Studies on Antheraea mylilla cocoonase and its use in cocoons cooking.

摘要

Cocoonase which is secreted as a natural phenomenon has its direct utility in softening of cocoons for reeling without altering the very organic nature of tasar silk. In the present study, efforts have been made to comprehend and utilize cocoonase for its future use in cocoon cooking. The emerging moth gradually release cocoonase from galea of their mouth parts in anterior inner portion of the cocoon (peduncle region). After releasing adequate volume of enzyme (around 400-600 micro L) for softening the peduncle region of cocoon, with the help of appendages emerging moth create outlet near the peduncle and escape from cocoon shell. Around 1000 mL cocoonase from 2000 eclosion stage A. mylitta have been collected and centrifuged in cold condition (4 degrees C) at 10000 rpm to minimise the impurity. To maintain buffer conditions, cocoonase was collected in pre chilled Tris buffer pH 9.2 and stored at -4 degrees C temperature for further use in cocoon cooking. When cocoons of A. mylitta (Daba ecorace) were subjected to initial water boiling at 100 degrees C on leisurely flame for 30-40 min followed by cocoon soaking in cocoonase for 20-24 h at 37 degrees C, the 80-90% softening of cocoon shell was found. Silk filament obtained from the cocoons cooked in cocoonase maintains natural tasar silk colour, softness and structure. The 50-52% silk recovery was observer in cocoonase cocoon cooking. By centrifuging used reaction mixture at 9000 rmp in cold condition to remove impurities and adding 10-15% volume of fresh cocoonase in reaction mixture left over enzyme solution can be reused once. More study is required to get better cocoonase cooking efficiency and consistent cooking with higher or comparable silk recovery than the ruling practices.Digital Object Identifier http://dx.doi.org/10.3923/ajft.2012.320.325