Germination-Inspired Enzymatic Degradation of Guar Galactomannan and Its Synergistic Skincare Effects with Aloe Polysaccharides

Galactomannan (GM) is a renewable biomass resource, but its direct application is limited by challenges such as high molecular weight and low water solubility. Inspired by the seed germination process, this study adopted a combined enzymatic hydrolysis strategy using α-galactosidase and β-mannanase, successfully achieving controllable regulation of GM molecular weight (1040 kDa–60 kDa) and significantly improving its functional properties and biological activities. Further research revealed that after complexation with aloe polysaccharide (AP), the composite polysaccharides (xGM-AP) exhibited significantly better hygroscopic moisturizing performance and antioxidant effects than single polysaccharides. Based on this, xGM-AP was introduced into a poly(vinyl alcohol) matrix to prepare a multifunctional hydrogel mask. The mask showed excellent mechanical properties (tensile strength of 234.84 MPa, elongation at break of 211.46%), long-lasting moisturizing property (86.46% moisture retention over 10 days), efficient ultraviolet (UV) shielding (96.15%), and significant cooling effects. Meanwhile, zebrafish embryotoxicity experiments verified the safety of polysaccharides. This study not only provides a feasible approach for customizing galactomannan (GM) with specific structures and functionalities, but also demonstrates its potential as a sustainable alternative to petroleum-derived or high-cost ingredients in skincare applications.