Antifungal and Antitoxigenic Effects of Selected Essential Oils in Vapors on Green Coffee Beans with Impact on Consumer Acceptability

Abstract

The main objective of this study is to evaluate the effect of selected essential oils thyme chemotype linalool (Thymus zygis L.), thyme chemotype tymol (Thymus vulgaris L.), eucalyptus (Eucalyptus globulus Labill.), lavender (Lavandula angustifolia Mill.), mint (Mentha piperita L.), almond (Prunbus dulcis Mill.), cinnamon bark (Cinnamomum zeylanicum Nees), litsea (Litsea cubeba Lour. Pers), lemongrass (Cympogon citrati L. Stapf), and ginger (Zingiber officinalis Rosc.) in the vapor phase on growth, sporulation, and mycotoxins production of two Aspergillus strains (Aspergillus parasiticus CGC34 and Aspergillus ochraceus CGC87), important postharvest pathogens of green and roasted coffee beans. Moreover, the effect of the essential oils (EOs) on the sensory profile of the coffee samples treated with EOs was evaluated. The major components of tested EOs were determined by gas chromatography and mass spectrometry (GC–MS) and gas chromatography with flame ionization detector (GC-FID). The results showed that almond, cinnamon bark, lemongrass, and litsea EOs are able to significantly inhibit the growth, sporulation, and mycotoxins production by toxigenic fungi. Sensory evaluation of coffee beans treated with EOs before and after roasting showed that some EOs (except lemongrass and litsea) do not adversely affect the taste and aroma of coffee beverages. Thus, application of the vapors of almond and cinnamon EOs appears to be an effective way that could serve to protect coffee during its transport and storage from toxigenic fungi.

The Vapor Phase of Selected Essential Oils and Their Antifungal Activity In Vitro and In Situ against Penicillium commune, a Common Contaminant of Cheese

“…Similar results to these EOs have been reported in previous studies against fungal species from the genus Aspergillus [ 10 , 11 , 21 , 29 ] and against some species from the genus Penicillium [ 22 , 23 , 30 ]. The growth of P. commune strain KMi–402 was also entirely inhibited by cumin and marjoram EOs after 14 days of cultivation at 25 °C and by fennel, anise, cumin, sage, and marjoram after 35 days of cultivation at 5 °C too.…”

“…They found the presence of fungal mycotoxin contamination (28 analytes) in all cheese samples, and the most often detected mycotoxin was cyclopiazonic acid (102.9%). The significant antitoxicogenic properties of EOs and their potential use for reducing or eliminating mycotoxins in food were previously confirmed [ 10 , 11 , 20 , 21 , 22 , 23 ]. Therefore, in this study, the antitoxicogenic activity of the tested EOs was also evaluated.…”

“…Gas Chromatography–Mass Spectrometry (GC–MS) with the following flame ionization detector (GC–FID) for chemical composition and relative proportions of EO constituents were used. The methods used are detailed in a previous study [ 11 ]. Authentication of the relative proportion of the EO constituents was confirmed by comparing their spectra with authentic standards (Sigma–Aldrich, Munich, Germany).…”

“…Due to their hydrophobicity, individual components of EOs easily pass through prokaryotic or eukaryotic cell membranes, interfering with molecular transport mechanisms and leading to cell lysis [ 9 ]. Some EOs can even inhibit the production of secondary metabolites, mycotoxins [ 10 , 11 ]. Laird and Phillips [ 12 ] compared studies of the antimicrobial and antifungal activity of EOs in the vapor and liquid phases and indicated that the use of the EO vapors seems to be more effective.…”

The Antifungal Activity of Cinnamon-Litsea Combined Essential Oil against Dominant Fungal Strains of Moldy Peanut Kernels

“…Xiang et al [ 26 ] found that cinnamaldehyde was the main chemical component of cinnamon EO. Hlebová et al [ 45 ] also reported that cinnamaldehyde was the most abundant component in cinnamon EO. For LEO, citral (31.27%) and limonene (30.56%) were the main components, which was consistent with that of Zhao et al [ 46 ] They analyzed litsea EO by GC-MS and found that the important components included α-pinene, limonene, linalool, citral, etc., among which, the predominant constituents were citral and limonene.…”