865 research outputs found

    Efeitos sinergistas da atividade antioxidante de cogumelos comestíveis: mistura de extratos fenólicos e polissacarídicos de Boletus edulis e Marasmius oreades.

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    Neste trabalho, avaliou-se a atividade antioxidante de diferentes misturas de Marasmius oreades e Boletus edulis (12,5/87,5, 25/75, 50/50, 75/25, 87,5/12,5) e comparou-se com os controlos (amostras individuais), com o objetivo de verificar qual das misturas contribui para efeitos sinergistas. As propriedades antioxidantes foram avaliadas por quatro métodos químicos e bioquímicos, sendo ainda determinados os fenóis totais (extratos fenólicos) e o teor em polissacáridos (extratos polissacarídicos). Foram observadas três tipos de interações utilizando as diferentes misturas de cogumelos: efeitos aditivos, sinergistas e antagonistas. Os resultados obtidos mostraram diferentes comportamentos nos ensaios de atividade antioxidante de acordo com as proporções utilizadas, indicando que as misturas de cogumelos permitem a ocorrência de diferentes interações químicas entre os compostos obtidos em cada espécie. Todas as diferentes proporções utilizadas de cada cogumelo demonstraram ter atividade antioxidante e, independentemente das proporções utilizadas, os extratos polissacarídicos apresentaram maior atividade antioxidante que os extratos fenólicos. Verificou-se também que a mesma mistura pode induzir um efeito sinergista num método de atividade antioxidante e um efeito antagonista noutro método de atividade antioxidante

    Insights in the antioxidant synergistic effects of combined edible mushrooms: phenolic and polysaccharidic extracts of Boletus edulis and Marasmius oreades

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    In a previous work, we reported the presence of Marasmius oreades in mixtures with antioxidant synergistic effects, and the mixture Boletus edulis and Marasmius oreades (50% of each) as having the highest antioxidant activity, but without synergism among the phenolic extracts. Herein, phenolic and polysaccharidic extracts from both species were combined in different proportions (12.5, 25, 50, 75 and 87.5%) and compared to controls (individual samples), in order to give insight in the contribution of each species to antioxidant synergistic effects. The antioxidant activity of the individual or combined extracts obtained from both edible mushrooms was evaluated through their 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity, reducing power, -carotene bleaching inhibition and lipid peroxidation inhibition in brain homogenates using thiobarbituric acid reactive substances (TBARS) assay. Synergism was the main observed effect among the combined extracts, either phenolic or polysaccharidic. However, the effect of each B. edulis and M. oreades proportion was not the same for all antioxidant activity assays. In fact, the same mixture exhibited sometimes opposite behaviours according with the performed antioxidant activity assay

    Gomphrena globosa L. as a novel source of food-grade betacyanins: Incorporation in ice-cream and comparison with beet-root extracts and commercial betalains

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    Currently, there are some examples of natural colourants with commercial use. However, these colourants are usually under-exploited, besides being obtained from a reduced number of plant or algal species. Accordingly, we propose using betalains obtained from an alternative plant species, Gomphrena globosa, which have a powerful colouring activity besides being strong antioxidants, as a novel ice-cream colourant. For comparison purposes, other ice-cream formulations were prepared, namely without colourants, added with commercial betalain or with Beta vulgaris extract. Besides evaluating the colour parameters L*, a* and b*, the nutritional parameters, individual sugars and fatty acids profiles were also studied. These parameters were evaluated throughout time, up to a maximum of 60 days of freeze (−22 °C) storage. Betacyanin quantification of each formulation was also performed to determine its maintenance along storage. In general, ice-creams prepared with G. globosa were similar (considering nutritional, colour, individual sugars and fatty acids profiles) to those including B. vulgaris extract, thereby validating the suitability of this alternative plant as a source of food colourants, particularly as ice-cream colourants. Furthermore, the positive effects induced by the addition of this natural colourant were maintained throughout storage time, as indicated by the markers distribution in the linear discriminant analysis.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2013); L. Barros and J.C.M. Barreira contracts and C.L. Roriz grant (SFRH/BD/117995/ 2016). This work was also funded by the European Structural and Investment Funds (FEEI) through the Regional Operational Program North 2020, within the scope of Project NORTE-01-0145-FEDER- 023289: DeCodE and Project Mobilizador ValorNatural®.info:eu-repo/semantics/publishedVersio

    Antioxidant and bioactive compounds of two wild edible mushrooms from Northeast of Portugal: Boletus poliporus and Boletus regius

