Avaliação de compostos fenólicos e atividade antioxidante em flores de Hibiscus rosa-sinensis L. com diferentes colorações

Abstract

Hibiscus rosa-sinensis L., traditionally used in ornamentation, has been gaining prominence as a non-conventional food plant (NCFP) due to its nutritional and functional potential. Its flowers, in addition to presenting ornamental beauty, stand out as potential sources of bioactive compounds with antioxidant activity. The evaluation and quantification of its chemical properties is relevant to increase consumption, as an accessible and healthy alternative to food. In this study, the concentration of total phenolic compounds and antioxidant activity were evaluated, via the DPPH method, in flowers with different colors (red, dark pink, pink, light pink, salmon and yellow), in fresh and dehydrated forms. The extracts were obtained by maceration in methanol, and the analyses were conducted by spectrophotometry. The statistical analysis indicated a significant interaction between the state of the flower and its color. The data suggest that both colouration and post-harvest processing directly influence the antioxidant potential and phenolic content of hibiscus flowers, which reinforces the importance of using this species as a natural source of antioxidants. The results demonstrated that the dehydrated flowers presented greater antioxidant activity, with emphasis on the yellow coloration (0.1573 mM ET g-1). The extracts of the dehydrated flowers also presented higher levels of phenolic compounds, with the highest value recorded for the light pink flower (3.106 mg EAG g-1).