Effects of Lycium barbarum polysaccharide on gelatinization properties of potato starch

In this research, the influences of Lycium barbarum polysaccharide (LBP) on gelatinization properties of potato starch (POS) were evaluated. The swelling power of POS was inhibited, and the leaching of amylose declined. The LBP increased the peak temperature (Tp), while decreased the enthalpy (Delta H) of gel from 6.62 to 4.87Jg(-1). Compared with pure POS gel, the hardness of POS gel added with 0.6% LBP decreased by 13% after storage for 20days. The syneresis of gels that exposed to four freeze-thaw cycles was significantly reduced from 65.8% to 41.2%. Rheological measurements revealed that the viscoelasticity of composites was enhanced. The addition of LBP can enlarge the particle size of composite gels, and make the microstructure of composite gels become smooth, compact, and thicker pore wall. Fourier-transform infrared spectroscopy (FTIR) and interaction force test showed that the hydrophobic bond was likely to be the main force. Practical applications The incorporation of LBP could improve the gelling characteristics of POS-based gel by delaying the change on gel hardness of POS composites during storage, and reducing the undesirable impact of freeze-thawing treatment on POS gel system. The research outcome of the gelling characteristics of POS-based gel can be used for frozen food, low-temperature refrigerated food, and soft food. And the results of rheological behavior on POS-based gel can be used in sauces, thickeners, and puddings.