Exploring chemical properties of essential oils from citrus peels using green solvent
Katheryn L. Vasquez-Gomez, Diner Mori-Mestanza, Aline C. Caetano, Guillermo Idrogo-Vásquez, Carlos A. Arce, Erick Aldo Auquiñivin Silva, Efraín M. Castro–Alayo, Rosita Cruz-Lacerna, Harvey A. Pérez-Ramos, César R. Balcázar-Zumaeta, Llisela Torrejón-Valqui, Cindy Yoplac-Collantes, Ives Yoplac, Segundo G. Chávez
Abstract
The research explored the chemical characteristics of essential oils (EOs) extracted from the peels of four citrus fruits grown in northeastern Peru (lime, sweet lemon, mandarin and orange). The essential oils were extracted by hydrodistillation using a green solvent, and subsequently, their physicochemical profile, bioactive, heat capacity, and RAMAN mapping were determined; in addition, the volatile composition was determined by gas chromatography (GC-MS), and the main phenols by liquid chromatography (UHPLC). The results evidenced that sweet lemon and mandarin essential oils had higher antioxidant activity (1592.38 and 1216.13 μmol TE/g) and total phenolic content (680.78 and 420.28 mg GAE/g). In contrast, sweet lemon peel essential oil had the highest total flavonoid content (23.18 mg QE/g). D-limonene was the most abundant aromatic compound in orange (>67 %), mandarin (>70 %), and sweet lemon (>72 %) EOs; however, in the lime, it was the lowest (37 %). The most abundant component was the cyclobutane, 1,2-bis(1-methylethylethylenyl)-, trans- (32 %).