A comparative investigation of anionic polysaccharides on the structure and gastrointestinal digestion of collagen fibrils.

Collagen, the most abundant and widely distributed functional protein in mammals, typically assembles into collagen fibrils through side-by-side packing. The purpose of this study was to comparatively investigate the fate of sea cucumber collagen fibrils in the gastrointestinal tract when interacting with different anionic polysaccharides (fucoidan (FUC), Kappa-carrageenan (K-car), sodium alginate (SA)). Results revealed that the gel properties and viscosity values of collagen fibrils were notably enhanced, and the rate of structural alteration in collagen fibrils was reduced when K-car and SA were introduced. Conversely, in the presence of FUC, collagen fibril viscosity decreased, and the secondary structure of collagen fibrils underwent changes. FUC was found to diminish the structural stability of collagen fibrils and accelerate the gastric digestion rate, which was further exacerbated by thermal treatment. All these anionic polysaccharides were observed to facilitate the formation of collagen peptide aggregates by binding to polysaccharides during intestinal digestion. This study bridged the knowledge gap regarding the impact of anionic polysaccharides on the gastrointestinal digestion of collagen fibrils, potentially paving the way for broader applications of collagen in the food industry. • The structure and digestion fate of sea cucumber collagens was investigated. • The presence of anionic polysaccharides inconsistently regulated collagen fibrils. • The presence of fucoidan (FUC) improved gastrointestinal digestion rate of fibrils. • Heat treatment increased the effect of FUC on digestion rate of collagen fibrils. • The presence of Kappa-carrageenan and sodium alginate reduced the digestion rate. [ABSTRACT FROM AUTHOR]