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BACKGROUND Aiming at the practical problems of low utilization rate and serious waste of soybean residue, the novel composite hydrogels based on okara cellulose before and after TEMPO oxidation and high polymers of chitosan (CH), carrageenan (CA) or Arabic gum (AG) were prepared by a homogeneous mixture in ionic liquid of this present study. RESULTS In the study, composite hydrogels fabricated from okara cellulose and CH, CA, or AG were prepared by dissolving them in an ionic liquid, heating (100°C, 3 h), and then soaking them in a 1:1 water-isopropanol solution. The composite hydrogels prepared from TEMPO oxidation-treated cellulose were physically crosslinked to CH, CA or AG. The results showed that the intramolecular hydrogen bonds in the amorphous regions of the cellulose were disrupted, while the intermolecular hydrogen bonds between the biopolymers were increased, which promoted the formation of composite gels with crystalline structures. The TEMPO treatment increased the gel strength. For instance, for the cellulose/CA gels, the hardness, fracturability, springiness and cohesiveness values were 5.9-, 4.3-, 2.4- and 3.6-fold higher than for the non-treated ones, respectively. The composite hydrogels exhibited good thermal stability, swelling properties, and mechanical properties. These novel composite polysaccharide-based hydrogels may therefore have great potential in various food and non-food fields. CONCLUSION In summary, the addition of polymers (CH, CA or AG) and TEMPO oxidized cellulose was suitable for increasing the swelling, textural properties, thermal stability and rheological properties of hydrogels, which provide new ideas and new methods for the preparation of bio-based composite hydrogels. This article is protected by copyright. All rights reserved.