EFFECT OF SPRAY DRYING CONDITIONS ON THE CHARACTERISTICS OF SERICIN POWDER FROM ERI SILK BOILING WATER

Sericin is a soluble protein extracted from Erik silk cocoon (Samia ricini) which is antioxidant and antimicrobial which can be applied in foods, drugs, cosmetics and apparels. In the apparel industry, the boiling water contained silk sericin component which need to be treated to save the environment. Therefore, this research will recover the sericin from the Eri boiling waste water. Eri silk cocoon was boiled in water at 95 °C (cocoon 800 g: water 10 l) for 90 min. The boiling water was concentrated to 2 °brix prior to spray drying. The inlet air temperature (130, 150 °C) and outlet air temperature (70, 80 °C) affected the moisture content of the sericin powder. The experimental results showed that moisture content of the sericin powder decreased with increasing inlet and outlet air temperature. The inlet air temperature of 150 °C and outlet air temperature of 80 °C gave lowest moisture content of 4.2% and water activity of 0.3. However, product yields obtained from different drying conditions were not significantly different (P>0.05). The composition of sericin powder was 70.63% protein, 23.51% ash, 5.79% moisture and 0.07% fat. Properties of sericin protein prepared by spray drying with different spray drying conditions had similar characteristics. This knowledge can be applied in the commercial production.