Comparative Study of Various Methods for Extraction of Antioxidant and Antibacterial Compounds from Plant Seeds

Extracts from seeds of five different plants were prepared in water, methanol, and ethanol by employing five different methods of extraction viz. Soxhlet method, ultrasonication, extraction by continuous shaking at room temperature, and microwave assisted extraction- with and without intermittent cooling. All these extracts were compared with respect to extraction efficiency, total phenol content, total flavonoid content, antioxidant capacity, and antibacterial activity. Soxhlet method proved best in terms of high extraction efficiency, and extraction of phenolic compounds. Microwave assisted extraction with intermittent cooling (MAE), room temperature extraction by shaking (ERT), and ulrasonication assisted extraction (UAE) proved good at extracting antibacterial compounds from plant seeds. Latter also proved effective at extracting antioxidant compounds. Extraction efficiency was found to have no notable correlation with any of the parameters assayed. Methanol proved most suitable solvent for extraction of flavonoids.