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Registros recuperados: 30 | |
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DUTRA, L. M.; TELES, P. H. V.; SANTOS, A. D. da C.; MELO, N. F. de; NAGATA, N.; ALMEIDA, J. R. G. da S.. |
The species of the genus Passiflora (Passifloraceae family) have been used as food, cosmetic and traditional herbal. As a result, the Passiflora species are widely cultivated and has an economic, medicinal and ornamental importance. The popular designation as ?passion fruit? and chemical profile of several Passiflora species remains unknown. The lack of chemical information contributes to the erroneous classification and adulteration. In recent years, special attention has been paid to the bioactivity and phytochemical profiles of several Passiflora species extracts. In this research, 1H NMR-based metabolic profiling coupled with chemometric tools was used to characterize and distinguish extracts obtained from different wild Passiflora species (P. alata,... |
Tipo: Artigo de periódico |
Palavras-chave: Maracujá do mato; 1H NMR; Quimiometria; Perfil metabólico; Atividades biológicas; Passiflora Edulis; Controle de Qualidade; Maracujá; Passiflora; Chemometrics; Quality control. |
Ano: 2023 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1150832 |
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LIMA, M. dos S.; PEREIRA, G. E.; FEDRIGO, I. M. T.. |
In vitro techniques are essential to assess the antioxidant potential of foods, although methods with diferent action mechanisms make troublesome data analysis. This article describes the use of artifcial neural network (ANN) to associate phenolic compounds with antioxidant activity in vitro (AOX) of grape juices. A multilayer perceptron (MLP) ANN was obtained with 28 phenolics quantifed, as input layers, and AOX measuring by DPPH, ABTS, FRAP, H2O2, and β-carotene/linoleic acid bleaching assay (βCLA) methods, as output layers. To improve discussion in food sciences, the ANN results were compared with Pearson?s correlation and principal component analysis (PCA), methods largely used in food studies. Pearson?s technique showed correlations... |
Tipo: Artigo de periódico |
Palavras-chave: Antioxidant methods; Bioactivity; Grape polyphenol; Chemometrics. |
Ano: 2021 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1135356 |
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Pereira,Antonio Carlos Prestes; Judacewski,Priscila; Coelho,Gabriel; Salem,Renata Dinnies Santos; Marinho,Marina Tolentino; Alberti,Aline; Zielinski,Acácio Antonio Ferreira; Demiate,Ivo Mottin; Nogueira,Alessandro. |
ABSTRACT: There are no specific technical regulations regarding the identity and quality of white mold surface-ripened cheeses in Brazil. These cheeses are sold both whole (Camembert-type) and in wedges (Brie-type). The aim of the study was to evaluate the physical and chemical properties; technological parameters and microbiological safety of 20 whole cheeses (Camembert-type) and 16 cheese wedges (Brie-type) produced in Brazil. Samples showed a wide range in sodium (91.0-731.0 mg/100 g, cheeses wedges) and calcium (238.0-1100.0 mg/100g, whole cheeses) contents. The cheese groups presented no significant differences in relation to the majority of the analyzed parameters. Listeria monocytogenes was reported in 5% of the whole cheese samples. The other... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cheese quality; Chemometrics; Camembert-type cheese; Brie-type cheese. |
Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782020000100752 |
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COSTA, M. C. A.; MATALLO, M. B.; FERREIRA, M. M. C.; QUEIROZ, S. C. do N. de; ALMEIDA, S. D. B.; FRANCO, D. A. S.. |
Abstract: Shikimic acid is a natural organic compound produced in the biochemical pathways of eukaryotic organisms and is generally utilized as a starting material of the antiviral drug Oseltamivir (Tamiflu®). This study shows the results of shikimic acid accumulation in Brachiaria plantaginea, an abundant, grassy plant found in Brazil and other countries in Africa and America, after glyphosate spraying at three different doses. B. plantaginea plants harvested after 6 days of exposure to the herbicide showed that shikimic acid accumulation increased by 345%, on average, compared to unsprayed plants. The combination of near infrared spectroscopy and multivariate analysis using partial least square regression was applied for the quantification of shikimic... |
