Hydrocolloid–polyphenol Co-assemblies for food structure design: Linking molecular binding, network mechanics, oxidative stability, and bioaccessibility

Hydrocolloid–polyphenol co-assemblies are emerging as multifunctional food matrices that can integrate texture control, antioxidant protection, interfacial stabilization, active packaging, and bioactive delivery. Although polyphenols are commonly regarded as antioxidants, pigments, or nutraceutical compounds, their capacity to act as molecular regulators of hydrocolloid structure and performance remains less systematically addressed. This review evaluates hydrocolloid–polyphenol systems through a structure–function perspective, focusing on how protein and polysaccharide hydrocolloids interact with phenolic acids, flavonoids, anthocyanins, tannins, catechins, curcumin, resveratrol, and polyphenol-rich extracts. Particular emphasis is placed on how hydrocolloid molecular architecture, polyphenol structure and dose, pH, ionic strength, processing history, and interactions with coexisting matrix components influence whether reversible association or persistent covalent/oxidative coupling produces reinforcement, controlled release, or undesirable aggregation. The review further examines gelation, rheology, water mobility, interfacial behavior, oxidative stability, oral lubrication and astringency, edible films and coatings, and gastrointestinal release. Quantitative formulation windows are highlighted where primary studies provide them, while the limits of transferring simplified-model observations to real foods are considered explicitly. Applications are evaluated across dairy and plant-based systems, gels, beverages, emulsions, sauces, edible coatings, active packaging, and delivery platforms. The resulting framework emphasizes application-specific binding regimes, sensory-aware formulation, standardized characterization, and validation in compositionally realistic food matrices.