Engineering Edible Double Network Hydrogels with Abalone- and Squid-like Textures from Carrageenan and Konjac Glucomannan

The development of edible hydrogels with both high strength and toughness remains a considerable challenge. Herein, we report an innovative and straightforward method to prepare robust kappa-carrageenan/konjac glucomannan (κ-car/KGM) double network hydrogels (DNs) through a single heating-cooling cycle followed by immersion in an Na₂CO₃ solution. This method effectively tuned the crosslinking densities of both the rigid κ-car-k⁺ first network and the ductile KGM second network. The resulting κ-car-k⁺/KGM-1:2 DNs demonstrated outstanding mechanical properties, exhibiting compressive strength approximately 10- and 20-fold greater than that of the corresponding single network (SN) κ-car-k⁺ and KGM hydrogels, respectively, accompanied by remarkable toughness. This enhancement is attributed to a sequential failure mechanism where the rigid κ-car-k⁺ network fractures first to dissipate energy, while the ductile KGM network remains intact to maintain structural integrity. Furthermore, the sensory profile of the κ-car-k⁺/KGM-1:2 DNs was remarkably similar to that of squid across all five evaluated attributes (hardness, elasticity, chewiness, brittleness, and palatability). Similarly, the κ-car-k⁺/KGM-1:1 DNs closely matched the sensory profile of abalone, particularly in elasticity, chewiness, brittleness, and palatability. These findings suggest the prepared edible DNs have great potential to simulate high-chewing seafood, offering a new pathway for designing advanced food materials from natural polysaccharides.