Efeito de diferentes métodos de extração sobre a atividade antioxidante e o perfil de compostos fenólicos da folha de mandioca

Abstract

Cassava (Manihot esculenta Crantz) leaves are agroindustrial residues with the potential for human consumption, being sources of protein, vitamins, minerals and antioxidant substances, especially phenolic compounds. The objective of the present study was to identify and quantify the phenolic compounds present in different cassava leaf flour (FFM) extracts, from the Pão da China cultivar, and evaluate their antioxidant potential. The phenolic compounds were extracted using the following three methods: a) refluxing with methanol/water (50:50, v/v); b) maceration with ethanol/water (50:50, v/v) followed by refluxing with acetone/water (70:30, v/v); c) maceration with methanol PA. The compounds were identified and quantified by high performance liquid chromatography, and the antioxidant activity determined by the ABTS and β-carotene/linoleic acid methods. Five phenolic compounds were found in the FFM extracts: gallic acid, gallocatechin, catechin, chlorogenic acid and epigallocatechin, extraction with methanol/water (50:50, v/v) revealing the presence of the greatest number of these compounds and the highest antioxidant potential. Of the phenolic compounds found in FFM, catechin was the major one, independent of the extraction method. It can be inferred that the antioxidant activity of the FFM extracts is related to the presence of phenolic compounds, since the sample with the highest content of these compounds demonstrated the highest antioxidant potential.