Optimization of Ultrasound-Assisted Extraction of Polyphenols and Flavonoids from Citrus Aurantium L. Var . Amara Engl. Fruit Peel Using Response Surface Methodology

Citrus aurantium fruit peel is a substantial source of polyphenols and flavonoids. An ultrasound-assisted procedure was used in this work for the extraction of these compounds from Citrus aurantium peels and additional steps of purification were carried out to yield flavonoid-enriched extract. Box–Behnken design was applied to optimize the ultrasound-assisted extraction (UAE) to obtain a flavonoid-enriched extract with the highest yields of polyphenols and flavonoids and the lowest yield of tannins. The optimal conditions of extraction were a solid-to-liquid ratio of 2.4 g/100 mL, an acetone concentration of 80