Research On Comprehensive Utilization Of Wheat Bran Protein And Fiber

As a byproduct of milling industry, the annual output of wheat bran is abundant and its price is very cheap. If it was further processed, it would bring considerable economic benefits and balance our diet so as to promote our health. This paper studied the comprehensive utilization of wheat bran, including the extraction and hydrolyzation of wheat bran protein,modification of wheat bran dietary fiber and its application in tomato sauce and concentrated orange juice.Firstly,the extraction and hydrolyzation process of wheat bran protein was studied. It is applicable to use alkaline to extract protein from wheat bran in industrial process. The results showed that the optimum extracting conditions were p H 9.5, at 50℃, 3.5 h, 1:30 of solid to water ratio. Under this condition, 53.12% protein would be able to get. Wheat bran protein was hydrolysised by hydrochloric acid. Under the condition of liquid to solid ratio 6: 1, the concentration of hydrochloric acid 4 mol/L, temperature 100℃, hydrolysis time 18 h, the degree of hydrolysis can reach 59.22%. According to the amino acids analysis results, the umami and sweet amino acids accounted for 53.77% of total amino acids of the hydrolysate and an appropriate addition can improve the sensory quality of umami juice.Secondly, in order to study the effect of wheat bran soluble dietary fiber added to concentrated orange juice, a complex cellulase enzyme Viscozyme L was used to hydrolysis wheat bran fiber to get the soluble fiber, and then added it to the juice. At a temperature of45℃, p H 4.5, enzyme 0.8%, solid to liquid ratio 1:15, hydrolysis time 2 h, 21.81% of wheat bran soluble dietary fiber can be got. The properties of fiber enriched juice changed: titratable acidity, browning potential, vitamin C and carotenoids decreased to some extent, soluble solids increased, the value of the color index L, a, Hue didn’t change apparently, b value increased and Chroma value firstly increased then decreased. Wheat bran soluble fiber didn’t affect the orange juice quality much.Thirdly, in order to make full use of wheat bran insoluble dietary fiber and make it more suitable for its application in foods, mechanical methods were used to modify the residue from the cellulase hydrolysate. This paper studied the high-pressure homogenization, high intensity ultrasonic and the combination of the two methods to process wheat bran dietary fiber with different concentrations. High pressure homogenization and its combination with high intensity ultrasonic can decrease the particle size of water-insoluble dietary fiber from wheat bran to about 10 μm and the latter can improve the surface a lot, so as to improve the water absorption, swelling capacity, oil holding capacity and other properties of wheat bran fiber. However, the ultrasonic treatment alone can hardly to decrease the particle size of wheat bran dietary fiber, and the properties of these samples are worse than the samples processed by the above method. Another factor that influences the properties is the fiber concentration.An appropriate increase in the concentration is beneficial to the particle decrease, but is not conducive to the quality of the subsequent drying of the sample.Finally, the effect of the modified wheat bran insoluble dietary fiber on the quality of ketchup was studied. Wheat bran insoluble dietary fiber can increase the viscosity modulus, elasticity modulus, viscosity, loss tangent and other rheological index, and it can also reduce water analysis of ketchup. It seems to have the potential to replace sodium carboxymethyl cellulose as a thickening in ketchup. Integrated sensory evaluation and the other indexes, the proper dosage of wheat bran dietary fiber was 2%.