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 peregrine 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 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 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 degrees 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%) were found to be 26.3 min for extraction time and 17.8 mL/g for 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%), total phenolic content (TPC), iodine value (IV), thermal stability, crystallization and melting behavior were determined and compared.