Evolution of phenolic compounds, organic acids and color parameters in tropical red wines during storage in bottles

Abstract

The understanding of phenolic and organic acid variation during wine storage in the bottle is important, because the commercial aspects, mainly color, and their antioxidant properties. Faced on scientific reference scarcity about this subjected for the tropical wines, this study evaluated the mainly factors involved in their phenolic compounds and organic acid evolution and these influence on color stability. Twenty-seven randomized samples of tropical red wines cultivars Tempranillo, Syrah and Petit Verdot, cultivated in São Francisco Valley (SFV), Northeast Brazil, summer harvest 2008, stored in bottle under 16º ± 1 ºC, were collected and analyzed at the 1, 6 and 12 months. The evolution of total phenolics, total anthocyanins, color parameters and organic acids was evaluated by spectrophotometry and high performance liquid chromatography UV-Vis. All wines showed, during the storage, tartaric, lactic and succinic acids, although Syrah wines presented the highest total organic acid content and stability. Petit Verdot wines showed the highest amounts of total phenolics, total anthocyanins and color intensity and weaker tonality, while Tempranillo and Syrah presented a similar evolution of total phenolics and great decreases of monomeric anthocyanins levels. These variations were due the grape cultivar characteristics and storage time. The presence of relationship between the changes in color intensity and total polyphenols (r = 0.74, p < 0.05) and anthocyanins (r = 0.72, p < 0.05) in these wines suggested degradation of the pigments. The despite following the traditional pattern of decrease in phenolic compounds during storage, the color parameters remained stable, suggesting an interference of profile acid in this parameter.