Effect Of Fresh Sweet Potatoes On Dough Characteristics And Qualify Steamed Bread

In order to expand the application scope of sweet potato in the traditional staple food and provide theoretical support for the actual production of sweet potato steamed bread in the future,the influence of the amount of sweet potato slurry added on the rheological characteristics of dough and the quality of steamed bread was investigated.In this paper,the effects of the addition amount of sweet potato slurry on dough characteristics and steamed bread quality were studied,and the quality improvement was carried out at the level of the highest sweet potato addition.The optimal process parameters of quality improvement were obtained by four-factor five-level quadratic orthogonal rotation combination test optimization.Under the optimal process parameters,the volatile flavor components of sweet potato taro and common taro were analyzed.Through the above experiments,the following conclusions can be drawn:The effect of adding amount of sweet potato pulp on the flour quality,tensile properties and dynamic rheological properties were studied.The results showed that the water absorption,formation time and stabilization time of the dough were decreased with the increase of the adding amount of sweet potato pulp,the dough weakening degree was increased,the flour index was decreased,the dough strength was enhanced,and the maximum resistance,pull ratio and stretch area of the dough were increased.The viscoelastic properties of the dough were significantly different,and the energy storage modulus G ’,loss modulus G "and tangent of loss Angle were all decreased with the increase of yams pulp.In conclusion,adding a proper amount of sweet potato pulp can improve the flour and stretch properties of the dough.The addition of sweet potato pulp destroys the network structure of the gluten and reduces the dynamic viscoelasticity of the dough.The effect of adding sweet potato pulp on the quality of steamed bread was studied.Results show that adding sweet potato raw slurry destroyed the gluten network structure,reducing the structure of the formation of gluten in dough gluten content,reduced the dough fermentation ability,thus affecting the quality of steamed bread,leading to the hardness of steamed bread,ankylosis,chew degrees increase,elastic,adhesiveness and resilience decreases,and at the same time make steamed bread volume and brightness to rise after falling.According to the single factor results of sweet potato raw pulp steamed bun measured in the above test,the optimal process parameters were obtained by optimizing the four-factor and five-level quadratic orthogonal rotation combination test on the basis of the addition amount of sweet potato raw pulp being 50%,and improve quality at the highest level.The addition amount of gluten was 4.2%,The Times of surface pressing was 13 times,the fermentation time was 60 min,and the awakening time was 20 min.Under this condition,the specific volume of steamed bread was 2.75 ml/g,the color difference was 71.38,the tensile strength of dough was 32.84 g,the elasticity of steamed bread was 0.93,and the sensory evaluation score was 92.0.Through solid phase microextraction combined with GC-MS analysis,the difference in flavor between sweet potato raw pulp and common white noodles prepared under the optimal process parameters was compared.The results showed that ethanol samples were found in the sweet potato taro and white-faced taro samples,and the content was the highest among all the measured volatile flavor components,which was the main source of taro flavor.In addition to ethanol,the substances detected in common taro and sweet potato taro are: 3-methyl-1-butanol,2,4-dimethylpentane,furfural.The special aroma source of sweet potato raw pulp should be cyclopropylmethanol,furfural,ethyl octanoate,3-fluorenone,etc.It provides apple flavor,rose,citrus,brandy and other aromas for sweet potato.