Green Extraction and Separation of Silk Sericin with High and Low Molecular Weight and Their Gelling Performances

Abstract Silk sericin, a water‐soluble protein with diverse biomedical applications, is typically extracted from silk cocoon through degumming. Traditional degumming methods like chemicals, soap, and alkali can cause environmental harm by generating toxic waste and reducing extraction yields. These methods also damage sericin's structural integrity, limiting its biomedical applications. In contrast, the green High Temperature High Pressure (HTHP) degumming method offers a sustainable, eco‐friendly approach by using water as a solvent, eliminating the need for harsh chemicals and reducing environmental impact. This method enhances sericin extraction efficiency and enables selective separation of high and low molecular weight fractions, which are crucial for biomedical applications. In this study, a green degumming method combining ultrasonic (US) assistance with HTHP (US‐HTHP) was applied without chemical reagents. We further separated high molecular weight sericin (HMSS) and low molecular weight sericin (LMSS) using gel filtration chromatography and compared their gelling, moisturizing, and antioxidant properties. Results revealed that under optimal conditions (40 min US time, 60 min degumming time, and 120 °C degumming temperature), the extraction yield obtained 31.8%, and sericin purity reached 96.23%. Additionally, different degumming conditions were found to control the ratio of HMSS to LMSS. The moisturizing, antioxidant, and gelling properties of HMSS were superior to those of LMSS, highlighting its significant advantages and application potential.