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The use of fennel polyphenols based ingredients as natural preservers for cottage cheese

Caleja, Cristina; Barros, Lillian; Antonio, Amilcar L.; Ćirić, Ana; Soković, Marina; Oliveira, M.B.P.P.; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
37.1%
There is a growing interest in the development of foods containing natural preservers that could replace synthetic additives associated to some toxic effects for consumers [1]. In the present work, it was demonstrated the antioxidant (free radicals scavenging activity, reducing power and lipid peroxidation inhibition) and antimicrobial (against bacteria such as Salmonella typhimurium and Bacillus cereus, and fungi such as Aspergillus niger, A. versicolor and Penicillium funiculosum) potential of a Foeniculum vulgare Mill. (fennel) decoction extract, highlighting the opportunity of using this ingredient as natural preserver. Chemical characterization of the extract, performed by HPLC-DAD-ESI/MS, revealed the presence of five flavonoids (mainly quercetin-3-O-glucoside) and twelve phenolic acids (mainly 5-O-caffeolylquinic acid). It was then incorporated (at EC25 value=0.35 mg/mL, previously determined by DPPH assay; [2]) in cottage cheese (prepared by Queijos Casa Matias Lda.) with the purpose of increasing the shelf life of the mentioned dairy product. The results showed that the use of the fennel polyphenols extract as a natural ingredient did not alter significantly the nutritional characteristics of control cottage cheese (including macronutrients...

Total polyphenols from Syzygium cumini (L.) Skeels fruit extract

MIGLIATO, Ketylin Fernanda; CARVALHO, Elisângela Simões de; SACRAMENTO, Luis Vitor Silva do; MELLO, João Carlos Palazzo de; BABY, André Rolim; VELASCO, Maria Valéria Robles; SALGADO, Hérida Regina Nunes
Fonte: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas Publicador: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.86%
A precise, accurate and low cost spectrophotometric method was developed and validated for routine determination of total polyphenols, as pyrogallic acid equivalents, from the percolated and lyophilized extract of Syzygium cumini (L.) Skeels fruits. Validation was assessed experimentally and data were rigorously treated by statistical analysis. Analytical parameters were: linearity, interval (range), precision and recovery/accuracy, limit of detection (LOD, μg mL-1) and limit of quantification (LOQ, μg mL-1). The visible spectrophotometric method presented linearity (r² = 0.9979 ± 0.0010) over the concentration range 0.25-7.5 μg mL-1 of standard pyrogallic acid, precision < 2.918171%, recovery/accuracy ranging from 96.228693 to 107.17701%, LOD = 0.21 μg mL-1 and LOQ = 0.64 μg mL-1.; Um método espectrofotométrico preciso, rigoroso e de baixo custo foi desenvolvido e validado para a determinação de polifenóis totais, utilizando-se como padrão o ácido pirogálico. O extrato dos frutos de Syzygium cumini (L.) Skeels foi preparado empregando-se o método de percolação com posterior liofilização. A validação foi executada experimentalmente e os dados foram submetidos à análise estatística. Os parâmetros analíticos considerados foram: linearidade...

The reduction of Cu(II)/neocuproine complexes by some polyphenols: Total polyphenols determination in wine samples

LEE, Gina; ROSSI, Maura Vincenza; COICHEV, Nina; MOYA, Horacio Dorigan
Fonte: ELSEVIER SCI LTD Publicador: ELSEVIER SCI LTD
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
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A new method is presented for spectrophotometric determination of total polyphenols content in wine. The procedure is a modified CUPRAC method based on the reduction of Cu(II), in hydroethanolic medium (pH 7.0) in the presence of neocuproine (2,9-dimethyl-1,10-phenanthroline), by polyphenols, yielding a Cu(I) complexes with maximum absorption peak at 450 nm. The absorbance values are linear (r = 0.998, n = 6) with tannic acid concentrations from 0.4 to 3.6 mu mol L(-1). The limit of detection obtained was 0.41 mu mol L(-1) and relative standard deviation 1.2% (1 mu mol L(-1); n = 8). Recoveries between 80% and 110% (mean value of 95%) were calculated for total polyphenols determination in 14 commercials and 2 synthetic wine samples (with and without sulphite). The proposed procedure is about 1.5 more sensitive than the official Folin-Ciocalteu method. The sensitivities of both methods were compared by the analytical responses of several polyphenols tested in each method. (C) 2010 Elsevier Ltd. All rights reserved.; Brazilian agency: FAPESP (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo); Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Brazilian agency: CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Brazilian agency: NEPAS (Node de Ensino...

