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Abstract(s)
Ao longo da história da Humanidade, as plantas e seus extratos foram utilizados em
diversos contextos, inclusivamente durante milhares de anos a medicina tradicional
dependeu fortemente de medicamentos derivados de plantas para tratar vários
problemas de saúde, em grande parte devido à presença de metabolitos biologicamente
ativos. Estes compostos, incluindo antioxidantes e agentes antimicrobianos, têm sido
utilizados devido aos seus potenciais benefícios à saúde. Quando se trata da indústria
alimentar e das tendências de consumo associadas, observa-se uma preferência cada vez
maior por produtos livres de conservantes sintéticos e minimamente processados.
Assim, são necessárias alternativas naturais, quer para aplicação direta nos alimentos,
quer para incorporação em embalagens.
De modo a valorizar e descobrir novas aplicações para diferentes recursos endógenos do
centro de Portugal, estudaram-se as suas atividades antimicrobiana e anti-biofilme em
três microrganismos patogénicos de origem alimentar: Pseudomonas aeruginosa,
Listeria monocytogenes, Staphylococcus aureus. Verificou-se que extratos aquosos de
folha de oliveira apresentaram atividade antimicrobiana contra P. aeruginosa e S.
aureus, que o extrato etanólico do mesmo recurso apenas apresentou em P. aeruginosa
e o metanólico somente em S. aureus. Extratos aquosos de folha de sabugueiro, extratos
aquosos e etanólicos de folha de medronheiro, extratos metanólicos de medronho e
extratos aquosos e etanólicos de folha de castanheiro demonstraram atividade inibitória
face aos três microrganismos testados, e extratos etanólicos da pele interior da castanha
são eficazes em S. aureus e L. monocytogenes. Relativamente à influência dos extratos
na formação de biofilme, verificou-se interferência de extratos aquosos de folha de
castanheiro em biofilmes de S. aureus e P. aeruginosa, de extratos aquosos de folha de
oliveira em S. aureus e ainda de um extrato metanólico e etanólico deste recurso em
apenas um destes microrganismos, respetivamente. Extratos aquosos de folha de
medronheiro são eficazes na inibição de formação de biofilmes de S. aureus e L.
monocytogenes, e um extrato aquoso de folha de sabugueiro demonstrou-se eficaz nos
três microrganismos. Em biofilmes maduros, destacou-se a ação de um extrato aquoso e
etanólico de folha de oliveira em biofilmes de P. aeruginosa e de um extrato aquoso de
folha de medronheiro em biofilmes de L. monocytogenes. Concluiu-se que os extratos
vegetais dos recursos testados têm potencial para apresentar uma nova alternativa
natural aos conservantes sintéticos, e consequentemente vir no futuro a ser utilizados
pela indústria alimentar.
Throughout mankind history, plants and their extracts were used in diverse contexts, for thousands of years traditional medicine heavily relied on plant-derived remedies to address various health concerns, in great part due to the presence of biologically active metabolites. These compounds, including antioxidants and antimicrobial agents, have been used for their potential health benefits. When it comes to the food industry and associated consumer trends, an increasing preference is observed for products free of synthetic preservatives and minimally processed. Instead, natural alternatives are needed, either for direct application to food or for incorporating into packaging. In this project, antimicrobial and anti-biofilm activities of several endogenous resources from central Portugal were studied on three food borne pathogens: Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus aureus. It was found that aqueous olive leaf extracts have antimicrobial activity against P. aeruginosa and S. aureus, ethanolic extract only for P. aeruginosa and methanolic only for S. aureus. Aqueous extracts of elderberry leaf, aqueous and ethanolic extracts of Arbutus unedo leaf, methanolic extracts of A. unedo fruit and aqueous and ethanolic extracts of chestnut leaf demonstrated inhibitory activity against the three microorganisms tested, and ethanolic extracts from the inner skin of the chestnut are effective on S. aureus and L. monocytogenes. Regarding the influence of extracts on biofilm formation, there was interference from aqueous chestnut leaf extracts on biofilms of S. aureus and P. aeruginosa, aqueous olive leaf extract in S. aureus and from methanolic and ethanolic extracts of this resource in only one of these microorganisms, respectively. Aqueous extracts of A. unedo leaf are effective in inhibiting biofilm formation of S. aureus and L. monocytogenes, and an aqueous extract of elderberry leaf has been shown to be effective against all three microorganisms. Regarding mature biofilms, the dispersal effects of aqueous and ethanolic extracts of olive leaves on P. aeruginosa biofilms and of A. unedo leaves aqueous extract on L. monocytogenes biofilms were particularly noteworthy. It was concluded that plant extracts from the tested resources have the potential to present a new natural alternative to synthetic preservatives, and consequently be used in the future by the food industry.
Throughout mankind history, plants and their extracts were used in diverse contexts, for thousands of years traditional medicine heavily relied on plant-derived remedies to address various health concerns, in great part due to the presence of biologically active metabolites. These compounds, including antioxidants and antimicrobial agents, have been used for their potential health benefits. When it comes to the food industry and associated consumer trends, an increasing preference is observed for products free of synthetic preservatives and minimally processed. Instead, natural alternatives are needed, either for direct application to food or for incorporating into packaging. In this project, antimicrobial and anti-biofilm activities of several endogenous resources from central Portugal were studied on three food borne pathogens: Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus aureus. It was found that aqueous olive leaf extracts have antimicrobial activity against P. aeruginosa and S. aureus, ethanolic extract only for P. aeruginosa and methanolic only for S. aureus. Aqueous extracts of elderberry leaf, aqueous and ethanolic extracts of Arbutus unedo leaf, methanolic extracts of A. unedo fruit and aqueous and ethanolic extracts of chestnut leaf demonstrated inhibitory activity against the three microorganisms tested, and ethanolic extracts from the inner skin of the chestnut are effective on S. aureus and L. monocytogenes. Regarding the influence of extracts on biofilm formation, there was interference from aqueous chestnut leaf extracts on biofilms of S. aureus and P. aeruginosa, aqueous olive leaf extract in S. aureus and from methanolic and ethanolic extracts of this resource in only one of these microorganisms, respectively. Aqueous extracts of A. unedo leaf are effective in inhibiting biofilm formation of S. aureus and L. monocytogenes, and an aqueous extract of elderberry leaf has been shown to be effective against all three microorganisms. Regarding mature biofilms, the dispersal effects of aqueous and ethanolic extracts of olive leaves on P. aeruginosa biofilms and of A. unedo leaves aqueous extract on L. monocytogenes biofilms were particularly noteworthy. It was concluded that plant extracts from the tested resources have the potential to present a new natural alternative to synthetic preservatives, and consequently be used in the future by the food industry.
Description
Keywords
Castanea Sativa Arbutus Unedo Atividade Anti Biofilme Atividade Antimicrobiana Bryonia Dioica Listeria Monocytogenes Olea Europaea Pseudomonas
Aeruginosa Sambucus Nigra Staphylococcus Aureus Vigna Unguiculata