Effects Of Hot Tempering On The Quality Of Wheat Flour And Steamed Bread

In this paper, under the condition of tempering has completed, the property of wheat flour has improved, the content of wet gluten has increased, gluten index has increased, muscular force has enhanced and the quality of wheat flour has improved by a physical method of hot tempering. Through the study about the different indicators of wheat flour under different tempering temperature and time,the main conclusions were shown as follows:The contents of ash was reduced by the tempering time increasing basically, with the tempering temperature increasing showed an increasing trend as a whole. With the increasing of tempering time, whiteness and land values increased and then decreased, the content of damaged starch was contrast, the activity of α- amylase was contrary with the land values, which trend was first decline after rising. With the tempering temperature increasing whiteness increased first and then decreased basically.With the tempering time increasing, wet gluten content, gluten index, SDSsedimentation value, sulfhydryl content was increased first and then decreased. Secondary structure has bad variation overall, β-folded was increased, α-helical structure was reduced, sulfhydryl content was reduced, protein content was increased under tempering temperature increasing. With the tempering time increasing and tempering temperature increasing lipase activity was increased and then decreased.With the tempering time increasing, pasting temperature was increased first and then decreased, peak viscosity was first increased then decreased. With the tempering temperature increasing, peak viscosity showed increasing trend overall. With the increase of tempering time, the water absorption of 40 ℃、50 ℃ was increased first and then decreased, the water absorption of 60 ℃ was decline directly; the water of absorption tended to decrease under tempering temperature increasing. The formation time of hot tempering was higher than room temperature. The variation of settling time was different under the change of tempering temperature. Most of tensile properties was extended with the proofing time increasing. Elongation value was rise first and then decreased with tempering time increasing.Under the tempering temperature of 50 °C, tempering time of 11 h, steamed bread quality was better, specific volume was larger, the colour was whiter and internal organizational structure was uniform compared to room temperature. It showed that moisture contents of wheat heap was evenly distributed, each part of wheat moisture contents has an appropriate proportions, wheat flour protein contents was higher than others. Within a certain range, the water absorption speed of dough was faster, the amount of water absorption was increased, the gluten network structure was better, dough strength was enhanced, gas holding capacity was increased, steamed bread specific volume was larger, internal organizational structure was uniform and soft, steamed bread was better overall by tempering temperature increasing.