316 research outputs found

    Avaliação da atividade antioxidante da casca e torta de noz-pecã [Carya illinoinensis (Wangenh) C. Kock]

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    Dissertação (mestrado) - Universidade Federal de Santa Catarina. Centro de Ciências Agrárias. Programa de Pós-graduação em Ciência dos AlimentosO processamento da noz-pecã resulta em subprodutos, como a casca, comercializada para preparar chá e a torta, resultante da prensagem para a obtenção do óleo, utilizada em panificação. No presente trabalho foi determinado a composição nutricional da casca, o teor de compostos fenólicos totais e de taninos condensados em diferentes extratos (éter, acetona, álcool e água) da casca e torta de noz-pecã, e, em extratos do chá da casca de noz-pecã. Além disso, foi estudada a atividade antioxidante dos diferentes extratos da casca e torta através dos sistemas ABTS [2,2#-azino-bis-(3- etilbenzotiazolina-6-ácido sulfônico)], DPPH (2,2-difenil-1-picrilhidrazil) e ß-caroteno/ácido linoléico. Neste último sistema a atividade antioxidante dos extratos foi comparada com a atividade de uma mistura de tocoferóis naturais (MT) e, o efeito sinérgico dos extratos e dos tocoferóis foi estudado através da mistura de ambos. A cor da casca e da torta foi determinada através de análise instrumental utilizando o sistema CIE Lab. De acordo com os resultados obtidos, a casca apresentou um teor elevado de fibras (48,6 %). Na casca da noz-pecã, os teores significativamente mais elevados (p < 0,05) para fenólicos totais e taninos condensados (118,4 mg GAE/g e 736,5 mg CE/g CE) e, a maior atividade antioxidante nos sistemas ABTS (2600,6 µmol TEAC/g) e DPPH (453,9 mg TEAC/g após 30 min. e, 617,4 mg TEAC/g após 24 horas), foram observados no extrato alcoólico. Na torta da noz-pecã, os teores mais significativos (p < 0,05) para fenólicos totais (16,4 mg GAE/g), taninos condensados (31,2 mg CE/g) e atividade antioxidante, nos sistemas ABTS (235,3 µmol TEAC/g) e DPPH (68,6 mg TEAC/g após 30 min. e, 100,3 mg TEAC/g após 24 h), foram observados na fração extraída com acetona. Para os extratos de chá da casca, o teor de compostos fenólicos totais determinado foi de 116,7 a 167,2 mg GAE/g e, de taninos condensados entre 35,5 e 48 mg CE/g. No chá, a atividade antioxidante no sistema ABTS, variou entre 1112,6 a 1763,2 µmol TEAC/g, e entre 305,6 a 488,4 mg TEAC/g (reação de 30 min.) e, de 482,5 a 683,7 mg TEAC/g (reação de 24 horas) para o sistema DPPH. Foi observada uma boa correlação entre o conteúdo de compostos fenólicos totais e a atividade antioxidante dos extratos para os diferentes métodos na casca, torta e no chá da casca de noz-pecã (r entre 0,9320 e 0,9980). A atividade antioxidante determinada pelo método ß-caroteno / ácido linoléico foi superior para a fração acetona (94,9 % de inibição da oxidação na concentração de 500 ppm na casca e, 93,1 % na concentração de 300 ppm na torta de noz-pecã). Para o chá o maior percentual de inibição da oxidação (96,4%) foi observado para a concentração de 500 ppm. Os tocoferóis apresentaram resultados inferiores quando comparados com os extratos da casca, torta e chá e, não foram observados efeitos sinérgicos para as misturas dos extratos e tocoferóis. A análise de cor da casca e torta indicou maior tendência aos tons vermelhos nas amostras com maior teor de taninos condensados. Os resultados indicaram um teor elevado de compostos fenólicos e elevada atividade antioxidante para a casca e torta de noz-pecã, sendo a atividade maior para a casca

    Actividad antioxidante y compuestos fenólicos de extractos de tortas de almendra de pecana [Carya illinoinensis (Wangenh.) C. Koch]

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    The total phenolic and condensed tannin contents of different Pecan kernel cake extracts (ether, acetone, alcohol and distilled water) were estimated and their antioxidant activities were evaluated through ABTS, DPPH and ß-carotene/linoleic acid systems. Color variations of the Pecan kernel cake were determined through an instrumental analysis using the CIE Lab system. Significantly higher levels (p < 0.05) of total phenolics, condensed tannins and antioxidant activity measured through the ABTS and DPPH (30 min and 24 h) systems were observed for the acetone extract (16.4 mg GAE/g; 31.2 mg CE/g; 235.3 μmol TEAC/g and 68.6 and 100.3 mg TEAC/g, respectively). The oxidation inhibition percentage in the ß-carotene/linoleic acid system varied from 37.9 to 93.1%, with the acetone extract at 300 ppm showing significantly superior results. The samples with the greatest tendency to show red tones presented the highest levels of condensed tannins.El contenido de taninos condensado y fenoles totales de diferentes extractos de tortas de almendra de pecana (éter, acetona, alcohol y agua destilada) fueron estimados y sus actividades antioxidantes fueron evaluadas mediantes los métodos con ABTS, DPPH y el sistema ß-caroteno/ácido linoleico. Las variaciones de color de la torta de almendra de pecana fueron determinadas mediante análisis instrumental usando el sistema CIE Lab. Los contenidos de fenoles totales, taninos condensados y actividad antioxidante, medida mediante los métodos con ABTS Y DPPH (30 min y 24 h), fueron significativamente más altos (p < 0.05) con el extracto de acetona (16.4 mg GAE/g; 31.2 mg CE/g; 235.3 μmol TEAC/g and 68.6 and 100.3 mg TEAC/g, respectivamente). El porcentaje de inhibición de la oxidación en el sistema ß-caroteno/ ácido linoleico vario desde 37.9 a 93.1% con el extracto de acetona a 300 ppm, mostrando resultados significativamente superiores. Las muestras con una mayor tendencia a tonos rojos presento los niveles más altos de taninos condensados

