LAUSR

The aim of the current research is to study the effect of parameters including: extraction time (sonication time), extraction temperature, and drying method on the extraction yield of phenolics from water mint (Mentha aquatica) under ultrasonic irradiation. Therefore, three drying methods (microwave-drying, oven-drying, and freeze-drying) were performed. The dried samples were then ground and extracted at three different temperatures (20, 40, and 60 °C) in an ultrasonic bath. The maximum total phenolic compounds (TPCs) of 0.2451 mg/g were attained by freeze-drying method regarding the following process conditions: the extraction time of 5 min, and the extraction temperature of 60 °C. The results demonstrated that the drying method and temperature, respectively, are the most effective parameters in the extraction of phenolic compounds from Mentha aquatica. Besides, observations indicated that sonication (under 42 kHz and 160 W sonication condition) would not bring any sensible effect on the extraction yield. Additionally, a cost evaluation of presented experiments has been made to investigate the economical evaluation. The calculations showed that the consumed electrical power in freeze-drying method is very high which would not be cost effective.