Carotenoids and polyphenols in nutricosmetics, nutraceuticals, and cosmeceuticals

Anunciato, Talita Pizza; Rocha Filho, Pedro Alves da
Fonte: WILEY PERIODICALS, INC; MALDEN Publicador: WILEY PERIODICALS, INC; MALDEN
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.01%
The market for cosmeceuticals continues with significant annual growth, but today consumers are more aware of nutritional products that contribute to both skin health and disease prevention. In the last 10 years, pharmacists, chemists, nutritionists, and physicians have been working together to develop new nutritional applications to satisfy peoples needs and demands. As a recent result of convergence phenomenon between cosmetics and food industries, nutricosmetics is a blurry area unfamiliar to many consumers and sometimes even to foods and cosmetics experts. Characterized by oral supplementation of nutrients, nutricosmetics are also known as beauty pills,beauty from within, and even oral cosmetics. The major claim is the antiaging effect, reducing wrinkles by fighting free radicals generated by solar radiation. Among the ingredients used in nutricosmetics, antioxidants represent the most crucial. The best-known antioxidants are carotenoids (beta-carotene, lycopene, lutein, zeaxanthin, and astaxanthin) and polyphenols (anthocyanidins, catechins, flavonoids, tannins, and procyanidins). This study presents an overview about the concept of nutricosmetics and gives us information about the difference between nutricosmetics, nutraceuticals...

Anti-atherogenic and anti-angiogenic activities of polyphenols from propolis

Daleprane, Julio Beltrame; Freitas, Vanessa da Silva; Pacheco, Alejandro; Rudnicki, Martina; Faine, Luciane Aparecida; Doerr, Felipe Augusto; Ikegaki, Masaharu; Salazar, Luis Antonio; Ong, Thomas Prates; Abdalla, Dulcineia Saes Parra
Fonte: ELSEVIER SCIENCE INC; NEW YORK Publicador: ELSEVIER SCIENCE INC; NEW YORK
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.27%
Propolis is a polyphenol-rich resinous substance extensively used to improve health and prevent diseases. The effects of polyphenols from different sources of propolis on atherosclerotic lesions and inflammatory and angiogenic factors were investigated in LDL receptor gene (LDLr-/-) knockout mice. The animals received a cholesterol-enriched diet to induce the initial atherosclerotic lesions (IALs) or advanced atherosclerotic lesions (AALs). The IAL or AAL animals were divided into three groups, each receiving polyphenols from either the green, red or brown propolis (250 mg/kg per day) by gavage. After 4 weeks of polyphenol treatment, the animals were sacrificed and their blood was collected for lipid profile analysis. The atheromatous lesions at the aortic root were also analyzed for gene expression of inflammatory and angiogenic factors by quantitative real-time polymerase chain reaction and immunohistochemistry. All three polyphenol extracts improved the lipid profile and decreased the atherosclerotic lesion area in IAL animals. However, only polyphenols from the red propolis induced favorable changes in the lipid profiles and reduced the lesion areas in AAL mice. In IAL groups. VCAM, MCP-1, FGF, PDGF, VEGF, PECAM and MMP-9 gene expression was down-regulated...

Use of grape polyphenols against carcinogenesis: Putative molecular mechanisms of action using in vitro and in vivo test systems

Gollucke, Andrea P. B.; Aguiar Júnior, Odair; Barbisan, Luis Fernando; Ribeiro, Daniel Araki
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 199-205
ENG
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37.1%
Polyphenols are present in foods and beverages and are related to sensorial qualities such as color, bitterness, and astringency, which are relevant in wine, tea, grape juice, and other products. These compounds occur naturally in forms varying from simple phenolic acids to complex polymerized tannins. Thus, it is reasonable to expect that grape-derived products elaborated in the presence of skins and seeds, such as wine and grape juice, are natural sources of flavonoids in the diet. Carcinogenesis is a multistep process that is characterized by genetic, epigenetic, and phenotypic changes. With increasing knowledge of these mechanisms, and the conclusion that most cases of cancer are preventable, efforts have focused on identifying the agents with potential anticancer properties. The use of grape polyphenols against the carcinogenesis process seems to be a suitable alternative for either prevention and/or therapeutic purposes. The aim of this article is to show the molecular data generated from the use of grape polyphenols against carcinogenesis using in vivo and in vitro test systems. © Mary Ann Liebert, Inc. and Korean Society of Food Science and Nutrition.

