Utilização de resinas de intercâmbio catiônico em vinho elaborado na campanha gaúcha

Abstract

The Campanha Gaúcha region proposes characteristic wines from New World producing regions and, especially, the red wines have been received a extensive acceptance by consumers in general. In the region, it is possible to reach a more sugar content in grapes on less rainy vintages during the maturation, but generally the acidity is low and pH values are higher; these parameters need to be inverses because they’re extremely important for the development of great white, rosé and sparkling wines. Thus, alternatives should be tested to resolve this problem and this work aimed to accompany the use of cation exchange resins in a rosé wine elaborated in Campanha Gaúcha, noting its effect on pH and total acidity mainly. The wine studied was elaborated by drawing off method with ‘Merlot’ and ‘Tannat’ grapes from Dom Pedrito, Rio Grande do Sul, Brazil, and winemaking began at February 2014. The resin used was commercial product pH-Stab® and after the application, three different treatments in triplicate were divided into wine bottles of 5 liter capacity: T1 – control (without using resins); T2 – 15 g.L-1 resins; T3 – 7.5 g.L-1 resins. Physicochemical analyzes were performed by method of Fourier transform infrared spectroscopy (FTIR) and after bottling it was developed sensorial analysis of all samples. To analyze statistically it, the data were submitted to analysis of variance, and the averages were compared by Tukey test at 5% probability. The analyzes performed in March, May and after bottling demonstrated lower pH for treatment with higher dose of resins (T2), acidity didn’t differ statistically between the samples. The pH values increased and the acidity decreased between analyzes of March and May because of malolactic fermentation. This decrease on pH caused from the resins is explained by cation exchange, because H+ ions are added to wine and they retire cations minerals, especially K+ (potassium) and Ca++ (calcium). The studied resin didn’t affect acidity, because it is more employed in stabilization and it isn’t liable for acidification of the product. On sensorial analysis of samples were not found significant differences. The use of cation exchange resins is a good alternative for oenological product, to reduce of pH in wines from regions such as Campanha Gaúcha, because it causes a rapid decrease, providing greater stability for the wine and qualitative gains.