Effects of Artemisia sphaerocephala Krasch Gumon on the Thermal, Textural and Rheological Properties of Potato Starch Gel

In order to explore the extraction technology of Artemisia sphaerocephala Krasch gum and study the effect of Artemisia sphaerocephala Krasch gum on the properties of potato starch gel, ultrasonic assisted water extraction method was used to extract Artemisia sphaerocephala Krasch gum, and the optimum conditions were obtained by orthogonal test. And the effects of potato starch added with Artemisia sphaerocephala Krasch gum on its properties were studied by differential scanning calorimetry and scanning electron microscope. The results showed that the yield of Artemisia sphaerocephala Krasch gum was as high as 20.7% when the ratio of material to liquid was 1:40, the temperature was 50 ℃, and the time was 1.5 h. The gelatinization initial temperature and gelatinization terminating temperature of potato starch paste were increased, and the enthalpy ΔH was also increased after adding Artemisia sphaerocephala Krasch gum. The microstructural observation showed that the starch paste network with a lower amount of Artemisia sphaerocephala Krasch gum (0.1%~0.5%) was more and more compact, with uniform distribution of pores and small interstices. At the same time, the textural characteristics of starch paste were observed, and the hardness and elasticity were increased. The dynamic rheological experiments showed that additive amount of Artemisia sphaerocephala Krasch gum at a lower level (0.1%~0.5%), the values of G' and G'' were significantly increased, the viscoelasticity of potato starch paste was increased, and the tanδ value was significantly decreased, and then additive amount of Artemisia sphaerocephala Krasch gum at a higher level (1.0%), the values of G' and G'' were significantly decreased. Static rheological experiments showed that the potato starch treated with Artemisia sphaerocephala Krasch gum was pseudoplastic fluid, and starch paste viscosity coefficient K increased, fluid index n decreased, the addition of Artemisia sphaerocephala Krasch gum was 0.3% potato starch paste decreased the thixotropic ring area, which improved the shear stability of the system. Therefore, a lower level (0.1%~0.5%) of Artemisia sphaerocephala Krasch gum could enhance the gel texture properties of potato starch, while a higher supplemental level (1.0%) had a negative effect on the gel texture properties.