Antimicrobial Activity of Some Essential Oils Against Microorganisms Deteriorating Fruit Juices

Abstract

Seventeen microbial species including 10 fungal taxa, two yeasts and five bacteria, were isolated from freshly prepared orange, guava and banana juices kept in open bottles at room temperature for 7 days. Eight different essential oils, from local herbs, were tested for their antimicrobial activity against these test organisms. The essential oils of Cymbopogon citratus, Ocimum basilicum and Origanum majorana were found to be highly effective against these microorganisms. Aspergillus niger, A. flavus and Saccharomyces cerevisiae, the most prevalent microorganisms in juice, showed the highest resistance against these essential oils. GC-MS analysis showed that while e-citral, a'-myrcene, and z-citral represent the major components (75.1%) of the essential oil of Cymbopogon citratus; bezynen,1-methyl-4-(2-propenyl), 1,8-cineole and trans-a'-bisabolene were the main components (90.6%) of Ocimum basilicum; whereas 3-cyclohexen-1-01,4-methyl-1(1-methylethyl)-(CAS), c-terpinene and trans-caryophyllene represent the major components (65.1%) of Origanum majorana. These three essential oils were introduced into juices by two techniques namely, fumigation and direct contact. The former technique showed more fungicidal effect than the latter one against A. flavus, A. niger, and S. cerevisiae. The essential oil of Cymbopogon citratus by comparison to other test oils showed the strongest effect against these fungi with a minimum inhibitory concentration of 1.5 µl/ml medium and a sublethal concentration of 1.0 µl/ml. The antimicrobial activity of this oil is thermostable at 121℃ for 30 min.

Antifungal Effect of Plant Essential Oils on Controlling Phytophthora Species

“…Both essential oils exhibited varying degrees of antifungal activities against Phytophthora species. The present data showed that C. citratus essential oil appear to be more toxic than O. basilicum essential oil against Phytophthora species (Table 4), which is in agreement with the results of other authors (Helal et al, 2006; Shadab et al, 1992). Essential oil of C. citratus showed potent inhibitory effect on the radial growth of P. capsici (91.9%), P. drechsleri (91.2%) and P. melonis (94.6%), as shown in Fig.…”

“…It was effective in inhibiting fungal viability and spore germination, so morphological changes of fungal hyphae were observed under light microscope by essential oil of C. citratus (Sulaiman Ali Al Yousef, 2013). The essential oils of C. citratus and O. basilicum were found to be highly effective against A. niger , A. flavus and Saccharomyces cerevisiae , whereas C. citratus essential oil showed the strongest activity against these fungi (Helal et al, 2006). …”

“…These compounds not only do not leave toxic residue to the environment but also have lower toxicity against mammals (Duke, 1985; Garcia et al, 2005). Essential oils activity of C. citratus and Ocimum species against plant pathogens tests have been conducted in vitro , with a few examples of greenhouse or field studies (Helal et al, 2006; Joyce Mendes Andrade Pinto et al, 2010; Kumar et al, 2010; Mahanta et al, 2007; Prakash et al, 2011; Paret et al, 2010; Somada et al, 2007). Few researches of essential oils have been reported in Oomycetes, such as Phytophthora citrophthora (Del Rio et al, 1998), P. cactorum (Lee et al, 2008) and P. capsici (Bi et al, 2012).…”

Comparative Study on the Quality and Antibacterial Activity of Spearmint (Mentha spicata) Leaves and Infusion

“…Essential oils of mint are extensively used in toiletry, food and pharmaceutical industries because of its aromatic, stimulate and carminative nature (Karicheri and Antony, 2016). There is a relationship between the chemical structure of the most abundant compounds in the essential oil and the antimicrobial activity (Helal et al, 2006).Despite the beneficial effects of herbs, some microorganisms and their metabolites can be found which could lead to serious health problems. Among the microorganisms that may be present, moulds are the most relevant, mainly due to their mycotoxins production capacity.…”

Formulation, Characterization, and Antitumor Properties of Trans- and Cis-Citral in the 4T1 Breast Cancer Xenograft Mouse Model

“…Citral has been used as a natural additive to food, cosmetics, and beverages due to its intense lemon aroma and flavor. (1, 2) Essential oils containing citral have been shown to exhibit antimicrobial, antifungal and antiparasitic properties,(3-7) making citral a natural preservative.…”