Vinhos brasileiros : teores totais e bioacessibilidade de As, Cd, Cu e Pb, teores de polifenóis totais e avaliação da rotulagem; Brazilian wine : total contents and bioaccessibility of As, Cd, Cu and Pb, total polyphenols contents and labeling assessement

Elaine Marra de Azevedo Mazon
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 26/02/2013 PT
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36.86%
O consumo de vinhos no Brasil aumentou cerca de 20% na última década, e sua comercialização vem se difundindo, principalmente, pelo aumento da oferta, aumento do poder aquisitivo da população brasileira, aumento da produção e pelos benefícios à saúde que lhe são atribuídos. A análise de elementos traço nos vinhos é de grande importância para o controle da qualidade, autenticidade, biodisponibilidade de metais e estudo da toxicidade, visando garantir a segurança alimentar para os consumidores. Este trabalho descreve o desenvolvimento de um método empregando a espectrometria de absorção atômica com forno de grafite para a determinação de arsênio (As), cádmio (Cd), cobre (Cu) e chumbo (Pb) em amostras de vinhos brasileiros. A digestão ácida preliminar não foi necessária no preparo de amostra. O programa de aquecimento, empregado no forno de grafite foi otimizado para os diferentes tipos de vinhos e as amostras foram diluídas na proporção de 1:3 com ácido nítrico (65% v/v) e peróxido de hidrogênio (30% m/m). A curva analítica foi preparada em meio aquoso e alguns modificadores foram investigados para cada elemento. As determinações foram realizadas nas seguintes faixas lineares 10-100 µg L-1 Cu; 5...

Rapid isolation of red wine polymeric polyphenols by solid-phase extraction

Jeffery, D.; Mercurio, M.; Herderich, M.; Hayasaka, Y.; Smith, P.
Fonte: Amer Chemical Soc Publicador: Amer Chemical Soc
Tipo: Artigo de Revista Científica
Publicado em //2008 EN
Relevância na Pesquisa
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A rapid technique for the isolation of polymeric polyphenols from red wine has been developed and validated. A copolymer reversed-phase SPE cartridge was utilized in conjunction with predominantly organic eluents to provide three phenolic fractions from red wine without the need for sample pretreatment. The first fraction contained the bulk of the monomeric and oligomeric phenolic material, while the second and third fractions contained the polymeric polyphenolic compounds, as determined by HPLC analysis. The two polymeric polyphenolic fractions differed in their solubility and extent of pigmentation, and the differences appeared to be related to wine age. This method contrasted with other available fractionation techniques because the interfering, nonpolymeric material can be removed in a single wash fraction, while the polymeric material is separated into two distinct fractions based on their diverse physicochemical properties. It is anticipated that the rapid access to discrete polymeric fractions afforded by this method will be of benefit in furthering the understanding of red wine polymeric polyphenols.; David W. Jeffery, Meagan D. Mercurio, Markus J. Herderich, Yoji Hayasaka, and Paul A. Smith

Optimization of the extraction process of polyphenols from cashew apple agro-industrial residues

Andrade,Renata Araújo Milanez de Sena; Maciel,Maria Inês Sucupira; Santos,Andrelina Maria Pinheiro; Melo,Enayde de Almeida
Fonte: Sociedade Brasileira de Ciência e Tecnologia de Alimentos Publicador: Sociedade Brasileira de Ciência e Tecnologia de Alimentos
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2015 EN
Relevância na Pesquisa
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The goal of this study was to determine the chemical composition of cashew apples agro-industrial residue and optimize the process of polyphenols extraction in this residue. The extraction process conditions were defined using a 24-1 fractional factorial experimental design using acetone and methanol as solvents. The independent variables were: time (30 to 90 min), temperature (30 to 50 °C), solvent concentrations (50% to 90%), agitation speed (100 to 300 rpm); the dependent variables were: total phenolic content and DPPH scavenging capacity. The optimized process was carried out by applying the Central Composite Rotational Design (CCRD) considering the results obtained with the 24-1 fractional factorial experimental design. The residue presented bioactive compounds in its composition, with emphasis on the content of total phenolic compounds (1975.64 mg/ 100 g). The extraction process was not affected by methanol; however, acetone affected the amounts of extracted phytochemicals. Extracts with high levels of polyphenols and strong DPPH scavenging capacity (> 80%) were obtained using 55% acetone, 30 minutes, 30 °C, and 150 rpm. The results showed that cashew apple residue is a potential natural source of bioactive compounds with strong antioxidant capacity. These compounds could be used partially or totally to replace synthetic antioxidants.

