Saccharification Experiment Study On Degermed Corn Added With Amylase Extruded At Low Temperature For Production Syrup

The technical flow of double enzyme method for starch sugar at home and abroad was: starch→steeping→germ separation→protein separation→starch washing→pulp-mixing→jet liquefaction→saccharifaction→enzyme deactivation→filtration→decoloration→ion exchange→syrup. The flow was wet method, which was a physical technics, and the starch was purer. But the method had disadvantage: (1) long process and high cost; (2) used large water and huge waste water;(3) the energy expending of the jet liquefaction was large. Aim at above disadvantage, Linko introduced high temperature extruded starch to produce syrup. But filtration speed of the saccharified liquid was slow and the saccharifaction time was long. Thus the paper studied the saccharification experiment used extruded degermed corn added amylase at low temperature. The corn was made by dry method and was degermed. The jet liquefaction was omitted. Thus it can reduce the investment, reducing environment pollution and save the energy cost, In order to get a new process to produce glucose syrup, it was studied the liquefaction, saccharifaction and refining of extruded degermed corn added enzyme. Thus it provided a new technical method to producing glucose syrup and corn deep processing.The paper studied the method of liquefaction and saccharifacton used extruded degermed corn added enzyme at the base of patents of and combined the achievement in order to obtain the technics of producing glucose syrup used degermed and providing technology support.(1)It was studied the influence of extrusion-saccharifaction system pararmeters(the content ofα-amylase during extrusion, screw rotate speed, the content ofα-amylase during liquefaction, liquefaction time, the content of glucoamylase added in saccharifaction) on the index of glucose syrup made from extruded degermed corn added thermostableα-amylases.The optimized pararmeters of extrusion-saccharifaction system were got through analysising and optimizing the index. The validated results showed that the process of producing glucose syrup used extruded degermed corn added thermostableα-amylases was feasible, and the index of validated results were advantage than those of contrast experiment.The optimized pararmeters of extrusion-saccharifaction system by orthogonal tests and validated experiments were below: the content of thermostableα-amylase during extrusion was 0.80L/t, screw rotate speed 140r/min, the content of thermostableα-amylase during liquefaction 0.60L/t, liquefaction time 20.0min, the content of glucoamylase added in saccharifaction 1.50L/t.(2)It was studied the influence of extrusion-saccharifaction system pararmeters on the index of glucose syrup made from extruded degermed corn added mesophilicα-amylase.The optimized pararmeters of extrusion-saccharifaction system were got through analysising and optimizing the index. The validated results showed that the process of producing glucose syrup used extruded degermed corn added mesophilicα-amylases was feasible, and the index of validated results were advantage than those of contrast experiment.The optimized pararmeters of extrusion-saccharifaction system by orthogonal tests and validated experiments were below: the temperature of barrel was 75℃, the content of mesophilicα-amylase during extrusion 10.0L/t, the content of mesophilicα-amylase during liquefaction 4.6L/t, liquefaction time 28.0min, the content of glucoamylase added in saccharifaction 0.9L/t.(3)Glucose syrup was made from starch through mixing, gelatinization, jet liquefaction, saccharifaction, refining. The process used extruded degermed corn added enzyme without jet liquefaction and the saccharifaction time was shorten from 36~40h to 12h. At the same time the material was degermend corn made by dry method, not the market starch. The wet method was deleted and saving water and protecting environment.(4)The main chemical component of degermed was starch, fat and protein happened complicated physical and chemical reaction.The extruder was sudden stop, opened the barrel immediately in 5 minutes and took the sample at the specified points. The index measured shown that starch was gelatinized and degraded, especially the extrudate of degermed corn added enmzye, reducing sugar was produced, the enzyme activity was lower, the content of fat and amylose was decrease. Starch-lipid complex was yield thus it decrease the utilization ration of starch to produce glucose.(5)Studied starch-lipid complex, starch-protein complex during extrusion by complex index, DSC, FTIR and X-ray.The results of CI extrudate of starh/germ mixture and starch/gluten meal mixture showed that the starch was complexed with lipid and gluten meal and produce new matter. The iodine affinity of amylose was decreased.There was not new groups of the diagram of native and extruded starch, it was shown that there was not a new material appeared, it could the crystalline forms was changed not chemical structure change. CI was increased with the added content of germ or gluten meal increased. The CI of extruded degermed added amylase was more than 55. But the complex was not steady and could separate.The results of DSC showed that the melt peak temperature was more than 100℃, the FTIR diagram of starch-lipid complex showed there was not new functional groups. The melt enthalpy increased with the content of palmitic acid.The results of FT-IR showed that there was not new characteristic peaks of group appeared in extruded starch/germ mixture. The FT-IR diagram of native and extruded starch there was not new group appeared of extruded starch compared to native starch.The results of X-ray showd that lots of microcrystalline disappered, submicrocrystallinity increased and the intensity of diffraction peak was decreased, and a new high intensity diffraction peak appeared. The crystallinity destroy of extruded degermed corn added mesophilicα-amylase was higher than that of extruded degermed corn added thermostableα-amylase. The diffraction intensity of extruded degermed corn added amylase was lower than that of native degermed cornnd and a new high intensity diffraction peak appeared.