Effects Of Peeling Degree And Grain Size On Nutritious Powder And Steamed Bread Quality

With the development of economy and the improvement of people's living standard,wheat bran nutrition has been widely concerned by the community.Wheat bran nutrients are more concentrated in the aleurone layer,the outer skin and the bran pericarp are almost full of cellulose which cannot be utilized by human body.The traditional milling method is to grind kernels after removing the bran,which deprives the wheat of a large number of nutrients.However,the whole direct grinding flour is more susceptible to the pollution of dust and pests.So the balance between nutrition and taste value of the industry has become the focus of research.In this study,I take wheat grain as the raw material,and the wheat is peeled to different degree by rice milling machine to get different levels of wheat bran nutritional powders(Hereinafter referred to as nutrition powder),and the effects of different peeling rate on the quality index and silty index of nutrition powder were explored.Furthermore,the nutrition powder with different peeling rate was used as raw material to make steamed bread,to study the effect of different peeling rate on the quality of steamed bread.Chooseing the best peeling rate after the comprehensive evaluation of nutrition powder nutrition quality,dough and bread quality.And then crushing it into different particle sizes,to explore the size of its land value,silty characteristics and the quality of bread products.The main research contents include the following aspects:(1)The quality indicators of the whole wheat flour industry standard(LS/T 3244-2015)include appearance,odor,moisture,ash,total dietary fiber,alkyl resorcinol,fatty acid value,sand content and magnetic metal content.The effects of skinning rate(0.00%?3.12%?9.84%?17.72%?21.77%)on the above quality indexes were investigated.In general,the effect of the peeling treatment on the appearance,odor and magnetic metal of the nutrient powder is not significant,The peeling rate of 3.12%can effectively reduce the ash content and dietary fiber content of nutrient powder,while the peeling rate increased to 17.72%and 21.77%,the dietary fiber content decreased significantly.At the same time peeling treatment also made the alkyl resorcinol content gradually decrease significantly,the sand content of nutrient powder whose peeling rate is 3.12%decreased slightly.In summary,the peeling rate less than 3.12%can remove the wheat surface dust and excessive dietary fiber,to effectively retain the nutrition powder nutrition.(2)This chapter explores the effects of peeling rate(0.00%?3.12%?9.84%?17.72%?21.77%)on value of chromatism,protein and B vitamins of nutrition powder.The results showed that with the increase of peeling rate,the L*value of the nutrient powder increased,the brightness gradually increased,while the red-green value a*and the yellow-blue value b*were decreasing.And the protein content and vitamin B of nutrient powder whose peeling time was 15 s,peeling rate was 3.12%,reached the highest level.It indicates that the low peeling rate(3.12%)was beneficial to the nutrient enrichment and the color of nutrition powder.(3)This chapter explores the effects of peeling rate(0.00%?3.12%?9.84%?17.72%?21.77%)on the value of flour falling,the silty index and the quality of flour products.The results showed that the maximum value of flour falling was in17.72%,and the water absorption rate decreased gradually with the increasing of peeling rate,the formation time decreased and the decline level was not significant.Stabilization time and silty index are gradually increased,and weakening degree is decreasing.The wheat steamed bread whose peeling rate is 21.77%has the maximum specific volume,with the increase of peeling rate,the color of steamed bread improved significantly,the appearance of the shape and structure score increased gradually,while the toughness slightly reduced.the conclusion of TPA test is:With the increase of peeling rate,steamed bread decrease in hardness,chewiness and adhesiveness.Springness,cohesion,recovery gradually increased.The sensory evaluation scores of steamed bread made with 21.77%were the highest,and integrated its nutritional value and sensory acceptance,when the skinning rate is 3.12%,it is easier for people to accept.(4)Based on the conclusion of the first three chapters,this study chooses tht wheat which was peeled 15 s to control the particle size,and explores the effects of grain size on the falling value of the flour,the silty index and the quality of the steamed bread.The result shows that the falling number increases first and then decreases with the decrease of grain size.The elasticity and toughness of nutrient powder which Particle size can though CQ16 are better,sensory assessment score is the highest.TPA experiment shows that the hardness and the chewiness of the steamed bread decrease first and then increase with the decrease in particle size,and springiness and resilience are also increased first and then reduced with the decrease in particle size.In general,the nutrient powder whose peeling time is 15 s and particle size can though CQ16 can effectively improve the dough silty index,enhance the taste of bread products.