increase in degradation of nutrients. Therefore, we devised new method for extraction of essential oil from the leaves of these plant spp. i.e. basil, lemongrass and coriander i.e. Ohmic and Ultrasonic. The Ohmic hydro distillation (OHD) extraction system was designed and set up along with the conventional hydro distillation (CHD) extraction system. The ultrasonic pre-treatment with CHD and OHD were also tried for leaves of the three plant spp. 100g leaves of each plant spp. were taken to extract the essential oil using all the four methods i.e. CHD, OHD, UCHD and UOHD. OHD extraction system resulted in 50% (2.5 hours of extraction time) time reduction with 0.41kW power consumption over CHD process which took 5 hr and 0.5 kW power whereas the extraction time was reduced by 15% using UCHD extraction system and the energy consumption of UCHD was also low (i.e. up to 18%) over CHD whereas by UOHD extraction system there was time saving up to 86% and energy consumption upto 74%. Therefore, we came up with an innovative, safe alternative extraction system i.e. UOHD which offers reduction in energy, cost and save time along with the increase in amount of essential oil.