Physicochemical Properties of Chitosan Extracted from Silkworm (Bombyx mori L.) Exuviae

This study investigated the chitosan content in various developmental stages of silkworms, specifically focusing on larval cuticle, moult exuviae and larval exuviae. The chitosan percentage varied significantly among different stages, with the highest content observed in bivoltine hybrid larval exuviae (19.37%) and the lowest in the 1st instar larval cuticle (9.93%). Chitosan content showed a consistent increase during moulting stages, reaching its peak in exuviae. The investigation extended to examine properties of chitosan, including moisture content, nitrogen content, ash content, degree of deacetylation (DD), solubility, viscosity and pH. Moisture content ranged from 5.80 to 7.84%, nitrogen content from 5.05 to 6.17%, ash content within 0.50 to 0.80% and DD from 85.10 to 92.71%. Solubility ranged from 92.25 to 98.25% and viscosity was measured between 47 and 58 cP. The pH values ranged from 6.72 to 7.49. These findings contribute valuable insights into the chitosan characteristics at different developmental stages of silkworms, providing a comprehensive understanding of its variations and potential applications.