Grape epicatechin conjugates prevent erythrocyte membrane protein oxidation

Epicatechin conjugates obtained from grape have shown antioxidant activity in various systems. However, how these conjugates exert their antioxidant benefits has not been widely studied. We assessed the activity of epicatechin and epicatechin conjugates on the erythrocyte membrane in the presence and absence of a peroxyl radical initiator, to increase our understanding of their mechanisms. Thus, we studied cell membrane fluidity by fluorescence anisotropy measurements, morphology of erythrocytes by scanning electron microscopy, and finally, red cell membrane proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Our data showed that incubation of red cells in the presence of epicatechin derivatives altered membrane fluidity and erythrocyte morphology but not the membrane protein pattern. The presence in the medium of the peroxyl radical initiator 2,2′-azobis(amidinopropane) dihydrochloride (AAPH) resulted in membrane disruptions at all levels analyzed, causing changes in membrane fluidity, cell morphology, and protein degradation. The presence of antioxidants avoided protein oxidation, indicating that the interaction of epicatechin conjugates with the lipid bilayer might reduce the accessibility of AAPH to membranes, which could explain in part the inhibitory ability of these compounds against hemolysis induced by peroxidative insult.

Fenologia, exigência térmica e produtividade de videiras 'Niagara Branca', 'Niagara Rosada 'e 'Concord' submetidas a duas safras por ciclo vegetativo

Este trabalho objetivou avaliar a fenologia, a demanda térmica e a produtividade das cvs. Niagara Branca, Niagara Rosada e Concord submetidas a uma poda seca no inverno e a uma poda verde no final da primavera, visando à obtenção de duas safras de uva por ciclo vegetativo. O experimento foi conduzido em vinhedo pertencente à Estação Experimental Agronômica de Eldorado do Sul-RS, na safra de 2007/2008. As plantas foram submetidas a duas épocas de poda de inverno (22-07-07 e 20-08-07), em cordão esporonado, e duas épocas de poda verde (15-11-07 e 17-12-07), mediante desponte do sarmento a partir da quarta gema acima do último cacho. Os subperíodos fenológicos considerados da videira foram: vegetativo, compreendendo da poda à brotação e da brotação à floração; e reprodutivo, abrangendo da floração à colheita. Os respectivos intervalos tiveram um acompanhamento com base no acúmulo de graus-dia. A produção por planta, sólidos solúveis totais e acidez total titulável foram avaliados em ambas as safras. As cultivares necessitaram aproximadamente de 1.500 graus-dia para completar seu ciclo, tanto na primeira como na segunda safra. A poda de inverno antecipada aumentou a duração do ciclo fenológico das plantas comparativamente à poda de agosto, devido ao aumento do subperíodo poda/floração nas videiras podadas precocemente. A antecipação da poda de inverno antecipou a colheita da primeira safra, possibilitando obter uvas precoces com maior valorização de mercado. A duração do ciclo fenológico da segunda safra foi menor se comparada à primeira safra, devido às temperaturas mais elevadas decorridas no desenvolvimento das plantas submetidas à poda verde. A produtividade da segunda safra foi maior quando a poda seca foi realizada em agosto, associada à poda verde em novembro. Nas plantas submetidas à poda verde, obteve-se uma segunda colheita em meados de março/abril, oferecendo vantagens econômicas ao viticultor e ampliando a disponibilidade da fruta ao consumidor.

Sensibilidade ao rachamento de bagas das videiras 'Concord', 'Isabel' e 'BRS Rúbea'

Com o objetivo de avaliar a sensibilidade ao rachamento de frutos, foram realizados diferentes testes de laboratório com bagas de uva para processamento das cultivares Concord, Isabel e BRS Rúbea. Para a determinação do índice de rachamento, bagas maduras foram imersas em água destilada e avaliadas a cada hora, durante um período de dez horas. Com o auxílio de um texturômetro, foram realizados testes mecânicos. Em testes de compressão, foram avaliadas, no momento de rompimento das bagas, pressão de compressão, energia de deformação e força máxima de compressão. Com uma sonda de menor calibre, as bagas foram perfuradas, obtendo-se a força máxima de perfuração e deformação de perfuração no rompimento da película. Em testes de relaxação, foram avaliados o grau de solidez e a velocidade inicial de decaimento. Foram avaliadas também as correlações entre o índice de rachamento, e os testes mecânicos. Tanto o índice de rachamento quanto os testes mecânicos apontaram para a cultivar BRS Rúbea como a mais resistente ao rachamento e a cultivar Concord como a mais suscetível. A 'Isabel' apresentou resistência intermediária. O índice de rachamento, apresentou forte correlação com as variáveis avaliadas nos testes mecânicos e possui bom potencial para a avaliação da sensibilidade ao rachamento de materiais distintos de videira.

