Physically modified starch carriers for food-derived peptides: Molecular interactions, gastrointestinal fate, and preservation of antioxidant and anti-inflammatory activities

Food-derived bioactive peptides are promising functional ingredients, but gastrointestinal degradation and uncertain exposure at their sites of action complicate their oral application. This critical review examines how physical modification of starch influences peptide encapsulation, gastrointestinal fate, and preservation of antioxidant and anti-inflammatory activities, with chemically modified and non-starch carriers considered only as comparators. Evidence is assessed in relation to starch origin, processing conditions, peptide characteristics, and measured endpoints. Peptide sequence, size, charge, and hydrophobicity interact with starch architecture to govern association, retention, and enzymatic accessibility. Experimental findings are consistent with hydrogen bonding and physical confinement, whereas inclusion of peptides within amylose helices requires stronger molecular verification. Greater structural order or resistance to starch digestion may improve retention while restricting release. Reported protection and activity preservation remain formulation-specific, with limited evidence for systemic delivery of intact peptides. Carriers release, peptide survival, bioaccessibility, epithelial transport, and systemic exposure are therefore evaluated as distinct endpoints. Chemical antioxidant capacity is likewise distinguished from cellular antioxidant and anti-inflammatory effects. A framework linking processing, the joint assembly of starch and peptides, digestive transformation, and exposure at the intended site of action is proposed. Its central principle is to balance protection with the availability of intact peptides or active digestion products. Standardized digestion, peptide sequence analysis, realistic food matrices, and safety assessment are priorities for translating these carriers into functional foods.