Antimicrobial Activities of Essential Oil and Hexane Extract of Florence Fennel [Foeniculum vulgarevar.azoricum(Mill.) Thell.] Against Foodborne Microorganisms

Abstract

The objective of this study was to determine the chemical compositions of the essential oil and hexane extract isolated from the inflorescence, leaf stems, and aerial parts of Florence fennel and the antimicrobial activities of the essential oil, hexane extract, and their major component, anethole, against a large variety of foodborne microorganisms. Gas chromatography and gas chromatography-mass spectrometry analysis showed that the essential oils obtained from inflorescence, leaf stems, and whole aerial parts contained (E)-anethole (59.28-71.69%), limonene (8.30-10.73%), apiole (trace to 9.23%), beta-fenchyl acetate (3.02-4.80%), and perillene (2.16-3.29%) as the main components. Likewise, the hexane extract of the plant sample exhibited a similar chemical composition, and it contained (E)-anethole (53.00%), limonene (27.16%), gamma-terpinene (4.09%), and perillene (3.78%). However, the hexane extract also contained less volatile components such as n-hexadecanoic acid (1.62%), methyl palmitate (1.17%), and linoleic acid (1.15%). The in vitro antimicrobial assays showed that the essential oil, anethole, and hexane extract were effective against most of the foodborne pathogenic, saprophytic, probiotic, and mycotoxigenic microorganisms tested. The results of the present study revealed that (E)-anethole, the main component of Florence fennel essential oil, is responsible for the antimicrobial activity and that the essential oils as well as the hexane extract can be used as a food preservative. This study is the first report showing the antimicrobial activities of essential oil and hexane extract of Florence fennel against probiotic bacteria.

A review on recent research results (2008–2010) on essential oils as antimicrobials and antifungals. A review.

“…Due to its antimicrobial effect against foodrelated pathogens the EO could be used as a food preservative, but one has to keep in mind that the exaggerated ingestion of fennel products could influence the bacterial flora in the gastrointestinal tract by inhibiting the growth of probiotic bacteria. [66] In the two following studies it becomes clear that the extent of the antimicrobial activity is, among other factors, dependent on the pH level and the composition of the food. [67,68] The qualification of several EOs as food preservatives was evaluated using four food-borne bacteria strains.…”

Assaying the potential autotoxins and microbial community associated with Rehmannia glutinosa replant problems based on its ‘autotoxic circle’

“…Therefore, these eight compounds were derived from R. glutinosa cultivation. According to previous studies, some compounds detected in this work have been reported as allelochemicals in other plants (Cetin et al 2010;Colvin and Gliessman 2011;Preston et al 2004;Roy and Barik 2014;Tang and Gobler 2011). Based on these reports and the availability of the chemicals and the specific dimensionality distribution in the soil, four chemicals and their mixtures were selected and tested for their potential autotoxic effects on R. glutinosa radicle growth ( Table 2).…”

Quantitative analysis of antimicrobial activity of Foeniculum vulgare: A review

“…This suppression of Staphylococcus aureus toxins was attributed to the high amount of anethole in F. vulgare essential oil (Qiu et al 2012). Therefore, anethole is an important antibiotic and food preservative agent that can be used in the pharmaceutical and food industries (Çetin et al 2010;Martins et al 2012).…”