Measurement of Tannic Substances in Forest Species

ABSTRACT This study aimed to quantify the tannic content of the barks and fruit of angico-vermelho, jurema-preta and acacia-negra using skin powder as detanizador agent. Materials from these species were ground and classified, with 12.5g of air dried particles subjected to extraction using a steam jacket type extractor to obtain 1000 ml of solution, using a completely randomized analytic design. The solution was evaluated using four treatments: angico bark; jurema bark; acacia bark and angico fruit. Three replicates per treatment were realized and subrepetitions were analyzed in triplicate. The results were interpreted by comparison of means with Tukey test at 5% significance. Best results in terms of total solids content, were observed in acacia bark (67.2%), differing statistically for angico bark (63.5%). The soluble solids content, in turn, was superior to angico bark (60.3%), differing statistically from acacia bark (49.8%). No statistically significant differences for tannin content were observed between acacia and angico barks, which presented values of 28.4 and 26.8%, respectively.

摘要 本研究旨在以皮粉（skin powder）为脱鞣剂，定量分析angico-vermelho、jurema-preta及acacia-negra的树皮与果实中的鞣质含量。研究将上述物种的原料粉碎分级，称取12.5g风干颗粒，采用蒸汽夹套式萃取装置进行萃取，最终得到1000mL萃取液，实验采用完全随机分析设计方案。实验设置4组处理方式：angico树皮、jurema树皮、金合欢树皮及angico果实，每组处理设置3次生物学重复，且亚重复均进行3次技术重复。结果通过均值比较结合5%显著性水平的Tukey检验进行分析。总固体含量方面，金合欢树皮组（67.2%）表现最优，与angico树皮组（63.5%）存在统计学差异；可溶性固体含量则以angico树皮组（60.3%）为最高，与金合欢树皮组（49.8%）存在统计学差异。金合欢树皮与angico树皮的鞣质含量无统计学显著差异，二者分别为28.4%与26.8%。