Characterization of the phenolic profile of edible flowers as a source of natural antioxidants

The edible flowers have been used since ancient times at traditional cuisine or alternative medicine, for their nutritional and health benefits. These benefits are attributed to their phenolic acids, organic acids and flavonoids (anthocyanins). Edible flower has great importance, due to the presence of bioactive compounds with antioxidant.

Therefore, the present study determine the phenolic composition and antioxidant capacity of six different edible flowers, namely Viola tricolor, Rosa, Pelargonium graveolens and two different species of Calendula officinalis L.. For each edible flower, the goal was to evaluate the phenolic composition and antioxidant capacity, and for that we performed the determination of the total polyphenolic, ortho-diphenols and flavonoids contents, as well as an accurate quantitative and qualitative determination of phenolic compounds by HPLC-DAD.

The results showed that there were significant differences in the content of phenolic compounds and antioxidant capacity of the analyzed edible flowers. The total phenolic content, ortho-diphenols, and flavonoids ranged 12.28 ± 0.29 to 82.06 ± 1.28 mg GA/g; between 0.89 ± 0.00 and 222.67 ± 0.02 mg GA/g and 5.53 ± 0.38 to 12.97 ± 0.71 mg CAT/g, respectively. For the antioxidant capacity, Rosa and Pelargonium graveolens was the flowers that presented the highest antioxidant capacity for the three methods. Regarding the determination of phenolic compounds by HPLC-DAD, 17 compounds belonging to flavonoids (flavonols and anthocyanins) and non-flavonoids (phenolic acids) groups were identified. Thus, this study revealed the possibility to use edible flowers with objective to replace synthetic antioxidants.