Optimization of ultrasound-assisted extraction of Moringa peregrina oil with response surface methodology and comparison with Soxhlet method

In this paper, ultrasound-assisted extraction (UAE)of oil from Moringa peregrina seeds was studied and compared with the Soxhlet method. Based on the response surface methodology (RSM), the extraction process variables such as liquid-to-solid ratio, ultrasound power, extraction time and temperature were investigated to achieve the highest yield. By screening these parameters, it was concluded that the liquid-to-solid ratio (mL/g)and extraction time were the significant parameters for oil extraction from Moringa peregrina using ultrasound treatment. The best possible range for the liquid-to-solid ratio (5-20 mL/g), extraction time (5-30 min), and optimum ultrasound power (348 W)as well as extraction temperature (30 °C)was obtained according to the single factor experiments. Afterward, the optimum process conditions which were determined by central composition design (CCD)to reach the maximum oil extraction yield (53.101 percent)were found to be 26.3 min for extraction time and 17.8 mL/g for the liquid-to-solid ratio. In addition, the gas chromatography analysis and the physiochemical characteristics of oil extracts obtained through UAE and Soxhlet techniques including peroxide value (PV), antioxidant activity (DPPH percent), total phenolic content (TPC), iodine value (IV), thermal stability, crystallization, and melting behavior were determined and compared.