STUDIES CONCERNING PHYSICO-CHEMICAL CHARACTERISTICS

Abstract

Wine is a complex matrix. Wine polyphenolic compounds represent only a few g/l, but they play a major part in the determination of wine sensory properties. Due to their high content in antioxidants (tannins, antocyans etc.) and positive effect on human organism, young red wines are recommended for consumption. Polyphenols show a great diversity in structure, so the anthocyanins and their derivatives are responsible for the colour of red wines and tannins are responsible for perception of astringency. [1, 2, 3] This paper presents the physico-chemical and organoleptic determinations on four red wines: Merlot (obtained from two wine-growing centers: Recas and Dealu Mare-Merei), Cabernet Sauvignon and Burgund Mare (Recas), all processed from the harvest of 2005. Due to the unfavorable climatic conditions of 2005, harvesting started by the end of august, the winemaking process ending in late October. Winemaking technology was different, so in Merei centre was used traditional technology and the thermovinification proces in Recas. The wine samples were collected after the wine was rack off first time. 2005 being an unfavorable year for high quality grape yield due to heavy rainfalls, the studied varieties accumulated lower sugar levels than their biologic potential. To determine the quality of these young wines, there were analyzed some physico-chemical characteristics (alcohol, total acidity, residual sugar, density, free SO2, dry extract, ash, etc.) and organoleptic properties (color, limpidity, flavour, taste). The alcohol content in the studied samples was situated between 11.4% vol. Burgund Mare and 12.4%vol. at Merlot and Cabernet Sauvignon. Acidity level is also important for preservation of wines. The samples have been values situated between 3.49 g/l H2SO4 in Merlot (Recas), 3.62 g/l H2SO4 in Cabernet Sauvignon, Burgund Mare (Recas) and 3.71 g/l H2SO4 in Merlot (Merei). The analyzed samples are dry red wines, with a small quantity of residual sugar (2.6 g/l in Burgund-Recas, 2.62g/l in Merlot-Merei) and half-dry red wines with 4.7 g/l sugar in Cabernet Sauvignon and 9 g/l in Merlot-Recas. Organoleptic determination of the analyzed wines showed characteristic score for young wines, typical astringency in each analyzed variety due to their tannin content; color varied from intensive dark red (Cabernet Sauvignon) to granat-red with lilac blend (Merlot) and light ruby (Burgund Mare). The pleasant and persistent flavour of wines was similar to the grape varieties they were obtained from. The organoleptic scores varied between 18.3 points for Merlot (Recas) and 17.9 for Burgund Mare (Recas) and were rather high considering the climatic conditions of 2005. The wines are extractive, velvety and delicate but with specific taste.