Study Of Liquefaction Process High Concentration Corn Starch Extrusion Enzymatic Complex Method

The study use corn starch as the main raw material, according to certain proportion with high temperature resistance of α-amylase and water mix, liquefaction technology was studied using extrusion enzyme complex technology, using the single factor and response surface method of extrusion enzyme complex liquefaction process optimization. Using high performance liquid chromatography(HPLC) method for optimal extrusion process of liquefied extrudate qualitative quantitative analysis. Corn starch was observed by a scanning electron microscope(SEM) before and after the extrusion apparent structure change. Using X-ray diffraction analysis of corn starch crystallinity changes before and after extrusion. Analysis by differential scanning calorimeter corn starch extrusion of thermodynamic properties before and after the change.The results as follows:(1) Using the single factor and response surface method for high concentration of corn starch enzyme Xie Fu single screw extruder legal liquefaction process is optimized, the results show that when the high temperature resistant alpha amylase content 40 u/g, extrusion temperature 140 ℃, the concentration of corn starch 70%, corn starch liquefaction extrudate DE value of 19.55%, close to the theoretical value and mathematical model of optimization of single screw extruder enzyme Xie Fu legal liquefaction process is feasible. Variance analysis results showed that the corn starch liquefaction extrudate DE value influence from strong to weak factors for high temperature resistant alpha amylase content > extrusion temperature > starch content.(2) Using the single factor and response surface method for high concentration of corn starch enzyme twin-screw extruder legal liquefaction process is optimized, the results show that when the high temperature resistant alpha amylase content 42 u/g, extrusion temperature 142 ℃, 71% corn starch concentration, the screw rotation speed 30 Hz, corn starch liquefaction extrudate DE value of 16.71%, close to the theoretical value and mathematical model of optimization of single screw extruder enzyme legal liquefaction process is feasible. Variance analysis results showed that the corn starch liquefaction extrudate DE value influence from strong to weak factors for high temperature resistant alpha amylase content > extrusion temperature > screw speed > corn starch concentration.(3) High performance liquid chromatography(HPLC) method for the best single screw extrusion process of liquefied extrudate oligosaccharides qualitative quantitative analysis. The results showed that the extrudate oligosaccharides can get good separation of components, linear is good, the recovery is 97.92% ~ 97.92%, relative standard deviation(RSD) is less than 3%(n =5). The method is stable and accurate, and suitable for the inspection and content determination of monosaccharides and oligosaccharides. Oligosaccharide samples of each component in the quality ratio of glucose, maltose, malt trisaccharide: four malt sugar, five malt sugar = 1.0:3.4:7.5:6.0:1.8.(4) Corn starch extrusion observed by a scanning electron microscope(sem) before and after the apparent structure change. The results showed that the corn starch granules surface is smooth, the structure is complete, after extrusion processing, starch particles become fleeciness rough surface and the surface appears in the hole, particle surface rendering striate. Using X-ray diffraction analysis of corn starch extrusion crystallinity changes before and after using single screw and twin screw extruder after corn starch crystallinity decreased. The results showed that: the original, the crystallinity of maize starch 32.7%, single screw extrusion process, reduce to 22.8%, the crystallinity of starch. Liquefaction of twin-screw extruder, reduce to 25.6%, the crystallinity of starch, indicating that some of starch molecular internal arrangement also destroyed. Analysis by differential scanning calorimeter corn starch extrusion of thermodynamic properties before and after the change. The results showed that the extrusion processing of corn starch, shows that there are new and different in the process of extrusion processing stability crystals appear, it is helpful to degradation enzyme in the process of heating up step by step it.