Study On The Effect Of Diferent Starch On Properties Of Mixed Dough And Quality Of Chinese Steamed Bread

The different sources of starch will greatly influence the quality of steamed bread,but the relative study is not clear enough.In this study,the starch in wheat flour was completely and partly?10%?replaced by seven different starches-wheat starch,potato starch,sweet potato starch,tapioca starch,corn starch,pea starch,mung bean starch..And the effects of replacement on dough characteristics,dough microstructure and steamed bread was investigated to provide a theoretical basis for the improvement of steamed bread quality.The main contents and results are as follows:1.According to the ratio of starch to gluten in flour?89:11?,simulated dough were formed by mixing starch and gluten,the pasting and rheological properties of simulated doughwere studied.It was found that the pasting temperature of all simulated dough decreased.The potato starch has large particle size and low amylose content,which led to high viscosity peak,and low initial pasting temperature,and the simulated dough with potato starch also had the same characteristics;The simulated dough made of tuber starch and legume starch had lower paste viscosity than that of cereals,and the pasting temperature of tuber starch was low;The hardness and chewiness of the gel of the pea starch were relatively larger due to its higher amylose content,and the storage modulus?G'?combined with the loss modulus?G'?of the dough were also large;Potato starch had high water holding capacity,and the T₂₁ value?bound water?of simulated dough was small,which meant the acting of starch and water were better than other starches.As can be seen from the microstructure of simulated dough,wheat starch included two types of particles?A and B?,evenly filled in the gluten network,which led to the gluten network well formed;Potato starch was also filled well in gluten network because of its large particles,and had a high water retention and swelling;The simulated dough of sweet potato,cassava and corn starch had compact structure and poor ductility as a result of its small particles leading small expansion.The steamed bread made of simulated dough was smaller than ordinary bread,however,the hardness,flexibility and chewiness were better than those of ordinary bread,the steamed bread of potato starch and legume starch simulation system had good hardness and chewiness,which had no significant positive correlation with amylose content and grain size.In summary.From the above,in addition to wheat starch,the simulation dough of potato starch of all was better.However,the simulation dough and steamed bread of tapioca starch and legume starch were poor.2.The starch in wheat flour was partly?10%?replaced by different starches to study the effect of the replacement on dough characteristic and bread quality.It was shown that the RVA results of the mixed flour were consistent with the results of the simulated dough system.Potato starch had high water holding capacity,consequently leading to small T21 value of the simulated dough and better water absorption of mixed dough than that of ordinary dough;The formation time of mixed dough shortened,and the stability of mixed dough with tapioca starch and pea starch decreased.The tensile energy,gluten quality and dough elongation of the mixed dough decreased,and the maximum tensile resistance increased,which meant addition of different starches weakened ductility of the dough.There was no significant difference in the water distribution of the mixed dough,probably because of the low substitution ratio,and little effect of different starches on the action of protein on water.The specific volume of steamed bread made of mixed flour decreased,and the chewiness and elasticity increased.3.The effects of different additions of potato starch?0%,5%,10%,15%,20%?on the characteristic of dough and its steamed bread product was studied.The peak viscosity,attenuation value,regenerated value and pasting temperature of the mixed dough decreased with the increasing of the addition amount;Dough gluten,gas holding capacity,specific volume,elasticity andchewiness were the best at 10%.So,the proper amount?10%?to add potato starch can improve dough characteristic and steamed bread quality.