## 4 Discussion
This aspect could explain the lower values obtained by measuring ABTS and DPPH radical scavenging activity, in comparison with the high antioxidant activity shown by the FRAP and ORAC method, which showed higher values that are justified by the high hesperidin content. On the other hand, the Ac extract from _Malpighia emarginata_, with 5% vitamin C, is also rich in phenolic compounds, such as anthocyanins, anthocyanin, phenolic acids (\(p\)-couramic, caffe, and ferulic acid), flavonoids (quercetin and kaempfer), and catechins ([PERSON], 2016; [PERSON], 2016). In addition, it contains \(\beta\)-carotene and minerals ([PERSON], 2016), which make it a functional fruit and justifies the results obtained from the different analyses carried out in the present study. The traditional ingredients from Spanish cuisine also had higher values in the antioxidant assays but behaved differently according to the method used for assessment. For instance, the antioxidant activity of oregano, paprika, and garlic was higher when measured by the FRAP method and ORAC method. The antioxidant activity of oregano is mainly due to the concentration of phenol and catechol groups in the molecular structure of its principal phenolic compounds, such as oreganoside. On the other hand, paprika is a source of important compounds for its antioxidant capacity, such as carotenoids, capsaicinoids, and vitamins C and E (\(\alpha\) and \(\gamma\)-tocopherol from pepper seeds) ([PERSON], 2016). However, the concentration of this kind of compound varies due to several reasons, like the crop, the degree of ripeness, or the temperature used to air-dry the peppers ([PERSON], 2016). This fact can explain the differences among the values published by USDA (USDA, 2016) and those obtained in the present study. Additionally, garlic is an excellent scavenger of hydroxyl radicals due to its content of flavonoids (quercetin and kaempfer) and organosulphurs (allyl-cysteine, dialyl sulphide, and dialyl trisulphide) ([PERSON], 2016). Thiosulphonated compounds, such as alicin, provide the characteristic odour to garlic, however, this compound is related to its anti-inflammatory activity but not with its antioxidant effect ([PERSON], 2016), which also can explain the obtained results in the present study. Finally, the obtained results regarding leafy green vegetables can also be related to their concentrations in phenolic compounds. For example, B, with the highest scavenging power against DPPH and ABTS radicals, is the principal source of nitrates, as was commented previously, and it is also rich in phenolic compounds, with 215.3 mg GAE 100 g\({}^{-1}\), like anthocyanins. In addition, the natural purple colour of beet is due to the presence of betanin, also known for its antioxidant power, being a derivative from betalamic acid, which is obtained from the L-DOPA molecule. Moreover, different authors have obtained comparative results, such as [PERSON] and [PERSON] ([PERSON] and [PERSON], 2016), who showed a 50% scavenging DPPH radical activity, or [PERSON] et al. (2016), who obtained a higher antioxidant capacity using ORAC and FRAP assays in beet of 11500 and 8600 \(\mu\)M TE 100 g\({}^{-1}\), respectively. However, the USDA (USDA, 2016) published a lower result more similar to that obtained in the present study of 1946 \(\mu\)M TE 100 g\({}^{-1}\). The remaining leafy green vegetables obtained similar results in the different antioxidant assays, which can be associated with the fact that they also share the same bioactive compounds: Phenolic acids (gallic, ferulic, caffe, and \(p\)-couramic acids), flavonoids (quercetin, kaempfer, and apigenin), and chlorophyll as the principal pigment responsible for their green colour. In the same way, it can also be appreciated that celery had a lower antioxidant capacity than other vegetables. However, this may be related to the lower phenolic content, also described previously, and the similar result shown by USDA (USDA, 2016).