Isabel grape (Vitis labrusca) is the variety mostly spread in the Serra Gaúcha Region which is used, among other purposes, to elaborate red table wines. This wine usually presents high acidity, due to the level of free tartaric acid. The purpose of this work was to evaluate the effect of different doses of calcium carbonate in acidity and in the Isabel wine composition of the Serra Gaúcha region. The study carried out at Embrapa Uva e Vinho consisted of application in Isabel wine, from the 2002 vintage, different concentrations of calcium carbonate (0,0; 0,5; 1,0; 1,5; 2,0; 2,5 and 3,0 g L-1). The experimental design was a randomized block with seven treatments and four replications. The wines were analyzed ten days after treatment. The determinations were accomplished by physical-chemical methods: density, alcohol, total titratable acidity, pH, reducing sugar, dry extract, reduced dry extract, ashes, optical density at 420, 520 and 620 nm, color intensity and coloration. The tartaric acid was measured by liquid chromatography. The potassium and calcium were analyzed by atomic absorption spectrometry. Results showed that besides the reduction of acidity, the calcium carbonate interfered in color, dry extract, ashes and in the mineral elements of the Isabel wine.
Vitis labrusca; desacidification; chemical composition
