Study On The Application And Quality Improvement Of Defatted Soybean Flour In Flour Products

Wheat flour has a wide range of applications and a large consumption,but wheat flour lacks the lysine required by the human body.Defatted soybean flour is obtained by rolling and crushing of defatted soybean meal.It is rich in protein,dietary fiber,minerals and other nutrients,and is rich in lysine.Therefore,adding defatted soybean flour to wheat flour can make up for the problem of insufficient lysine content in wheat flour to a certain extent.Biscuit is a kind of leisure flour food made of low gluten flour,which has the advantages of long storage period and convenient consumption.Steamed bread is a fermented flour food made of medium gluten flour,which is one of the most important staple foods in China.Bread is a fermented flour food made of high-gluten flour,which is widely loved by young consumers.Adding defatted soybean flour to the above three flour foods can broaden the application of defatted soybean flour in different consumption scenarios.However,the addition of defatted soybean flour may lead to the decrease of specific volume,the increase of hardness and the formation of beany flavor.Therefore,in this study,different methods were used to improve the quality of defatted soybean flour biscuits,steamed bread and bread,and the nutrition of the final product was evaluated.Firstly,the application and quality improvement of defatted soybean flour in crisp biscuits were explored.Phospholipids and papain were used to increase the amount of defatted soybean flour in crisp biscuits and reduce the hardness of biscuits.The results showed that the hardness of biscuits could be reduced from 3571.24 g to 2229.70 g when the addition amount of phospholipid was 0～0.8%.When the addition amount of papain was 0～0.035%,the hardness of biscuits could be reduced from 3030.84 g to 2086.51 g.The formula of defatted soybean flour crisp biscuits was further optimized by orthogonal experiment.The results showed that the biscuits with 20% defatted soybean flour,0.6% phospholipids and 0.035% papain had the lowest hardness.The dietary fiber content of the optimal biscuits was 19.88%,and the protein content was 15.23%.The essential amino acid index(EAAI),nutritional index amino acid score(AAS)and chemical score(CS)scores were high,indicating that the addition of phospholipids and papain could effectively increase the addition of defatted soybean flour in crisp biscuits and improve the quality of crisp biscuits.Secondly,the application and quality improvement of defatted soybean flour in steamed bread were explored.The fermentation of sourdough in cold storage was used to increase the addition of defatted soybean flour in steamed bread,and the problems of beany flavor and specific volume decrease of defatted soybean flour added to steamed bread were solved.The results showed that the specific volume of the improved final product became larger,the beany smell was reduced,and the internal structure was more delicate.The addition of defatted soybean flour increased from 2% to 7%.The effect of the fermentation process of sourdough in cold storage on the volatile flavor substances of soybean steamed bread was studied.It was found that the peak area and types of ketones and esters related to the pleasant flavor of steamed bread became larger and more after fermentation in cold storage,and the content of substances related to beany flavor decreased,indicating that fermentation in cold storage could reduce the beany flavor.The results showed that the steamed bread containing 7% defatted soybean flour had a dietary fiber content of 4.24%,a protein content of 15.89%,and an essential amino acid index(EAAI).The nutritional index amino acid score(AAS)and chemical score(CS)scores were higher,indicating that the fermentation of sourdough in cold storage could increase the addition of defatted soybean flour in steamed bread and improve its quality.Finally,the application and quality improvement of defatted soybean flour in bread were explored.Fermented with sourdough in cold storage,the beany flavor in bread disappeared,the specific volume increased and the pore structure improved.The addition of defatted soybean flour in bread was increased to 8%.The protein content of bread containing 8%defatted soybean flour was 17.16%,and the dietary fiber content was 4.02%.Compared with the blank fast fermented bread,the protein content was increased by 3.27%,and the dietary fiber content was increased by 0.40%.In addition,the score of essential amino acid index(EAAI),nutritional index amino acid score(AAS)and chemical score(CS)of bread containing 8% defatted soybean flour were all high,which indicated that its protein nutritional value was high.