Tannins quantification in barks of Mimosa tenuiflora and Acacia mearnsii

Abstract

Due to its chemical complexity, there are several methodologies for vegetable tannins quantification. Thus, this work aims at quantifying both tannin and non-tannin substances present in the barks of Mimosa tenuiflora and Acacia mearnsii by two different methods. From bark particles of both species, analytical solutions were produced by using a steam-jacketed extractor. The solution was analyzed by Stiasny and hide-powder (no chromed) methods. For both species, tannin levels were superior when analyzed by hide-powder method, reaching 47.8% and 24.1% for A. mearnsii and M. tenuiflora, respectively. By Stiasny method, the tannins levels considered were 39.0% for A. mearnsii, and 15.5% for M. tenuiflora. Despite the best results presented by A. mearnsii, the bark of M. tenuiflora also showed great potential due to its considerable amount of tannin and the availability of the species at Caatinga biome.