Study on the measurement of persimmon tannins' content with sodium carbonate-phenol solution
According to the similar structure of catechin and persimmon tannin, and according to the same color change during two reaction processes between persimmon juice-sodium carbonate-phenol solution and catechin-sodium carbonate-phenol solution, and at the same wavelength with absorbing peak of these two kinds solution, the paper firstly presents a new measurement method of persimmon tannins抯 content. This method is more convenient, time-saving and safer. By analysis, sodium carbonate-phenol solution can react with persimmon tannin with the color change. Compared with methanol method, the contents of tannin are close and have good relativity each other. Hence, the conclusion can be drawn that the sodium carbonate - phenol method determining persimmon tannin抯 content is feasible, catechin can be used as standard substance in this method, the measuring wavelength is 420nm.