The impact of polyphenols on chondrocyte growth and survival: a preliminary report

Fern??ndez-Arroyo, Salvador; Huete-Toral, Fernando; P??rez de Lara, Mar??a Jes??s; C??diz-Gurrea, Mar??a de la Luz; Legeai-Mallet, Laurence; Micol Molina, Vicente; Segura Carretero, Antonio; Joven, Jorge; Pintor, Jes??s
Fonte: Co-Action Publishing Publicador: Co-Action Publishing
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.1%
Background: Imbalances in the functional binding of fibroblast growth factors (FGFs) to their receptors (FGFRs) have consequences for cell proliferation and differentiation that in chondrocytes may lead to degraded cartilage. The toxic, proinflammatory, and oxidative response of cytokines and FGFs can be mitigated by dietary polyphenols. Objective: We explored the possible effects of polyphenols in the management of osteoarticular diseases using a model based on the transduction of a mutated human FGFR3 (G380R) in murine chondrocytes. This mutation is present in most cases of skeletal dysplasia and is responsible for the overexpression of FGFR3 that, in the presence of its ligand, FGF9, results in toxic effects leading to altered cellular growth. Design: Different combinations of dietary polyphenols derived from plant extracts were assayed in FGFR3 (G380R) mutated murine chondrocytes, exploring cell survival, chloride efflux, extracellular matrix (ECM) generation, and grade of activation of mitogen-activated protein kinases. Results: Bioactive compounds from Hibiscus sabdariffa reversed the toxic effects of FGF9 and restored normal growth, suggesting a probable translation to clinical requests in humans. Indeed, these compounds activated the intracellular chloride efflux...

Comparison of protective effects of four polyphenols on neuropathology and behavior of APP/PS1-21 transgenic mice, a model of Alzheimer’s disease

Li, Chaoyun
Fonte: Universität Tübingen Publicador: Universität Tübingen
Tipo: Dissertation; info:eu-repo/semantics/doctoralThesis
EN
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Alzheimer’s disease (AD) is one of the most important neurodegenerative disorders, bringing about huge medical and social burden worldwide. It is a multifactorial disease, clinically characterized by progressive cognitive loss, neuropsychiatric and behavioral disorders. Neuropathological examination of the brains of AD patients reveals extracellular amyloid beta (Aβ) plaques in brain parenchyma and increased neuro-inflammation. Natural polyphenols, most common compounds in foods and herbal beverages, are a large class of phytochemical that are composed of aromatic and one or more phenolic rings. Four polyphenolic compounds (namely Hesperidin, Icariin, Dihydromyricetin and Baicalin) with potential neuroprotective properties were selected for further evaluation. In the current study, potential therapeutic effects of these four polyphenols were evaluated in the transgenic APP/PS1 mouse model of cerebral amyloidosis. 5-months old transgenic mice were treated by Hesperidin, Icariin, Dihydromyricetin, Baicalin (100 mg/kg body weight) or vehicle by gavage, respectively. Therapeutic effects of these polyphenols were monitored by behavioral tests of nesting construction and social interaction. Then, the mice were sacrificed and tissues were taken for the pathological investigation. After a relatively short-term treatment of 10 days...

