Extraction of Phenolic Compounds from Orthosiphon Stamineus (Misai Kucing) Using Deep Eutectic Solvent Incorporated with Assistive Extraction Techniques
Yoke Shan Wong

Department of Chemical Engineering, Sustainable Process Engineering Centre (SPEC), Faculty of Engineering, Universiti Malaya, 50603, Kuala Lumpur, Malaysia
*wyokeshan[at]gmail.com

Abstract

Phenolic compounds are known to have a significant effect on human defense system due to their anti-inflammatory efficacy. This could slow down the aging process and strengthen human immune system. With the growing interest in phenolic compounds extraction, a medicinal herb that is widely found in South East Asia conturies, called Orthosiphon Stamineus, also commonly known as Misai Kucing or Java Tea, are utilized in this study to extract valuable phenolic compounds. In this study, we investigated extraction of phenolic compounds using choline chloride-based deep eutectic solvents paired with four types of hydrogen bond donor (lactic acid, ethylene glycol, glycerol and urea) as the extraction of phenolic compounds has been geared towards a sustainable and green path with the use of environmentally benign solvents such as deep eutectic solvent (DES). Assistive extraction techniques such as microwave and ultrasound were incorporated with DES in order to minimize the extraction time and maximize the yield. All the DES used showed satisfactory extraction yield of phenolic compounds, as compared to 70 percent ethanol (conventional solvent). Choline chloride - ethylene glycol has exhibited the highest total phenolic content extraction regardless the extraction methods (microwave or ultrasound). Also, microwave-assisted extraction has greater impact on the phenolic compound extraction yield as compared to ultrasound-assisted extraction.

Keywords: green extraction, deep eutectic solvent, phenolic compound, microwave-assisted extraction

Topic: Food biotechnology and bioprocess engineering