Sazonalidade ambiental no teor de fenólicos e atividade antioxidante de própolis em áreas de floresta e savana de Roraima

Abstract

The type of vegetation, the season and the physical state of propolis can interfere in its composition, quality and quantity produced. This study aimed to study the propolis produced in Roraima by Apis mellifera in areas of forest and savannah and rain and dry periods, based on the chemical composition and antioxidant activity. The ethanol extract solutions were prepared by maceration and solvent addition, with varying color. By spectrophotometric methods were quantified phenolics and flavonoids. Determination of antioxidant activity was evaluated using the method of 2,2-diphenyl-1-picrylhydrazyl radical sequestration and oxidation of β-carotene/linoleic acid system. The production of propolis samples collected in forest areas was higher in the rainy season and the dry season were the most collected in savanna areas. The higher phenolic content was observed in both the dry period phytophysiognomies. Flavones and flavonols in the two areas studied showed the highest levels during the dry season. The higher amounts of flavanones and diidroflavonois were detected in samples from areas of forest and savannah during the dry season. The anthocyanin content were higher than the other flavonoids classes, and better results for forest were obtained during the dry season, and in the savannah during the rainy. This class stood out due to high levels presented and also results for the quantification of anthocyanins in propolis not be common in the literature. The antioxidant activity determined by the oxidation of β-carotene / linoleic acid system was observed during the rainy season in forest areas, and in the savannah the highlight was the propolis collected during drought. On the other hand, the capacity analysis activity by DPPH was higher in the dry season, the two studied vegetation types. This activity by both methods was significant, with very high values when compared to literature data. Pearson correlation of phenolic compounds and flavonoids with antioxidant capacity was observed ranging from moderate to strongly positive (r2 = 0.5 to 1.0).