Alginate-pomegranate peels' polyphenols beads: effects of formulation parameters on loading efficiency

Zam,Wissam; Bashour,Ghada; Abdelwahed,Wassim; Khayata,Warid
Fonte: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas Publicador: Universidade de São Paulo, Faculdade de Ciências Farmacêuticas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2014 EN
Relevância na Pesquisa
37.01%
Calcium alginate beads containing pomegranate peels' polyphenol extract were encapsulated by ionic gelation method. The effects of various formulation factors (sodium alginate concentration, calcium chloride concentration, calcium chloride exposure time, gelling bath time maintaining, and extract concentration) on the efficiency of extract loading were investigated. The formulation containing an extract of 1 g pomegranate peels in 100 mL distilled water encapsulated with 3 % of sodium alginate cured in 0.05 M calcium chloride for 20 minutes and kept in a gelling bath for 15 minutes was chosen as the best formula regarding the loading efficiency. These optimized conditions allowed the encapsulation of 43.90% of total extracted polyphenols and 46.34 % of total extracted proanthocyanidins. Microencapsulation of pomegranate peels' extract in calcium alginate beads is a promising technique for pharmaceutical and food supplementation with natural antioxidants.

Impacto de la interacción entre polifenoles de té verde y proteínas del lactosuero sobre las propiedades biológicas y funcionales de las mezclas; Impact of the interaction between green tea polyphenols and whey proteins on the biological and functional properties of mixed systems

von Staszewski, Mariana
Fonte: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires Publicador: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires
Tipo: info:eu-repo/semantics/doctoralThesis; tesis doctoral; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em //2011 SPA
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37.3%
El objetivo del presente trabajo fue estudiar la interacción entre polifenoles de té verde y proteínas del lactosuero y su impacto sobre las propiedades funcionales y biológicas de los componentes. Los estudios realizados muestran que los polifenoles poseen una fuerte afinidad por todas las proteínas del lactosuero estudiadas y a todos los pH analizados. El tamaño de los complejos formados es máximo cercano al punto isoeléctrico de cada proteína por lo que la insolubilidad de los mismos está mayormente determinada por su carga superficial. La presencia de polifenoles aceleró el proceso de gelificación tanto de β- lactoglobulina (β-lg) como de caseinomacropeptido (CMP). Resultados similares se observaron con WPC. A pH 6,0, pudieron utilizarse concentraciones de polifenoles de hasta 0,5% (p/v) sin producir precipitación del sistema y sin afectar negativamente la viscoelasticidad y la textura de los geles de proteína o WPC. Las variedades de té verde argentino mostraron excelentes capacidades como agentes antioxidantes y antimicrobianos. La formación de complejos entre los polifenoles de té verde y el WPC disminuyó significativamente estas actividades. La actividad antimicrobiana del té verde en presencia de WPC se observó principalmente frente a bacterias gram positivas. Además...

Polyphenols and mitochondria: An update on their increasingly emerging ROS-scavenging independent actions

Speisky Coso, Hernán Elías; Ferreira Parker, Jorge Federico; Sandoval Acuña, Cristián
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo de revista
EN
Relevância na Pesquisa
37.27%
Artículo de publicación ISI; Polyphenols, ubiquitously present in fruits and vegetables, have been traditionally viewed as antioxidant molecules. Such contention emerged, mainly from their well established in vitro ability to scavenge free radicals and other reactive oxygen species (ROS). During the last decade, however, increasing evidence has emerged supporting the ability of certain polyphenols to also exert numerous ROS-scavenging independent actions. Although the latter can comprise the whole cell, particular attention has been placed on the ability of polyphenols to act, whether favorably or not, on a myriad of mitochondrial processes. Thus, some particular polyphenols are now recognized as molecules capable of modulating pathways that define mitochondrial biogenesis (i.e., inducing sirtuins), mitochondrial membrane potential (i.e., mitochondrial permeability transition pore opening and uncoupling effects), mitochondrial electron transport chain and ATP synthesis (i.e., modulating complexes I to V activity), intra-mitochondrial oxidative status (i.e., inhibiting/inducing ROS formation/removal enzymes), and ultimately mitochondrially-triggered cell death (i.e., modulating intrinsic-apoptosis). The present review describes recent evidence on the ability of some polyphenols to modulate each of the formerly mentioned pathways...

