## 2 Materials and Methods
### Enological Parameters  
The basic enological parameters [pH, relative density, total alcohol content (% vol. ), total acidity (g tartaric acid L\({}^{-1}\)), and volatile acidity (g acetic acid L\({}^{-1}\))] were determined, in triplicate, according to the International Organization of Vine and Wine Compendium methods of analysis [12]. Chromatic Characteristics, Total Polyphenol Index (TPI), Total Anthocyanin Content (TA), Antioxidant Activity (AA) and Total Condensed Tannins (TCT)  
_The chromatic characteristics:_ (i) color intensity, (ii) tonality, and (iii) color density in the wine samples were determined according to methods OIV-MA-AS2-07B [13] and Glories [13] using a spectrophotometer (ThermoSpectronic Heyios \(\gamma\), Cambridge, England). All analyses were carried out in triplicate. The color intensity (CI) was calculated as the sum of the absorbance at 420, 520, and 620 nm (CI = A\({}_{420}\) + A\({}_{520}\) + A\({}_{620}\)). The tonality (T) was calculated as the ratio of absorbance at 420 nm to absorbance at 520 nm (T = A\({}_{420}\)/A\({}_{520}\)). The color density (CD) was calculated as the sum of the absorbance at 420 and 520 nm (CD = A\({}_{420}\) + A\({}_{520}\)). Also, Glories colorimetric index [14] percentages of the colors yellow, red, and blue were obtained using the absorbance values at 420, 520, and 620 nm as follows:  
* Yellow, Y (%) = (A\({}_{420}\)/CI) \(\times\) 100
* Red, R (%) = (A\({}_{520}\)/CI) \(\times\) 100
* Blue, B (%) = (A\({}_{620}\)/CI) \(\times\) 100  
_Total polyphenol index (TPI)_ was evaluated by measuring the absorbance at 280 nm on a UV-visible spectrophotometer (Helios Gamma model, UVG 1002E) [15]. The TPI was determined after diluting the wine sample 100 times. Analyses were run in triplicate. _Total anthocyanin content (TA)_ was determined according to [PERSON] et al. [16]. Briefly, the absorbance of the samples was measured at 540 nm using a UV-visible spectrophotometer (Helios Gamma model, UVG 1002E) and the total anthocyanin content was calculated using the formula by [PERSON] et al. [16]. Analysis was run in triplicate, and results were expressed as equivalents of malvidin 3-O-glucoside (mg L\({}^{-1}\)). _Antivoxidant activity (AA)_ was evaluated using three methods:  
* The free radical scavenging capacity using the ABTS\({}^{\star\star}\)[2,2\({}^{\prime}\)-azino-bis (3-ethylbenzothazoline-6-sulphonic acid)] method described by [PERSON] et al. [17], with absorbance being measured at 734 nm (UV-visible spectrophotometer, Helios Gamma model, UVG 1002E). Calibration curve (3.5-5.0 mmol Trolox L\({}^{-1}\)) with good linearity (R\({}^{2}\)\(\geq\) 0.999) was used for the quantification. Analyses were run in triplicate and results were expressed as mmol Trolox L\({}^{-1}\). * The free radical scavenging capacity was also measured using the DPPH\({}^{\bullet}\) method as proposed by [PERSON] et al. [18], with absorbance being measured at 517 nm. The inhibition percentage of the DPPH\({}^{\bullet}\) radical was determined according to the following Equation (1): \[\left[\frac{AC\ (0)-AA\ (t)}{AC\ (0)}\right]\times 100\] (1) where \(AC\ (0)\) is the absorbance of the sample at \(t=\) 0 min, and \(AA\ (t)\) is the absorbance of sample at \(t=\) 16 min. Analyses were carried out in triplicate. * The ferric reducing/antioxidant power (FRAP) was performed on a modified version of the method by [PERSON] et al. [19]. It is based on the reducing power of antioxidants, which will reduce the Fe\({}^{3+}\) to Fe\({}^{2+}\) in the form of a blue complex (Fe\({}^{2+}\)/TPTZ). Absorbance was measured at 593 m. Analyses were run in triplicate and results were expressed as mmol Trolox L\({}^{-1}\). _Total condensed tannins (TCT)_ were determined according to Ribereau-Gayon and Stonestreau [20]. Briefly, the samples were prepared in two test tubes, one for the control (tube 2) and the other for the hydrolysis (tube 1); in this tube, 4 mL of wine diluted in 1:50 distilled water, 2 mL of distilled water, and 6 mL of HCl 12 N were added successively.