Physicochemical Profiles and Antifungal Efficacy of Essential Oils from Citrus Sinensis and Citrus Aurantifolia

Abstract

Citrus essential oils represent an important socio-economic resource due to their wide range of applications. This study investigated the physicochemical properties and antifungal activity of orange (Citrus sinensis) and lime (Citrus aurantifolia) essential oils (EO). Essential oils were obtained by hydrodistillation of fruit peels, and physicochemical parameters including acid value, ester value, refractive index, and density were determined in accordance with ISO standards. Antifungal activity was evaluated against Aspergillus flavus and Aspergillus parasiticus using a broth microdilution assay to determine minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs). Each assay was performed in triplicate. Statistical analyses were performed using GraphPad Prism 5 software. Extraction yields were 0.90% for orange and 1.22% for lime. Citrus sinensis EO exhibited a low relative density (0.835), a refractive index of 1.467, a low acid value (2 mg KOH/g), and an ester value of 25 mg KOH/g. In contrast, Citrus aurantifolia EO was characterized by a slightly higher relative density (0.861), a lower refractive index (1.3949), a markedly higher acid value (11.11 mg KOH/g), and a higher ester value (30.05 mg KOH/g). The essential oil of C. aurantifolia demonstrated pronounced antifungal activity against A. flavus (MIC = 20 µL mL⁻¹; MFC = 25 µL mL⁻¹). These findings indicate that citrus essential oils possess acceptable quality attributes and significant antifungal potential, highlighting their promising prospects for valorization across diverse industrial sectors. They could be valorized in food preservation due to their antifungal properties. They may also be incorporated into the development of cosmetic formulations.