Biochemical, Phytochemical, and Antioxidant Characterization of Sweet Orange (<i>Citrus Sinensis</i>) Processing By-Products from Côte d'Ivoire

Background: Sweet orange (Citrus sinensis), is a widely cultivated fruit valued globally for its high ascorbic acid content. In Côte d'Ivoire, the fruit is predominantly processed for juice production within both informal and industrial sectors. However, processing by-products—namely the peel, pulp membrane, and seeds—constitute a major fraction of the total fruit mass and are routinely discarded, representing a significant loss of valuable bioresources. Aims: This study aimed to evaluate the valorization potential of these agricultural by-products by establishing their biochemical and phytochemical composition profiles. Material and Methods: Processing by-products of C. sinensis were obtained from Abidjan, Côte d'Ivoire. Physical yield and ascorbic acid content (via DCPIP titration) were evaluated on fresh matrices, whereas oven-dried specimens (65 °C, 48 h) were pulverized for compositional analysis. Proximate parameters (moisture, ash, crude fiber, fat, protein, sugars, and Atwater caloric values) were determined following standard AOAC protocols. Phytochemical screening included spectrophotometric quantification of total phenolics, flavonoids, and condensed tannins, alongside DPPH radical-scavenging assays. Data were analyzed through one-way ANOVA with Duncan's multiple range test and principal component analysis (PCA). Results: High moisture levels (57.28 – 76.31%) indicated high perishability of the raw by-products. On a dry matter basis, proximate concentrations varied significantly across tissues: total carbohydrates ranged from 73.4 ± 0.06 % to 93.16 ± 0.47%, crude fat from 0.2 ± 0.02 to 7.17 ± 0.04%, and crude protein from 0.98 ± 0.01 to 8.26 ± 0.03%. Additionally, ash and crude fiber contents ranged from 2.98 ± 0.13 to 6.64 ± 0.11% and 2.31 ± 0.04% to 14.16 ± 0.03% respectively, confirming high energetic value. Ascorbic acid in fresh samples ranged between 7.49 ± 1.18 and 150.36 ± 3.6 mg 100g-1 fresh mass. Total phenolic contents spanned 0.39 ± 0.02 to 1.07 ± 0.00 g 100g-1 DM, flavonoids ranged from 5.31 ± 0.13 to 88,57 ± 0.11 mg 100g-1 DM, and condensed tannins ranged from 136.64 ± 5.02 and 194.73 ± 7.8 mg 100g-1 DM. Conclusions: Given their substantial nutritional and bioactive profiles, C. sinensis processing by-products represent promising, low-cost candidates for human food fortification, animal feed formulations, and cosmeceutical applications. Keywords: Citrus Sinensis; Citrus By-Products; Waste Valorization; Bioactive Compounds; Antioxidant Capacity; Functional Foods.