Foodborne, disease-causing microorganisms are increasingly resistant to commercial antibiotics. Thus, there is a need for the development of new agents capable of acting efficiently in the control of these pathogens. Terpenoids and phenylpropanoids stand out for having high biological activity and a broad spectrum of action. The objectives of this study were to evaluate the antibacterial potential of limonene, β-citronellol, carvone, carvacrol, eugenol and trans-cinnamaldehyde and to investigate the mechanism of activity of these compounds against the bacteria Escherichia coli and Staphylococcus aureus. The terpene and phenylpropanoid compoundswere purchased and their antibacterial potential was assessed by macrodilution. The mechanism of action was verified by tests of potassium ion efflux, salt tolerance, extravasation of cellular contents, absorption of crystal violet and morphological changes analyzed by electron microscopy. Bacteriostatic and bactericidal effects caused by the compounds carvone, carvacrol, eugenol and transcinemaldehyde were observed in both species; antibacterial activity against only S. aureus was observed for β-citronelol and limonene. Reduced salt tolerance was found for strains of E. coli treated with carvacrol and S. aureus treated with β-citronelol. There was extravasation of cellular materials induced by treatments with carvone, carvacrol, eugenol and trans-cinnamaldehyde in both microorganisms. The absorption of crystal violet increased for E. coli after incubation with each treatment. Deleterious effects and morphological changes were observed. Therefore, the monoterpenes and phenylpropanoids under study are potentially applicable for antimicrobial use against E. coli and S. aureus, and the mechanism of action involves changes in membrane permeability without cell lysis.

The objectives of this study were to chemically characterize and evaluate the antioxidant activity of essential oils Cinnamodendron dinisii Schwacke (pepper) and Siparuna guianensis Aublet (negramina). The essential oil was isolated by hydrodistillation using a Clevenger modified apparatus, and the identification and quantification of constituents, through GC/MS and GC-FID analysis. The antioxidant activity was evaluated using β-carotene/linoleic acid system and the DPPH radical sequestering method. In chromatographic analysis, the majority constituents found in the essential oil of C. dinisii were bicyclic monoterpenes, α-pinene (35.41%), β-pinene (17.81%), sabinene (12.01%) and sesquiterpene bicyclogermacrene (7.59%). In the essential oil of the fresh leaves of Siparuna guianensis Aublet, acyclic monoterpene, β-myrcene (13.14%), and sesquiterpenes, germacrene-D (8.68%) and bicyclogermacrene (16.71%) were identified. The antioxidant activity was low by the β-carotene/linoleic acid test and was not evidenced by the DPPH test, for both oils evaluated.

Objetivou-se neste estudo caracterizar quimicamente e avaliar as atividades antioxidante e antibacteriana dos óleos essenciais de citronela (Cymbopogon nardus), canela (Cinnamomum zeylanicum) e gengibre (Zingiber officinale). A obtenção do óleo essencial foi realizada utilizando a técnica de hidrodestilação por meio do aparelho de Clevenger modificado e a identificação e quantificação dos constituintes pelas análises em CG/EM e CG-DIC. A avaliação da atividade antibacteriana foi realizada por meio da técnica difusão cavidade em ágar, utilizando os microrganismos Staphylococcus aureus ATCC 6538, Listeria monocytogenes ATCC 19117, Escherichia coli ATCC 11229, Salmonella Cholerasuis ATCC 6539 e Pseudomonas aeruginosa ATCC 15442. A atividade antioxidante foi avaliada utilizando sistema β-caroteno/ácido linoléico e o método de seqüestro de radicais DPPH. Nas análises cromatográficas, os constituintes majoritários encontrados no óleo essencial de C. nardus foram citronelal (47,12%), geraniol (18,56%) e citronelol (11,07%), no óleo essencial de C. zeylanicum foram identificados (E)- cinamaldeído (77,72%), acetato de (E)-cinamila (5,99%) e o monoterpenóide 1,8-cineol (4,66%) e, para Z. officinale os majoritários foram geranial (25,06%), neral (16,47%), 1,8-cineol (10,98%), geraniol (8,51%), acetato de geranila (4,19%) e o canfeno (4,30%). Os óleos essenciais apresentaram atividade antibacteriana tanto para bactérias Gram-negativas como para bactérias Gram-positivas, sendo que o óleo essencial de C. zeylanicum foi o mais eficiente. A atividade antioxidante foi evidenciada pelo teste β-caroteno/ácido linoléico, respectivamente, para C. nardus, seguido de Z. officinale e C. zeylanicum, e pelo teste do DPPH foi observada apenas para C. nardus. The aims of this study were to chemically characterize and to evaluate the antioxidant and antibacterial activities of the citronella (Cymbopogon nardus), cinnamon (Cinnamomum zeylanicum) and ginger (Zingiber officinale) essential oils. The essential oil extraction was performed by the using of hydrodistillation through the modified Clevenger apparatus, and identification and quantification of the constituents by the GC/MS and GC-FID analysis. Evaluation of antibacterial activity was performed by using agar well diffusion method, with Staphylococcus aureus ATCC 6538, Listeria monocytogenes ATCC 19117, Escherichia coli ATCC 11229, Salmonella Cholerasuis ATCC 6539 and Pseudomonas aeruginosa ATCC 15442. The antioxidant activity was evaluated by using β-carotene/linoleic acid system and the radical scavenging DPPH method. In chromatographic analysis the major constituents of C. nardus essential oil were citronellal (47.12%), geraniol (18.56%) and citronellol (11.07%), in the C. zeylanicum essential oil were identified (E)-cinnamaldehyde (77.72%), acetate (E)-cinnamyl (5.99%) and the monoterpenoid 1,8-cineole (4.66%) as major components, and in Z. officinale the majority were geranial (25.06%), neral (16.47%), 1,8-cineole (10.98%), geraniol (8.51%), geranyl acetate (4.19%) and camphene (4.30%). The essential oils showed antibacterial activity for both Gram-negative and Gram-positive microorganisms, and the most efficient was C. zeylanicum essential oil. The antioxidant activity was observed, when using β-carotene/ linoleic acid system, for C. nardus, followed by Z. officinale and C. zeylanicum and, when using DPPH test, activity was observed only for C. nardus

The meat and meat product industry has evolved according to the needs of the market. Consumers are increasingly seeking quality in food. Thus, the concern regarding the excessive use of additives such as preservatives and antioxidants has driven research towards natural, healthy and safe substitutes. Essential oils and plant extracts have been shown to be a good option for resolving this problem. They are completely natural with biological activity, which mainly includes prevention of oxidation and the proliferation of microorganisms, thus arousing the interest of the industry and consumers. This review will present studies published in the last five years regarding the potential of essential oils and plant extracts to act as preservatives and antioxidants in meat and meat products. The forms of application, innovations in the area, alternatives to the incorporation of essential oils and extracts in meat products, effects caused in food, and limitations of applications will be detailed and discussed.

The identification of the chemical compounds of the essential oil was performed with a gas chromatograph coupled to a mass spectrometer. The oil was left in the presence and absence of light and submitted to different temperatures to evaluate its stability. The yields of the major compounds were evaluated every fifteen days. Citral and myrcene, the major compounds of the essential oil, were degraded over time in both the presence and absence of light, but temperature only influenced the degradation of myrcene