Dendrobium officinale
polysaccharide enhances the freezing stability of wheat starch gel by modulating water state and reinforcing fractal network
Zhang Tong, Fu Xiong, Wang Ping‐Ping, Chen Jian‐Sheng, Xie Yu, Chen Chun Abstract
BACKGROUND
Frozen starch gels are prone to structural deterioration and hardening. Conventional cryoprotective strategies often fail to preserve both texture and nutritional quality. This study aimed to elucidate the mechanism by which Dendrobium officinale polysaccharide (DOP) enhances the freezing stability of wheat starch gels through multiscale structural reorganization.
RESULTS
Dendrobium officinale polysaccharide reduced suppressed starch granule swelling by 1700 g kg −1 and reduced amylose leaching by 2.30%, while increasing the microscopic elastic constant (α) from 0.32 to 0.41 at an assumed backbone fractal dimension (x) of 1.0, indicating a shift toward less strong‐link‐dominated behavior within the transition regime. This transition, driven by DOP‐starch self‐assembly, yielded a structure characterized by rigid aggregates interconnected by flexible linkages. Consequently, the gel network became denser, as evidenced by an increase in the rheological fractal dimension from 2.15 to 2.37. During 30‐day frozen storage, DOP effectively mitigated starch retrogradation, restricted the increase in freezable water content, and reduced brittle fracture. Notably, the optimized structure modulated by 12 g kg −1 DOP redirected resistant starch formation from retrograde starch toward RS5 amylose–polysaccharide complexes, thereby harmonizing high enzymatic resistance (resistant starch content increased by 3.30%) with a pleasing frozen texture (hardness decreased by 3.31 N).
CONCLUSIONS
This work provides novel insights into the multiscale mechanisms by which polysaccharides improve the low‐temperature stability of starch‐based foods and demonstrates the potential of DOP to maintain frozen texture and nutritional functionality. © 2026 Society of Chemical Industry.