Dietary grapes (Vitis vinifera) feeding attenuates ethanol-induced oxidative stress in blood and modulates immune functions in mice.

Ethanol metabolism is known to induce overwhelming production of reactive oxygen species (ROS) and also to cause associated immune dysfunction. Several interventional agents of plant origin, in particular fruits and vegetables have been used to counteract these alterations induced by ethanol. In this study, we investigated the efficacy of dietary feeding of skin and flesh of grapes (Vitis vinifera L.) on the alterations in immune and vascular functions in mice with liver abnormalities induced by chronic ethanol consumption. Results revealed that feeding of both grape skin and flesh (2.5 g/kg body wt/day) effectively attenuated the oxidative stress and alterations in immune function and angiogenesis induced by chronic ethanol consumption (1.6 g/kg body wt/day for 12 weeks) in mice. The antioxidant actions of the grape skin and flesh as observed in this study might be attributed to the polyphenols present in the grapes.

Avaliação físico-química e sensorial de uvas Benitaka comercializadas no Estado do Piauí - Brasil / Physico-chemical and sensorial evaluation of Benitaka grapes commercialized in the state of Piauí-Brazil

In view of the vast commercialization of the Benitaka variety of grapesin the city of Picos-PI and nearby regions, the present study aimed to evaluate samples of mature grapes (Vitis vinifera L.) acquired in supermarkets and also in the two main streetmarkets of the city according to their sensorial and physico-chemical characteristics and the frequency of physiological alterations observed in the grapes of this variety. For the physico-chemical analysis, the samples were randomly chosen and the titratable acidity - AT (% of tartaric acid), the contents of soluble solidsSS (oBrix), the SS/AT ratio, as well as weight, width and size of the berries were determined. The sensorial analysis of the samples was conducted by seventeen judges using the Quantitative Descriptive Analysis - QDA. To evaluate the presence of physiological alterations in the fruits, a visual evaluation of the 'Benitaka' grapes was conducted followed by the completion of a form containing the total number of grapes in the bunches and eleven common flaws in the grapes. The samples commercialized in the main street market were the ones which had the highest values for Brix and Brix/Acidity and the sensorial attributes of sweetness and flavor were the ones which most contributed for the global quality. All the samples presented high percentage of berries with severe faws, which is the only negative trait evaluated in the Benitaka grapes analyzed. Samples acquired in the main streetmarket of the city of Picos - PI presented the highest sensorial grades as well as the best Brix/acidity ratio, thus indicating that the attributes related to flavor were the ones which most influenced on the acceptance of the grapes.

Dada la extensa comercialización de La Benitaka en la ciudad de Picos-PI y regiones adyacentes, en este estudio objetivamos evaluar muestras de uva (Vitis vinifera L.) madura compradas en supermercados y las dos principales férias libres de la ciudad cuanto a sus características sensoriales, físico-químicas y frecuencia de los cambios fisiológicos observados en esta variedad de uva. Para los análisis físico-químicos lãs muestras fueron seleccionadas al azar y se determinaron la acidez titulable - AT (% de ácido tartárico), los sólidos solubles - SS (Brix), la relación SS/AT, el peso, anchura y volumen de las bayas. El análisis sensorial de las muestras fue realizado por diecisiete jueces por medio de Análisis Descriptivo Cuantitativo - QDA. Para evaluar la presencia de cambios fisiológicos en la fruta fue realizada una evaluación visual de las uvas 'Benitaka' seguida del llenado de un formulario que contiene el número total de uvas en el racimo y once defectos más comunes en La fruta. Las muestras adquiridas en la feria central presentaron valores más elevados para SS y SS/ AT y los atributos sensoriales de dulzor y "flavor" fueron los que más contribuyeron a la calidad como un todo. Todas las muestras presentaron un alto porcentaje de frutos con defectos graves, que fue la única característica evaluada negativamente en la uva Benitaka analizada. Las muestras de uvas compradas en la feria central de la ciudad de los Picos - PI, Brasil, presentaron las más altas notas sensoriales y la mejor relación Brix/acidez, indicando que, principalmente los atributos relacionados con el sabor fueron más influyentes en la aceptación de las uvas.

Tendo em vista a ampla comercialização da variedade 'Benitaka' na cidade de Picos-PI e regiões adjacentes, o presente estudo teve como objetivo avaliar amostras de uva (Vitis vinifera L.) maduras adquiridas em supermercados e também nas duas principais feiras-livres da cidade quanto às características sensoriais, suas características físico-químicas e a frequência de alterações fisiológicas observadas nas uvas desta variedade. Para a realização das análises físico-químicas as amostras foram escolhidas aleatoriamente e determinados a acidez titulável - AT (% de ácido tartárico), o teor de sólidos solúveis - SS (Brix), a relação SS/AT, bem como peso, largura e tamanho das bagas. A análise sensorial das amostras foi realizada por dezessete julgadores pela análise descritiva quantitativa - ADQ. Para avaliar a presença de alterações fisiológicas nos frutos, foi realizada uma avaliação visual das uvas 'Benitaka' seguida do preenchimento de um formulário contendo o número total de uvas nos cachos e onze defeitos mais comuns em frutas. As amostras comercializadas na feira central foram as que obtiveram os maiores valores para SS e SS/AT e os atributos sensoriais de doçura e 'flavor' foram os que mais contribuíram para a qualidade global. Todas as amostras apresentaram elevados percentuais de bagas com defeitos graves, sendo esta a única característica negativa avaliada nas uvas 'Benitaka' analisadas. As amostras de uvas adquiridas na feira central da cidade de Picos - PI apresentaram as maiores notas sensoriais assim como a melhor relação Brix/acidez, indicando que principalmente os atributos relacionados ao sabor foram os que mais influenciaram na aceitação das uvas.

