Qualitative and quantitative evaluation of tannins in bark extracts of some indigenous plants of Pakistan

Abstract

Plant barks contain more tannin than any other plant part. In the present study two extraction techniques were applied to extract tannins from bark of some indeginous plants of Pakistan. The tannins were extracted from the barks of plants by maceration & ultrasonic extracion. Folin-Ciocalteu method was conducted to measure the total phenolic content in bark extracts of some plants. Polyvinylpyrrolidone (PVPP) solution was used to bind the tannins, so that the non-tannins (NT) content value can be detected. Thus, the total tannins (TT) content was measured. Qualitative tests for the determination of the presence of polyphenols/tannins were also conducted. It was seen that highest tannin content was present in plant Cassia fistula whereas the lowest tannin content was present in Quercus dilatate.