Recent progress in understanding the structural characteristics of fucoidan and its effects on food matrix functionality and starch digestibility.

Fucoidan, a sulfated polysaccharide enriched in α-L-Fucp, has attracted considerable attention due to its structural complexity and functional versatility in food systems. This review provides a novel synthesis by systematically integrating evidence on fucoidan's molecular architecture, interaction mechanisms, and functional outcomes. Its effects on pasting properties, rheological behavior, textural attributes, thermal transitions, water distribution, and microstructural organization in food matrices are critically examined. Particular emphasis is placed on its capacity to modulate starch digestibility and postprandial glycemic response through enzyme inhibition, promotion of resistant starch formation, and alteration of starch microstructure. The technological potential of fucoidan in starch-based, meat, and dairy systems is also addressed. Remaining challenges include clarifying structure-function relationships, interactions with other hydrocolloids, stability during processing, and variability among sources. Collectively, this review advances a mechanistically grounded and application-oriented framework, providing new insights into the utilization of fucoidan as a functional food ingredient.