Development of Corn Fiber Gum-Soybean Protein Isolate Double Network Hydrogels Through Synergistic Gelation

Corn fiber gum (CFG)-soybean protein isolate (SPI) double network (DN) hydrogel was fabricated under the action of laccase and D-(+)-gluconic acid delta-lactone (GDL) at room temperature. Time sweep dynamic rheological analysis indicated that laccase and GDL work synergistically to enhance the gel strength of CFG-SPI DN hydrogels. The gel strength of CFG-SPI DN hydrogel was higher than those of hydrogels prepared by either constituent. Uniaxial compression test and texture profile analysis showed that CFG-SPI DN hydrogel integrated the mechanical properties of CFG and SPI networks, whose fracture strain was 20 times higher than that of CFG hydrogel, while the hardness was about twice the value that of SPI hydrogel. Scanning electron microscopy observation confirmed that both CFG and SPI participated in the formation of CFG-SPI DN hydrogel. CFG-SPI DN hydrogel showed a more regular and denser microstructure as compared with hydrogels prepared by single constituent. CFG-SPI DN hydrogels with various mechanical properties, water-holding capacities and microstructures were prepared by controlling the concentrations of CFG and SPI. Among which, CFG-SPI double network hydrogel with 7.0% SPI and 1.0% CFG exhibited the highest hardness and water-holding capacity.