Antimicrobial activities of various essential oils against foodborne pathogenic or spoilage moulds

Abstract

The use of essential oils in the food industry, as natural sanitizing agents, requires the definition of optimal conditions. The aim of the present work was to evaluate some antimicrobial activity parameters as mycelial growth inhibition, minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of six essential oils against Aspergillus niger, Aspergillus terreus, Chaetomium globosum, Penicillium chrysogenum, Penicillium pinophilum, Trichoderma harzianum and Trichoderma viride. The antimicrobial activity of essential oils was monitored by the macrodiluition technique. The mycelial growth inhibition, fungistatic and fungicidal concentrations were recorded for each strain that showed sensitivity to the essential oils. The essential oils of catnip, cinnamon, tea tree and thyme essential oils exhibited a large spectrum antimicrobial activities; those of clary sage and laurel inhibited the mycelial growth in a few fungal strains. The essential oils of cinnamon and thyme had the lowest MIC and MFC values against all the fungi assayed, followed by catnip, tea tree, clary sage and laurel. The use of these natural products rather than, the currently used antifungal chemicals, may be of interest given that: i) essential oils are of natural origin which means they are safer for human health and the environment and ii) there is less chance that the pathogenic microorganisms will develop resistance.

In vitroantifungal activity of terpinen-4-ol, eugenol, carvone, 1,8-cineole (eucalyptol) and thymol against mycotoxigenic plant pathogens

“…However, the development of new pesticides is of interest to struggle with the evolution of resistant pathogens and to replace the compounds lost due to the new registration requirements (Dayan et al 2009). Plant extracts and essential oils have been investigated for their antimicrobial activity (Bakkali et al 2008;Isman 2000), starting from the idea that the secondary metabolism of plants have evolved to oppose pathogens (Brenner 1993 (Angelini et al 2006;Bishop and Reagan 1998;Bowers and Locke 2000;Inouye et al 2000). In a previous study we have examined the effects of TTO and of its major purified components (terpinen-4-ol, γ-terpinen and 1,8-cineole) on two mycotoxigenic fungi, i.e.…”

Antimicrobial packaging system for minimally processed fruit

“…As reported by several authors (Angelini et al, 2006;Wuryatmo et al, 2003), the degree of the growth of microorganisms could be related to the concentration of the active agents tested.…”

The in vitro effect of Garden Thyme (Thymus vulgaris L.) extract on Brachyspira hyodysenteriae

“…Their efficiency against a large variety of pathogens and food-borne germs has been proven by recent investigations [11,13,14]. Several of the studies [1,15,16] indicated the sensitivity of Gram-positive bacteria, while others [17][18][19] have shown expressed sensitivity of Gram-negative bacteria.…”