## 3 Results and Discussion
### Effect of Chitosan on Color Features and Anthocyanins Composition of Wine
\begin{table}
\begin{tabular}{c c c c} \hline \hline  & **C** & **KT** & **KTs** \\ \hline _Glucosides_ & & & \\ Df-3-glc & 6.05 \(\pm\) 0.07 a & 6.14 \(\pm\) 0.08 a & 5.95 \(\pm\) 0.24 a \\ Cn-3-glc & 2.65 \(\pm\) 0.14 a & 2.61 \(\pm\) 0.03 a & 2.44 \(\pm\) 0.23 a \\ Pt-3-glc & 10.06 \(\pm\) 0.25 a & 9.99 \(\pm\) 0.06 a & 9.96 \(\pm\) 0.13 a \\ Pn-3-glc & 6.22 \(\pm\) 0.14 a & 6.08 \(\pm\) 0.06 a & 6.08 \(\pm\) 0.08 a \\ Mv-3-glc & 39.49 \(\pm\) 1.32 a & 39.75 \(\pm\) 0.37 a & 39.79 \(\pm\) 0.60 a \\ total glc & 64.47 \(\pm\) 1.90 a & 64.57 \(\pm\) 0.54 a & 64.22 \(\pm\) 0.68 a \\ _Acetylglucosides_ & & & \\ Df-3-acetylglc & 0.22 \(\pm\) 0.00 a & 0.22 \(\pm\) 0.01 a & 0.23 \(\pm\) 0.01 a \\ Pn-3-acetylglc & 0.18 \(\pm\) 0.02 a & 0.19 \(\pm\) 0.01 a & 0.17 \(\pm\) 0.05 a \\ Mv-3-acetylglc & 0.56 \(\pm\) 0.02 a & 0.56 \(\pm\) 0.01 a & 0.56 \(\pm\) 0.02 a \\ Mv-3-coumaroylglc & 0.42 \(\pm\) 0.01 a & 0.42 \(\pm\) 0.01 a & 0.42 \(\pm\) 0.02 a \\ total acetylglc & 1.39 \(\pm\) 0.05 a & 1.40 \(\pm\) 0.02 a & 1.38 \(\pm\) 0.05 a \\ _Ethyl-bridged adducts_ & & & \\ Mv-3-glc (epi) catechchin & 0.77 \(\pm\) 0.05 a & 0.75 \(\pm\) 0.01 a & 0.76 \(\pm\) 0.02 a \\ Mv-3-glc-ethyl-(epi)-catechin & 0.60 \(\pm\) 0.02 a & 0.59 \(\pm\) 0.01 a & 0.58 \(\pm\) 0.02 a \\ Mv-3-glc-ethyl-(epi)-catechin & 1.05 \(\pm\) 0.01 a & 1.04 \(\pm\) 0.01 a & 1.05 \(\pm\) 0.02 a \\ Mv-3-glc-ethyl-(epi)-catechin & 0.77 \(\pm\) 0.02 a & 0.76 \(\pm\) 0.03 a & 0.78 \(\pm\) 0.01 a \\ total ethyl epi (cat) & 3.18 \(\pm\) 0.06 a & 3.13 \(\pm\) 0.02 a & 3.16 \(\pm\) 0.03 a \\ _B-type vitisins_ & & & \\ B-type vitisin of Pt-3-glc & 0.19 \(\pm\) 0.02 a & 0.17 \(\pm\) 0.01 a & 0.18 \(\pm\) 0.01 a \\ B-type vitisin of Pn-3-glc & 0.20 \(\pm\) 0.01 a & 0.20 \(\pm\) 0.01 a & 0.22 \(\pm\) 0.01 a \\ B-type vitisin of Mv-3-glc (vitisin B) & 0.95 \(\pm\) 0.08 a & 0.91 \(\pm\) 0.01 a & 0.93 \(\pm\) 0.04 a \\ total B-type & 1.35 \(\pm\) 0.09 a & 1.28 \(\pm\) 0.03 a & 1.32 \(\pm\) 0.04 a \\ _A-type vitisins_ & & & \\ A-type vitisin of Mv-3-glc (vitisin A) & 1.02 \(\pm\) 0.03 a & 0.99 \(\pm\) 0.01 ab & 0.97 \(\pm\) 0.01 b \\ A-type vitisin of Pt-3-glc & 0.72 \(\pm\) 0.02 a & 0.67 \(\pm\) 0.00 b & 0.70 \(\pm\) 0.01 a \\ total A-type & 1.75 \(\pm\) 0.01 a & 1.66 \(\pm\) 0.01 b & 1.67 \(\pm\) 0.02 b \\ _Vinylphenol adducts_ & & & \\ Mv-3-glc-4-vinyl (epi) catechchin & 0.44 \(\pm\) 0.02 a & 0.40 \(\pm\) 0.00 b & 0.38 \(\pm\) 0.01 b \\ Pinotin A & 0.24 \(\pm\) 0.04 a & 0.24 \(\pm\) 0.02 a & 0.22 \(\pm\) 0.02 a \\ Pn-3-glc-4-vinylphenol & 0.14 \(\pm\) 0.02 a & 0.11 \(\pm\) 0.00 b & 0.13 \(\pm\) 0.01 ab \\ Mv-3-glc-4-vinylphenol & 0.82 \(\pm\) 0.06 a & 0.78 \(\pm\) 0.02 a & 0.82 \(\pm\) 0.03 a \\ Mv-3-glc-4-vinylguaiacol & 0.14 \(\pm\) 0.02 a & 0.11 \(\pm\) 0.01 a & 0.13 \(\pm\) 0.02 a \\ Total vinyl & 1.77 \(\pm\) 0.11 a & 1.65 \(\pm\) 0.05 a & 1.68 \(\pm\) 0.07 a \\ Total anthocyanins & 149.28 \(\pm\) 3.95 a & 148.72 \(\pm\) 1.09 a & 148.27 \(\pm\) 1.52 a \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Anthocyanins content of wines after 7 days of treatment with chitosan. In the same row, different letters indicate significant differences according to [PERSON]’s test (\(p<0.05\)). \(n=3\). C: no addition; KT: 0.5 g/L of solid chitosan; RTS: 0.5 g/L of chitosan in solution. The above statement partly coincides with our results, where reduced co-pigmentation and polymerization observed in chitosan-treated samples (Table 3) corresponded to increased luminance (L*) and increased yellowness (b*). These results are in line with the lower color intensity found for KT and KTS (Table 1). Judging by our results on co-pigment composition, a lower chroma (C*) would be expected. Surprisingly, treatments with chitosan exhibited higher C* and b* values, i.e., increased red color vividness as reported on Table 3. This also depended on the removal by chitosan of some specific pigments as discussed below. Color perception of samples was compared by calculating \(\Delta\)E*ab, where \(\Delta\)E*ab > 3 indicates differences visible to the human eye [36].