Utilization of Essential Oils from Citronella and Geranium as Natural Preservative in Mayonnaise

Abstract

Background: Essential oils are one of the natural products that are used in different aspects of life due to biological activities. The current investigated was aimed to study the effect of essential oils of citronella (Cymbopogon nardus), geranium (Pelargonium graveolens) and there mixture as a source of natural antioxidant and antimicrobial in formulating a new mayonnaise product during storage to improve its nutraceutical value and shelf-life. Methodology: The essential oils were added to oil of new mayonnaise formula at the rates of 50, 100 and 150 µl/100 gm from Cymbopogon nardus and Pelargonium graveolens and 100 µl/100 gm from there mixtures. The effect of essential oils on oxidative stability, sensory characteristics and microbial evaluation of mayonnaise was studied during 4 months. Results: The results of essential oils analyzed using GC/MS technique indicated that the major components of citronella oil were citronella (48.73%) and geraniol (33.39%), meanwhile geraniol (40.49%) the major of geranium oil. The essential oils of citronella significantly cytotoxic at high concentrations whereas geranium oil did not show any cytotoxicity. The oils were investigated antimicrobial activity against 7 bacteria strains and 3 fungi strains. Citronella oil had a stronger antibacterial and antifungal potential against selected microorganisms at low concentration was more effective than geranium oil. Sensory evaluation of mayonnaise samples prepared by add essential oils showed no significantly (P >0.05) effect on texture properties. But, odour and appearance indicated that the addition of (citronella 100, geranium 150 and mixture 100 µl/100gm) gave a better rating score in the mayonnaise samples. At the end of storage the peroxide and acid value of mayonnaise formed with essential oils significantly lower than control. Also, Decreasing in microbial loadings of all mayonnaises samples tested were noticed by increasing the essential oils concentration in mayonnaise samples. Mayonnaise prepared with citronella, geranium at concentration 100 and 150 µl/100 gm respectively exhibited lowest total count bacteria and fungi. Conclusion: So, the addition of essential oils prolonged the oxidative stability of mayonnaise and they can be used as antibacterial agents.