Study On The Effects Of Adding Sweet Potato Flour On Dough Characteristic And Quality Of Steamed Bread

Study the effect of sweet potato powder on gastric acid secretion and the effect of the dough characteristics and the quality of steamed bread,and to provide theoretical basis for the feasibility of the staple food of sweet potato.This study combined with the animal experiment and the adaptability evaluation experiment of adding sweet potato power steamed bread to research the feasibility of the sweet potato staple food,on this basis,study the effects of adding sweet potato power on the dough properties and the steamed bread quality,then improve the dough properties through adding vital gluten and the steamed bread production process was optimized.The results were as follows:(1)In the case of sweet potato powder added amount of less than 20%,SD rat gastric pH and gastric acidity did not change significantly;sweet potato flour addition amount increased to 30%,50%and 100%,SD rat gastric pH of 30%and 50%group was significantly lower than the group without tadding sweet potato powder(p<0.05),but their was no significant difference between 100%group;there was no significantly differences of SD rat gastric acidity between 50%sweet potato powder group and 100%sweet potato powder group,no significant differences between the other groups.Add sweet potato flour steamed bread does not make the body produce discomfort,stomach symptoms did not appear.(2)With the increase of the amount of sweet potato powder,dough water absorption,formation time,stability time and farinograph quality number(FQN)decreased,the degree of softening gradually increased,the dough extensibility decreased,tensile resistance first increased and then decreased,and the tensile energy and extensile rate at different fermentation time with a different variation;peak viscosity,through viscosity,breakdown value,final viscosity,setback value and peak time decreased gradually;the springiness?cohesiveness and resilience of steamed bread decreased gradually,the hardness,gumminess,adhesiveness and chewiness of adding sweet potato power steamed bread were significantly increased compared with the wheat flour bread of control group,Steamed bread specific volume reduced,brightness,colour and lustre is dim,the sensory evaluation score decreased,the production of steamed bread with intense aromas of sweet potato.(3)With the increase of wheat gluten and sweet potato powder added amount,mix flour dough formation time no significant change,stability time gradually increased,dough water absorption decreased,Starch gelatinization speed reduced significant during the heating process,but the weakening rate of protein networks has no significant change,a significant increase in the speed of amylase hydrolyzed starch;significantly reduce the viscosity under the action of heat and mechanical force,significantly lower falling number.After adding wheat gluten,the dough-holding capacity of the gas has been restored,the maximum swelling height has improved,do a observation for the fermented dough through scanning electron microscope and found that the gluten network structure is better than the same proportion only add the sweet potato power dough.(4)Through the single factor experiment to determine the optimum process parameters for making steamed bread from adding wheat gluten and sweet potato powder mixed flour,when the addition amount of vital gluten is 3%,the addition amount of water is 52%,and mixing time is 3.5,the specific volume value of steamed bread and sensory evaluation score reaches the maximum value;when the fermation time is 50min,steamed bread sensory evaluation score reached maximum value.Through the orthogonal experiment,we found that the factors which influence the sensory evaluation score of the steamed bread making from mixed flour added vital wheat gluten and sweet potato powder in order are:fermentation time>water addition amount>mixing time>vital gluten addition amount,optimum conditions:the fermentation time is 45min,the addition amount of water is 51%,the mixing time is 3.5min,the addition amount of vital gluten is 2.7%.