Quantitative Determination of Tannins in Plants of Bosnia and Herzegovina
The quality of medicinal herbs containing tannin as an active component depends on the kind and content of tannin. Tannin is determined by using various methods which are usually mentioned in pharmacopoeias. In our paper we examined the content of tannin in plant material using the following methods: a method according to Ph. Yug. II, Ph. Yug III, Ph. Yug IV, a method with casein, a method of precipitation with brucine, and a method of relative astringency (RA) determination (tbl. 1 and 2). Our results showed that the obtained values of the content of tannin depended on the method which was used. Therefore, it is necessary to specify the method with the obtained value for the content of tannin. In spite of numerous examinations of the content of tannin in the plant material which were performed by the authors, it was difficult to determine the best method since, beside tannin, there were other phenolic and also non-phenolic substances in the plant material more or less influencing the content of tannin. The results obtained in this paper contribute to a better knowledge of the analytics and quality of tannin and the plant material which contains tannin as an active component.