Optimization of ultrasound‐assisted extraction of antioxidative phenolic compounds from Deverra scoparia Coss. & Durieu (flowers) using response surface methodology

The current study aims to optimize the ultrasound-assisted extraction of Deverra scoparia Coss. & Durieu (flowers) antioxidative phenolic compounds using response surface methodology (RSM). A Box–Behnken design model has been conducted to investigate the effect of three factors, namely the extraction period, temperature, and sample-to-methanol ratio, on five responses, namely: extraction yield (Y%), Total Phenolic Content (TPC), Flavonoids Content (FC) and two antioxidant tests DPPH˙ and FRAP. The used model, proposed to run the extraction at 50°C for 55 min duration with a sample-to-methanol ratio (wt/vol) of 1:70 g/mL. Under optimum conditions (proposed), the experimental values of extraction yield, TPC, FC, DPPH-IC50, and FRAP-IC50 were 10.785%, 922.107 mg GAE/100 g dry matter, 255.634 mg QE/100 g dry matter, 0.113 g/L and 0.066 g/L, respectively. The experimental values were in agreement with the predicted values, indicating the capability of the model and succeed of RSM in optimizing the extraction conditions. Practical applications Algerian ethnopharmacological data, considered and believed that D. scoparia herb has numerous therapeutic characteristics, such as hepatitis, digestive difficulties, and urinary infections. However, and according to our literature survey, we noticed that most of the reported studies done on this plant were focusing only on their essential oils, and there was a severe shortage of studies done on this plant in Algeria that investigated its phenolic compounds. Hence, this research aims to optimize the recovery of D. scoparia phenolic compounds by using a green extraction (UAE). On the other hand, the extract under optimum conditions could, therefore, be used in the future to deliver good substitutes to the synthetic antioxidants, and so, enriches the database of pharmaceutical and food application.