Foam-like materials produced from milk and sodium montmorillonite clay using a freeze-drying process

Fresh milk and sodium montmorillonite clay can be used to prepare foam-like materials via an environmentally sustainable freeze-drying process. The enzyme transglutaminase (Tgase) was demonstrated to be an effective cross-linker; treatment of milk with Tgase contributed to the formation of a gel network. The mechanical properties of milk/clay composites after freeze-drying were greatly improved (e.g. compressive moduli increasing from 1.4 to 13 MPa). Milk beyond its expiration date was also used in this research, demonstrating that dairy products unsuitable for human consumption can be turned into useful engineering materials.