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In recent years the wine sector has been characterized by an increased focus on the diversification of wine products. This change has been welcomed by consumers. In fact, today's consumers are willing to experiment with new products and unusual combinationswhich has stimulated research aimed at the discovery of native grape varieties suitable for for winemaking. In this context, particular attention are receiving vines for the production of dessert wines. Many regions have made efforts in the search for varieties and techniques able to better promote the drying process. At CREA-VE Turi-BA, there is an ongoing recovery and exploitation of indigenous grape varieties in the regions of Southern Italy and today more than 3,000 accessions of wine grapes are preserved. In the present work we have investigate the possibility of the use of certain accessions of Vitis vinifera varieties (collection CREA-VE Turi-BA) deemed attractive for the production of dessert wines. Accessions presenting a good sugar content and a good titratable acidity were selected; namely, Greco bianco b. (named Q19) and Mantonico bianco b. (named R8) were compared to the cv of Malvasia di Lipari b. Ampelographic and ampelometric analyses, followed by molecular analysis, were carried out for varietal assessment. A rate of the grapes were fermented immediately after harvest with standard procedure, in comparison to rates vinified after withering. The latter was made in a greenhouse type structure with parts of natural and unforced air, without any additional energy expense. At the end of the process, a loss in weight of the grapes equal to 30–35% was realized. The grapes are then stemmed, crushed, pressed and fermented by selected yeast under controlled temperature. Upon completion of the fermentation and subsequent stabilization, the wines were analyzed for the most important enological parameters and subjected to evaluation by a panel of expert tasters. Chemical analysis of wines showed that an alcohol content ranging to 11–12% volume was reached with in the standard wine-making; whilst, for the vinification of dried grapes the alcohol content was equal to 16% vol for Mantonico bianco b. and 18% vol. for and Greco bianco. Organoleptic analysis of the wines showed a greater appreciation for both of dessert wines. The best ratings were given for the olfactory characteristics (floral and fruity aromas) and taste characteristics. In particular, the Greco bianco b. had excellent scores slightly lower than Malvasia di Lipari b. Therefore, the tested varieties have shown a good potential for the production of dessert wines related to typicality of the grape and the region. Dessert wines produced, have a complex flavor profile and interesting for the high acidic component, which improved the taste perception of wine and attenuated the sensation of sweetness. That feature could allow a good wine aging, too.

Monomeric and polymeric flavan-3-ols (proanthocyanidins) content in grapes is higher in seeds compared to berry skins. Monomeric flavan-3-ols are more astringent, however, they can combine with other monomer, with anthocyanins and with mannoproteins released by yeast and therefore lose their harsh features in wines. Proanthocyanidins extracted during fermentation and maceration processes in red wines, are important for the organoleptic characteristics of the product and for its aging. There is a difference between skins and seeds proanthocyanidins, with the latter being perceived as more harsh and astringent. One of the most important purposes of refinement and aging of red wines very rich in polyphenols is the slow loss of bitterness. Instead, for wines ready to drink seeds tannins can give bitter overtones, therefore reducing their quality since consumers generally prefer a reduced astringency and attenuated bitterness. This paper investigates the possibility of employ some new seedless grapes crossings of Vitis vinifera L., obtained in recent breeding programs carried out at the CREA-VE of Turi, for the production of improved red and rosé wines made with traditionally red winemaking.

According to the CODEX STAN 255 (2007), table grapes can be harvested when the refractometric index reaches at least 16° Brix. Grapes with a lower refractometric index are accepted provided the sugar/acid ratio (Total Soluble Solids/Tritatable Acidity – TSS/TA) is at least equal to 20:1 if the Brix level is comprised between 12.5° and 14° Brix, 18:1 if the Brix level is comprised between 14° and 16° Brix. Some table grapes grown in Mediterranean climate can accumulate TSS higher than 16° Brix, with low levels of acidity, thus leading to a TSS/AT ratio even greater than 30: 1. Grapes that accumulate TSS less than 12.5° Brix and low TA levels, hardly reach the recommended ratio TSS/TA of 20:1, rather stopping at lower values. Based on these considerations in 2012 an experimental trial of four years started on a total of 103 table grape cvs. Phenological phases in relation to the acidic and sugar content were measured in order to assess the TSS/TA ratio and build regression lines with TSS. Almost all cvs. showed a significant linear regression, with R2 values higher than 0.80 and a standard error between 00.18 and 1.74. TSS values of 103 cvs. at TSS/TA ratio of 20:1, predicted by means of linear regression equations, , were subjected to cluster analysis based on Euclidean Distance. We identified nine clusters, of which the first two with the predicted TSS between 10.04° and 11.77° Brix (7 cvs.) and 12.08° and 12.62° Brix (7 cvs.), respectively. Some of the cvs. showing TSS values below 12.5° Brix at the TSS/TA of 20: 1, were subjected to a test panel of 24 tasters, who were asked to indicate the acceptability of these grapes on hedonic scale of 9 points. Preliminary results showed that for some table grapes with TSS below 12.5° Brix, a SST/AT ratio lower than the recommended 20:1 can be proposed, while preserving an acceptability by the consumer. These results suggest a more modern perspective on grapes nutritional intake, which takes into account the real needs of Western countries where diabetes, hyperglycemia, obesity and cardiovascular diseases are the main dismetabolisms arising from a diet too rich in calories. These grapes thus represent a new frontier and an opportunity for producers of table grapes, who want to enterprise a market share on “grape diet”, and represent a genetic basis for breeding aimed at obtaining new hypocaloric grape cultivars.