Green Solvents and Ultrasound-Assisted Extraction of Bioactive Orange (Citrus Sinensis) Peel Compounds

Byproducts such as orange peel have potential uses because of their bioactive compounds, which are important for their potential to reduce the risk factors of diseases caused by aging. The lack of effective techniques and the high levels of pollution produced by the conventional extraction of bioactive compounds using organic solvents have highlighted the need to enhance the 'green chemistry' trend. This study evaluates the use of ultrasound to extract bioactive compounds from orange peel. The antioxidant capacity, phenolic content, ascorbic acid, total carotenoids, and HPLC profile of phenolic compounds from orange peel extracts were obtained by a physicochemical evaluation. The results demonstrate that the optimal conditions for the ultrasound-assisted extraction of bioactive orange peel compounds were a power of 400 W, a time of 30 min, and 50% ethanol in water. These conditions were used to obtain a total carotenoid concentration of 0.63 mg ß-carotene/100 g, vitamin C concentration of 53.78 mg AA/100 g, phenolic concentration of 105.96 mg GAE/100 g, and antioxidant capacity of ORAC = 27.08 mM TE and TEAC = 3.97 mM TE. The major phenolic compound identified in all orange peel extracts was hesperidin, with a maximum concentration of 113.03 ± 0.08 mg/100 g.