# Effect of Chitosan on the Removal of Different Types of Tannins from Red Wines
## 3 Results and Discussion
### The Effect of Chitosan on Wines Rich in Tannins of Different Origin
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline  & \multicolumn{3}{c}{**Delphination**} & \multicolumn{3}{c}{**Cyanidian 3-Glucoside**} & \multicolumn{3}{c}{**Potunidin 3-Glucoside**} & \multicolumn{3}{c}{**Peonidin 3-Glucoside**} & \multicolumn{3}{c}{**Malvidin 3-Glucoside**} & \multicolumn{3}{c}{**Malvidin 3-Glucoside**} & \multicolumn{3}{c}{**Malvidin 3-Gill-**} & \multicolumn{3}{c}{**Malvidin 3-Gill-**} \\  & \multicolumn{3}{c}{**3-Glucoside**} & \multicolumn{3}{c}{**(mg/L)**} & \multicolumn{3}{c}{**(mg/L)**} & \multicolumn{3}{c}{**(mg/L)**} & \multicolumn{3}{c}{**(mg/L)**} & \multicolumn{3}{c}{**(mg/L)**} & \multicolumn{3}{c}{**(mg/L)**} \\ \hline W & 248.92 \(\pm\) 14.36 & \({}^{\ast}\)A & 10.97 \(\pm\) 0.76 & AB & 174.10 \(\pm\) 4.40 & \({}^{\ast}\)A & 91.77 \(\pm\) 0.64 & B & 609.42 \(\pm\) 16.31 & \({}^{\ast}\)A & 150.20 \(\pm\) 2.50 & \({}^{\ast}\)A & 44.80 \(\pm\) 1.48 & AB \\ WdC & 2014.6 \(\pm\) 6.36 & \({}^{\ast}\)A & 9.96 \(\pm\) 0.54 & \({}^{\ast}\)A & 162.20 \(\pm\) 4.06 & a & 89.67 \(\pm\) 3.78 & a & 577.55 \(\pm\) 8.49 & a & 144.99 \(\pm\) 11.41 & a & 43.40 \(\pm\) 1.85 & a \\ CT & 2426.2 \(\pm\) 20.99 & AB & 7.85 \(\pm\) 1.08 & C & 169.50 \(\pm\) 4.96 & \({}^{\ast}\)A & 96.58 \(\pm\) 3.27 & \({}^{\ast}\)A & 520.92 \(\pm\) 17.89 & B & 148.40 \(\pm\) 3.00 & A & 47.28 \(\pm\) 2.03 & A \\ CT & 2149.2 \(\pm\) 24.50 & a & 9.98 \(\pm\) 0.83 & b & 154.95 \(\pm\) 4.54 & ab & 92.88 \(\pm\) 1.22 & a & 740.10 \(\pm\) 31.68 & c & 1 & 40.01 \(\pm\) 6.77 & a \\ ET & 205.24 \(\pm\) 29.95 & \({}^{\ast}\)B & 9.48 \(\pm\) 1.14 & BC & 155.95 \(\pm\) 9.65 & C & 90.33 \(\pm\) 2.78 & b & 591.98 \(\pm\) 1.60 & \({}^{\ast}\)B & 126.45 \(\pm\) 14.41 & b & 37.89 \(\pm\) 1.10 & C \\ ET-C & 203.45 \(\pm\) 4.22 & \({}^{\ast}\)C & 11.69 \(\pm\) 0.21 & A & 158.82 \(\pm\) 3.18 & \({}^{\ast}\)BC & 93.90 \(\pm\) 1.59 & AB & 544.34 \(\pm\) 26.09 & B & 123.31 \(\pm\) 7.75 & B & 43.87 \(\pm\) 0.99 & B \\ GT-C & 194.60 \(\pm\) 3.22 & a & 12.68 \(\pm\) 1.07 & A & 158.23 \(\pm\) 1.29 & b & 90.03 \(\pm\) 4.73 & a & 516.52 \(\pm\) 26.71 & b & 124.36 \(\pm\) 6.41 & b & 42.19 \(\pm\) 2.51 & a \\ \hline \end{tabular} Different letters indicate a statistically significant difference among treated wines, according to [PERSON]’s (HSD) analysis (\(\sigma<0.05\)). The effect of tannins addition is expressed with a capital letter on wines W, CT, ET, and GT (A, B, C) and the effect of chosen addition is expressed with a lowercase letter on wines W, CT, ET, and GT’s (a, b, C). The asterisk (\({}^{\ast}\)) indicates a statistical difference between each kind of wine before and after the treatment with chosen. All data are expressed as means \(\equiv\) standard deviation.  
\end{table} 
Table 2: Effect of tannins and C on native anthocyanins concentrations (mg/L). The effect detected for monomeric and polymeric anthocyanins is evident also for total anthocyanins and for main chromatic characteristics (Table 3). In agreement with literature [43; 44], colour intensity and tonality slightly increased after the addition of tannins (Table 3). However, for all wines the addition of chitosan determined a slight decrease in CI and, for CT and ET, also in hue. Because CT and ET showed a lower content of polymeric pigments compared with GT, it is likely that, in wine treated with condensed tannins and ellagitannins, anthocyanins are more involved in copigmentation reactions influencing colour intensity [45]. A parameter useful to understand the effect of a treatment on human visual perception was given by SieLAB analysis and it is the \(\Delta\)E. The \(\Delta\)E value is used to express the overall colour difference between a sample and the control. According to [PERSON] et al. (1999) [46], two samples show a visible difference if \(\Delta\)E calculated between them is higher than 1.5. In this study, we performed the calculation of \(\Delta\)E with the aim to understand if the effect of C addition was significant (Table 4).