ABSTRACT Grape juices have been valued due to their potential health benefits, which have demanded increased grape productivity and quality. Five grape cultivars grown in Brazil, Isabel Precoce, Carmem, Violeta, Concord and Bordo were evaluated in 2013 and 2014 seasons for bioactive components and also for juice processing quality traits. Production cycle was the longest for Carmem but lower and similar for Violeta, Isabel, Bordo and Concord. Isabel showed higher productivity (5.4 kg∙plant-1) but lowest soluble solids content (16.9 °Brix), anthocyanins (26.7 mg∙100 g-1) and total phenolics (110.7 mg∙100 g-1). The highest anthocyanins contents were observed in Violeta (189.9 mg∙100 g-1) and Bordo (133.8 mg∙100 g-1). These cultivars were also rich in phenolics (356.1 and 239.5 mg∙100 g-1, respectively). The highest anthocyanin and total phenolics concentrations were found in Violeta juice (2.68 and 6.33 g∙L-1) followed by Bordo (1.44 and 2.86 g∙L-1). Isabel juice had the lowest content, 0.14 and 1.29 g∙L-1, respectively. Biogenic amines were found at low concentrations only in the juices. Putrescine and spermidine were the major amines detected in juices. Phenylethylamine was detected only in Bordo juice from 2013 season and tryptamine was detected only in 2014 season. Blends were preferred over varietal juices except for Carmem.

ABSTRACT In the Brazilian Southeast, the production of high quality wines is attained by a new management approach called double pruning. This management changes the harvesting of wine grape (Vitis vinifera L.) from wet summer to dry winter through a two pruning procedures carried out during the year. The first pruning is done during the winter to induce a vegetative cycle (all clusters are removed) and a second pruning is done during the summer to induce the reproductive cycle. In this study, ten different rootstocks were compared in order to optimize yield and wine quality of Syrah vines conducted under autumn-winter season by double pruning approach. Syrah grapevines grafted onto ‘Rupestris du Lot’ and ‘IAC 766’ showed the highest pruning weight, while ‘110 Richter’ and ‘161-49 Courdec’ induced the lowest cane vigor. The average production of two seasons identified ‘IAC 766’, ‘Kober 5BB’ and ‘Rupestris du Lot’ as the most productive rootstocks. In both seasons, the grape quality was more influenced by the plant development status than by rootstocks. ‘Syrah’ wine from vigorous and high yielding rootstocks, ‘IAC 766’ and ‘Rupestris du Lot’, showed satisfactory wine phenolic composition and alcohol/acidity balance. This study showed that vigorous rootstock increased yield without compromising grape and winter wine quality of Syrah grapevines subjected to double pruning management in the Brazilian Southeast.

The performance of Syrah grapevine under protected cultivation with different plastic films was evaluated during 2012 and 2013 seasons in South of Minas Gerais State. Agronomical and physiological measurements were done on eight years old grapevines, grafted onto ‘1103 Paulsen’ rootstock cultivated under uncovered conditions, covered with transparent and with diffuse plastic films. Both plastic covers induced the highest shoot growth rate and specific leaf area. The diffuse plastic induced greater differences on leaf area, pruning weight and leaf chlorophyll content as compared to uncovered vines. Grapevines under diffuse plastic also had the lowest rates of photosynthesis, stomatal conductance and transpiration. Leaf starch, glucose and fructose contents were not affected by treatment, but leaf sucrose was reduced by transparent plastic. The leaf and stem water potential were higher under diffuse plastic. In 2013, grapevines under diffuse plastic showed the highest yields mainly due to decreased rot incidence and increased cluster weight. Furthermore, berries under diffuse plastic showed the highest anthocyanins concentration. The use of diffuse plastic induces more agronomical benefits to produce Syrah grape under protected cultivation.