Ciclo de produção e demanda térmica de clones da videira 'Concord' sobre diferentes porta-enxertos

O objetivo do trabalho foi determinar a duração do ciclo de produção e a necessidade térmica de seis clones de 'Concord' sobre três porta-enxertos no norte do Paraná. Foram avaliados os clones '22', '28', '49', '202', '211' e '225', obtidos pela Embrapa Uva e Vinho, e enxertados sobre os porta-enxertos 'IAC 766', 'IAC 572' e '420-A'. O trabalho foi realizado em área experimental pertencente ao Centro Tecnológico da COROL - Cooperativa Agroindustrial, localizado no município de Rolândia-PR. O experimento foi realizado em esquema fatorial (6 clones x 3 porta-enxertos), em delineamento inteiramente casualizado, com cinco repetições. As plantas foram conduzidas em sistema de latada, no espaçamento de 4,0 m x 2,0 m, e as avaliações foram realizadas nas safras de 2009/2010 e 2010/2011. Verificou-se que dentre os clones de 'Concord' avaliados, o '202' apresenta a menor duração do ciclo entre a poda e a colheita, sendo portanto o mais precoce. Dentre os porta-enxertos, o '420-A' induz a maior taxa de acúmulo diário de sólidos solúveis do mosto, proporcionando redução do ciclo total e da demanda térmica dos clones de 'Concord', enquanto o 'IAC 572' induz a menor taxa, promovendo aumento do ciclo e da demanda térmica dos clones.

A mechanistic approach to methylene blue sorption on two vegetable wastes: Cork bark and grape stalks

Two vegetable wastes, cork bark and grape stalks, were investigated for the removal of methylene blue from aqueous solution. The effects of contact time, dye concentration, pH, and temperature on sorption were studied relative to adsorption on a commercially-activated carbon. The highest adsorption yield was obtained within the pH range 5 to 10 for grape stalks and 7 to 10 for cork bark. The sorption kinetics of dye onto activated carbon and grape stalks was very fast. Kinetics data were fitted to the pseudo-first and second order kinetic equations, and the values of the pseudo-second-order initial rate constants were found to be 1.69 mg g-1 min-1 for activated carbon, 2.24 mg g-1 min-1 for grape stalks, and 0.90 mg g-1 min-1 for cork bark. Langmuir maximum sorption capacities for activated carbon, grape stalks, and cork bark for methylene blue estimated by the Orthogonal Distance Regression method (ODR) were 157.5 mg g-1, 105.6 mg g-1, and 30.52 mg g-1, respectively. FTIR spectra indicated that carboxylic groups and lignin play a significant role in the sorption of methylene blue. Electrostatic forces, n-p interactions, cation-p, and p-p stacking interactions contribute to methylene blue sorption onto grape stalks and cork bark. Grape stalks can be considered an efficient biosorbent and as a viable alternative to activated carbon and ion-exchange resins for the removal of methylene blue

Determination of polyphenol contents and antioxidant capacity of no-alcoholic red grape products (vitis labrusca) from conventional and organic crops

The polyphenol contents and antioxidant capacity of Brazilian red grape juices and wine vinegars were analyzed. Additionally, it was analyzed the human polyphenol absorption and acute effect in plasmatic oxidative metabolism biomarkers after juice ingestion. The organic Bordo grape juice (GBO) presented a higher level of trans-resveratrol, quercitin, rutin, gallic acid, caffeic acid and total flavonoids then other juices and vinegars as well as antioxidant capacity. The plasmatic polyphenol increased 27.2% after GBO juice ingestion. The results showed that juices and vinegars from Brazilian crops present similar chemical and functional properties described in studies performed in other countries.

Grape juice quality control by means of ¹H nmr spectroscopy and chemometric analyses

This work shows the application of ¹H NMR spectroscopy and chemometrics for quality control of grape juice. A wide range of quality assurance parameters were assessed by single ¹H NMR experiments acquired directly from juice. The investigation revealed that conditions and time of storage should be revised and indicated on all labels. The sterilization process of homemade grape juices was efficient, making it possible to store them for long periods without additives. Furthermore, chemometric analysis classified the best commercial grape juices to be similar to homemade grape juices, indicating that this approach can be used to determine the authenticity after adulteration.

