Study On Functional Properties And Application Of Black Wheat Bran By Air Explosion

As the main by-product of wheat processing,bran has ample sources,both nutritional and economic value.At present,wheat bran is mainly used as fodder and lacks deep processing and reuse.How to maximize the potential value of bran development and improve its economic and social benefits is a difficult problem in front of people.As an emerging food processing technology,airflow-puffing technology provides a new idea for the comprehensive utilization of wheat bran.In this study,Xinong black wheat bran was treated by air-expansion technology to study the changes in soluble dietary fiber（SDF）content,physiochemical properties,and antioxidant activity under different pressures.The effects of different bran addition on the texture and sensory quality of cake was also studied.The main results are as follows:（1）In terms of sensory and structural aspects,the color of the wheat bran obtained after the airflow-puffing gradually changed from light yellow to brown-black as the treatment pressure increased,and the flavor gradually changed from the coke aroma to a burnt taste.In addition,the puffing treatment causes the bran structure to become loose and porous,which can absorb more substances and have a certain influence on the physicochemical properties of the bran.（2）In terms of physical and chemical properties,air-expansion has a significant effect on SDF content,physicochemical and functional properties in bran（P<0.05）.The content of SDF in wheat bran increased first and then decreased,and the SDF content was significantly higher than that of untreated wheat bran.It reached the highest level at 0.7 MPa which was increased from the initial 12.47±0.18%to 23.59±0.33%.The WHC continued to increase from 1.18±0.03mL/g to 2.32±0.15 mL/g,and the maximum pressure was 1.1 MPa.The SC was consistent with the trend of SDF content,reaching a maximum of 2.07±0.18 mL/g at 0.8 MPa;while the OHC decreased with increasing pressure.The functional properties of wheat bran after air-expansion were significantly increased compared with unexpanded At pH 2,the cholesterol adsorption capacity reached a maximum of 2.23 mg/g at 0.8 MPa,and at pH 7,it reached a maximum of6.39 mg/g at 0.6 MPa.The cation exchange capacity reached a maximum of 0.14 mmol/g at 0.8MPa,and there was a positive relationship between NO^2-adsorption and pressure at the same pH.It can be seen that the physical and chemical properties of wheat bran are higher at a comprehensive level of 0.8 MPa.（3）In terms of antioxidant activity,air-expansion had a significant effect on total phenolic content and antioxidant activity of bran（P<0.05）.The total phenol content increased first and then decreased with increasing treatment intensity,reaching a max of 6.38 mg/g at 1.0 MPa,which was 2.6 times that of untreated.The antioxidant index was consistent with the total phenol content.DPPH·free radical scavenging capacity,hydroxyl free radical scavenging rate and reducing power after treatment were significantly higher than untreated（P<0.05）,which were 1.8 times,1.5 times,and 5 times that of the untreated ones.Thus,the air-expansion technology is a powerful method for extracting phenolic compounds from wheat bran,and when the treatment pressure is 1.0 MPa,the total phenol content and antioxidant activity of wheat bran are the strongest.（4）For the application of expanded bran,the study found that with the increase of bran addition,the hardness and chewiness of the cake both first decreased and then increased,and reached the lowest when the added amount was 6%,while the elasticity of the cake decreases.The sensory score of the cake increased first and then decreased,and the score was highest when the bran added amount was 6%.Therefore,the optimum amount of expanded bran was determined to be 6%.The cake made under this condition had a good taste and a unique aroma of wheat bran.The total phenolic content,DPPH·free radical scavenging ability and hydroxyl free radical scavenging rate of the cakes with wheat bran were significantly increased.It shows that the addition of expanded wheat bran in cakes is an effective way to increase the utilization of bran and enhance the nutritional properties of baked goods,and has a good prospect for development.