## 3 Results and Discussion
### Enological Parameters
It is important to consider that the _Fondillon_ samples under analysis in the current study were around 25 years old, and the reported increase in these two parameters in the Madeira wines could have happened at the beginning of the aging period also in the _Fondillon_, but the values reported in the current study are representative of the final steady state. This is a possible explanation for the fact that the \"_solera_\" factor did not affect the values of these enological parameters. Regarding the alcohol content, it is reported that it must have at least 16% and it is of the outmost importance to remark that \"no fortification can be done\" [23]. The alcoholic content of the analyzed wines ranged between 18.30 (_solera_ 1996) and 21.17% \(v/v\) (_solera_ 1930), with a mean of 19.28% (Table 1). A general trend was found, with alcohol content increasing with the wine _solera_ (R\({}^{2}\) = 0.848; \(p<0.01\)). A study carried out by [PERSON] [27], on the aromatic characterization of the _Fondillon_ samples being marketed on 2013 (10 brands), showed that the mean alcohol content was 16.65% \(v/v\), with values \begin{table}
\begin{tabular}{c c c c c c} \hline \multirow{3}{*}{**pH**} & \multicolumn{2}{c}{**Relative Density (20 \({}^{\circ}\)C)**} & \multicolumn{2}{c}{**Total Alcohol Content**} & \multicolumn{2}{c}{**Total Acidity**} & \multicolumn{1}{c}{**Volatile Acidity**} \\ \cline{2-6}  & & **(g mL\({}^{-1}\))** & **(\% _v/v_)** & **(g tartaric acid L\({}^{-1}\))** & **(g acetic acid L\({}^{-1}\))** \\ \cline{2-6}  & & & **ANOVA** & \\ \cline{2-6}  & **NS** & **NS** & **\(\ast\ast\)** & **\(\ast\ast\)** & **\(\ast\ast\ast\)** \\ \cline{2-6}  & & & **Tukey Multiple Range Test \(\ddagger\)** & \\ \hline
1980 & 3.35 & 0.9959 & 18.90 ab & 8.33 ab & 1.50 a \\
1987 & 3.51 & 0.9984 & 18.44 ab & 7.65 b & 1.13 cd \\
1996 & 3.43 & 0.9970 & 18.30 b & 7.28 b & 1.16 cd \\ Minimum & 3.35 & 0.9959 & 18.30 & 7.28 & 1.01 \\ Maximum & 3.82 & 1.0098 & 21.17 & 10.01 & 1.50 \\ Legal threshold \({}^{\ddagger}\) & & \(>\)16 & \(>\)3.5 & \(<\)1.5 \\ \hline \end{tabular}  
* NS = not significant at \(p<0.05\); ** and *** significant at \(p<0.01\), and 0.001, respectively. \({}^{\ddagger}\) Values (mean of three replications) followed by the same letter, within the same column, were not significantly different (\(p<0.05\)), according to [PERSON]’s least significant difference test \({}^{\ddagger}\)[20].  
\end{table} 
Table 1: _Cont._ranging between 15.7 and 18.10%. The values found in the current study are higher than those reported in the older study, and this might occur due to the age of the studied wines. [PERSON] et al. (2015) found that the average alcoholic content for young Madeira wines was up to 18%, while a slight increase above 19% was reported for 10-year-old wines, although no statistical support was provided. It is important to remember that Madeira wines are \"fortified\", reaching alcoholic contents in the range 15-22% ([PERSON], 2018), while the alcoholic content of _Fondillon_ is only due to the fermentation of the natural sugars of Monastrell grapes by the yeast. As a conclusion for this section, it can be stated that all _Fondillon_ samples under analysis were within the legal limits established by the regulation of the DOP Alicante, and the physico-chemical profile of _Fondillon_ seems not to be affected by the \"_solera_\" factor due to the long aging time of the wines, above 25 years. Chromatic Characteristics, Total Polyphenol Index (TPI), Total Anthocyanin Content (TA), Antioxidant Activity (AA) and Total Condensed Tannins (TCT)  
Color is one of the most important organoleptic aspects of a wine, as it can be an indicator of quality and can influence consumer acceptance and its satisfaction degree. This attribute depends mainly on (i) the grape type and enological parameters at harvest, (ii) unification processes, and (iii) aging type and time ([PERSON], 2018). The hue and intensity of the color are parameters mainly linked to the content of anthocyanins, which are extracted from the grape during maceration.