| China is the major producer of corn.Because cron is the main material of starch,syrup and alcohol in the industry,so it palys an important role in production of agriculture and industry.However,the corn use ratio of industry in our country is low,which is only 50-60%.Corn processing industries yield many by-products such as CGM when they yield corn starch,but beause of the bad water-solubility,special stink,the imbalance of amino amid constitution and the deficiency of tryptophan and lysine which is the necessary amino amid of human body,the use of CGM is limited and they are feed or wasted.This action ont only wastes the corn resources,but also the environment is polluted greatly.Jilin is the major producer province of corn in china.Because the comprehensive utilization of corn in corn processing industry is insufficient,so corn industrial advantages of jilin province haven't played outAt present,some researchers are studying the modification of CGM in order to improve the additional value of corn industry and promote processing characteristics of CGM.to degrease and remove impurity on CGM through supercritical CO2 fluid extraction, the study use some advanced technology to modified CGM,including twin-screw extrusion technology, enzymolysis modification technology,in order to improve the soluble protein content and increase its solubility,and then improve its physicochemical properties such as water-holding capacity, gerase holding capacity, emulsifying property and foamability. so we can develop and use the protein resource of CGM adequately.The combination of production with environmental protection and economic benefit with social benefit will come true.The results are mainly as follow:1.To degrease and remove impurity on CGM through supercritical CO2 fluid extraction, the fat content reduced from original 6.25%to 0.37%, removing rate was reached to 94.08%. The color of CGM is faint yellow and the foul smell is barely.so the effect of supercritical CO2 fluidextraction on derosination,decoloration,deodorization is remarkable.2.The defatted CGM was modified by twin-screw extrusion machine. The optimal extrusion technology was determined by 3-variable,3-level response surface methodology on the basis of single factor experiment, the moisture content,Extrusion temperature and rotate speed were response factors and the content of Soluble protein was response value. The result indicate, when moisture content is 68%, extrusion temperature is 163℃, rotate speed is 30Hz, the content of soluble protein is 3.43%.the physicochemical properties have remarkable improvement.3.The defatted corn protain was modified by Alcalase 2.4L, alkali protease and papain,The optimal degradation technology was determined by 3-variable,3-level response surface methodology on the basis of single factor experiment, Enzyme/substrate ratio, enzymolysis temperature and pH value were response factors and the content of Soluble protein was response value. Under the best technological conditions, the content of Soluble protein reached 51.9%,45.2%,20.1%respectively.4.Under the condition of different hydrolyzing degree,the physicochemical properties of CGM by enzymolysis have remarkable improvement.The physicochemical properties of modified CGM under different hydrolyzing degree are as follows:.Alcalase 2.4L:water-holding capacity is 2.98g/g;hydroscopicity is 3.96 g/g;gerase holding capacity is 1.79 g/g; emulsifying property is 26.59m2/g;Emulsion stability is 42.4min; foamability is 235%; foam stability is 176%.Alkali protease:water-holding capacity is 2.87 g/g;hydroscopicity is 3.87 g/g;gerase holding capacity is 2.33 g/g;emulsifying property is 25.9m2/g;Emulsion stability is 41.3min; foamability is 205%;foam stability is 142%.Papainis:water-holding capacity is 2.47g/g; hydroscopicity is 3.45g/g; grease holding capacity is 1.98g/g;emulsifying property 12.34 m2/g;Emulsionstability25.34min;foamabilityl70%;foam stability84%.
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