## 2 Discussion
Accordingly, the LC-MS generated from the extracts of two varieties of the blue maize revealed the existence of phenolic compounds with nutraceutical properties in different proportions; hence, the corn varieties can be assigned different beneficial properties because of the different constituent concentrations. The results illustrate the presence of the same anthocyanins, but in different proportions, which was expected considering the different soil compositions in which each crop has grown. It is especially important to determine the fingerprints for each cultivar from the separation, identification, and quantification of some compounds that serve as biomarkers. The combined use of these two powerful analytical tools (i.e., HPLC coupled with mass spectrometry) has enabled the identification of several bioactive compounds from different natural products and derived [95; 96; 97; 98]. Related to the above, [PERSON] et al. [86] developed a study to isolate phenolic compounds and carotenoids from ten different colored maize genotypes from Mexico, USA, France,Serbia, and the Netherlands but grown in Serbia. In said study, the authors extracted the phenolic acids from the kernels using a mixture of acetone/methanol/water as extractant agent before alkaline hydrolysis with NaOH. Those hydrolyses were extracted with nonpolar solvents and dried with N\({}_{2}\). Then, they were dissolved in methanol for HPLC analysis on a C18 column, measuring at 280 nm, and identifying the phenolic acid peaks by comparing retention times and absorption versus standards used to construct a calibration curve. On the other hand, anthocyanins from the samples were analyzed by UPLC (Ultra-high-performance liquid chromatography), through a C18 column, coupled with MS equipped with a heated electrospray interface. The anthocyanins of the mixtures extracted were identified and quantified by comparison with the standards of C3G, PG3G, cyanidin 3,5-diglucoside (C3,5 DG), and pelargonidin-3,5-diglucoside (PG3,5 DG). Additionally, the total phenolic content was determined following the procedure described by [PERSON], measuring the absorbance at 725 nm and expressing the content as GAE per kg of dry mass. Furthermore, the total flavonoid content was spectrophotometrically determined by measuring the absorbance of the extracts mixed with NaNO\({}_{2}\) and reacted with AlCl\({}_{3}\) to get flavonoid-aluminum complexes that were measured at 510 nm, after being treated with NaOH and centrifuged, as described previously by [PERSON] et al. [99]. The total antioxidant capacity was spectrophotometrically evaluated for the ten maize varieties through the use of two methodologies, ABTS and DPPH. For the ABTS methodology, a solution of ABTS with K\({}_{2}\)S\({}_{2}\)O\({}_{8}\) was prepared and left standing in the dark overnight to generate the radical ABTS\({}^{\bullet+}\). The solution of the radical was adjusted to obtain an absorbance of 0.7 \(\pm\) 0.02 at 734 nm. For the case of DPPH, the solution was prepared in ethanol and adjusted to an absorbance of 1.0 \(\pm\) 0.05 at 525 nm. In both cases, the samples were added to ABTS\({}^{\bullet+}\) or DPPH\({}^{\bullet}\) to measure the scavenging activity associated with the bioactive compounds extracted from maize. The obtained results were expressed as TE per kg of dry mass by comparison with this analog of vitamin E.  
Moreover, the application of anthocyanins in the food industry as pigments and because of its radical scavenging properties has led to the use of maize as a low-cost anthocyanin-rich vegetal source. Similarly, the higher the antioxidant activity is the higher phenolic content. The information above indicates that the use of spectrophotometric and spectrometric methods is required to evaluate the potential use of vegetables as a source of bioactive compounds acting positively in human health. On the other hand, [PERSON] et al. [100] have reported the obtain of anthocyanins from Mexican pigmented maize due to their beneficial properties to health.