Chemical profiling and bioactivity of essential oils from citrus sinensis peels and whole fruits: influence of extraction method on antioxidant and antimicrobial potential

This study assessed how extraction method and tissue source influence yield, composition, and bioactivity of Citrus sinensis (Valencia Late) essential oils (EOs). Hydrodistillation of fruit peel (EO-FPE-CS), cold-pressed peel oil (EO-FPE-CP-CS), and hydrodistillation of whole fruit (EO-WFP-CS) produced significantly different yields (p = 0.027), with EO-FPE-CS highest (≈1.5%) and EO-FPE-CP-CS lowest (≈0.6%). GC–MS profiling showed D-limonene dominance (46.27–92.33%) and higher oxygenated monoterpenes (up to 13.57%) in hydrodistilled oils. Principal component analysis (PC1 = 81.5%, PC2 = 18.5%) separated EO-FPE-CS from EO-FPE-CP-CS, reflecting oxygenate-rich versus hydrocarbon-dominant profiles, while EO-WFP-CS clustered with intermediate volatiles. Antibacterial assays revealed EO-FPE-CS as the most active, inhibiting S. aureus, and S. epidermidis (p < 0.01), with EO-WFP-CS moderately effective and EO-FPE-CP-CS inactive. Antifungal tests against five postharvest pathogens confirmed EO-FPE-CS as most potent, particularly against C. gloeosporioides and G. citri-aurantii. while all three essential oils demonstrated strong DPPH radical scavenging activity.