## 3 Results and Discussion
### Influence of Variety  
Total acid content is defined as the concentration of organic acids in the grape or wine [38]. Total acids in white wine samples varied from 4.63 \(\pm\) 0.09 to 6.63 \(\pm\) 0.05 g L\({}^{-1}\). The content of organic acids, tartaric and malic, was studied in white wines as they are considered as one of the important descriptors of wine. Tartaric acid (2,3-dihydroxybutanediolic acid) is a predominant acid in wines and represents about 50% of total acids in wine [39]. In our wines, the concentration of tartaric acids was similar. Thus, tartaric acid in chardonnay wines ranged from 1.63 to 2.93 g L\({}^{-1}\) (mean: 2.37 g L\({}^{-1}\)). Pinot blanc wines contained tartaric acid in a range of 2.04 to 2.78 g L\({}^{-1}\) (mean: 2.37 g L\({}^{-1}\)) and pinot gris wines presented 1.63-2.77 g L\({}^{-1}\) (mean: 2.30 g L\({}^{-1}\)). During the fermentation and aging process, its concentration decreases as a result of the formation of tartrates. The content of malic acid is usually highest at the beginning of the alcoholic fermentation, and afterwards it converts into lactic acid, spontaneously or in the presence of malotactic bacteria, during the malolactic fermentation. During this process, the content of malic acid decreases and the content of lactic acid increases in wine [40]. In our study, most of the wines contained malic acid in concentrations higher than 1 g L\({}^{-1}\), except wines CH4 and PG6, which contained 0.07 and 0.77 g L\({}^{-1}\), respectively, which means that malolactic fermentation was almost completed in these wines. In addition, chardonnay wines contained from 0.07 to 2.50 g L\({}^{-1}\) malic acid (average: 1.27 g L\({}^{-1}\)), in pinot blanc acid was present in a range of 1.03-2.43 g L\({}^{-1}\) (average: 1.61 g L\({}^{-1}\)) and in pinot gris  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Wine** & **Alcohol** & **Total** & **Tartaric** & **Alcid** & **Luctic Acid** & **Fructose** & **Glucose** & **TPC** & **TAA** \\ \hline \multirow{3}{*}{**Sample**} & \multirow{3}{*}{**L**[\%]} & **[g L\({}^{-1}\)]** & **[g L\({}^{-1}\)]** & **[g L\({}^{-1}\)]** & **[g L\({}^{-1}\)]** & **[g L\({}^{-1}\)]** & **[g L\({}^{-1}\)]** & **[g L\({}^{-1}\)]** & **[mg L\({}^{-1}\) GAE]** & **[\% Inhibition** \\  
wines from 0.77-1.87 g L\({}^{-1}\) (average: 1.36 g L\({}^{-1}\)). [PERSON] [18] reported that content of malic acid in white and rose wines is usually in the range between 1-3 g L\({}^{-1}\). Content of lactic acid was in most cases below 1 g L\({}^{-1}\), except wines CH4, PB8 and CH10. The obtained results for total acids, tartaric and malic acids in the white Slovak wines were comparable to those reported in the literature for wines from various regions, including Spain, Brazil, Chile, France [41; 42; 43; 44]. Glucose and fructose are the main fermentable sugars in wine must. During alcoholic fermentation, yeasts convert most of the glucose and fructose present into alcohol and CO\({}_{2}\). Grape musts contain equal amounts of glucose and fructose, and during fermentation glucose is consumed at a higher rate than fructose, which leads to an increased proportion of fructose as fermentation progresses, as was also observed in our wines. In general, all wines contained a higher amount of fructose (on average: 3.81 g L\({}^{-1}\) for chardonnay wines; 4.17 g L\({}^{-1}\) for pinot blanc wines and 2.47 g L\({}^{-1}\) for pinot gris wines) compared to glucose (on average: 0.63 g L\({}^{-1}\) for chardonnay wines; 1.22 g L\({}^{-1}\) for pinot blanc wines and 1.53 g L\({}^{-1}\) for pinot gris wines). The higher values for fructose compared to glucose, obtained for the wine samples, can be explained by the preference of _Saccharomyces cerevisiae_ yeasts to ferment glucose, resulting in larger residual amounts of fructose in wines. [PERSON] et al.