Grape rust caused by Phakopsora euvitis, a new disease for Brazil

A ferrugem da videira foi constatada pela primeira vez no Brasil, ocorrendo em parreirais (Vitis spp.)comerciais no estado do Paraná tendo recentemente atingido também o Estado de São Paulo. O fungo Phakopsora euvitis foi identificado como o agente causal da doença. Esta ferrugem ocorre preferencialmente em folhas maduras causando a desfolha precoce das plantas infetadas.

Mechanical behavior of 'Niagara Rosada' grape berry detachment

The 'Niagara Rosada' grape is the main Brazilian table grape belonging to the Labrusca family. It develops medium, cylindrical and compact bunches with berries presenting a pinkish skin and a foxy flavor that is valued in the Brazilian market. These berries are tender and have a pedicel-berry connection provided by the vascular bundles and surrounding skin. This cultivar is very susceptible to berry drop mainly caused by vibration and senescence. The objective of this study was to evaluate the temporal mechanical behavior of the pedicel-berry detachment, using resistance indexes extracted from traction force-deformation curves. Test results showed two different detachment types. In the first one, which exhibited higher average resistance, a considerable portion of the vascular bundle came out attached to the pedicel and in the second type; the vascular bundle was retained inside the berry. The proposed indexes based on maximum detachment force, force at 0.2; 0.5; 1.0 and 1.2 mm, and maximum force to corresponding deformation ratio did not discriminate the senescence of the berry.

Adaptation of "Niagara Rosada" grape must to winemaking by partial cluster dehydration

This study aimed to verify the influence of partial dehydration of "Niagara Rosada" grape clusters in physicochemical quality of the pre- fermentation must. In Brazil, during the winemaking process it is common to need to adjust the grape must when the physicochemical characteristics of the raw material are insufficient to produce wines in accordance with the Brazilian legislation for classification of beverages, which establishes the minimum alcohol content of 8.6 % for the beverage to be considered wine. Therefore, given that the reduction in the water content of grape berries allows the concentration of chemical compounds present in its composition, especially the concentration of total soluble solids, we proceeded with the treatments that were formed by the combination of two temperatures (T1-37.1ºC and T2-22.9 ºC) two air speeds (S1: 1.79 m s-1 and S2: 3.21 m s-1) and a control (T0) that has not gone through the dehydration treatment. Analysis of pH, Total Titratable Acidity (TTA) were performed in mEq L-1, Total Soluble Solids (TSS) in ºBrix, water content on a dry basis and Concentration of Phenolic Compounds (CPC) in mg of gallic acid per 100g of must. The average comparison test identified statistically significant modifications for the adaptation of must for winemaking purposes, having the treatment with 22.9 ºC and air speed of 1.79 m s-1 shown the largest increase in the concentration of total soluble solids, followed by the second best result for concentration of phenolic compounds.

Sweet grape mini tomato grown in culture substrates and effluent with nutrient complementation

The objective of this study was to evaluate production of Sweet Grape mini tomato (Lycopersicum esculentum Mill.) using culture substrates and nutrient solution sewage effluent, applied by drip irrigation (fertigation). The experiment was conducted at the University of Goiás State (UEG-UnUCET), from June to November 2011 in Anápolis-GO, Brazil. The experimental design was a 2 x 3 factorial arrangement in a randomized complete block design with four repetitions. The plots were made by combining two nutrient solutions, effluent supplemented with mineral fertilizers (EcS); conventional nutrient solution (SnC); in addition three cultivation substrates: 60% of fine sand washed + 40% substrate composed by 20% coconut fiber plus 80% pine bark (S1); 20% coconut fiber and 80% pine bark (S2) and natural coconut fiber (S3). Sewage effluent were determined nitrate, calcium, potassium, manganese, total phosphate, total iron, magnesium, chloride, sulphate, boron, zinc and molybdenum. We evaluated average mass and average number of fruits per bunch, total fruit and total yield per plant. Statistical difference absence among tested solutions indicates sewage effluent can be used as an alternative source of nutrients in growing mini tomatoes in hydroponics.

