Extraction Of Corn Bran Hemicellulose By The Combined Enzyme-Alkali Method And Its Application

Removal of starch from corn bran by high temperature resistant α-amylase.Based on single factor test,Box-Benhnken center combination test was used to optimize,and the optimum process conditions for starch hydrolysis in corn husk were determined.It is the amount of enzyme added is 1462.3U / g,the solid-liquid ratio is 1/10,the p H is6.5,the reaction temperature is 95℃,and the reaction time is 4.0min.Under this condition,the residual amount of starch is 1.97%.Removal of protein from corn bran by neutral proteinase.Based on the single factor test,the optimal process conditions for corn husk deproteinization by Box-Benhnken combined test were: the amount of enzyme added was 24000 U / g,The solid-liquid ratio was 1/10,the p H was 7.5,the reaction time was 3.0,and the reaction temperatures were 50℃.Under this condition,the residual amount of protein was 2.33%.Extraction of hemicellulose from corn bran by Na OH solution.Based on a single factor test,the optimal process conditions for hemicellulose extraction from corn husks were determined through a Box-Benhnken combination test.The amount was8.0%,the solid-liquid ratio was 1:12,the extraction temperature was 75 ℃,and the extraction time was 2.0h.Under these conditions,the hemicellulose extraction rate was 52.8%.The structure of corn bran hemicellulose was analyzed.SEM analysis showed that there was agglomeration of hemicellulose,The microstructure of corn husk hemicellulose is similar to spherical structure.X-ray diffraction analysis shows that the crystal structure of corn husk hemicellulose has not changed obviously,and it is still a typical amorphous structure.Thermal analysis shows that the main weight-loss temperature of corn husk hemicellulose is between 190 ℃ and 350 ℃,and the weight-loss rate is the largest at 267℃.Elevate the bonds between xylose,arabinose,galactose,and glucose to break.When the temperature reached 600℃,20% of the samples remained undecomposed.The undecomposed part may be due to the small amount of lignin in the sample,or it may be caused by the salts in it.Infrared spectroscopy,nuclear magnetic resonance proton spectroscopy,and ion chromatography analysis showed that corn hull hemicellulose is mainly composed of xylose,arabinose,galactose,and glucose,with xylose accounting for a maximum of67.72%,followed by arabinose and galactose,respectively They were 17.6% an d3.81%.Hemicellulose / chitosan / glycerin composite membrane material was prepared using corn hull hemicellulose as the raw material.Based on the single factor test,Box-Benhnken center combination test was used to determine the optimal process conditions for the preparation of the composite membrane: hemi-fiber The amount of element is 2.4%,the amount of chitosan is 0.4%,and the amount of glycerol is 0.6%.The p H value is 2.5 and the drying temperature is 55℃.Under these conditions,the tensile strength of the composite film is 15.57 MPa,and the elongation at break is271.43%.The structure and properties of the corn peel hemicellulose composite film were analyzed.X-ray diffraction,scanning electron microscopy,and thermal analysis results showed that the crystal structure of the hemicellulose composite film had not changed substantially,and had good surface characteristics and Thermal stability.The composite membrane has certain antibacterial properties and good thermal solubility and degradation properties against E.coli and Staphylococcus aureus.