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    Free radicals are produced in the normal natural metabolism of aerobic cells, mostly in the form of reactive oxygen species (ROS). Maintenance of equilibrium between free radicals production and antioxidant defenses is an essential condition for normal organism functioning [1 ,2]. Although almost all organisms are equipped with antioxidant defense, the antioxidant supplements, or natural products containing bioactive compounds, may be used to help reduce oxidative damage to the human body (3]. Indeed, natural matrices with antioxidant activity, in particular mushrooms, are used to aid the endogenous protective system, increasing interest in the antioxidative role of functional foods or nutraceutical products (2]. The present study describes the antioxidant properties and bioactive compounds of wild edible mushrooms (Boletus porosporus and Boletus regius) collected in Northeast of Portugal (Bragança). The antioxidant properties were assessed through the evaluation of the reducing power, radical scavenging activity and lipid peroxidation inhibition of the samples. The individual profiles of organic acids and phenolic compounds were obtained by high performance liquid chromatography coupled to photodiode array detector (HPLC-POA) and the tocopherols were characterized by HPLC-fluorescence.The Boletus regius sample revealed the best results in all the antioxidant activity assays, with the highest reducing power, highest scavenging activity and highest lipid peroxidation inhibition. Phenolic acids and a related compound (cinnamic acid) were found in both studied species and B. regius revealed the highest content in total phenolic compounds (23.49 mg/1 00 g dw), mainly due to the presence of two possible flavonoids. The highest levels of total tocophero ls were found in B. regius (763.80 j.Jg/1 00 g dw). The highest content in quinic and oxalic acids were found in B. porosporus(1.93 and 0.34 g/1 00 g dw, respectively), while B. regius revealed the highest level of citric acid (3.32 g/1 00 g dw).The results suggest that species of wild mushrooms from Northeast Portugal are a potential source of antioxidants to be explored.FCT and COMPETE/QREN/EU: project PTOC/AGR-ALI/110062/2009, PEst-PTDC/AGRALI/110062/2009 CIMO strategic project and L B. grant (BPD/4609/2008

    Edible mycorrhizal mushrooms as sources of bioactive phenolic compounds.

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    Mushrooms are emerging as one of the most appreciated foods on a global basis. Besides their nutritional properties and unique organoleptic characteristics, mushrooms might act as functional foods in view of the medicinal properties of their bioactive compounds [1,2]. Those medicinal properties are often due the antioxidant activity of specific molecules such as phenolic compounds [3]. In the present work, five edible mycorrhizal mushoom species (Amanita caesarea, Cortinarius anomalus, Cortinarius violaceus, Lactarius volemus and Suillus luteus) from Northeast Portugal were studied for their phenolic compounds profile and composition. The analyses were performed by High Performance Liquid Chromatography coupled to Diode Array detection (HPLC-DAD). Phenolic acids (protocatechuic, p-hydroxybenzoic and p-coumaric acids) were the major phenolic compounds. Cortinarius anomalus presented the highest content in phenolic acids (8.70.4 mg/100 g dw), while Lactarius volemus revealed the minimal values (0.50.1 mg/100 g dw). Nevertheless, the profiles in phenolic acids were somehow similar, since p-hydroxybenzoic acid was the main compound in all the assayed species, except Suillus luteus, in which protocatechuic acid predominated. The obtained results suggest mycorrhizal mushrooms as suitable sources of natural healthy products to be included in our diet. This study is integrated in a research project intending to valorise the traditional native mycological flora of Northeast Portugal, of great interest for the economical development of this region

    Improving the antioxidant activity of medicinal and aromatic plants by applying electron beam irradiation

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    Irradiation techniques have been applied for decontamination of aromatic and medicinal herbs. Their popularity in the pharmaceutical and food industry requires specific criteria in terms of microbiological safety [1, 2]. In this study the objective was to evaluate the effects of different doses of electron beam (EB) irradiation (0 kGy – control, 1 kGy and 10 kGy) on the antioxidant activity of Aloysia citrodora P., Melissa officinalis L., Melittis melissophyllum L. and Mentha piperita L.. The antioxidant properties of their infusions and methanolic extracts were evaluated through free radicals scavenging activity, reducing power and inhibition of lipid peroxidation in brain homogenates (TBARS assay). By comparing the results obtained from control and irradiated samples, it was evident that EB induced an increase in the ability to scavenge DPPH radicals and in the reducing power, independently of plant species and extract type. Nevertheless, a similar conclusion could not be performed for TBARS assay. In this case, the infusions from EB irradiated samples have also showed a higher effectiveness as lipid peroxidation inhibitors; however, some of the methanolic extracts (particularly those obtained from A. citrodora and M. piperita) did not allow an activity as high as the one observed in control samples. Even so, an increase in TBARS formation inhibition was also achieved in the methanolic extracts of M. melissophyllum and M. officinalis (this latter, only when a 10 kGy dose was applied). According to the described effects, it might be concluded that the application of EB irradiation is an effective way of increasing the antioxidant activity of the methanolic and aqueous extracts prepared from the assayed aromatic and medicinal plants.The authors are grateful to project PRODER nº 53514, AROMAP, for financial support of the work and E. Pereira grant, and to Fundação para a Ciência e a Tecnologia (FCT, Portugal) for financial support to CIMO (strategic project PEst-OE/AGR/UI0690/2014), J.C.M. Barreira grant (BPD/72802/2010) and L. Barros “Compromisso para a Ciência 2008” contract. The authors are also grateful to “MaisErvas - Aromáticas e Medicinais” for samples providing and to Dr. A. Rafalski, for e-beam irradiations and Prof. A. Chmielewski, General Director of the Institute of Nuclear Chemistry and Technology, Warsaw, Poland, for allowing e-beam irradiations