Preservation of endangered Tunisian grapevine cultivars using embryogenic cultures

The preservation of embryogenic lines derived from several endangered local grapevine cultivars was studied. Embryogenic calluses were obtained from immature anthers of eight cultivars, sampled on both fruity-cuttings and field grown vines. Anthers at the 'separated flower' stage, derived from fruity-cuttings, resulted in an increased induction of somatic embryogenesis, compared to those derived from the field. Pro-embryogenic calluses were induced on Chée and Pool (1987) basal medium, supplemented with 9 micron M of 2,4-dichlorophenoxyacetic acid (2,4-D) and 11.35 micron M of thidiazuron (TDZ) under dark conditions. Different anther zones (filament, abaxial, adaxial, lateral zones and entire anthers) were involved in somatic embryogenesis induction. The percentages of granular and yellowish pro-embryogenic calluses ranged between 15.6 percent and 34.8 percent in 'Kahli Kerkennah' and 'Muscat Raf-raf' cultivars, respectively. Although, morphological diversifications of pro-embryogenic calluses (several necrosis and spontaneous maturation) were observed on the induction mediumafter 5 subcultures. The reduction of 2,4-D and TDZ levels to 4.52 micron M and 2.89 micron M respectively, induced granular and yellowish embryogenic material. Thus, Chée and Pool (1987) (CP) enriched with 4.52 micron M of 2,4-D and 2.89 micron M of TDZ revealed to be the most appropriate for long-term maintenance. In fact, all the cultivars presented high and regular embryo maturation rates after 12, 24, 36 and 48 months of cultivation on this medium, under light conditions. After 4 years, they still exhibit high germination and regeneration abilities. Germination of somatic embryos was achieved on Murashige and Skoog (1962) basal-medium, with rates ranging from 69 percent to 96 percent. Only 5 percent of somatic embryos were concerned by morphological variations. The regenerated plantlets presented a normal phenotype under controlled greenhouse conditions, compared to mother plants.

Phytoplasma and virus detection in commercial plantings of Vitis vinifera cv. Merlot exhibiting premature berry dehydration

A new and devastating physiological disorder of Vitis vinifera cv. Merlot was recently reported, known as premature berry dehydration (PBD), which is characterized by plant growth reduction, induction of general senescence and pedicel necrosis in the fruit, causing significant reductions in vineyard production. The causes of this disease remain unclear and previous reports suggest that it may be associated with phloem disruption and water provision. For this reason, any factor causing phloem disturbances could cause an important change in the berry water status. As some micro-organisms have been reported to disrupt phloem flow, we analyzed the occurrence of phytoplasma and viruses in commercial vineyards presenting PBD. In this study, a phytoplasma was detected by electron microscopy and nested PCR while virus infections were diagnosed by RT-PCR in samples collected during two growing seasons. The presence of phytoplasma only in samples from grape plants with PBD suggests that this pathogen may be one of the causal agents of this disorder. We suggest that the influence of other factors, such as virus infections, agronomic handling and environmental conditions also modulate berry dehydration. This is the first study at the microscopic and molecular levels that correlates phytoplasma presence with PBD.

Argentinean cultivars of Vitis vinifera grow better than european ones when cultured in vitro under salinity

Argentinean Vitis vinifera cultivars although originated from Europe, have clear ampeIographic and genotypic differences as compared with the European cultivars currently used in wine making. In vitro evaluation of salt tolerance has been used in many species. Our hypothesis was that Argentinean cultivars are more tolerant to salinity than European ones. Three European cultivars, Malbec, Cabernet Sauvignon and Chardonnay and four Argentinean cultivars, Cereza, Criolla Chica, Pedro Gimenez and Torrontes Riojano were tested by in vitro culture. Treatments included: 1) Control, 2) 60 mEq/L of a mixture of three parts of NaCl and one part of CaCl2 and 3) 90 mEq/L of the salt mixture. Results from two experiments (I and II) are reported. No differences were found in plant survival, expressed as % of the respective control, among cultivars. Leaf area, leaf, stem and total dry matter (DM) in Experiment I and leaf area, leaf number and leaf, stem, root and total DM in Experiment II, were higher in Argentinean cultivars than in European ones. We conclude that Argentinean cultivars show better performance in growing under salinity, especially in the highest salt concentration. Differences among cultivars, inside each group, were found for most of the measured variables.