Citrus sinensis Peel Oil Extraction and Evaluation as an Antibacterial and Antifungal Agent

Microorganisms. 2023 Jun 26;11(7):1662. doi: 10.3390/microorganisms11071662.

Abstract

Throughout the tropical and subtropical climates, the genus Citrus can be found. The current study was conducted to extract the Citrus sinensis peel oil and evaluate its antibacterial, antifungal and antiparasitic potential. Petroleum ether was used to extract the C. sinensis peel oil through a Soxhlet apparatus. The antimicrobial and antifungal potential was determined via agar well diffusion method and minimum inhibitory concentrations (MIC) were calculated (test bacterial strains: Staphylococcus aureus, Escherichia coli and Streptococcus agalactiae; test fungal strains: Aspergillus flavus, Aspergillus niger, Altrnaria alternata). Antiparasitic activity against Leishmaniatropica was determined following standard protocol using amphotericin-B as positive and Dimethyl Sulfoxide (DMSO) as a negative control and the percentage inhibition was calculated. The oil extracted was brownish yellow with a tangy smell, water-insoluble, density (0.778 g/cm3) and specific gravity (0.843 g/cm). In antibacterial activity, the diameter of the zone of inhibition was maximum against E. coli (14 mm) and minimum for S. agalactiae (10 mm). While in antifungal activity diameter of the zone of inhibition was maximum against A. flavus (12.5 mm) and minimum for A. alternata (8.6 mm). S. agalactiae exhibited the minimum MIC value (6 mg/mL) and in fungal strains A. alternata exhibited the minimum value (2 mm). Citrus sinensis peel oil displayed antileishmanial efficiency of 60% at 50 μg/mL concentration after 48 h of incubation. C. sinensis peel oil demonstrated antimicrobial capabilities, implying that it could be used as a natural preservative in food or as an effective treatment against a variety of pathogenic organisms. Industries should extract oil from the waste of citrus fruits which will be beneficial from an economic point of view.

Keywords: Citrus sinensis; antimicrobial effectiveness; industries; minimum inhibitory concentration; natural preservative.