    Irradiação com feixe de eletrões como um método de preservação da composição química de plantas aromáticas e medicinais

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    Introdução: Desde os tempos mais antigos que as plantas aromáticas e medicinais têm sido utilizadas não só como alimento, mas também para aplicações terapêuticas. Essas plantas têm propriedades medicinais com grande potencial de utilização no tratamento de diversas doenças, uma vez que são uma fonte natural de compostos bioativos. A irradiação com feixe de etetrões é utilizada para vários fins, destacando-se como uma técnica de descontaminação mas também de preservação das matrizes onde é aplicada. Objetivos: Neste trabalho foram avaliados os efeitos de diferentes doses de irradiação com feixe de eletrões (O kGy - controlo, 1 kGy e 10 kGy) na composição química e nutricional de Aloysia citrodora P. (limonete), Melissa officinalis L. (cidreira), Melittis melissophyllum L. (bretónica) e Mentha piperita L. (hortelã-pimenta). Materiais e Métodos: O valor nutricional foi determinado através de metodologias oficiais de análise de alimentos, avaliando o teor em proteínas, tfpidos, glúcidos e cinzas. O perfil individual de açúcares foi determinado por HPLC-RI, os ácidos gordos por GC-FID, os ácidos orgânicos por HPLC-PDA e os tocoferóis por HPLC-fluorescência. Resultados e Discussão: De um modo geral, os parâmetros avaliados mantiveram-se praticamente inalterados, independentemente da espécie vegetal ou da dose de irradiação. Em relação ao perfil em açúcares, as principais modificações consistiram num decréscimo do conteúdo de dissacáridos. As variações mais notáveis em ácidos orgânicos foram observadas nas espécies de plantas com os maiores teores nessas moléculas, particularmente o decréscimo observado nas amostras de cidreira e bretónica. Entre os tocoferóis, as isoformas a e p foram as mais susceptíveis à irradiação, sendo que a aplicação de 1 kGy tendeu a aumentar os níveis de tocoferóis no limonete, enquanto que 10 kGy surtiu o mesmo efeito na bretónica. A amostra de hortelã-pimenta apresentou os níveis mais elevados de tocoferóis, independentemente da dose aplicada. Finalmente, tendo em conta o teor em ácidos gordos, as amostras irradiadas apresentaram maiores valores percentuais de ácidos gordos monoinsaturados do que as amostras controlo. Conclusão: Tendo em conta os efeitos descritos, pode concluir-se que, de um modo geral, a aplicação de irradiação com feixe de eletrões nas doses 1 e 10 kGy é uma forma eficaz de conservar as propriedades químicas e nutricionais das espécies estudada

    Gamma irradiation as a safe alternative to preserve the chemical and bioactive characteristics of plants used for therapeutic purposes

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    As plantas usadas pela indústria requerem tecnologias de conservação e descontaminação eficazes a fim de garantir a sua utilização nas melhores condições. A irradiação é uma tecnologia capaz de descontaminar as plantas, mantendo as propriedades químicas, organoléticas, nutricionais e bioativas. Neste estudo avaliaram -se os efeitos da irradiação gama relativamente nas propriedades químicas, nutricionais e antioxidantes de várias plantas aromáticas e medicinais. Em geral, uma comparação entre as amostras não -irradiadas (controlo) e irradiadas mostrou que o tratamento por irradiação não causou alterações suficientes para definir um perfil químico específico. Assim, a irradiação gama (até 10 kGy) é uma tecnologia viável para as espécies estudadas.Plants used by the industry require effective conservation and decontamination technologies in order to ensure their use in the best conditions. Irradiation is a technology for plants decontamination that maintains their chemical, organoleptic, nutritional and bioactive properties. This study evaluated the effects of gamma irradiation on chemical, nutritional and antioxidants properties of several medicinal and aromatic plants. In general, a comparison between non -irradiated (control) and irradiated samples showed that irradiation treatment did not originate a specific chemical profile. Thus, gamma irradiation (up to 10 kGy) is a viable technology for the studied species.Os autores agradecem ao projeto PRODER n.º 53514, AROMAP, pelo suporte financeiro do trabalho e da co -autora E. Pereira, e à Fundação para a Ciência e a Tecnologia (FCT, Portugal) pelo suporte financeiro ao CIMO (projeto estratégico PEst -OE/AGR/UI0690/2014). Agradecem ainda a “MaisErvas – Aromáticas e Medicinais” pelas amostras fornecidas.info:eu-repo/semantics/publishedVersio

