# Antioxidant Activity and Polyphenolic Content of North Macedonian Wines
## 3 Results and Discussion
### Antioxidant Activity  
The antioxidant activity of all wine varieties was evaluated by measuring the radical scavenging activity assay (DPPH) and the reduction potential of antioxidants (FRAP and CUPRAC assays). Red varieties exhibit high variations of antioxidant activity measured by the FRAP assay, displaying a range of 4.45-10.27 mmol TT/L (Table 1). The highest values were observed for wines from the Vranec variety, while the lowest results were recorded for wines of the Stanushina variety. Stanushina and Kratoshija wines show much higher variability in the antioxidant activity with lower values than \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Wine Variety**} & \multirow{2}{*}{**Sample No**} & \multicolumn{2}{c}{**TTC (g TE/L) LA**} & \multicolumn{2}{c}{**TTC (g CE/L) VA**} & \multicolumn{2}{c}{**TAC (mg/L)**} \\ \cline{3-5}  & & & **(\(\pm\)s, n = 3)** & \\ \hline \multirow{5}{*}{**Kratoshija**} & **K1** & 2.52 \(\pm\) 0.18 & 1.20 \(\pm\) 0.05 & 225.72 \(\pm\) 4.82 \\  & **K2** & 2.22 \(\pm\) 0.58 & 1.56 \(\pm\) 0.01 & **291.63 \(\pm\) 1.32** \\  & **K3** & 2.03 \(\pm\) 0.22 & **0.19 \(\pm\) 0.01** & 96.06 \(\pm\) 0.46 \\  & **K4** & **2.94 \(\pm\) 0.02** & **1.70 \(\pm\) 0.01** & 216.47 \(\pm\) 1.47 \\  & **K5** & **0.72 \(\pm\) 0.02** & 0.27 \(\pm\) 0.04 & **60.50 \(\pm\) 1.26** \\ \hline \multirow{5}{*}{**Stanushina**} & **S1** & **2.60 \(\pm\) 0.05** & **0.92 \(\pm\) 0.11** & **82.51 \(\pm\) 0.60** \\  & **S2** & 0.73 \(\pm\) 0.02 & **0.12 \(\pm\) 0.02** & 33.48 \(\pm\) 0.56 \\  & **S3** & 0.51 \(\pm\) 0.05 & 0.17 \(\pm\) 0.01 & 35.62 \(\pm\) 0.72 \\  & **S4** & **0.33 \(\pm\) 0.03** & 0.32 \(\pm\) 0.04 & 24.52 \(\pm\) 2.52 \\  & **S5** & 2.03 \(\pm\) 0.04 & 1.52 \(\pm\) 0.01 & **21.24 \(\pm\) 0.28** \\ \hline \multirow{5}{*}{**Vranec**} & **V1** & 3.86 \(\pm\) 0.06 & 1.78 \(\pm\) 0.04 & 272.58 \(\pm\) 16.01 \\  & **V2** & 2.91 \(\pm\) 0.03 & **1.07 \(\pm\) 0.03** & 225.27 \(\pm\) 3.44 \\ \cline{1-1}  & **V3** & **3.90 \(\pm\) 0.03** & **2.20 \(\pm\) 0.01** & 216.95 \(\pm\) 7.19 \\ \cline{1-1}  & **V4** & 2.32 \(\pm\) 0.09 & 1.45 \(\pm\) 0.01 & **273.06 \(\pm\) 1.80** \\ \cline{1-1}  & **V5** & 2.86 \(\pm\) 0.05 & 1.92 \(\pm\) 0.01 & 196.43 \(\pm\) 5.17 \\ \cline{1-1}  & **V6** & **2.23 \(\pm\) 0.03** & 1.37 \(\pm\) 0.03 & **121.15 \(\pm\) 3.12** \\ \hline \hline \end{tabular}  
* All results are presented as mean value of three measurements (n = 3) together with the standard deviation (\(\pm\)s).  
\end{table} 
Table 2: Total tannin content (TTC) by the leucoanthocyanin (LA) method and the vanillin assay (VA) and total anthocyanin content (TAC) of the three red varieties examined (the lowest and the highest values within each variety are shown in bold) *. Vranec wines. Compared to red wines, white wines are known to exhibit very low antioxidant activity which was found to lie within the range 0.95-1.07 mmol TE/L. The results obtained from the CUPRAC assay demonstrated a similar trend in the antioxidant activity of the analysed varieties. The reducing power of the antioxidants of red wines was found within the range 7.24-15.8 mmol TE/L. As shown in Table 1, the antioxidant activity measured with the CUPRAC assay decreased in the order: Vranec > Kratoshija > Stanushina. Similar to the results from the FRAP assay, Vranec shows consistency in the results for the selected samples, whereas Kratoshija and Stanushina both expanded their variability through a larger range of values. White wines showed much lower antioxidant activity in a limited range of 1.35-1.60 mmol TE/L, compared to red wines. The radical scavenging activity of red wines measured by the DPPH assay were found to be within the range of 4.11-11.73 mmol TE/L (Table 1). Vranec wines show higher radical scavenging activity than Kratoshija and Stanushina. These results are consistent with the literature [17; 20]. Similarly to the previous assays, white wines demonstrated low radical scavenging activities (0.51-1.30 mmol TE/L).