Tipo: Separatas |
Palavras-chave: NIR spectroscopy; PLS regression; Brachiaria plantaginea; Gramínea; Shikimic acid; Chemometrics. |
Ano: 2016 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1066054 |
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Belo,Renata França Cassimiro; Augusti,Rodinei; Lopes,Paulo Sérgio Nascimento; Junqueira,Roberto Gonçalves. |
In order to determine the variability of pequi tree (Caryocar brasiliense Camb.) populations, volatile compounds from fruits of eighteen trees representing five populations were extracted by headspace solid-phase microextraction and analyzed by gas chromatography-mass spectrometry. Seventy-seven compounds were identified, including esters, hydrocarbons, terpenoids, ketones, lactones, and alcohols. Several compounds had not been previously reported in the pequi fruit. The amount of total volatile compounds and the individual compound contents varied between plants. The volatile profile enabled the differentiation of all of the eighteen plants, indicating that there is a characteristic profile in terms of their origin. The use of Principal Component Analysis... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chemometrics; Biodiversity; Cerrado native fruit. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612013000500018 |
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BRAGA, D. C.. |
A adstringência é uma sensação tátil, gerada pela redução da lubrificação na cavidade oral, comumente causada pela interação de compostos fenólicos com as proteínas salivares. No pedúnculo do cajueiro, a adstringência é o principal problema que limita a sua aceitabilidade, sendo um dos maiores obstáculos para a expansão do mercado. Este trabalho buscou caracterizar o perfil sensorial e o perfil de compostos fenólicos de pedúnculos de cajueiro, e por meio de quimiometria, correlaciona-los buscando os possíveis marcadores químicos da adstringência do caju. Foram analisados pedúnculos de nove clones da safra 2017. A análise sensorial foi baseada em uma análise descritiva de provadores previamente selecionados e treinados, registrando a intensidade dos... |
Tipo: Teses |
Palavras-chave: Anacardium occidentale L; UPLC; Análise sensorial; Chemometrics. |
Ano: 2019 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1106803 |
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Campbell,Patrícia Morais da Matta; Fernandes Filho,Elpídio Inácio; Francelino,Márcio Rocha; Demattê,José Alexandre Melo; Pereira,Marcos Gervasio; and,Clécia Cristina Barbosa Guimarães; Pinto,Luiz Alberto da Silva Rodrigues. |
ABSTRACT Quantification of soil properties is essential for better understanding of the environment and better soil management. The conventional techniques of laboratory analysis are sometimes costly and detrimental to the environment. Thus, development of new techniques for soil analysis that do not generate residues, such as spectroscopy, is increasingly necessary as a viable way to estimate a wide range of soil properties. The objective of this study was to predict the levels of organic carbon (OC), clay, and extractable phosphorus (P), from the spectral responses of soil samples in the visible and near infrared (Vis-NIR), medium infrared (MIR), and Vis-NIR-MIR using different preprocessing methods combined with five prediction models. Soil samples were... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Spectral analysis; Reflectance; Chemometrics. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832018000100314 |
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Lima,Daniel Braga de; Agustini,Bruna Carla; Silva,Eliz Guimarães da; Gaensly,Fernanda; Cordeiro,Rodrigo Becker; Fávero,Maria Luiza Drechsel; Brand,Debora; Maraschin,Marcelo; Bonfim,Tania Maria Bordin. |
Wine production in the northern Curitiba, Paraná, Brazil, specifically the communes of Colombo and Almirante Tamandaré, is based mainly on the utilization of Vitis labrusca grapes var. Bordô (Ives). Total sugar content, pH, and total acidity were analyzed in red wine samples from 2007 and 2008 vintages following official methods of analysis. Moreover, total phenolic, flavonoid, and tannin contents were analyzed by colorimetric methodologies and the antioxidant activity was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical methodology. Phenolic compounds were identified by high performance liquid chromatography. The total phenolic content of wine samples presented concentrations varying between 1582.35 and 2896.08 mg gallic acid.L-1 since... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Rural; Winery; Chemometrics; Common wine; HPLC; Viniculture. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612011000300038 |
