2001 Volume 10 Pages 71-79
The process of hot air drying of cocoons facilitates evaporation of moisture from the cocoon shell and pupa there by hardening the sericin to the suitable extent. Based on the temperature profiles used in the drying process, the degree of drying and hardening of sericin varies. Indian multi-bivoltine cocoons were hot air dried in a batch type hot air drier using different temperature profiles and cooked using open pan and two-pan method of cooking system. Studies indicated that both the temperature profiles and method of cooking has significant influence on reeling performance of Indian multi-bivoltine cocoons. It was observed that higher initial temperature used during drying i.e. 130℃ has significantly better reeling performance than 120℃, 100℃ and 90℃ in terms of better reelabiity, raw silk %, lower waste % and sericin loss %. Further two pan cooking method showed a significant improvement in reeling performance compared to open pan cooking method for hot air dried cocoons. The improvement in the reeling peformance of hot air drying profile is presumably because of hardening of the sericin to the suitable extent. The earlier understanding that higher temperature would denature the sericin and affect the reeling performance does not appear to be true in case of Indian multi-bivoltine cocoons presumably due to the loose shell structure of the cocoons.