Characteristics of Tannins

CHARACTERISTICS OF TANNINS

1)    Tannins are colloidal solutions with water.

2)    Non crystalline substance.

3)    Soluble in water (exception of some high molecular weight structures), alcohol, dilute alkali, and glyc-erin.

4)    Sparingly soluble in ethyl acetate.

5)    Insoluble in organic solvents, except acetone.

6)    Molecular weight ranging from 500 to >20,000.

7)    Oligomeric compounds with multiple structure units with free phenolic groups.

8)  Can bind with proteins and form insoluble or soluble tannin—protein complexes.