Study On Enzymatic Modification Assisted By Superfine Grinding Of Millet Bran And Its Application In Biscuits

As a by-product of millet processing,millet bran is easy to go rancid because of its high fat content and low price.It is often used as feed,resulting in a waste of resources.In order to improve the comprehensive utilization rate of millet bran,reduce the waste of resources,increase the SDF content in millet bran,and enhance the nutritional value of millet bran,the defatted millet bran was prepared by optimizing defatting technology,and the water-soluble dietary fiber content of millet bran was increased by ultra-fine pulverization and enzymolysis modification,and it was applied to the development of millet bran biscuits.(1)Study on ultrasonic-assisted degreasing process of ethanol.Response surface methodology was used to optimize the defatting process of millet bran,and the changes before and after defatting were analyzed.The results showed that the best combination of defatting technology of millet bran was solid-liquid ratio of 1:17g/m L,ultrasonic time of 15 min,ultrasonic power of 600 W and ultrasonic temperature of 55°C.Under these conditions,defatting rate reached 95.32%.After defatting,the fat content of millet bran decreased from 13.37% to 0.67%,and the protein and dietary fiber were retained.Scanning electron microscope analysis of rice bran showed that defatted rice bran was dispersed and difficult to aggregate,which could further increase the utilization value of millet bran.(2)Ultrafine grinding to prepare different millet bran micropowder.Planetary ball mill was used to micronize millet bran,and the results were compared and analyzed.The results showed that the content of soluble dietary fiber(SDF)was increased from6.53% to 8.63% by 32.16% after superfine grinding.Ultrafine grinding can also significantly enhance the uniformity and fluidity of powder,and improve its hydration characteristics.(3)Study on superfine grinding assisted enzymatic modification process.Taking the SDF content as the response value,the modification process conditions were optimized by response surface methodology.The results showed that the addition of cellulase was335U/g,the addition of xylanase was100U/g,the enzymolysis time was65 min,and the p H was 4.4.Under these conditions,the SDF content of rice bran obtained by enzymolysis was 14.82%,which was close to the theoretical value of14.646%,and the relative error was only 1.19%.(4)Development of rice bran dietary fiber biscuit.The response surface methodology was used to optimize the formula of dietary fiber biscuits from millet bran.The best formula was modified millet bran with 9.22%,butter with 29% and sugar with21%.Under these conditions,the sensory score was the highest.The protein content of millet bran biscuit was 9.6%,and the nutritional reference value was 16%.The fat content is 13.7%,and the nutritional reference value is 23%.The carbohydrate content is 56.6%,and the nutritional reference value is 19%.The dietary fiber content is 16.1%,and the nutritional reference value is 64%.The sodium content is 0.247%,and the nutritional reference value is 12%.The energy reached 1761 k J/100 g,and the nutritional reference value was 21%.To sum up,in this study,the content of SDF was increased through degreasing and modification,and the nutritional value of millet bran was enhanced.The development of millet bran products was helpful to enhance the economic benefits of agricultural and sideline products,improve their comprehensive utilization rate and avoid resource waste.