High-pressure-induced noncovalent grape polyphenol-corn starch assembly: Multi-scale structure, in vitro digestion, and IDDSI-based texture design

The structural, rheological, mechanical, and digestive properties of grape seed oligomeric proanthocyanidins (GSOP), grape seed polyphenols (GSP), and grape skin anthocyanins (GSA)-corn starch (CS) complexes formed by high hydrostatic pressure (HHP; 600 MPa, 15 min) were investigated for easy-swallowing food design. FTIR and interaction analyses indicated that polyphenols bound CS mainly via hydrogen bonding, notably reorganizing short-range order, lamellar structure, and crystallinity. These changes increased viscosity/viscoelasticity in HCS-1.5% GSA (K increased by 17.56 Pa.sⁿ upward and 95.03 Pa.sⁿ downward), redistributed moisture mobility, and reduced gel hardness by 12.84-41.72% (p < 0.05). Resistant starch increased from 16.66% to 29.15% in GSP-treated systems, indicating reduced digestibility and highlighting the roles of polyphenol molecular weight and hydroxyl density. International Dysphagia Diet Standardization Initiative tests classified orally processed cookies containing selected complexes as Level 4. These favorable swallowability results support reduced-glycemic, storage-stable starch-based foods and provide a multi-scale framework for functional starch design.