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

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.

Erosive potential of different types of grape juices

The purpose of the present study was to evaluate the erosive potential of different types (concentrated and powdered) and commercial brands of industrialised grape juices. The pH of all five fruit drinks was measured at two time points: immediately after preparation and 24 hours later. Sixty specimens of bovine enamel were randomly allocated and immersed in different types of grape juice (n = 10) for 10 minutes four times a day for fifteen days. The enamel alteration was analysed using surface Knoop microhardness (KHN) and surface roughness (R-a) tests at baseline and on the 5th, 10th and 15th days of the experiment. Two way ANOVA, Tukey's post hoc and Pearson's correlation tests were used for statistical analysis (alpha = 5%). The grape juices presented pH values ranging from 2.9 to 3.5. All of the tested juices promoted significant enamel mineral loss (p < 0.05) on the first evaluation (5th day of immersion) and produced a significant increase in the mean roughness from the 10th day on when compared to the control group (p < 0.05). By the 15th day, all of the beverages had produced surface roughnesses that were significantly higher than that of the control group. The results suggest that all grape juices, regardless of their commercial presentation, present erosive potential.

Production and characterization of an alcoholic fermented beverage from grape must and beer wort

Mestrado Vinifera Euromaster - Instituto Superior de Agronomia - UL

Aplicações de métodos de classificação e calibração multivariada acoplados com técnicas espectroscópicas em amostras ambientais e alimentos

Este trabalho de pesquisa descreve dois estudos de caso de métodos quimiométricos empregados para a quantificação de hidrocarbonetos policíclicos aromáticos HPAs (naftaleno, fluoreno, fenantreno e fluoranteno) em água potável usando espectroscopia de fluorescência molecular e a classificação e caracterização de sucos de uva e seus parâmetros de qualidade através de espectroscopia de infravermelho próximo. O objetivo do primeiro estudo é a aplicação combinada de métodos quimiométricos de segunda ordem (N-PLS, U-PLS, U-PLS/RBL e PARAFAC) e espectrofluorimetria para determinação direta de HPAs em água potável, visando contribuir para o conhecimento do potencial destas metodologias como alternativa viável para a determinação tradicional por cromatografia univariada. O segundo estudo de caso destinado à classificação e determinação de parâmetros de qualidade de sucos de uva, densidade relativa e teor de sólidos solúveis totais, foi medida por espectroscopia de infravermelho próximo e métodos quimiométricos. Diversos métodos quimiométricos, tais como HCA, PLS-DA, SVM-DA e SIMCA foram investigados para a classificação amostras de sucos de uva ao mesmo tempo que métodos de calibração multivariada de primeira ordem, tais como PLS, iPLS e SVM-LS foram usadas para a predição dos parâmetros de qualidade. O princípio orientador para o desenvolvimento dos estudos aqui descritos foi a necessidade de metodologias analíticas com custo, tempo de execução e facilidade de operação melhores e menor produção de resíduos do que os métodos atualmente utilizados para a quantificação de HPAs, em água de torneira, e classificação e caracterização das amostras de suco de uva e seus parâmetros de qualidade

Ingestão de suco de uva tinto orgânico melhora a densidade capilar funcional e a hiperemia reativa pós-oclusiva em triatletas

A atividade física intensa está associada com as adaptações biológicas que envolvem a melhora da homeostase da glicose, da capacidade antioxidante e da microcirculação cutânea. A ingestão insuficiente de antioxidantes na dieta pode levar ao estresse oxidativo e disfunção endotelial que afetam a microcirculação. Suco de uva tinto orgânico, uma importante fonte de polifenóis, com reconhecida função antioxidante e, portanto, o seu consumo pode melhorar o estado antioxidante, e assim, o metabolismo da glicose e a função endotelial. O objetivo deste estudo foi avaliar o efeito do consumo diário de suco de uva tinto orgânico, sobre a concentração plasmática de ácido úrico, atividade da superóxido dismutase eritrocitária (E-SOD), concentração sérica da insulina, glicemia e HOMA IR-2, além de suas relações com os parâmetros da microcirculação em triatletas. Participaram do estudo 10 triatletas do gênero masculino (28 15 anos). As amostras de sangue foram coletadas antes (basal) e após 20 dias de ingestão de suco de uva tinto orgânico (300mL/dia). Em relação ao valor basal, a insulina sérica (p = 0,02) e o ácido úrico (p = 0,04) aumentaram, enquanto a glicose plasmática (p <0,001) e a E-SOD diminuíram (p = 0,04) após os 20 dias de intervenção. Os parâmetros da microcirculação também foram influenciados pela ingestão de suco de uva tinto orgânico, foi observado redução no tempo necessário para o retorno dos eritrócitos à velocidade de basal após isquemia (TRBCmax) (p = 0,04), aumento da densidade capilar funcional (DCF, p = 0,003) e da velocidade dos eritrócitos após a isquemia (VELmax p <0,001). A redução da glicemia foi determinante direta do aumento da DCF (p = 0,04), enquanto níveis séricos de insulina (p = 0,04) e a redução na atividade da SOD-E (p = 0,04) foram negativamente associados com a redução do TRBCmax. Os resultados do presente estudo sugerem que a ingestão de suco de uva melhora a capacidade antioxidante, a homesostase glicêmica e a microcirculação de triatletas.

