A great amount of American grapes is employed to produce homemade juice in the Serra Gaúcha Region. The purpose of this work was to evaluated the effects of Vitis labrusca cultivars (Isabel, Bordô (Ives), Concord) and a Vitis vinifera cultivar (Cabernet Sauvignon), in the juice composition. The juice was prepared at Embrapa in Bento Gonçalves, RS, in the 2003 vintage. The juices had been evaluated as classic analysis: density, °Brix, total and volatile acidity, pH, °Brix total acidity ratio, made by the physical-chemical methods. The volatile components ethanol, methanol and acetaldehyde were determined by gas chromatography. The mineral elements Ca, Mg, Mn, Fe, Cu and Zn had been analysed by atomic absorption when the K, Na and Rb by flame emission. The results showed variability among juices from different grape varieties. Cabernet Sauvignon juice dintinguished by the smaller methanol and ethanol quality and the highest concentration of volatile acidity and Fe. The Bordô and Concord have shown less level of total acidity and Mn.
grape; processing; characterization