    Qualidade nutricional de agrião armazenado em atmosferas modificadas enriquecidas em gás inerte

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    O agrião (Nasturtium offidnale R. Br. ) é uma planta de crescimento rápido da família Brassicaceae consumida em sopas e saladas. Contudo, tal como a maioria dos vegetais, é altamente perecível. A utilização de embalagens com atmosfera modificada ou protetora tem aumentado nos últimos anos dado o seu potencial para prolongar a vida útil de vegetais minimamente processados. Esta técnica consiste em alterar a atmosfera dentro da embalagem, com o objetivo de abrandar o metabolismo e de prevenir reações de oxidação, evitando assim alterações de qualidade associadas a processos de maturação e senescência. A utilização de gases inertes tem sido testada, mas os estudos são ainda muito limitados. Neste sentido, este trabalho teve como objetivo avaliar os efeitos induzidos por diferentes atmosferas na qualidade nutricional de agrião minimamente processado durante o armazenamento refrigerado e selecionar o tratamento mais eficaz na extensão da vida útil. Amostras silvestres de agrião, recolhidas na região de Bragança, foram lavadas em água corrente e uma porção imediatamente analisada (controlo não armazenado). O restante material fresco foi embalado em atmosferas enriquecidas em azoto, árgon e ar (atmosfera controlo passiva), armazenado a 4°C durante 7 dias e posteriormente analisado. Determinou-se o teor em água, proteínas, lípides, glúcidos e cinzas e o valor energético seguindo métodos oficiais de análise; os perfis em açúcares, ácidos orgânicos, tocoferóis e ácidos gordos foram analisados por técnicas cromatográficas; e as propriedades antioxidantes avaliadas por ensaios químicos e bioquímicos. Tendo em conta a contribuição de todos os parâmetros de qualidade avaliados, foi possível concluir que o embatamento passivo foi o menos eficiente em preservar os atributos de qualidade característicos das amostras controlo não armazenadas. Por outro lado, o embalamento em atmosfera enriquecida em árgon foi a escolha mais acertada para preservar a qualidade global das amostras. Adicionalmente, este estudo destacou as propriedades nutricionais e antioxidantes do agrião, realçando assim o interesse da sua reinclusão nas dietas atuais

    Gamma irradiation as a practical alternative to preserve the chemical and bioactive wholesomeness of widely used aromatic plants

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    Aromatic plants require effective conservation technologies to expand their use. Irradiation might ensure plant decontamination, while maintaining their chemical, organoleptic, nutritional and bioactive qualities. In this study, the effects of gamma irradiation (1 and 10. kGy) in chemical, nutritional and antioxidant properties of Aloysia citrodora, Melissa officinalis, Melittis melissophyllum and Mentha piperita were evaluated. Gamma irradiation (up to 10. kGy) caused some statistically significant changes. However, when analyzed under an integrated approach, unirradiat ed and irradiated samples were grouped indiscriminately, indicating that irradiation treatment did not cause sufficient changes to define a specific chemical profile. Interestingly, each species was differentially affected by irradiation treatment. Overall, it might be considered that gamma irradiation (up to 10. kGy) is a feasible conservation technology for the assayed Lamiaceae and Verbenaceae species. This is an interesting result because the 10. kGy dose guarantees disinfested and decontaminated samples.The authors are grateful to project PRODER no. 53514, AROMAP, for financial support of the work and E. Pereira grant, and to Fundação para a Ciência e a Tecnologia (FCT, Portugal) for financial support to CIMO (strategic project PEst-OE/AGR/UI0690/2011). L. Barros thanks “Compromisso para a Ciência 2008” for her contract. J.C.M. Barreira also thanks FCT, POPH-QREN and FSE for his grant (BPD/72802/2010). The authors are also grateful to “MaisErvas— Aromáticas e Medicinais”.info:eu-repo/semantics/publishedVersio
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