Optimization of Ultrasound-Assisted Extraction via Sonotrode of Phenolic Compounds from Orange By-Products Razola Díaz, María del Carmen Guerra Hernández, Eduardo Jesús Rodríguez Pérez, Celia Gómez Caravaca, Ana María García Villanova Ruiz, Belén Verardo, Vito Box-Behnken Design Phenolic compounds Antioxidant activity Orange peel Sonotrode ultrasound-assisted extraction HPLC-MS Orange peel is the main by-product from orange juice industry. It is a known source of bioactive compounds, mostly phenolic compounds, and it has been widely studied for its healthy activities. Thus, this research focuses on the establishment of ultrasound-assisted extraction of phenolic compounds in orange peel using a sonotrode. For this purpose, a Box–Behnken design of 27 experiments was carried out with four independent factors—ratio ethanol/water (v/v), time (min), amplitude (%), and pulse (%). Quantitative analyses of phenolic compounds were performed and the antioxidant activity was measured by ABTS and DPPH methods. The validity of the experimental design was confirmed by ANOVA and the optimal sonotrode extraction conditions were obtained by response surface methodology (RSM). The extracts obtained in the established conditions were analyzed by High Performance Liquid Chromatography (HPLC) coupled to mass spectrometer detector and 74 polar compounds were identified. The highest phenolic content and antioxidant activity were obtained using 45/55 ethanol/water (v/v), 35 min, amplitude 90% (110 W), and pulse 100%. The established method allows an increment of phenolics recovery up to 60% higher than a conventional extraction. Moreover, the effect of drying on phenolic content was also evaluated. 2021-05-20T10:52:53Z 2021-05-20T10:52:53Z 2021 info:eu-repo/semantics/article Razola-Díaz, M.d.C.; Guerra-Hernández, E.J.; Rodríguez-Pérez, C.; Gómez-Caravaca, A.M.; García-Villanova, B.; Verardo, V. Optimization of Ultrasound-Assisted Extraction via Sonotrode of Phenolic Compounds from Orange By-Products. Foods 2021, 10, 1120. https://doi.org/ 10.3390/foods10051120 http://hdl.handle.net/10481/68587 10.3390/foods10051120 eng eu-repo/grantAgreement/EC/H2020/817936 http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Atribución 3.0 España MDPI