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Santos,Antonio Odair; Kaye,Oren. |
Leaf water potential is a measure commonly used to describe crop water status and water stress dynamics. The established method for determining leaf water potential using a pressure chamber is cumbersome and subject to operator error as well as time/temperature limitations. These limitations prohibit the intensive sampling required to support proactive water management of commercial crops, including vineyards. Particular for grapevines there is need for faster, more precise and more reliable tools for determining leaf water potential in the field. Portable Near-infrared spectroscopy and multivariate data analysis were applied for the modeling and prediction of leaf water potential in grapevines. For field-grown wine grapes the most significant and... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: PLS; Irrigation; Spectrometry; Chemometrics. |
Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162009000300001 |
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Jacq, Kévin; Perrette, Yves; Fanget, Bernard; Sabatier, Pierre; Coquin, Didier; Martinez-lamas, Ruth; Debret, Maxime; Arnaud, Fabien. |
In the case of environmental samples, the use of a chemometrics-based prediction model is highly challenging because of the difficulty in experimentally creating a well-ranged reference sample set. In this study, we present a methodology using short wave infrared hyperspectral imaging to create a partial least squares regression model on a cored sediment sample. It was applied to a sediment core of the well-known Lake Bourget (Western Alps, France) to develop and validate a model for downcore high resolution LOI550 measurements used as a proxy of the organic matter. In lake and marine sediment, the organic matter content is widely used, for example, to reconstruct carbon flux variations through time. Organic matter analysis through routine analysis methods... |
Tipo: Text |
Palavras-chave: Hyperspectral imaging; Chemometrics; Near-infrared spectroscopy; High resolution analysis; Organic matter. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00478/59018/61636.pdf |
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ALVES FILHO, E. G.; ZOCOLO, G. J.; DIAS, N. da S.; BRITO, E. S. de; CANUTO, K. M.; SOUSA, J. A. de; NASCIMENTO, R. F. DO; LOPES, G. S.; MATOS, T. K. B.; GUEDES, J. A. C.; LUZ, L. R.. |
Tipo: Artigo de periódico |
Palavras-chave: Quimiometria; UPLC-QTOF-MSE; Dactylopius opuntiae; Cactaceae; Chemometrics; Schlumbergera (Cactaceae). |
Ano: 2021 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1133073 |
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CASTRO, C. B. DE; LUZ, L. DOS R.; GUEDES, J. A. C.; PORTO, D. D.; SILVA, M. F. S.; SILVA, G. S. DA; RIBEIRO, P. R. V.; CANUTO, K. M.; BRITO, E. S. de; ZAMPIERI, D. DE S.; PESSOA, C. do Ó.; ZOCOLO, G. J.. |
Myracrodruon urundeuva (aroeira-do-sertão) is a species threatened with extinction due to anthropogenic exploitation. Phytochemical analysis of bark, branch and leaf extracts revealed the presence of several compounds such as flavonoids, phenols, tannins, quercetin derivatives and anacardic acids. Dereplication methodology was performed to tentatively identify 50 compounds analyzed by ultra-performance liquid chromatography coupled with an electrospray ionization quadrupole time-of-flight mass spectrometry operating in MSE mode (UPLC-QTOF-MSE). The extracts exhibited anti-tumor effect in cancer cells HCT-116 (colorectal), SF-295 (glioblastoma), HL-60 (leukemia), and RAJI (leukemia). Also, these results correlate with the principal component analysis (PCA)... |
Tipo: Artigo de periódico |
Palavras-chave: UPLC-MS/MS; Quimiometria; Atividade citotóxica; Aroeira do sertão; Bioma Caatinga; Myracrodruon Urundeuva; Aroeira; Caatinga; Espécie Nativa; Vegetação Nativa; Chemometrics; Cytotoxicity. |
Ano: 2020 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/1119316 |
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Registros recuperados: 30 | |
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