In Albania the autochthonous cv. ‘Shesh i Zi’ it is well known for red wine production. During the wine production, the main problem with this variety is the collapse of its color after alcoholic ...fermentation. The purpose of this study is to assess the impact of oak chips and stems during alcoholic fermentation. In this study, were used 100 kg grapes of cv. ‘Shesh i Zi’ from Tirana area. For the production of wines were used three different vinification schemes (classic, oak chips and stems). The wines were analyzed by spectrophotometric methods such total tannins, total anthocyanins, color parameters. The obtained results were statistically analyzed with Statistix 9 software. Wines produced in the presence of stems and oak chips increase the formation of bonds between tannins and anthocyanins preserving the color of the wines.
The quality of rosé wines significantly depends on their phenolic composition, particularly tannins, anthocyanins, and their derivatives, which determine the perceived color of these products and ...their color evolution throughout the storage and shelf-life periods. This study investigated the impact of phenolic content on the oxidation and color evolution of five different model rosé wines obtained by blending a fixed amount of grape tannins with varying concentrations of oenocyanin to modulate their respective ratio and color intensity. The solutions were monitored for color and pigment changes promoted by oxidation in a Fenton-like environment. The findings revealed a potential correlation between the initial phenolic concentration and the different degrees of oxidation within each solution, resulting in significant variations in CIELAB data. Overall, all solutions exhibited a substantial decrease in redness, with losses ranging from 23% in the darkest solution to 43% in the lightest one compared to their initial levels. Additionally, their color profiles shifted toward yellow hues, up to triple the original value, indicating the degradation of the pigments responsible for the characteristic rosé color. Greater amounts of anthocyanins preserved higher Fe(II) concentrations over time, suggesting the antioxidant role of these compounds. The whole dataset also permitted the evaluation of the different oxidation susceptibilities of individual anthocyanins, among which derived pigments, such as vitisins, proved to be notably more stable than native pigments, particularly delphinidin and petunidin.
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