Modulation of endogenous antioxidant system by wine polyphenols in human disease

Miranda, Andrés; Vergara, Leonardo; Rodrigo, Ramón
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo de revista
EN
Relevância na Pesquisa
37.18%
Artículo de publicación ISI; Numerous studies indicate that moderate red wine consumption is associated with a protective effect against all-cause mortality. Since oxidative stress constitutes a unifying mechanism of injury of many types of disease processes, it should be expected that polyphenolic antioxidants account for this beneficial effect. Nevertheless, beyond the well-known antioxidant properties of these compounds, they may exert several other protective mechanisms. Indeed, the overall protective effect of polyphenols is due to their large array of biological actions, such as free radical-scavenging, metal chelation, enzyme modulation, cell signalling pathways modulation and gene expression effects, among others. Wine possesses a variety of polyphenols, being resveratrol its most outstanding representative, due to its pleiotropic biological properties. The presence of ethanol in wine aids to polyphenol absorption, thereby contributing to their bioavailability. Before absorption, polyphenols must be hydrolyzed by intestinal enzymes or by colonic microflora. Then, they undergo intestinal and liver metabolism. There have been no reported polyphenol adverse effects derived from intakes currently associated with the normal diet. However...

HPLC-DAD methodology for the quantification of organic acids, furans and polyphenols by direct injection of wine samples

Pereira, Vanda; Câmara, José S.; Cacho, Juan; Marques, José C.
Fonte: Wiley Interscience Publicador: Wiley Interscience
Tipo: Artigo de Revista Científica
Publicado em /01/2010 ENG
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This article proposes a simple and sensitive HPLC method with photo-diode array detection for the analysis of organic acids, monomeric polyphenols and furanic compounds in wine samples by direct injection. The chromatographic separation of 8 organic acids, 2 furans and 22 phenolic compounds was carried out with a buffered solution (pH 2.70) and acetonitrile as mobile phases and a difunctionally bonded C18 stationary phase, Atlantis dC18 (250 4.6 mm, 5mm) column. The elution was performed in 12 min for the organic acids and in 60 min for the phenolic compounds, including phenolic acids, stilbenes and flavonoids. Target compounds were detected at 210 nm (organic acids, flavan-3-ols and benzoic acids), 254 nm (ellagic acid), 280 nm (furans and cinnamic acid), 315 nm (hydroxycinnamic acids and trans-resveratrol) and 360 nm (flavonoids). The RSD for the repeatability test (n55) of peak area and retention times were below 3.1 and 0.3%, respectively, for phenolics and below 1.0 and 0.2% for organic acids. The RSDs expressing the reproducibility of the method were higher than for the repeatability results but all below 9.0%. Method accuracy was evaluated by the recovery results, with averaged values between 80 and 104% for polyphenols and 97–105% for organic acids. The calibration curves...

A new and improved strategy combining a dispersive-solid phase extraction-based multiclass method with ultra high pressure liquid chromatography for analysis of low molecular weight polyphenols in vegetables

Silva, Catarina L.; Haesen, Nathaly; Câmara, José S.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em /10/2012 ENG
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This paper reports on the development and optimization of a modified Quick, Easy, Cheap Effective, Rugged and Safe (QuEChERS) based extraction technique coupled with a clean-up dispersive-solid phase extraction (dSPE) as a new, reliable and powerful strategy to enhance the extraction efficiency of free low molecular-weight polyphenols in selected species of dietary vegetables. The process involves two simple steps. First, the homogenized samples are extracted and partitioned using an organic solvent and salt solution. Then, the supernatant is further extracted and cleaned using a dSPE technique. Final clear extracts of vegetables were concentrated under vacuum to near dryness and taken up into initial mobile phase (0.1% formic acid and 20% methanol). The separation and quantification of free low molecular weight polyphenols from the vegetable extracts was achieved by ultrahigh pressure liquid chromatography (UHPLC) equipped with a phodiode array (PDA) detection system and a Trifunctional High Strength Silica capillary analytical column (HSS T3), specially designed for polar compounds. The performance of the method was assessed by studying the selectivity, linear dynamic range, the limit of detection (LOD) and limit of quantification (LOQ)...

