Glycine-amidated pectin confers freeze-thaw stability to noodles via ordered network construction and controlled structural adjustment

To improve the quality stability of freeze-thaw noodles, glycine-amidated pectin was applied and its anti-freeze-thaw mechanism was systematically investigated through structural, microscopic, rheological, and textural characterization. Results showed that modified pectin induced high-crystallinity starch structure and α -helix-rich protein conformation (50% initial content), establishing dense and uniform matrix structure. After 5 freeze-thaw cycles, treated noodles exhibited highest α -helix content (40%), minimal β -sheet increase, and presented sparse rounded micropores rather than dense honeycomb-like tearing defects. Modified pectin-treated noodles exhibited springiness and chewiness retention rates exceeding 85%, significantly higher than those of the control, with shortest optimal cooking time (1.0 min). Water absorption and cooking loss followed the order of modified pectin < control < natural pectin, with modified pectin maintaining the lowest levels. This study revealed a two-stage stabilization mechanism of initial ordered network construction and controlled adjustment under freeze-thaw stress, providing theoretical foundations for high-quality freeze-thaw noodle development.