04114naa a2200241 a 450000100080000000500110000800800410001910000130006024501180007326000090019152033620020065300230356265300260358565300160361170000120362770000190363970000240365870000210368270000170370370000150372070000230373577301140375811262782017-06-20       2017    bl uuuu     u00u1 u    #d1 aWURZ, D.  aTIMING OF LEAF REMOVAL MODIFIES CHEMICAL AND PHENOLIC COMPOSITION OF SAUVIGNON BLANC WINE.h[electronic resource]  c2017  aThe high altitude regions of Santa Catarina have been shown to be suitable for the elaboration of high quality wines, however, this is a recent activity, most of the management techniques employed in the vineyards, such as leaf removal, is based in other regions, with distinct edaphoclimatic characteristics. In this context, the objective of this work was to evaluate the effect of different defoliation times on the chemical and phenolic composition of Sauvignon Blanc wine in high altitude regio ns of Santa Catarina  Brazil. The experiment was conducted in the 2015 and 2016 seasons, in a vineyard located in the city of S??o Joaquim ? Santa Catarina State (28??17'39"S and 49??55'56"W, 1230m a.s.l.). The defoliation was carried out in cluster zone during phenological stages: full bloom, buckshot berries, pea-sized berries, veraison, 15 days after veraison and control without leaf removal. During harvest, severity of Botrytis cinerea was assessed by visual evaluation through a diagrammatic scale. A total of 60 kg of grapes were manually harvested from each treatment for winemaking. The microvinifications were carried out in the experimental Winery of Santa Catarina State University. For the wine samples from each season, total acidity (meq L-1), pH, total polyphenol content (mg L-1 of gallic acid) and color (Abs 420nm) were performed. For the wines of the 2015 harvest, phenolic compounds were analyzed: gallic acid, catechin, vanillic acid, P-coumaric acid and rutin. The experimental design was completely randomized with four replicates. The data were submitted to analysis of variance (ANOVA) and compared by the Scott Knott Test (P &lt 0.05). The chemical composition of Sauvignon Blanc wine was affected as a result of leaf removal timing, defoliation carried out in full bloom, buckshot berries and pea-sized berries reduced total acidity and increased pH of the wines in both seasons. For wine color, in both seasons, it was found a greater yellow coloration in wines originated from grapes where the plants were not defoliated. This was related to severity of Botrytis bunch rot, which presented higher values (44%) in plants not defoliated. While plants defoliated in the full bloom, buckshot berries and pea-sized berries stages, was verified a severity of 13%, 14% and 21%, respectively. The increase of yellow coloration is due to the oxidation of catechins and epicatechins, which is related to the increase of Botrytis bunch rot. In the 2015 season there were no influence of leaf removal timing in total polyphenols, however, in the 2016, the defoliation performed in full bloom resulted in lower polyphenols contents. Wines from non-defoliated plants presented higher values of catechin, rutin, Pcoumaric acid and gallic acid, related to yellow coloration of wines and greater susceptibility to darkening and oxidation. For vanillic acid, wines from non defoliated plants have the lowest values, this compound is important in wine preservation. Defoliation is an important management technique in high altitude regions of Santa Catarina - Brazil, it improves wine chemical composition, and if carried out during the stages of full bloom, buckshot berries and pea-sized berries can reduce the severity of Botrytis bunch rot; and avoid the formation of phenolic compounds related to the processes of oxidation and darkening.  aBotrytis bunch rot  ahigh altitude regions  apolyphenols1 aBEM, B.1 aALLEBRANDT, R.1 aMARCON FILHO, J. L.1 aBRIGHENTI, A. F.1 aOUTEMANE, M.1 aRUFATO, L.1 aKRETZSCHMAR, A. A.  tIn: WORLD VINE AND WINE CONGRESS, 40., 2017, Sofia, Bulg??ria. Abstracts... Bulg??ria: OIV, 2017. p. 143-145.