Abstract: Changes in the thermal properties, microstructure, rheological properties, gelatinization properties and texture of wheat starch were examined in the presence of low-dose rutin or quercetin, as well as the effect of rutin and quercetin on wheat starch-iodine complex. It was found that the onset gelatinization temperature (T0), peak gelatinization temperature (TP) and gelatinization conclusion temperature (TC) of wheat starch did not change significantly after adding rutin or quercetin. The retrogradation enthalpy (ΔH2) increased significantly by 85.71% and 85.71%, respectively, and the retrogradation degree (R) also increased significantly by 156.09% and 93.24%, respectively. At the same time, electron microscopy showed that rutin and quercetin accelerated the retrogradation process, decreasing the storage modulus and loss modulus. Rapid visco analysis (RVA) results showed that rutin and quercetin decreased the peak viscosity of wheat starch by 5.56% and 18.10%, minimum viscosity by 6.41% and 21.32%, final viscosity by 3.28% and 14.22%, and peak time by 1.93% and 4.16%, and increased setback by 3.36% and 0.52%, and pasting temperature by 0.63% and 3.25%, respectively. Moreover, rutin and quercetin reduced the hardness of wheat starch by 44.60% and 34.52%, adhesiveness by 60.79% and 30.95%, and springiness by 2.94% and 3.13%, and increased cohesion by 16.13% and 16.13%, respectively. Quercetin could interact strongly with wheat starch, form V-type inclusion complex. In general, rutin and quercetin can significantly influence the physicochemical properties of wheat starch.

Key words: rutin, quercetin, wheat starch, physicochemical properties