Carrots texture alteration via polyphenol interaction from the perspective of cell wall polysaccharide.

Heat processing degrades the pectin network, leading to texture softening in plant-based foods. This study demonstrates that polyphenol treatment, particularly with procyanidin, effectively preserves the texture of steamed carrots compared to monomeric catechin. The optimal treatment (1.5% procyanidin, 30 min) uniquely enhanced cell wall integrity, induced distinctive pigmentation. It crucially reversed pectin thermal degradation by promoting a shift from soluble fractions to covalently cross-linked forms. This structural reinforcement manifests as enhanced pectin thermal stability and reduced methyl esterification (inhibiting β-elimination), thereby rendering the molecular structure more stable. Molecular dynamics simulation confirmed that procyanidin forms stronger complexes with pectin, especially NSP, via van der Waals forces and hydrogen bonds. These multi-scale findings establish that the degree of polymerization of procyanidins is key to strengthening the cell wall network, providing a targeted strategy for texture regulation in processed vegetables.