GC-MS Profiling and Phytochemical Screening of Tanzania Orange (Citrus Sinensis) Peel Essential Oils: Implication for Nutraceutical and Industrial Applications

Abstract

Citrus sinensis (sweet orange) peels, though commonly discarded as waste, contain valuable nutrients such as vitamin C, fiber, phenolics, and flavonoids justifying the need to convert this waste into beneficial products. The objective of this study was to assess the nutritional composition, phytochemical constituents, and essential oil profile of sweet orange peels to explore their potential applications. Methodologically, proximate analysis, elementary analysis, and qualitative phytochemical screening were conducted, alongside successive solvent extraction using hexane, ethyl acetate, and methanol to ensure comprehensive separation of phytochemicals; fresh peels were also subjected to steam distillation using TIRDO-fabricated equipment to obtain essential oils, which were analyzed through GC–MS. The results showed that the peels contained high protein (12.5%) and crude fiber (14.8%), making them suitable for incorporation into processed foods; phytochemical screening revealed the presence of multiple bioactive compounds, including alkaloids, cardiac glycosides, flavonoids, glycosides, phenols, resins, saponins, steroids, tannins, terpenoids, and triterpenoids, with anthraquinones absent across all solvents. GC–MS analysis identified limonene (92.2%) as the major essential oil component, followed by myrcene (2.3%), sabinene (1.5%), linalool (1.4%), octanal (1.3%), α-pinene (0.6%), and trace amounts of decanal, α-terpineol, β-bisabolene (0.2%), and γ-terpinene (0.1%). In conclusion, the study demonstrates that sweet orange peels and their essential oils are promising sources of nutritionally and industrially valuable compounds suitable for edible medicinal use and diverse industrial applications.