Ultrasound‐assisted extraction optimization of polyphenols, flavonoids, and antioxidant compounds from fruit of Melia azedarach using a glycerol‐based green deep eutectic solvent

Abstract

For sustainable extraction of bioactive components from Melia azedarach fruit, ultrasound-assisted extraction (UAE) and a green deep eutectic solvent (DES) glycerol-ammonium acetate (GAA) were studied with optimization under response surface methodology with variables temperature, amplitude, and DES concentration (DC). The three-level, three-factorial Box–Behnken design (BBD) was applied to study three extraction conditions: temperature (30–50°C), amplitude (50%–100%), and DES concentration (50%–90%) to obtain highest level of total phenol (TP), total flavonoid (TF), iron chelating activity (ICA), and anti-radical activity (DPPH). The optimized conditions for the responses were 50°C temperature, 50% DC, and 100% amplitude and the observed values for TP, TF, ICA, and DPPH were found 17.11 mg GAE /g DW, 11.33 mg RE/g DW, 52.66%, and 72.84%, respectively. The model was strongly supported by validation study, which indicates GAA-UAE is an effective green method for extracting bioactives from M. azedarach and the lower error rates (≤5.60) between predicted and observed values for TP, ICA, and DPPH models showed that these responses are more predictable compared with those of TF. Practical applications The study proposes an ultrasound-assisted green and efficient approach for extraction of bioactive natural products from the fruit of the medicinal plant Melia azedarach. The optimized method developed can be used to obtain polyphenols, flavonoids, and other antioxidant bioactives from this abundantly available plant for industrial application for various medicinal and food preservation purposes.