Preservation of the endogenous antioxidant system of fish muscle by grape polyphenols during frozen storage

Pazos, Manuel; González, M. Jesús; Gallardo, José Manuel; Torres, Josep Lluís; Medina, Isabel
Fonte: Springer Publicador: Springer
Tipo: Artículo Formato: 22195 bytes; application/pdf
ENG
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37.23%
6 pages, 2 figures, 2 tables.-- Printed version published May 2005.; The capacity of a phenolic extract, OW, obtained from grape (Vitis vinifera) by-products, and of a purified fraction of procyanidins from OW, fraction IV, for preservation of endogenous antioxidants of fatty fish was investigated during frozen storage. They were used in muscle concentrations of 0.01% (w/w). Grape polyphenols were compared with propyl gallate, a synthetic antioxidant. The exogenous compounds were added to minced mackerel (Scomber scombrus) muscle and horse mackerel (Trauchurus trauchurus) fillets, before freezing at –10 °C. The results demonstrated that grape polyphenols and propyl gallate inhibit the depletion of endogenous agr-tocopherol, ubiquinone-10 and total glutathione. Grape polyphenols and propyl gallate showed similar efficiency for preservation of ubiquinone, in both minced and filleted muscle, and total glutathione, in minced muscle. Total glutathione in the fillets was better maintained by propyl gallate than grape polyphenols. The endogenous antioxidant more efficiently preserved by grape polyphenols and propyl gallate was agr-tocopherol. Its loss elapsed faster in the order control> OW>fraction IV>propyl gallate. The depletion of agr-tocopherol was highly correlated with the evolution of lipid oxidation. The development of lipid oxidation was repressed...

Stability of polyphenols in chokeberry (Aronia melanocarpa) subjected to in vitro gastric and pancreatic digestion

Bermúdez-Soto, María J.; Tomás Barberán, Francisco; García-Conesa, María Teresa
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 259768 bytes; application/pdf
ENG
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10 pages, 3 tables, 2 figures.; Berries and red fruits are dietary sources of polyphenols with reported health benefits. As part of the diet, polyphenols are ingested as complex mixtures immersed in a food matrix which is digested in the gut. Epithelial cells lining the gut are regularly exposed to these digested mixtures. To understand the effects of dietary polyphenols on human gut health it is essential to determine their stability and fate in the lumen. In this work, we investigated the effects of an in vitro gastric and pancreatic digestion on the stability and composition of the major polyphenols in chokeberry juice. Digestion was carried out with a mixture of pepsin-HCl for 2 h, followed by a 2 h incubation with pancreatin and bile salts at 37 °C with shaking, in the absence of light and under N2. After digestion, the chokeberry samples were acidified, filtered and HPLC-DAD/HPLC–MS–MS analysed to determine the content of total soluble recovered phenolics. Gastric digestion had no substantial effect on any of the major phenolic compounds in chokeberry, namely anthocyanins, flavan-3-ols, flavonols and caffeic acid derivatives. However, these compounds were significantly altered during the pancreatic digestion and this effect was more marked for anthocyanins (approximately 43% was lost during the 2 h treatment with pancreatin). Flavonols and flavan-3-ols decreased by 26% and 19%...

Quantification of polyphenols with potential antioxidant properties in wines using reverse phase HPLC

Paixão, Neuza; Pereira, Vanda; Marques, José C.; Câmara, José S.
Fonte: WILEY-VCHVerlagGmbH Publicador: WILEY-VCHVerlagGmbH
Tipo: Artigo de Revista Científica
Publicado em /02/2008 ENG
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A RP-HPLC method with photodiode array detection (DAD) was developed to separate, identify and quantify simultaneously the most representative phenolic compounds present in Madeira and Canary Islands wines. The optimized chromatographic method was carefully validated in terms of linearity, precision, accuracy and sensitivity. A high repeatability and a good stability of phenolics retention times (a3%) were obtained, as well as relative peak area. Also high recoveries were achieved, over 80.3%. Polyphenols calibration curves showed a good linearity (r2 A0.994) within test ranges. Detection limits ranged between 0.03 and 11.5 lg/mL for the different polyphenols. A good repeatability was obtained, with intra-day variations less than 7.9%. The described method was successfully applied to quantify several polyphenols in 26 samples of different kinds of wine (red, ros and white wines) from Madeira and Canary Islands. Gallic acid was by far the most predominant acid. It represents more than 65% of all phenolics, followed by p-coumaric and caffeic acids. The major flavonoid found in Madeira wines was trans-resveratrol. In some wines, (–)-epicatechin was also found in highest amount. Canary wines were shown to be rich in gallic, caffeic and p-coumaric acids and quercetin.