Physicochemical, nutritional and antioxidant characterization of three vegetables (Amaranthus hybridus L., Chenopodium berlandieri L., Portulaca oleracea L.) as potential sources of phytochemicals and bioactive compounds

The aim of this work was the characterization of three endemic plant species [quelite cenizo and quintonil ( quelite s), and purslane], from Mexico, in terms of their physicochemical, nutritional and antioxidant properties. These species are highly used by rural populations in their local dishes. Nevertheless, scarce information exists about their nutritional and functional properties. The experimental included physicochemical properties, nutrimental composition, qualitative and quantitative analysis of antioxidants by HPLC. The results showed that purslane was the sample with the highest concentration of total carotenoids (2.85 mg/g DW), and with the highest antioxidant activity by DPPH and FRAP methods. Quelite cenizo and purslane displayed similar values for antioxidant activity by ABTS method, nevertheless, the former showed higher values for total phenolics (10.24 mg GAE/g DW) and flavonoids (17.57 mg QE/g DW) content than the latter. Finally, quintonil showed similar results for total chlorophyll (70.50 mg/g DW) and protein (3.65 g/100 g FW) to those found in quelite cenizo. The contents of Fe, Ca, and Mg were higher in quintonil, meanwhile the contents of P, K and Zn were higher in quelite cenizo. The analysis by HPLC also showed the presence of ferulic, and chlorogenic acids as the most abundant phenolic acids, meanwhile rutin and phloridzin were the main flavonoids in the quelites , displaying higher contents than in the purslane. Therefore, it can be assumed that these samples possess high nutritional quality and could be considered for their use in strategies to improve food security in rural populations.