Study On Processing Of Whole Purple Potato Flour Steamed Bread And Nutritional Characteristics

The gluten protein was not exist in whole purple potato flour.When added to wheat flour,the texture and processing properties of the dough will be deteriorated,which will affect the quality of steamed bread.This paper mainly explored the composition and nutritional characteristics of the whole purple potato flour and its effect on the dough characteristics and the processing technology of the steamed bread.It optimizes the suitable whole purple potato flour steamed bread making process,and on this basis,the additive is used as high as possible.The quality of steamed bread was optimized under the proportion of purple potato whole powder,provided theoretical basis and technical support for the industrial production application of purple potato whole flour.Firstly,the chemical composition and functional substances of the whole purple potato powder were analyzed.The results showed that the moisture content of the whole purple potato flour was 6.59%,which was only about half of the wheat flour,but the ash content was 2.17%,which was four times that of the wheat flour.The fat content was 1.55%,which was twice that of wheat flour.The crude starch content and crude protein content are basically the same,but the types and composition of the two are quite different.The whole purple potato powder was rich in antioxidants,and the total phenol content is 76.6 ?g GAE/m L,the anthocyanin content was 24.15 mg/100 g,and the polyphenol oxidase activity was 0.327,which was higher than that in ordinary potatoes.The 0%?50% different ratio of whole purple potato flour and wheat flour were compounded,and the farinograph properties,pasting properties,fermentation rheological properties and microstructure of the blends were determined.In terms of the farinograph properties of the dough,with the addition of the whole purple potato flour,the water absorption rate of the dough increased from 58.7% to 103.2%,and the dough development time increased from 2.4 min to 5.8 min,but the stabilization time decreased from 3.1 min to 1.1 min.Both the degree of softening and the farinograph index increased,indicating that the addition of the whole purple potato flour reduced the stability of the dough.With the increase of the total amount of whole purple potato flour,the peak viscosity of the blends increased from 278.5 to 540.0,and the final viscosity increased from 437.8 to 563.1.When the addition amount reached 50%,the peak viscosity and final viscosity were not different from the control group.The addition of whole purple potato flour delayed the peak time from 25.9 min in the control group to 29.4 to 30.0 min,indicating that the starch gelatinization rate was slowed down.With the increased of the whole purple potato flour,the gas production capacity of the dough increased,and the gas production increased from 1473 m L to 2293 m L,but the gas holding capacity decreased,and the gas retention ratio decreased from 77.7% to 62.7%.As the gas holding capacity of the dough is weakened,the height of the dough is gradually reduced with the addition of the whole purple potato powder,from 25.5 mm to 9.6 mm.The microstructure also indicated that the addition of the whole purple potato flour weakens the gluten structure,making the gluten network sparse and loose.In order to obtain the optimal production process of whole purple potato flour steamed bread,the effect of different whole purple potato flour addition on the quality of steamed bread was explored.The sensory score was taken as the investigation factor.The four-factor five-level orthogonal experiment analysis can be used to obtain the purple potato.The optimum conditions for the whole purple potato flour steamed bread were: 109 min for the first fermentation time,1.1% for the yeast,13.39 min for the second fermentation time,23.39% for the whole purple potato flour,and 84.35 for the sensory score.In order to increase the content of purple potato powder,the quality of steamed bread was optimized by adding gluten,sodium carboxymethyl cellulose and artemisia glue on the basis of 50% addition.The best formula was obtained by response surface experiment.The addition amount of gluten meal was 10.67%,the addition amount of sodium carboxymethyl cellulose was 0.49%,and the addition amount of artemisia glue was 0.19%.Under this condition,the sensory score had a maximum value of 85.47 points.