The central composite rotatable design by response surface methodology was applied for optimization of ultrasonic extraction conditions of Bene hull (Pistacia atlantica subsp. Mutica) polyphenols. The sonication time, temperature and ethanol-water ratio were independent parameters studied for the extraction optimization. Total polyphenols and antioxidant potentials of extracts in terms of ferric reducing antioxidant potential (FRAP), DPPH scavenging activity and oxidative stability index (OSI) were determined. The obtained data were well consistent with the polynomial equations by significant variation in linear, quadratic and interaction impacts of the process factors. The optimized extraction conditions were sonication time, 26.91 min, temperature, 50.42 °C and ethanol concentration, 55.84%. The total polyphenols, DPPH, FRAP an OSI of optimal extract were 304.47 mg GAE/g, 72.47%, 54.04 mmol/100g and 8.55 h, respectively. High performance liquid chromatography (HPLC) analysis of optimal extract detected presence of epicatechin, chlorogenic, sinapic, caffeic and gallic acids.

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