Optimization of Ultrasound-Assisted Extraction via Sonotrode of Phenolic Compounds from Orange By-Products

• Published in: Foods Vol. 10; no. 5; p. 1120
• Main Authors: Razola-Díaz, María del Carmen, Guerra-Hernández, Eduardo Jesús, Rodríguez-Pérez, Celia, Gómez-Caravaca, Ana María, García-Villanova, Belén, Verardo, Vito
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 18.05.2021; MDPI
• Subjects: Acids; Amplitudes; antioxidant activity; Antioxidants; Bioactive compounds; Box–Behnken design; By products; Byproducts; Citrus fruits; Design of experiments; Drying; Ethanol; Experimental design; Food science; Fruit juices; Fruits; High performance liquid chromatography; HPLC-MS; Liquid chromatography; Moisture content; Optimization; orange peel; Oranges; Phenolic compounds; Phenols; Response surface methodology; sonotrode ultrasound-assisted extraction; Ultrasonic imaging; Ultrasound; Variance analysis; St Louis Missouri; United States > US; Germany
• ISSN: 2304-8158; 2304-8158
• DOI: 10.3390/foods10051120

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.