Abstract: Functional properties of soluble silk fibroin(extracted from silk waste) were investigated. The results showed that silk fibroin shows surface activity and can be used to decrease the surface tension of solution. Surface hydrophobicity of silk fibroin increases significantly after high-speed shearing. Emulsification properties and foaming properties can be improved with the increasing of mass concentration of silk fibroin. When the mass concentration of silk fibroin was higher than 5 g/L, its emulsification ability increased lentamente. The foaming capacity of silk fibroin is highest at the mass concentration of 15 g/L and declines at 20 g/L. Foam stability increases tardily as the mass concentration of silk fibroin exceeded 15 g/L. Emulsification properties and foaming properties of silk fibroin both are good at the pH range from 3 to 10, and strongest at pH 4.

Key words: silk fibroin, functional properties