J. D. G. Maia

Efeito de reguladores de crescimento em uva apirênica, cv. BRS Clara

The objective of this study was to evaluate the effect of different concentrations of gibberellic acid (AG3), thidiazuron (TDZ) and forchlorfenuron (CPPU) on the size of bunches and berries and on the total soluble solids content, when applied in different concentrations on the seedless grapes, cv. BRS Clara. The grapevines were grafted on the rootstock IAC 572, trained in the pergola system and, spaced 2.5 x 2.0m and irrigated by micro sprinklers. The experiments were carried out at the Embrapa Grape and Wine Experimental Station for Tropical Viticulture in Jales, SP. The bunches were directly sprayed with the plant growth regulators, either individually or combined, in concentrations from 0 to 4mg.L-1 of CPPU; 0 to 10mg.L-1of TDZ and 0 to 90mg.L-1 of AG3. Generally, the application of growth regulators improved the quality of the bunches of the cv. BRS Clara; the use of TDZ and CPPU, combined with AG3, produce a synergistic effect, causing a better response than the isolated use of AG3; the treatments with 60mg.L-1 of AG3, 20mg.L-1 of AG3 + 4mg.L-1 of CPPU and 10mg.L-1 of AG3 + 5mg.L-1 of TDZ provide the best results for increase in the berries diameter; the application of AG3 before flowering cause excessive abortion which reduced the commercial value of the bunches. High concentrations of plant growth regulators decrease the content of total soluble solids.The objective of this study was to evaluate the effect of different concentrations of gibberellic acid (AG3), thidiazuron (TDZ) and forchlorfenuron (CPPU) on the size of bunches and berries and on the total soluble solids content, when applied in different concentrations on the seedless grapes, cv. BRS Clara. The grapevines were grafted on the rootstock IAC 572, trained in the pergola system and, spaced 2.5 x 2.0m and irrigated by micro sprinklers. The experiments were carried out at the Embrapa Grape and Wine Experimental Station for Tropical Viticulture in Jales, SP. The bunches were directly sprayed with the plant growth regulators, either individually or combined, in concentrations from 0 to 4mg.L-1 of CPPU; 0 to 10mg.L-1of TDZ and 0 to 90mg.L-1 of AG3. Generally, the application of growth regulators improved the quality of the bunches of the cv. BRS Clara; the use of TDZ and CPPU, combined with AG3, produce a synergistic effect, causing a better response than the isolated use of AG3; the treatments with 60mg.L-1 of AG3, 20mg.L -1 of AG3 + 4mg.L -1 of CPPU and 10mg.L-1 of AG3 + 5mg.L -1 of TDZ provide the best results for increase in the berries diameter; the application of AG3 before flowering cause excessive abortion which reduced the commercial value of the bunches. High concentrations of plant growth regulators decrease the content of total soluble solids.

Pre-drying and submerged cap winemaking: Effects on polyphenolic compounds and sensory descriptors. Part II: BRS Carmem and Bordô (Vitis labrusca L.)

Brazilian wine production is dominated by the use of American grape cultivars (Vitis labrusca L.) and their hybrids. In this context, this study analyzed the phenolic composition and sensory profile of Bordô and BRS Carmem red wines elaborated from traditional and two alternative winemaking technologies: grape pre-drying and submerged cap of chaptalized musts. Anthocyanins and pyranoanthocyanins apparently seemed to be affected by the thermal process (60°C), causing their degradation. In addition, the decrease of the concentration of these compounds could be suggested as a result of possible oxidation and hydrolysis reactions of anthocyanin 3-glucosides. Stilbenes were also affected by thermal degradation; however, flavan-3-ols and HCAD seemed to be less affected by the drying process. Submerged cap winemaking resulted in an increase of the anthocyanin and pyranoanthocyanin compounds due to the constant contact between the must and pomace during the alcoholic fermentation. The antioxidant capacity seemed not to be affected by thermal degradation, since the products of Maillard reaction also present antioxidant properties. Pre-dried wines were described as structured due to their higher flavan-3-ols content, and with high color intensity probably due to the formation of Maillard reaction products. The submerged cap wines presented an intense violet hue due to their high anthocyanin derivative concentrations and showed strong correlation with all other classes of the phenolic compounds.

Pre-drying and submerged cap winemaking: Effects on polyphenolic compounds and sensory descriptors. Part I: BRS Rúbea and BRS Cora

In contrast to the most worldwide used grape varieties, wine production in Brazil is mainly devoted to the elaboration of table wines from American grapes and hybrids. These grapes show initial disadvantages such as low soluble solids content in their optimal stage of ripening and poor color quality. Based on this, the Brazilian Agency EMBRAPA Grape and Wine has developed BRS type cultivars in order to enhance the quality of the table wines. This study analyzed the phenolic composition and sensory profile of BRS Rúbea and BRS Cora red wines elaborated by traditional and two alternative winemaking technologies: grape pre-drying and submerged cap of chaptalized musts. Pre-dried wines presented low concentrations of anthocyanins/pyranoanthocyanins and flavonols, suggesting that they were partially degraded by the thermal treatment (60°C). These wines were described as bitter and full-bodied because of their higher flavan-3-ols content, suggesting that these compounds were not greatly influenced by thermal degradation. Submerged cap was described as persistent to the palate and with an intense violet hue due to its high anthocyanin and flavonol concentrations. The antioxidant capacity presented a weak relationship with the anthocyanins and stilbenes, but was intensely related to the % of galloylated flavan-3-ols.

Grapevine breeding programs in Brazil

Abstract The grapevine was introduced in Brazil by European colonizers and immigrants in the sixteenth century. The lack of technical knowledge and the soil and climate conditions, distinct from other parts of the world where viticulture was already established, impaired the initial development of the crop in the country. However, envisioning the advantages of tropical conditions for grapevine production allowed its expansion to more favourable areas in South and Southeastern Brazil. Currently, Brazilian viticulture has reached the stage of producing grapes for quality wines with geographical indications. Genetic breeding programs were instrumental to the development of novel, more adapted genotypes by controlled hybridizations and clonal selection. The most important grape breeding programs conducted in the country are led by Instituto Agronomico de Campinas and Embrapa Grape and Wine, who are also engaged in the conservation and characterization of grapevine germplasm by traditional and modern techniques. The institutions have developed adapted rootstocks and scion genotypes for in natura consumption and juice and wine processing. The most important wine genotypes are briefly described in this chapter, along with their geographical distribution in the country.