Construction of a xanthan gum–sodium carboxymethylcellulose hydrogel for enhanced gastrointestinal stability and <i>in vivo</i> calcium bioavailability of <i>Mytilus edulis</i> ‐derived peptide–calcium complex

BACKGROUND: Calcium is an important mineral nutrient for the body, playing a crucial role in bone growth. However, it has been demonstrated that calcium bioavailability is reduced due to the action of gastric acid and digestive enzymes on peptide-calcium chelates. Therefore, enhancing the structural stability of calcium in the complex environment of the gastrointestinal tract through a novel delivery system is a key strategy for improving calcium bioavailability. In this study, hydrogels (XC) composed of xanthan gum (XG) and sodium carboxymethylcellulose (CMC) were employed as carriers for Mytilus edulis protein hydrolysate-calcium (ME-Ca), thereby forming composite hydrogels (XCME-Ca). RESULTS: ) was observed to restore femur and tibia weight by 12.18% and 26.66%, respectively, and length by 5.19% and 15.34%, respectively, when compared with the model group. Furthermore, the maximum bone load attained 87.44% and 88.69% of the control group, respectively, with significant reparative effects observed on microstructural damage in both the femur and the tibia. CONCLUSION: The results indicate that the development of the hydrogel system addresses key issues such as poor stability and low bioavailability of peptide-calcium chelates in the gastrointestinal environment, providing an innovative solution to enhance their calcium absorption efficacy. © 2026 Society of Chemical Industry.