Antifungal activity of Pelargonium graveolens essential oil and its use in preserving fresh orange juice during short-term storage

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The present study focused on the extraction and quality analysis of Pelargonium graveolens oil, as well as its use in preserving fresh orange juice during short-term storage as a natural alternative to synthetic compounds. The yield of extraction and physicochemical properties of the essential oil were evaluated, and subsequently tested for antimicrobial activity using the agar diffusion method. Freshly squeezed orange juice was transferred into three sterile 100 mL bottles. P. graveolens essential oil was sterilized by filtration through a 0.22 ?m membrane under aseptic conditions and added at 0 ?L (control), 50 ?L, and 100 ?L doses. Samples were stored at room temperature for microbial analysis. Gas chromatography–mass spectrometry (GC-MS) analysis of oil identified citronellol as the major constituent, followed by geraniol. The antifungal and antimicrobial activity of the essential oil was very significant against Candida albicans, but weak against Staphylococcus aureus and Pseudomonas aeruginosa. Interestingly, complete inhibition was observed in orange juice stored at room temperature with the highest essential oil concentration. Bacterial growth was also not observed in juice samples, regardless of whether they were treated with or without essential oil. The results indicate that the essential oil of P. graveolens exhibits significant antifungal activity and, therefore, may be used as a natural preservative in fresh juices to improve microbiological stability during short-term storage.