3.2. Chemical composition of sericin powder
The chemical composition of sericin powder was presented in Table 2. It can be seen from these results that the main composition of sericin powder was protein, with a concentration above 90%. Sugar concentration only accounted for 0.9% although Hyogo and Yoshiko (1967) reported that sericin is a glycoprotein containing glucosamine, galactosamine, mannose and galactose. Ash concentration accounting for 4.2% suggested sericin powder from wastewater possibly contained a little salt.