Optimizing Procedures of Ultrasound-Assisted Extraction of Waste Orange Peels by Response Surface Methodology

• Main Author: Feng, C.-H (Author)
• Format: Article
• Language: English
• Published: MDPI 2022
• Subjects: antioxidant; Antioxidants; chemistry; Citrus sinensis; hesperidin; methanol; Methanol; plant extract; Plant Extracts; response surface methodology; solvent; Solvents; sweet orange; ultrasound-assisted extraction; waste orange peels
• Online Access: View Fulltext in Publisher

 The simultaneous effects of three continuous factors: solvent concentration (50–100%), treated times (25–85 min), treated temperatures (25–55◦C), and two categorical factors: type of solvents (methanol or ethanol) and ultrasonic frequency (28 kHz or 40 kHz) on ultrasonic-assisted extraction yield from waste orange peels were evaluated and optimized by response surface method-ology. Fourier Transform Infrared (FTIR) spectroscopy with a wavelength of 500 cm−1 to 4000 cm−1 was employed to rapidly identify the orange extracts. The significant polynomial regression models on crude extraction, sediments after evaporation, and precipitation yield were established (p < 0.05). Results revealed that solvent concentration affected crude extraction and precipitation yield linearly (p < 0.01). The optimal and practical ultrasound-assisted extraction conditions for increasing the precipitation yield were using 61.42% methanol with 85 min at 55◦C under 40 kHz ultrasonic frequency. The spectra of extracts showed a similar fingerprint of hesperidin. © 2022 by the author. Licensee MDPI, Basel, Switzerland.