Structural properties and gastrointestinal digestion fate of collagen fibrils covalently connected with fucosylated chondroitin sulfate derived from sea cucumber

Collagens, being the abundant structural proteins in many animal-derived food materials, generally assemble in the hierarchical level of collagen fibrils. Our previous study found that sea cucumber collagen fibrils are covalently connected with fucosylated chondroitin sulfate (fCS), giving an indication of one special molecular form of collagen fibrils in food materials. Herein, this study aimed to investigate the structural properties and gastrointestinal digestion fate of the collagen fibrils with fCS. The presence of covalent fCS could regulate the rheological properties and change collagen fibrils with more ordered secondary structures after thermal treatment at 80℃. The cooperation of covalent fCS delayed the degradation of collagen fibrils from fibrillar to punctate structures with reduced digest rate in the gastric digestion stage and accelerated the formation of peptide aggregates with high molecular weight during the intestinal digestion process, which contributed to deep understanding of the digestion fate of different types of collagen fibrils.