Abstract
The astringency of multivalent metallic salts, vegetable tannins, dehydrating solvents and halogenated acetic acids were measured organoleptically to obtain their threshold values which varied from 0.038% to 0.075%. The astringency of these substances were also accompanied by bitter, sour or sweet taste. Dehydrating solvents such as alcohol and acetone were not astringent but gave hot sensation in the mouth.
The astringents formed insoluble complex with water soluble protein. The tannins of high molecule formed the complex more easily than those of low molecule. The metallic salts did not form the insoluble complex at low concentration but formed soluble complex resulting in remarkable astringency.
When the all astringents were taken into consideration, there was no significant relationship between their astringency and the quality of the complex with protein.
