PERSIMMON TANNIN DETECTING PAPER

摘要

PURPOSE:To easily detect the presence or absence of persimmon tannin without eating a persimmon by impregnating a compd. or compsn. which is colored or discolored by easily reacting with the persimmon tannin in paper, thereby forming detecting paper. CONSTITUTION:For example, filter paper is immersed in an aq. soln. of 2% ferric chloride and is dried for about 2hr at about 80 deg.C after air drying. The flesh of the sweet persimmon and the flesh of the astringent persimmon are respectively brought into pressurized contact with the persimmon tannin detecting paper obtd. in such a manner and the color tones thereof are observed. As a result, the yellow color tone of the detecting paper does not change even after the pressurized contact in the case of the sweet persimmon; whereas, the color tone of the detecting paper which is yellow before the pressurized contact changes to black in the part where the flesh is brought into pressurized contact in the case of the astringent persimmon. The presence or absence of the persimmon tannin is thereby easily and exactly detected.