## 2 Discussion
The color of food products represents a major quality characteristic; thus, it must be assessed by measuring the hue parameters. The term L* represents the clarity or brightness of a sample; hence, L* = 100 represents white, and L* = 0 represents black. In contrast, the a* and b* parameters have positive and negative values, with values a*+ denoting a tendency represented by the red color and a*\(-\) by green. Additionally, b*+ is yellow, and b*\(-\) is blue. In the laboratory, it is also common to determine the color intensity of a sample as the sum of the absorbances of the sample at 620 (blue color), 520 (red color), and 420 nm (yellow color). Another parameter for determining this is the tone or tint of the sample by calculating the ratio Abs 420/Abs 520 [59]. Studies on color have led to the understanding of the importance of the compounds responsible for providing this characteristic in wines and the importance of their localization within the cell. Spectrophotometrically evaluating the extractability of phenolic compounds, tannins, and anthocyanins from inside the cell wall of a grape cell, where they are protected from degradation, is easy [60]. Additional studies have demonstrated the adherence of anthocyanins to the polysaccharides and proteins of the cell wall, causing a diminishing in the compound content [61]. For this, it is important to determine the chromatic characteristics of wine through the spectrophotometric measure of its color intensity. A member of this research group has been working on analyzing these chromatic properties in wines from Spain by evaluating the effect of enzymatic treatments on anthocyanin extraction through a comparison of the color intensities of treated wine with untreated wine. The results evidenced an increase in the color intensities of treated wine of more than 20% with a total phenolic content of 25% and a total monomeric anthocyanin content of 23%, which are higher than those obtained for untreated wine [62]. Additionally, the usage of a combination of petolytic enzymes was demonstrated as an alternative for increasing the color intensity in wines by more than 18% [59]. The antioxidant activity is a key parameter for determining the bioactive properties of foods. The antioxidant property of a substance is defined as its capacity to prevent or diminish the oxidation caused by the electron transfer from a donor to an acceptor. The oxidative processes in human beings cause the proliferation of unstable chemical species. These processes alter the normal metabolism and are associated with multiple disorders and illnesses, such as cancer, diabetes, metabolic syndrome, aging, Parkinson's disease, Alzheimer's disease, heart disease, and stroke, among others [63; 64; 65; 66]. Several natural antioxidants are well known and alphabetically classified as antioxidants C (carotenoids), E (enzymes), G (glutathione), L (lipids), and P (phenolics) [67]. Many spectrophotometric techniques are useful in antioxidant characterization. At present, the most frequently applied techniques are the 2,2-diphenyl-1-picrylhydraz1 (DPPH) [68] and the 2,2'-azino-bis-(3-ethylbenzothazoline-6-sulfonic acid (ABTS) radical scavenging assays [69]. Other related methodologies have been reported in the literature [70; 71], including ferric-reducing antioxidant power (FRAP) [72], oxygen radical absorption capacity (ORAC) [73], Trolox equivalent antioxidant capacity (TEAC) [74], \(N\),\(N\)-dimethyl-\(p\)-phenylenediamine (DMPD) [75], and Cu(II) reduction capacity assay (CUPRAC) [76]. DPPH testing is an easy and fast method, which is especially important for lipophilic antioxidants [77]. The approach consists of preparing a methanol solution of DPPH to form the DPPH*, a stable radical of purple color that can be spectrophotometrically measured at 515 nm. This radical can accept one hydrogen from the antioxidant to form a yellow-colored DPPH2 that comes from the antioxidant substance, a reaction that causes a diminishing in the absorbance at 515 nm.