Compostos fenólicos, atividade antioxidante e efeito da sazonalidade na composição mineral em folhas de Cecropia obtusa Trécul. E. Cecropia palmata Will. (Cecropiaceae).

Abstract

To contribute to the knowledge about the chemical, photochemical and biological Cecropia palmata and Cecropia obtusa, this study aimed to evaluate the antioxidant potential, the mineral content in the dry matter and teas, and the influence of seasonality in the composition mineral sheets Cecropia palmata and Cecropia obtusa. In Chapter I were quantified by spectrophotometry the total phenolic content by Folin - Ciocalteu, flavonoids and antioxidant activity by DPPH reagent (2,2- diphenyl-1-picryl hidrazila) in extracts of leaves of Cecropia palmata and Cecropia obtusa. The result for Cecropia obtusa of total phenols was 429,94 ± 23,04 mg of gallic acid equivalent per gram of sample , and Cecropia palmata 357,82 ± 10,57 . The flavonoids for Cecropia obtusa was 62,652 ± 1,13 mg quercetin equivalent per gram of sample, and the Cecropia palmata were 54,014 ± 0,29 . The amount of sample needed to describe the initial concentration of DPPH in 50% (EC50) for Cecropia obtusa was 179.941 EC50 g / ml EC50 and Cecropia palmata 253,91 mg / mL. The results show that these two species have antioxidant activity, and Cecropia obtusa has higher amounts of total phenols, flavonoids and antioxidant activity compared to Cecropia palmata. In Chapter II were evaluated by atomic absorption spectrometry, the levels of minerals: calcium, copper, iron, potassium, magnesium, sodium, manganese and zinc in the dry matter and leaf teas Cecropia palmata and Cecropia obtusa in different seasonal periods. Data were analyzed by chemometric methods explanatory. The results show that the interaction between season and plant species interferes with the concentration of most minerals analyzed, and that the two species obtained in the period of greatest rainfall, show greater similarity in relation to the contents of the variable calcium, copper and manganese. The concentration of minerals in the tea was reduced in relation to dry matter, suggesting that the use of a cup of tea per day, according to the methodology used, can be a possible source of minerals without risk of toxicity.