ABSTRACT
The aim of this study was to determine the proximate, phytochemical and mineral content of Citrus aurantium (Bitter Orange) peels. Fresh peels were air-dried, ground into fine powder, and subjected to standard methods for proximate, phytochemical, and mineral analyses. Proximate composition was determined using methods such as Soxhlet extraction for crude fat, Kjeldahl method for protein, and gravimetric techniques for ash and moisture content. Phytochemical screening, both qualitative and quantitative, was conducted using reagents and techniques like Folin-Ciocalteu for polyphenols and sodium hydroxide tests for flavonoids. Mineral analysis was performed using Atomic Absorption Spectrophotometry (AAS) for calcium, magnesium, iron, zinc, and copper. The proximate analysis revealed high carbohydrate (59.45 ± 0.21%) and fiber (15.42 ± 0.13%) content, moderate protein levels (6.98 ± 0.06%), and low fat (3.68 ± 0.06%) and moisture content of fresh (67.50 ± 0.13%) and dried (8.45 ± 0.11) peels, highlighting the peel's nutritional value. Phytochemical screening indicated that ethanolic extracts were more efficient in extracting compounds such as flavonoids, phenols, and terpenoids compared to aqueous extracts. Quantitative analysis showed significant concentrations of polyphenols (85.20 ± 2.10 mg/100g) and vitamin C (48.35 ± 1.02 mg/100g) in the ethanolic extract, showing the peel's antioxidant potential. Oxalic acid (6.50 ± 0.45 mg/100g) and phytic acid (10.75 ± 0.65 mg/100g) were of moderate levels. Mineral analysis identified calcium (245.6 ± 0.47 mg/100g) and magnesium (83.3 ± 1.9 mg/100g) as predominant elements, with iron (21.5 ± 1.2 mg/100g) and zinc (3.4 ± 0.1 mg/100g) emphasizing the peel's contribution to dietary mineral intake, while copper was absent. These findings establish Citrus aurantium peel as a promising candidate for developing functional foods and a good & recommended source of minerals compared to other popular plants (like Moringa oleifera leaf), leveraging its rich nutrient profile and bioactive components. The superior extraction efficiency of ethanol shows the importance of solvent selection in maximizing the therapeutic and nutritional potential of plant-based materials. Future research could explore the bioavailability and pharmacokinetics of these compounds to further substantiate their health benefits.
