Chemical characterization of the Allium sativum and Origanum vulgare essential oils and their inhibition effect on the growth of some food pathogens

Abstract

This study sought to evaluate the chemical composition of the Allium sativum and Origanum vulgare essential oils and their effect on the growth inhibition of microorganisms, such as P. aeruginosa, S. Choleraesuis, A. flavus, A. niger and P. simplicissimum, important food contaminants. The main constituents of the oregano essential oil were 4-terpineol (27.03%), γ-terpinene (20.04%), and β-cymene (6.34%), and the main constituents of the garlic essential oil were diallyl trisulfide (38, 81%), diallyl disulfide (25.23%), and methyl allyl trisulfide (12.52%). Inhibition zones were formed in in vitro tests on the bacteria S. Choleraesuis and P. aeruginosa, except for A. sativum against P. aeruginosa. The inhibition of mycelial growth caused by the oregano essential oil occurred with the concentrations of 0.10, 0.03 and 0.05 mg mL -1 for the A. flavus, A. niger and P. simplicissimum fungi, respectively. The CMI for the garlic oil began at the 0.03 mg mL -1 concentration for all species of fungi. The oils presented an inhibitory effect against the microorganisms studied and constitute an alternative for microbiological control in food.Keywords: essential oil, food contaminants, chemical composition. RESUMO: Caracterização química e efeito inibitório dos óleos essenciais deAllium sativum e Origanum vulgare frente ao crescimento de alguns patógenos de alimentos. Objetivou-se avaliar a composição química e o efeito inibitório dos óleos essenciais de Allium sativum e Origanum vulgare frente ao crescimento dos micro-organismos Pseudomonas aeruginosa, Salmonella Choleraesuis, Aspergillus flavus, Aspergillus niger e Penicillium simplicissimum, importantes patógenos causadores de contaminações em alimentos. Para quantificação e identificação dos constituintes químicos dos óleos, utilizou-se cromatógrafo gasoso acoplado a espectrômetro de massas. Os principais constituintes do óleo essencial de orégano foram o 4-terpineol (27,03%), γ-terpineno (20,04%), β-cimeno (6,34%), e do alho, o dialil trissulfeto (38,81%), dialil dissulfeto (25,23%), metil alil trissulfeto (12,52%). Os resultados dos testes in vitro sobre as bactérias S. Choleraesuis e P. aeruginosa indicaram a formação de halo de inibição e revelaram o efeito inibitório para os referidos óleos, exceto para o óleo de A. sativum frente a P. aeruginosa. Para os fungos A. flavus, A. niger e P. simplicissimum a inibição do crescimento micelial provocada pelo óleo essencial de orégano ocorreu a partir das concentrações de 0,10, 0,03 e 0,05 µg mL -1 , respectivamente, sendo que a CMI para o óleo de alho iniciou-se a partir da concentração 0,03 µg mL -1 para todas as espécies de fungos. Foi possível verificar que os óleos possuem efeito inibitório sobre os microrganismos estudados, sendo, portanto, uma alternativa no controle microbiológico de alimentos.Palavras-chave: óleo essencial, contaminantes alimentares, constituição química

Essential Oil’s Chemical Composition and Pharmacological Properties

“…This leads in some case to a huge difference between chemotype of the same plants collected in different areas or different period of time during the same day or during different maturity stages. This has been reported for Allium sativum [24][25][26] and for Lavandula angustifolia [14,[27][28][29][30] and Melissa officinalis [4,12,13,16,[31][32][33][34][35][36]].…”

Origanum Vulgare and Thymbra Capitata Essential Oils from Spain: Determination of Aromatic Profile and Bioactivities

“…Also, the Mexican report [27] gives high values for α-pinene and terpinen-4-ol. An Italian report [28] shows the highest value for linalool; the Brazilian oil [29] gave a high value for α-terpinene and the Tunisian oil [30] contained a high concentration of p-cymene. The studied samples showed the highest concentration of carvacrol, followed by the Serbian [31] and Italian reports [28].…”

Fungitoxicity of Essential Oils on Plasmopara Viticola,causal Agent of Grapevine Downy Mildew

“…In the worldwide literature, there is a significant increase in the number of studies that seek to find antifungal activity of essential oils as an alternative control of several plant pathogens, with promising results for cinnamon (RANASINGHE et al, 2002;KISHORE et al, 2007;MAQBOOL et al, 2010), eucalyptus (LORENZETTI et al, 2012), marjoram (FIALHO, 2012), melaleuca (FRASSON et al,2010), peppermint (CHAGAS et al, 2014) oregano (MALLET et al, 2014) and white thyme oils (PERINA et al, 2015). Aiming at to contribute to one more option to control the downy mildew of the grapevine, the objective of this study was to evaluate the antifungal effect of essential oils on the spore germination of P. viticola, a causal agent of grapevine downy mildew.…”