Characterization of Essential Oils from the Skin of <em>Citrus limetta</em> Risso, <em>Citrus limetta</em> Sp., <em>Citrus reticulata</em> and <em>Citrus sinensis</em> Grown in Northeastern Peru

Abstract

The revaluation of agri-food waste to provide consumers with bioactive compounds for a healthy and environmentally sustainable diet is growing exponentially in society. In the present work, the chemical and physical properties of essential oils (EO) extracted from the peels of four citrus fruits grown and commercialized in Amazonas, Peru: lime (Citrus limetta Risso), sweet lemon (Citrus limetta sp.), mandarin (Citrus reticulata) and orange (Citrus sinensis) were determined. The essential oils were extracted using green solvent and then their antioxidant capacity was determined by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2&amp;#039;-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) free radical scavenging technique; the total phenolic content using Folin Ciocalteu&amp;#039;s reagent. Total flavonoids, refractive index, density, specific heat capacity, Ramam mapping and main phenolic compounds were also determined by liquid chromatography (UHPLC-DAD). It was found that lime and mandarin essential oils had higher antioxidant capacity (1592.38 and 1216.13 μmol TE/g) and higher total phenolic content (680.78 and 420.28 mg AGE/g); while sweet lemon peel essential oil had higher total flavonoid content (23.18 mg QE/g). Given their characteristics, these essential oils have a high potential for use in the food and/or pharmaceutical industry.