The silk filament forming the cocoon shell is composed of two brins (proteins) named fibroin and covered by silk gum or sericin. The amount of sericin ranges from 19 to 28 percent according to the type of cocoon.
The composition of the cocoon shell is given below:
The composition of the cocoon shell is given below:
- Fibroin -- 72-81 percent
- Sericin -- 19-28 percent
- Fat and wax -- 0.8-1.0 percent
- Colouring matter and ash -- 1.0-1.4 percent