Rapid method for the determination. of organic acids in wine by capillary electrophoresis with indirect UV detection

A capillary electrophoresis method for organic acids in wine was developed and validated. The optimal electrolyte consisted of 10 mmol/L 3,5-dinitrobenzoic acid (DNB) at pH 3.6 containing 0.2 mmol/L cetyltrimethylammonium bromide as flow reverser. DNB was chosen because it has an effective mobility similar to the organic acids under investigation, good buffering capacity at pH 3.6, and good chromophoric characteristics for indirect UV-absorbance detection at 254 nm. Sample preparation involved dilution and filtration. The method showed good performance characteristics: Linearity at 6 to 285 mg/L (r > 0.99); detection and quantification limits of 0.64 to 1.55 and 2.12 to 5.15 mg/L, respectively; separation time of less than 5.5 min. Coefficients of variation for ten injections were less than 5% and recoveries varied from 95% to 102%. Application to 23 samples of Brazilian wine confirmed good repeatability and demonstrated wide variation in the organic acid concentrations. (C) 2008 Elsevier Ltd. All rights reserved.

Análise isotópica (δ¹³C) e legalidade em néctares de uva

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Determination of selenium in nutritionally relevant foods by graphite furnace atomic absorption spectrometry using arsenic as internal standard

A method has been developed for the direct determination of Se in nutritionally relevant foods by graphite furnace atomic absorption spectrometry. Tungsten/rhodium carbide coating on the integrated platform of a transversely heated graphite atomizer or W coating with co-injection of Pd(NO3)(2) were used as a permanent modifiers. Samples and reference solutions were spiked with 500 mu g L-1 As and absorbance variations due to changes in experimental conditions were minimized. For 20 mu L aqueous analytical solutions delivered into the graphite tube, analytical curves in the 5.0-40 mu g L-1 with good linear correlation were established. Pyrolysis and atomization temperatures were evaluated using pyrolysis and atomization curves, respectively. The optimized heating program (temperature, ramp time, hold time) of the graphite tube of the Perkin-Elmer SIMAA 6000 atomic absorption spectrometer was: dry steps (110 degrees C, 5 s, 10 s; 130 degrees C, 15 s, 15 s); air-assisted pyrolysis step (600 degrees C, 20 s, 40 s; 20 degrees C, 1 s, 40 s); pyrolysis step (1300 degrees C, 10 s, 20 s); atomization step (2100 degrees C, 0 s, 4 s); clean step (2550 degrees C, 1 s, 5 s). The method was applied for Se determination in coconut water, coconut milk, soybean milk, cow milk, tomato juice, mango juice, grape juice and drinking water samples and four standard reference materials and results were in agreement at 95% confidence level. The lifetime of the tube was 500 firings and the relative standard deviations of measurements of typical samples containing 25 mu gL(-1) Se were 3.0% and 6.0% (n = 12) with and without internal standardization, respectively. The limits of detection were in the 0.35 mu g L-1-0.7 mu g Se L-1 range. The accuracy of the proposed method was evaluated by an addition-recovery experiment and all recovered values were in the 98-109% range. (c) 2004 Elsevier Ltd. All rights reserved.

Análise isotópica (δ13c) e legalidade em néctares de uva

The aim of this work was to develop an isotopic analysis method to quantify the carbon of C3 photosynthesis cycle in grape nectar and to identify the commercial beverages in disagreement to the Brazilian Ministry of Agriculture, Livestock and Food Supply (MAPA) regulation. The nectars were produced in a laboratory, according to the Brazilian Law. Adulterated beverages with quantity of grape juice lower than the legal limit were also produced. Isotopic analysis measured the relative isotopic enrichment of grape nectar and its purified sugar fraction. Based on these results, it was possible to estimated the quantity of source C3 by means of isotopic dilution equation. To determine the existence of adulteration in commercial nectars, it was necessary to create a legal limit according to the Brazilian Law. One of the twelve commercial brands of nectar analyzed was classified as adulterated. The developed methodology proved to be efficient to quantify the carbon of C3 origin and identify the adulterated commercial grape nectar.

Produção de vinho de uvas dos cultivares Niágara Rosada e Bordô: análises físico-químicas, sensorial e recuperação de etanol a partir do bagaço

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise isotópica do gás carbônico de espumantes comercializados no Brasil

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Secagem por atomização do suco de uva: microencapsulação das antocianinas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Produção de bebida mista de extrato hidrossolúvel de soja e suco de uva submetida a diferentes doses de radiação gama

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Caracterização química e sensorial de bebida mista de soja e uva

The aim of this study was to produce mix beverages of grape juice and soybean hydrosoluble extract (SHE) in laboratory scale. The raw materials were soybean (variety BRS 213), grape (species Vitis labrusca, variety Niagara Rosada), citric pectin, water and sugar. The mix beverage was produced with different proportions of SHE and grape juice (1:1; 1:1.5 and 1:2; respectively; m/m) and different soluble solids concentrations (10, 12 and 14 °Brix) obtained by adding granulated sugar (sucrose). Soybean hydrosoluble extract, grape juice and mix beverages were chemically analyzed (humidity, ash, protein, lipids, carbohydrate, reducing sugars, total reducing sugars, sucrose, titratable acidity and pH). The mix beverages were sensorial analyzed through the acceptance test (hedonic scale). The results of chemically analyzed were expressed as mean and standard deviation and the results of sensorial analyzed were submitted to variance analysis and the means were compared using the Tukey test at 5% of probability. The pH of mix beverages was lower than 3.9, without addition of acidulants. Sugar addition to mix beverages (10; 12 and 14ºBrix) increased the levels of soluble solids, total reducing sugar and carbohydrates, but it did not interfere in the reducing sugar concentration. The increased proportion of grape juice in mix beverages allowed observing the elevation of titratable acidity and reducing sugars levels, as well as the pH reduction. The increase of grape juice in mix beverage did not interfere in the acceptance of mix beverages. The more sweetened beverages were preferred by the sensory panel.

Propriedades físicas e mecânicas de cimentos de ionômero de vidro encapsulados e não encapsulados

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)