4. Conclusion
In this work, we developed a novel extraction procedure to recover sericin from silk industry wastewater by using a chilled ethanol precipitation method, which was an effective and simple method. We focused on studying the physiochemical, structural, and biological properties of sericin obtained by this method. The physiochemical analysis results suggested that sericin power contained high degree purity of sericin, and this protein represented a family of proteins with wide-ranging molecular weight distribution. CD analysis results suggested that its major conformation was random coil that decreased slightly after being treated with ethanol, and the appearance of β-Turn conformation maybe associated with the packing of molecular chains induced by ethanol. In this study, we also found the biological activities of sericin powder, including antioxidant activity and tyrosinase inhibitory activity, which functions are important for potential application of sericin to food manufacture. In the future we are interested in studying enzymatic hydrolysis of sericin to produce small bioactive peptides, which will be more suitable for the development of functional foods than native sericin.