Conventional and Microwave Assisted Extraction of Eulophia ochreta Lindl and Zingiber cassumunar Roxb: An Comparitive Account

MAE is the simplest and the most economical technique for extraction of many plant derived compounds. Conventional techniques as heating, boiling, or refluxing can be used to extract the plant material, however, the disadvantages are the loss of active constituents due to ionization, hydrolysis and oxidation during extraction as well as the long extraction time. Other techniques like ultrasonic assisted extraction (UAE) and microwave assisted extraction (MAE) have also become of interest as alternatives for conventional methods. Microwave extraction can be the better alternative to conventional extraction. Microwave assisted extraction requires shorter time, less solvents, higher extraction rate and better products with lower loss. There is less risk of decomposition and oxidation of phytoconstituents. An attempt has been made to make use of microwave for extraction of two indigenous drugs Eulophia ochreta lindl and Zingiber cassumunar Roxb. The widely used plants were selected on the basis of their phytochemical profile. In the present study, the tubers of Eulophia ochreata lindl and roots of Zingiber cassumunar Roxb were subjected to successive solvent extraction using petroleum ether, chloroform, methanol, water etc. Similarly the powders of both the drugs were subjected to extraction using microwave. The parameters selected for comparison were time required and % yield. Trial and error methods was followed to select different intensity and to set time. It was observed that there was significant increase in the yield but the time required was much less as compared to conventional extraction. The results were found to be encouraging to conduct further studies.