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Abstract(s)
A Mentha cervina L. Opiz (Lamiaceae) é um tipo de menta que cresce selvagem nas margens dos rios nas regiões do noroeste da Península Ibérica. É uma planta aromática utilizada para fins culinários, especialmente para aromatizar pratos de peixe, e pelas suas propriedades medicinais em infusões com propriedades digestivas. O objectivo principal deste trabalho foi analisar a actividade antioxidante e antimicrobiana de extractos da Mentha cervina - aquosos, hidroetanólicos e óleo essencial -, de modo avaliar o seu potencial para o desenvolvimento de ingredientes funcionais para aplicação na indústria alimentar e cosmética. Os extractos obtidos das tinturas (misturas etanol/água) e das infusões foram caracterizadas quanto à actividade antioxidante pelo método de ABTS.+, ao teor de fenólicos totais pelo método de Folin-Ciocalteu e ao seu perfil de compostos fenólicos por LC-MS/MS. A actividade antioxidante do óleo essencial foi avaliada pelo método de TEAC. A actividade antimicrobiana do óleo foi avaliada pelo método de difusão em disco e CMI, sendo que esta, nas tinturas e infusões, foi avaliada pelo método de difusão em agar por poços. O potencial biológico de actividade antioxidante de todos os extractos foi avaliado pelo método de protecção do ADN da oxidação. Os extractos hidroetanólicos do caule a 65% de etanol e da folha a 40% de etanol apresentaram a maior actividade antioxidante na solução, mas quando avaliada com base no extracto seco foi o caule a 65 % de etanol que demonstrou a maior actividade. Em relação ao teor de fenólicos totais, o extracto das folhas a 65 % etanol evidenciou o maior teor na solução. No entanto, usando o extracto seco, para além das folhas, o caule a 65 % etanol apresentou também um elevado teor de compostos fenólicos. Todos os extractos, excepto o óleo essencial, protegeram o ADN da degradação por oxidação, porém os extractos hidroetanólicos demonstraram maior protecção. Os principais compostos fenólicos identificados por LC-MS/MS nos extractos aquosos e hidroetanólicos foram o ácido caféico e o ácido clorogénico. As tinturas e as infusões não inibiram o crescimento de qualquer dos microrganismos testados, contudo o óleo essencial foi capaz de inibir a E. coli, a Salmonella spp., o S. aureus, a Listeria innocua, o B. cereus, a Candida albicans e a Yarrowia lipolytica, com concentrações mínimas inibitórias diferenciadas para cada microrganismo testado. O óleo essencial da Mentha cervina demonstrou maior eficácia sobre as bactérias Gram negativas e as leveduras, o que se confirmou pela inibição total observada na sua curva de crescimento.
Mentha cervina (L.) Opiz (Lamiaceae) is a type of mint that grows wild in the river banks of the north-western regions of the Iberian Peninsula. It is an aromatic plant used for culinary purposes, especially to aromatize fish dishes, and for its medicinal properties, namely in infusions with digestive properties. The main objective of this work was to analyze the antioxidant and antimicrobial activity of Mentha cervina extracts - infusions, tinctures and essential oils - in order to assess its potential for the development of functional ingredients that may be applied in the food or cosmetic industries. The antioxidant activity of the tinctures (ethanol/water mixtures) and of the infusions was assessed by the ABTS.+ method, total phenol content by the Folin-Ciocalteu method and the LC-MS/MS analysis was performed directly on the crude extracts for the identification of phenolic compounds. For the essential oil the TEAC method was applied to evaluate the antioxidant properties. The antimicrobial activity of essential oil was assessed by disc diffusion and MIC assays, being this property, in the tinctures and infusions, analysed by the agar well diffusion method. The biologic potential for antioxidant activity of all extracts was analysed by the protection of DNA from oxidation . The hydroethanolic extracts of stem at 65 % ethanol and of leaves at 40 % ethanol showed the highest antioxidant activity. However, when the analysis was based on dry matter only the stem at 65% ethanol exhibited the highest antioxidant capacity. The extract obtained from leaves at 65 % ethanol presented a highest total phenol content in solution. Nevertheless, when the study was based on dry matter, the stem at 65 % ethanol revealed the highest content of phenolic compounds. All extracts, except for the essential oils, protected DNA from degradation by oxidation, but hydroethanolic extracts showed the highest protection. The main phenolic compounds identified by LC-MS/MS in the extracts where caffeic acid and cholorogenic acid. Both tinctures and infusions didn‟t inhibit the pathogenic or food contaminants microorganisms, but the essential oil inhibited E. coli, Salmonella spp., S.aureus, S. aureus ATCC, Listeria innocua, B. cereus, Candida albicans and Yarrowia lipolytica. Essential oil of M. cervina showed better efficiency against Gram negative bacteria and yeast, demonstrated by the complete inhibition observed in their growth curve.
Mentha cervina (L.) Opiz (Lamiaceae) is a type of mint that grows wild in the river banks of the north-western regions of the Iberian Peninsula. It is an aromatic plant used for culinary purposes, especially to aromatize fish dishes, and for its medicinal properties, namely in infusions with digestive properties. The main objective of this work was to analyze the antioxidant and antimicrobial activity of Mentha cervina extracts - infusions, tinctures and essential oils - in order to assess its potential for the development of functional ingredients that may be applied in the food or cosmetic industries. The antioxidant activity of the tinctures (ethanol/water mixtures) and of the infusions was assessed by the ABTS.+ method, total phenol content by the Folin-Ciocalteu method and the LC-MS/MS analysis was performed directly on the crude extracts for the identification of phenolic compounds. For the essential oil the TEAC method was applied to evaluate the antioxidant properties. The antimicrobial activity of essential oil was assessed by disc diffusion and MIC assays, being this property, in the tinctures and infusions, analysed by the agar well diffusion method. The biologic potential for antioxidant activity of all extracts was analysed by the protection of DNA from oxidation . The hydroethanolic extracts of stem at 65 % ethanol and of leaves at 40 % ethanol showed the highest antioxidant activity. However, when the analysis was based on dry matter only the stem at 65% ethanol exhibited the highest antioxidant capacity. The extract obtained from leaves at 65 % ethanol presented a highest total phenol content in solution. Nevertheless, when the study was based on dry matter, the stem at 65 % ethanol revealed the highest content of phenolic compounds. All extracts, except for the essential oils, protected DNA from degradation by oxidation, but hydroethanolic extracts showed the highest protection. The main phenolic compounds identified by LC-MS/MS in the extracts where caffeic acid and cholorogenic acid. Both tinctures and infusions didn‟t inhibit the pathogenic or food contaminants microorganisms, but the essential oil inhibited E. coli, Salmonella spp., S.aureus, S. aureus ATCC, Listeria innocua, B. cereus, Candida albicans and Yarrowia lipolytica. Essential oil of M. cervina showed better efficiency against Gram negative bacteria and yeast, demonstrated by the complete inhibition observed in their growth curve.