    Propiedades antioxidantes de la infusión de la cáscara de nuez Pecana [Carya illinoinensis (Wangenh.) C. Koch]

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    The nutritional composition of Pecan nut [Carya illinoinensis (Wangenh.) C. Koch] shells and the total phenolic and condensed tannin contents of Pecan nut shell infusion were determined and the antioxidant activity of the infusion was evaluated through ABTS, DPPH and β-carotene/linoleic acid systems. The shell presented high fiber content (48% ± 0.06), the total phenolic content ranged from 116 to 167 mg GAE/g and the condensed tannin content was between 35 and 48 mg CE/g. The antioxidant activity varied from 1112 and 1763 μmol TEAC/g in the ABTS system. In the DPPH method, the antioxidant activity was from 305 to 488 mg TEAC/g (30 minutes reaction) and from 482 to 683 mg TEAC/g (24 h reaction). The oxidation inhibition percentage obtained in the β-carotene/linoleic acid system varied from 70 to 96%. The results indicated the high phenolic content and antioxidant activity of Pecan nut shell infusion.La composición nutricional de la cáscara de nuez Pecana [Carya illinoinensis (Wangenh.) C. Koch] y los contenidos de fenoles totales y de taninos condensados de la infusión de la cáscara de nuez Pecana se determinaron en este trabajo. La actividad antioxidante de la infusión se evaluó a través de los sistemas ABTS, DPPH y β-caroteno/ácido linoleico. La cáscara presentó un contenido elevado de fibras (48% ± 0,06), el contenido de fenoles totales varió de 116 a 167 mg GAE/g y el de taninos condensados se encontró entre 35 y 48 mg CE/g. La actividad antioxidante varió entre 1112 y 1763 μmol TEAC/g en el sistema ABTS. Por el método DPPH, la actividad antioxidante fue de 305 a 488 mg TEAC/g (30 minutos de reacción) y de 482 a 683 mg TEAC/g (24 h de reacción). El porcentaje de inhibición de la oxidación que se obtuvo en el sistema β -caroteno/ácido linoleico varió de 70 a 96%. Los resultados indicaron un elevado contenido de fenoles y una elevada actividad antioxidante para la infusión de la cáscara de nuez Pecana

    Pervasive gaps in Amazonian ecological research

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    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Educomunicação e suas áreas de intervenção: Novos paradigmas para o diálogo intercultural

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    oai:omp.abpeducom.org.br:publicationFormat/1O material aqui divulgado representa, em essência, a contribuição do VII Encontro Brasileiro de Educomunicação ao V Global MIL Week, da UNESCO, ocorrido na ECA/USP, entre 3&nbsp;e 5 de novembro de 2016. Estamos diante de um conjunto de 104 papers executivos, com uma média de entre 7 e 10 páginas, cada um. Com este rico e abundante material, chegamos ao sétimo e-book publicado pela ABPEducom, em seus seis primeiros anos de existência. A especificidade desta obra é a de trazer as “Áreas de Intervenção” do campo da Educomunicação, colocando-as a serviço de uma meta essencial ao agir educomunicativo: o diálogo intercultural, trabalhado na linha do tema geral do evento internacional: Media and Information Literacy: New Paradigms for Intercultural Dialogue

    Catálogo Taxonômico da Fauna do Brasil: setting the baseline knowledge on the animal diversity in Brazil

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    The limited temporal completeness and taxonomic accuracy of species lists, made available in a traditional manner in scientific publications, has always represented a problem. These lists are invariably limited to a few taxonomic groups and do not represent up-to-date knowledge of all species and classifications. In this context, the Brazilian megadiverse fauna is no exception, and the Catálogo Taxonômico da Fauna do Brasil (CTFB) (http://fauna.jbrj.gov.br/), made public in 2015, represents a database on biodiversity anchored on a list of valid and expertly recognized scientific names of animals in Brazil. The CTFB is updated in near real time by a team of more than 800 specialists. By January 1, 2024, the CTFB compiled 133,691 nominal species, with 125,138 that were considered valid. Most of the valid species were arthropods (82.3%, with more than 102,000 species) and chordates (7.69%, with over 11,000 species). These taxa were followed by a cluster composed of Mollusca (3,567 species), Platyhelminthes (2,292 species), Annelida (1,833 species), and Nematoda (1,447 species). All remaining groups had less than 1,000 species reported in Brazil, with Cnidaria (831 species), Porifera (628 species), Rotifera (606 species), and Bryozoa (520 species) representing those with more than 500 species. Analysis of the CTFB database can facilitate and direct efforts towards the discovery of new species in Brazil, but it is also fundamental in providing the best available list of valid nominal species to users, including those in science, health, conservation efforts, and any initiative involving animals. The importance of the CTFB is evidenced by the elevated number of citations in the scientific literature in diverse areas of biology, law, anthropology, education, forensic science, and veterinary science, among others

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost
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