Características físico-químicas dos vinhos tintos da indicação de procedência Vale do São Francisco

Abstract

The region of the Submédio San Francisco Valley seeks to consolidate itself in the market of fine wines through the Identification of Provenance, in structuring. In this context, the objective of this work was to carry out physical-chemical analyzes necessary for the typification process of all red, varietal and cut wines from the first season of the indication of Vale do São Francisco. The wines were evaluated for classical and chromatic oenological parameters, phenolic and organic acid composition, and in vitro biological activity, using spectrophotometric, colorimetric and chromatographic methods. Averages and multivariate analysis were applied to evaluate the results. The results of pH and sulfur dioxide were higher and lower than those recommended in the current legislation, respectively. The dry extract presented values suggesting full-bodied wines. All the wines presented high concentrations of phenolic compounds reflected in the biological activity, being important to highlight the aging potential of the same ones. In addition, the wines are reddish-blue in color, suggestive of young red wines. The profile of organic acids shows that the wines present preponderance of lactic acid, a characteristic feature of the grapes grown in the Region that present high concentrations of malic acid. The acids of the acetic series present concentrations below 1.2 mg.L-1, demonstrating the oxidative and microbiological stability of the wines. Catechin, p-coumaric acid, quercetin and myricetin may be used as typical references of these wines. High concentrations of flavonols, flavan-3-ols, phenolic acids and stilbenes were obtained in Touriga Nacional wines. Principal component analysis accounted for 71.00% of the total data variance. The first main component characterized all the wines, except for the cut Cabernet Sauvignon-Syrah-Alicant Bouschet-Touriga Nacional-Aragonês (winery I) and Ruby Cabernet (winery II), for the tonality, yellow and red percentage, dry matter, total polyphenol indices and total polyphenol concentration. The other wines were characterized by the second main component by the percentage of blue. The red wines of the Indication of Origin studied demonstrate typical characteristics as a function of the phenolic composition and of organic acids, pH, and coloration of young wines.