‘Sweet grape’ tomato post harvest packaging

ABSTRACT This paper aims at evaluating the shelf life of mini tomatoes (Lycopersicum esculentum Mill.) cultivar ‘Sweet Grape’, grown in hydroponics, and stored under environmental and refrigerated conditions inside different packages. We adopted a completely randomized design, in which treatments were combinations of storage conditions: environment (e) and refrigerated (r) with packaging: polyvinyl chloride film (PVC); low-density polyethylene (LDPE); biofilm of tomato fruit of Solanum lycocarpum A.St.-Hil (lobeira) (TFB); cassava starch biofilm (CSB); carnauba wax (Copernicia prunifera) (CW), and without packaging - control (C). Physicochemical and sensory tests were carried out at the beginning (day zero), and at 8, 19, and 33 days of storage (DS). Fruit stored inside PVCr, LDPEe, LDPEr, and CWr had an acceptable shelf life of 33 days. The use of cassava and tomato starches were not effective in controlling fruit fresh weight loss. ‘Sweet Grape’ tomato postharvest conservation was enhanced under refrigerated conditions. The sensory evaluation results revealed that CWr treatment most pleased appraisers, while PCV had the highest rejection rate.

The action of red wine and purple grape juice on vascular reactivity is independent of plasma lipids in hypercholesterolemic patients

Although red wine (RW) reduces cardiovascular risk, the mechanisms underlying the effect have not been identified. Correction of endothelial dysfunction by RW flavonoids could be one mechanism. We measured brachial artery reactivity by high-resolution ultrasonography, plasma lipids, glucose, adhesion molecules (ICAM-1 and VCAM), and platelet function in 16 hypercholesterolemic individuals (8 men and 8 women; mean age 51.6 ± 8.1 years) without other risk factors. Twenty-four normal subjects were used as controls for vascular reactivity. Subjects randomly received RW, 250 ml/day, or purple grape juice (GJ), 500 ml/day, for 14 days with an equal wash-out period. At baseline, all 16 subjects were hypercholesterolemic (mean LDL = 181.0 ± 28.7 mg/dl) but HDL, triglycerides, glucose, adhesion molecules, and platelet function were within normal limits. Brachial artery flow-mediated dilation was significantly decreased compared to controls (9.0 ± 7.1 vs 12.1 ± 4.5%; P < 0.05) and increased with both GJ (10.1 ± 7.1 before vs 16.9 ± 6.7% after: P < 0.05) and RW (10.1 ± 6.4 before vs 15.6 ± 4.6% after; P < 0.05). RW, but not GJ, also significantly increased endothelium-independent vasodilation (17.0 ± 8.6 before vs 23.0 ± 12.0% after; P < 0.01). GJ reduced ICAM-1 but not VCAM and RW had no effect on either molecule. No significant alterations were observed in plasma lipids, glucose or platelet aggregability with RW or GJ. Both RW and GJ similarly improved flow-mediated dilation, but RW also enhanced endothelium-independent vasodilation in hypercholesterolemic patients despite the increased plasma cholesterol. Thus, we conclude that GJ may protect against coronary artery disease without the additional negative effects of alcohol despite the gender.

Colour, phenolic content and antioxidant activity of grape juice

Viticultural practices in the State of Santa Catarina, Brazil, have shown economic growth, with the production of grapes used to produce wines and grape juice. Grapes are rich in phenolic compounds which have drawn attention not only because of their important role in the development of products derived from grapes, but also for their potential beneficial health effects. The objective of this study was to evaluate commercial, organic and homemade grape juices produced in Santa Catarina. Grape juices were analyzed for total phenolic content, colour, and antioxidant activity. The commercial juices had the highest average values for total monomeric anthocyanins and total phenolics. There was a strong positive correlation (R = 0.9566) between the antioxidant activity and total phenolic content for the commercial juice. In addition, the Principle Components Analysis showed a strong positive correlation between the red colour and total monomeric anthocyanins. However, the total monomeric anthocyanis and polymeric anthocyanins showed a negative correlation.

Effect of trellising system on grape and wine composition of Syrah vines grown in the cerrado region of Minas Gerais

Based on the concept that the trellising system affects not only sunlight interception and carbon assimilation, but also the fruitzone microclimate, which has a great impact on fruit composition and consequently on wine quality, the effect of two trellising systems - Vertical Shoot Position (VSP) and modified Geneva Double Curtain (GDC) - on wine and berry composition of Syrah grapes grown in João Pinheiro, Northeast region of Minas Gerais State, Brazil was investigated. The parameters such as pH, berry size and weight, and seeds total phenolic contents were not affected by the training system. The GDC system produced fruits with the highest Brix and lowest titratable acidity. Berries from the VSP system presented lower anthocyanin concentration than those from the GDC system. Similar results were found for the total phenolic content of the skin of grape berries from the VSP system. GDC wines were characterized by high anthocyanin content and red color, resulting in wines with high color intensity. These data suggest that in the tropical region of Minas Gerais state, with high temperature and high sunlight intensity, the trellising system, which protects bunches against excessive radiation, should be chosen.