Study On Preparation Of Waxy Corn Starch And Its Effect On Dough Propertiesand Qualities Of Flour Products

Waxy corn originated in China. After the corn was introduced into China, the hard corn starch was planted in the southwest region of China, and the waxy type was gradually developed by artificial selection. The genetic function of waxy corn WX gene changes endosperm starch types in waxy corn, which is almost composed of the branched chain starch. As the content of branched starch in common corn is 70%~75%, if we want pure branched starch,we must separate it from normal corn starch.But such a phenomenon would not happen to waxy corn starch, the transparency, viscosity and solubility the of the waxy corn starch is very high and it is easy to be gelatinization. The waxy corn starch has been widely used in food. In recent years, more and more attention has been paid to the deep processing of waxy corn, but the traditional starch extraction process is relatively low and the pollution of sulfur dioxide is produced. Preparation of waxy corn starch by enzymatic hydrolysis method is less, and the reaction conditions are relatively simple, so the waxy corn starch is prepared by enzyme hydrolysis method. At present, there have been many studies on dough characteristics and noodle quality of corn starch, but there are few studies on waxy corn starch on dough properties and qualities of flour products. Therefore, this experiment used waxy corn starch as the main materials, evaluated its effect on dough properties and qualities of noodles, steamed bread and bread, in order to improve the qualities of flour products and provide a theoretical basis for industrial production. The main results were as follows:(1) The best technical conditions of enzymatic hydrolysis to preparate waxy corn starch is that add the amount of 0.1g protease, the hydrolysis temperature is 45 degrees Celsius and the time of enzymatic hydrolysis is 15 hours.(2) Waxy corn starch can effectively improve the quality of dough and tensile properties, For the wheat flour, when the additive amount of waxy corn starch was 4%, the effect of improvement was most.(3) Waxy corn starch could improve the whiteness and cooking quality of noodles, increase the hardness and elasticity of the noodles, when the additive amount of waxy corn starch was 0%~4%, it can increase the cohesive and recovery of noodles, improve the fracture strength of noodles, effectively improve the sensory quality of noodles, through the testing sensory evaluation and TPA of noodles, it could be identified that the additive amount of waxy corn starch should be 4% in noodles.(4) Waxy corn starch can effectively improve the specific volume and color of steamed bread, increase the hardness and elasticity of the steamed bread.When the additive amount of waxy corn starch was 0%~4%,it can improve the cohesive and recovery of steamed bread and improve the sensory quality of steamed bread,. through the testing sensory evaluation and TPA of the steamed bread, it could be identified that the additive amount of waxy corn starch should be 4% in the steamed bread.(5) Adding waxy corn starch can improve the color of bread, effectively improve the texture characteristics of bread, enhance the sensory quality of bread, and ultimately improve the quality of bread. Comprehensive analysis of the effect of waxy corn starch on bread quality index, it can be identified that the additive amount of waxy corn starch should be 6% in bread.