OPTIMIZATION OF ULTRASOUND ASSISTED EXTRACTION OF HESPERIDIN FROM ORANGE PEEL

Abstract

Genus Citrus contain high levels of polyphenols widely known for having antioxidant properties; their presence can be greater in citrus peel than in fruit pulp. The main flavonoid in orange peel is hesperidin. On the other hand, conventional extraction of phytochemical compounds using organic solvents produces high pollution, which is why 'green' extraction techniques are required (1). The aim of this investigation was identify the optimal conditions to extract hesperidin from orange (Citrus sinensis) peel using ultrasounds and environmentally friendly solvents. A comparative analysis was carried out employing response surface methodology for the following variables: power, time and ethanol percentage in water. Orange peel was cut in squares of side 0.6 cm and ultrasound treated (Qsonica), citrus peel extracts were passed through a Sep-Pak® cartridge (Phenomenex) and then analyzed by high-performance liquid chromatography into Agilent 1120 system LC (Agilent-Technologies); the chromatographic peak was compared with standard hesperidin (Sigma-Aldrich). The optimum extraction conditions were as follows: power 400 W, extraction time 18.95 min and ethanol 22.8% in water; the maximum concentration of hesperidin was 113.02 mg/100 g. In conclusion, the results evidence that ultrasound-assisted extraction is an effective and non-conventional technology suitable for citrus waste valorizatio.