Phytochemicals screening, antioxidant capacity and chemometric characterization of four edible flowers from Brazil

Edible flowers are receiving renewed interest as potential sources of bioactive compounds. The present study aimed to investigate the presence of bioactive compounds and antioxidant activity of some exotic flowers present in Brazil such as Amaranthus hypochondriacus, Tropaeolum majus (red), Tropaeolum majus (orange) and Spilanthes oleracea L. The content of total phenolic compounds, flavonoids, condensed, hydrolysable tannins and anti-oxidante capacity were determined. The identification and quantification of the phenolic compounds was performed through the UHPLC-QDa-MS system. The compounds p-coumaric acid and ferulic acid were identified and quantified for the first time in all flowers. Tropaeolum majus (red) presented the hightest amounts of total phenolic compounds and hydrolysable tannins. Also, it presented the highest antioxidant capacity for ORAC and FRAP assays. Thus, this study showed the diversity and abudance of natural antioxidants present in edible flowers, which could be explored for application in functional foods and pharmaceuticals.