Study Of Pretreatment Of Sorghum Flour On The Quality Improvement Of Its Steamed Buns

The sorghum powder had poor viscoelasticity, rough taste and poor taste, which affected its processing quality and edible quality, leading to its limited addition in food. The purpose of this paper was to study the extrusion and ultrahigh pressure pretreatment process to improve the processing characteristics of sorghum powder, and enhanced the quality of sorghum flour bread, which laid the foundation for processing of sorghum bread.The difference of the main components between sorghum powder and wheat flour was analyzed, and the effect of the proportion of sorghum powder in wheat sorghum mixed powder on the flour characteristics, gelatinization characteristics, dough tensile properties and the quality of the finished bread were investigated. The results showed that the processing characteristics of the mixed powder and the quality of the finished buns showed a decreasing trend with the increasing of sorghum added.In order to improve the application quality of sorghum powder in steamed bread processing, the extrusion process of sorghum powder was studied at first. The extrusion process parameters had important influence on the quality and processing characteristics of sorghum powder. Based on the gelatinization degree of sorghum powder and the sensory quality of finished bread, the single factor and orthogonal test were carried out with the water content, temperature and screw speed as the factors. The optimum technological parameters were as follows: water content 21%, temperature 150 ℃, screw speed 110 r/min. On the basis of this process, the effects of the same proportion of extruded sorghum powder and common sorghum powder on the dough character and the quality of the finished bread were studied. It was found that the sensory score of sorghum powder bread was higher than that of ordinary sorghum flour bread in the same proportion.Secondly, ultrahigh pressure sorghum powder processing technology was studied. It mainly explored the effects of ultrahigh pressure on sorghum wheat flour quality, pasting characteristics and sensory quality of mixed flour bread. The results showed that the ultra high pressure technology could improve the water absorption,Stability time and formation time, reduce the degree of weakening; and improve the sorghum powder gelatinization temperature, reduce the return value; and increase the comprehensive sensory score of finished bread. Taking the time of keeping pressure and pressure as factors, the sensory quality of steamed bread was taken as the index, the optimum technological parameters were studied by orthogonal test: the holding time was 25min and the pressure was 300MPa.In order to investigate the effect of two methods on sorghum powder, the texture and sensory score of steamed bread were used as indexes. The sensory score of the extruded bread was 89.5, higher than the high pressure steamed bread, and the results showed that extrusion treatment had the best effect on sorghum powder.The effect of the key processing technology on the quality of extruded sorghum bread was studied. By using the sorghum powder and wheat flour as the raw materials, and the sensory quality of steamed bread as the index, the single factor and response surface experiments were carried out. The optimum parameters were dough stirring time 12 min,dough fermentation time 101 min, steamed bread baking time 13min.