Effects of different hydrocolloids on gelatinization and gels structure of chestnut starch

The effects of carboxymethyl chitosan (CMC), xanthan gum (XG) and sodium alginate (SA) on the gelatinization, rheology, gel properties, crystal form, functional group, water distribution and microstructure of chestnut starch (CS) were studied. The addition of CMC reduced the peak viscosity (PV), trough viscosity (TV) and final viscosity (FV) of CS gel, but increased the setback viscosity (SB) and breakdown viscosity (BD). XG and SA increased all viscosity values (PV, FV, TV, SB, and BD) of CS gel, and XG increased more significantly with the same addition amount. XG and SA were positively correlated with gel strength and viscoelasticity, while CMC was negatively correlated. XG and SA reduced the spin–spin relaxation time (T2), and promoted the water in the sample to gradually change to the bound water state, while CMC increased T2, resulting in more free water content. Results also showed that the addition of CMC, XG and SA did not produce new functional groups and original crystal structure disappeared after CS gelatinization, and the addition of 0.5% XG and 0.1% SA made the structure more orderly. The addition of CMC, XG and SA made the structure of CS uniform. These results will provide a theoretical basis for the production of food and non-food industrial products, and provide new insights for the application of other starches and hydrocolloids.