Stabilization Of Wheat Aleurone Layer Flour And Its Effect On The Quality Of Chinese Steamed Bread

Wheat aleurone layer is the most nutritious ingredient in wheat grains due to it concentrates major dietary fibers and biologically active compounds.Adding it to wheat flour to make Chinese steamed bread is of great significance for balancing people's daily diet.Although,wheat aleurone layer flour is a good source of nutrients,it has certain disadvantages due relatively high levels of lipids and various of microorganisms and enzymes,so it is prone to oxidative rancidity.In this study,the effect of extrusion treatment,superheated steam treatment and microwave treatment on stabilization of wheat aleurone layer flour were investigated before adding it back to wheat flour.Then,it was focused on the effect of the stabilization aleurone layer addition on the components of wheat flour,dough rheology and steamed bread quality.The purpose of this subject was to explore the optimal aleurone layer addition amount for making traditional Chinese steamed bread and the maximum degree of addition amount that consumers could accept.The conclusions were made as follows:1.All three methods could effectively reduce the fatty acid value in wheat aleurone layer flour.Combined with orthogonal tests,the optimum conditions were selected during stabilization treatment,which were the extrusion temperature of 145°C,the material moisture content of 24%,and the host frequency of 18 Hz during extrusion treatment;the superheated steam temperature of 210°C,the material moisture of 24%,and the processing time of 4min during superheated steam treatment;the microwave power of 600 W,the material moisture content of 20%,and the irradiation time of 180 s during microwave irradiation treatment,respectively.Through comparative analysis of the safety and nutrition index of the materials under the optimal processing parameters,it was concluded that the extrusion treatment had the best stabilization effect.2.The addition of wheat aleurone layer flour increased the nutritional value of flour.When the addition amount was 25%,it could meet the requirement of dietary fiber content in whole wheat flour standard,and when the addition amount was 30%,it could meet the requirement of alkyl resorcinol content in whole wheat flour standard.The addition of wheat aleurone layer flour reduced the wet gluten content and quality of the flour,which made the dough prone to weaken under the action of mechanical stirring,while improved the thermal stability of the starch paste.As the added amount of aleurone layer increased,the weakly bound water in the gluten-starch matrix would become bound water and increase the dough's ability to retain water.This would help delay the aging of steamed bread,but if the added amount of aleurone layer was too high would seriously affect the rheological properties of the dough,reduce the ability of the gluten network structure to retain gas,and adversely affect the quality of the dough.3.The addition of wheat aleurone layer flour would result in a smaller specific volume and darker color of the steamed bread,but the appropriate amount of addition would help improve the quality and taste of the steamed bread.Through the comparative analysis of related indicators,it could be determined that steamed bread made with Jiaozi starter had better quality.The sensory evaluation and texture evaluation results of steamed bread were basically the same.The textural properties results showed that the optimum adding range for steaming aleurone-layer steamed bread with Jiaozi starter was 10%?15%,and the optimum adding range for steaming aleurone-layer steamed bread with yeast starter was 5%?10%.From the sensory evaluation results,it could be seen that the aleurone-layer steamed bread with an addition amount of less than 30% was acceptable to consumers,but the aleurone-layer steamed bread with an addition amount of 35% or higher had poor taste and could not be accepted by consumers.