Changes in antioxidative capacity and phenolic compounds in quinoa (Chenopodium quinoa Willd.) plant extracts during growth cycle

In this study, the changes in the antioxidative capacity and phenolic compounds content in the aerial part of the quinoa (Chenopodium quinoa Willd.) plant during its growth cycle were analysed. These parameters were evaluated at six progressive morphological stages from the early vegetative to the grain fill stage. The extracts obtained from the early and late vegetative stage were characterized by the highest content of total phenolic compounds. In the first three stages of growth high values of the Trolox equivalent antioxidant capacity (TEAC) were determined. The lowest value of ferric reducing antioxidant power (FRAP) was observed in the early vegetative stage. The highest antiradical activity against DPPH radical was noted for extract obtained from late vegetative plants. The profile of phenolic compounds was characterized by the presence of five compounds. Based on UV-DAD spectra, one was described as p-coumaric acid derivative, the other four as flavonols.