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

• Published in: Molecules (Basel, Switzerland) Vol. 27; no. 7; p. 2268
• Main Author: Feng, Chao-Hui
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 31.03.2022; MDPI
• Subjects: Antioxidants - chemistry; Chemical precipitation; Citrus fruits; Citrus sinensis - chemistry; Coronaviruses; Ethanol; Evaporation; Flavonoids; Fourier transforms; Hesperidin; Methanol; Microscopy; Plant Extracts - chemistry; Polynomials; Regression analysis; Response surface methodology; Sediments; Severe acute respiratory syndrome coronavirus 2; Solvents; Solvents - chemistry; Spectrum analysis; Ultrasonic imaging; Ultrasound; ultrasound-assisted extraction; waste orange peels; Yield; Japan; response surface methodology; ultrasound-assisted extraction; waste orange peels; hesperidin
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules27072268

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 methodology. 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.