Chemical Composition and Antimicrobial Activity of Leaf, Ripe and Unripe Peel of Bitter Orange (Citrus aurantium) Essential Oils

Abstract

A B S T R A C T Background and Objectives:The chemical composition and antimicrobial activity of bitter orange (Citrus aurantium) leaf, ripe and unripe peel essential oils, cultivated in southwest of Iran, were investigated. Materials and Methods:The analysis of chemical composition of hydro-distilled essential oils was carried out by GC-MS. The disc diffusion and broth micro-dilution were used to assay the antimicrobial effect of achieved essential oils.Results: According to the GC-MS analysis, 34, 39 and 21 components were determined in the leaf, ripe and unripe peel, respectively. The results revealed that the main components of all essential oils were linalool and limonene. The oxygenated monoterpene and hydrocarbonated monoterpene were the main chemical groups of leaf and peel essential oils, respectively. Although all of the examined essential oils had antimicrobial potential, the leaf and unripe peel essential oils with MIC of 4.67 mg/ml were the most effective against the bacteria and yeast species, respectively, and the ripe peel essential oil was the weakest one. The growth of Saccharomyces cerevisiae was controlled in the treated orange juices. The antifungal activity of essential oils was increased by rising up in their concentration and decreased by passing time. Unripe and ripe essential oils showed the strongest and weakest anti yeast potential, respectively. Conclusions:The essential oils of leaves and ripe and unripe peels of bitter orange could be used as natural preservatives in food industry.

Chemical Composition and Biological Activities of Lemon (Citrus limon) Leaf Essential Oil

“…Although the growth of all examined microorganisms was inhibited by different concentrations of lemon leaf essential oil, the result of disc diffusion showed B. cereus and S. typhi were the most sensitive and resistant bacteria against the essential oil, respectively. Similar results were also reported by others indicating that the essential oil of citrus leaf was active against both Gram positive and Gram negative bacteria, thought it was more effective on Gram-positive strains (33,(36)(37)(38). Indeed, the lemon leaf essential oil was less effective against Gram-negative compared to Gram positive bacteria.…”

“…All bacterial strains were maintained in a viable state via inoculation on Mueller-Hinton Broth (MHB, Oxoid) and overnight incubation at 37°C. Disc diffusion method: Antibacterial activity of different concentrations of the essential oils was evaluated with agar disc diffusion assay as described previously with some modification (36). Briefly, Mueller-Hinton Agar (Merck, Darmstadt, Germany) were prepared, autoclaved and transferred aseptically to sterilized petri plates.…”

Bitter orange peel essential oil: A review of the different factors and chemical reactions influencing its composition

“…Table 7 compares the world major producing countries of bitter orange essential oil to the different growing locations of bitter orange essential oils studied in the literature. One can observe that even if Argentina, Haiti, Morocco, Paraguay and Uganda are in the top fifteen of the world major producing countries of bitter orange oil, to our knowledge the composition of the bitter orange peel cultivated in those countries has never been studied in the literature.…”

“…Several studies concerning the influence of the ripening stages of bitter oranges on peel oil composition have been reported in the literature. 7,28,31,36,47,51,67 Citrus are non climacteric, which means that once fruits are harvested, the maturation process stops and they do not ripen further. 1 The colour of the peel is an indicator of the maturity of the fruit.…”

Comparative study of the inhibitive action between the bitter orange leaf extract and its chemical constituent linalool on the mild steel corrosion in HCl solution

“…The strong bands in the region of 1033 in CA spectrum and 1090 cm −1 in linalool spectrum are assigned to the O-symmetric and asymmetric stretching vibrations and the C-O stretching vibration. The percentage of Linalool in the hydro-distilled leaf extract was found by Azhdarzadeh et al 21 and by Trabelsi et al 22 to be 32.60 and 22.11, respectively. Figure 3.…”