Abstract
The treatment of raw silk fiber with tannic acid solution and then with the solution of a mixture of potassium dichromate and aluminum chloride greatly reduces the weight loss upon the degumming with a protease. However, the loss is not so much reduced for the fibers treated with tannic acid solution and then with the solution of antimonyl potassium tartarate or only with the solution of the metal salt mixture. These observations suggest that an interaction between tannic metal complex and the tyrosine residue takes place in the fiber, interfering the enzymic hydrolysis at the specific residue. It was also found that the weight loss of raw silk fiber by reducing with appropriate reagent is smaller than that of the untreated one. Such a reduction treatment is not effective for the degumming.
