Modulating texture and retrogradation of potato starch gels with curdlan and gellan gum: Insights from structural
Ziping Zeng1, Yongxia Fu2, Zhenyu Liu1
1Innovation Center for Advanced Brewing Science and Technology, College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, China; Key Laboratory of Monitoring and Assessment on Novel Food Raw Materials, State Administration For Market Regulation, Sichuan University, Chengdu 610065, China.
Abstract:
Potato starch (PS) gels are widely favored by consumers for their smooth texture and palatable quality. However, their relatively weak gel structure during processing and susceptibility to retrogradation during storage limit broader application. This study investigated the effects of different concentrations of curdlan (CD) and gellan gum (GG) on the stability and retrogradation properties of PS gels. Both CD and GG enhanced gel hardness, springiness, storage modulus, and thermal stability. The optimal degree of structural recovery (DSR) value was achieved with 30% CD addition, whereas GG induced a concentration-dependent increase in DSR. GG exhibited superior compatibility with PS, forming a more uniform and continuous gel network as observed in SEM images, and promoting an amorphous structure in X-ray diffraction (XRD) patterns. In the PS-CD system, hydrogen bonding dominated at low CD concentrations, while electrostatic interactions became more prominent with increasing CD content. In contrast, the PS-GG system was governed primarily by strong electrostatic interactions and weaker hydrogen bonds. Furthermore, both CD and GG delayed retrogradation, as indicated by minimal shifts in T₂ (LF-NMR transverse relaxation time) and particularly T₂₃, associated with more mobile water. These findings provide mechanistic insight for designing PS-based gels with improved structural stability and storage performance.
