Processing Conditions Optimization And Qualities Analysis Of Purple Sweet Potato Starch Noodles

In order to improve the quality of purple sweet potato starch noodle, we investigate the optimal ratio of sweet potato starch and purple sweet purple flour and correlation between physicochemical properties of sweet potato starch and the quality of its starch noodle at different ratio of purple sweet potato flour. We also optimize its processing parameters to get the optimal freezing and drying parameters. Furthermore, we study the effect of the quality of purple sweet potato starch noodle by different food additives and select the best types and adding amounts. The main study results are as follows:(1) The purple sweet starch flour content has the significant influence on the physicochemical properties of sweet potato starch and its starch noodles quality. There is correlationship between parameter of sweet potato starch physicochemical properties and sweet potato starch noodle quality. With the decreasing of swelling power and solubility, the gel strength increase, thus, the quality of starch noodle is enhanced.(2) The sweet potato starch quality was investigated, under 12% purple sweet potato flour content and different freezing and drying conditions, to get the optimal processing parameters. The result show that the sweet potato starch noodle has the best quality, the swelling index and cooking loss are 226.22% and 1.58%, after freezing at 4 °C for 8 h and drying at 65 °C for 30 min.(3) 8 kinds of food additives were chosen to evaluate their influences on the properties of sweet potato starch(with 12% purple sweet potato flour) by using single factor experiments and Box-Behnken experiments. The optimal contents of Xanthan gum, Guar gum, Ca Cl2 and soybean protein were 0.21%, 0.18%, 0.40% and 2.00%, respectively. Its gel strength, swelling power and solubility are 204.92 g, 22.09% and 11.55%.(4) The starch noodles obtained under the optimal conditions showed brighter and deeper purple color, higher cutting deformation, tensile strength and lower cutting force and stretch deformation, and it also had the lower swelling index, cooking loos, broken rate and release content of anthocyanin.