The Research On The Solvent Extraction Of Oil In Corn DDGS

The output of corn DDGS rises day by day.As the substitute of soy bean meal, corn DDGS has high content of oil and high content of corn yellow pigment which make the corn DDGS’s quality unstable, limit the further use of in the feed industry. So this paper makes a research of the composition of domestic corn DDGS and NIRS analysis of corn DDGS,then study the solvent extraction with hexane,compare the quality of corn DDGS after defatting with before.The details are as follows:we get50samples of12factory from the major producing areas in China.They are heilongjiang,jilin, shandong,and henan province.The result show that the content of oil in corn DDGS is between5.21%and15.40%, its variable coefficient is10.11%. the average value of crude protein content is between25.21%and29.87%, crude fiber between4.04%and11.28%, water between8.07%and15.80%, DDS between25.46%-38.59%. The value of L ranges from42.83to53.2, a from5.59to8.39, b from15.41to22.96.The correlation analysis show that the content of ash is significantly related to the content of DDS(p<0.05),the content of oil is extremely significantly related to the value of b(p<0.01).If we process the spectrum of corn DDGS with Standard MSC+Detrend,2,4,4,1mathematic treatment, PLS regression analysis, the SEC of the spectrum model is0.23,the RSQ of the spectrum is0.90.we use10corn DDGS samples to examine the spectrum model, we get RSQ=0.92>0.9, RSD=5.92%<10%, RPD=4>3, the accuracy of the model is good for detecting the content of oil.After that,we get the optical technology of removing the oil in corn DDGS at the liquid ratio1:2(m:v)as follows:three times for extraction,temperature at55℃,rotating speed of50r/min.We compare the oil from corn DDGS with the corn germ oil,we find that the content of tocopherol,phytosterol,corn yellow pigment,oryzanol are1475.7μg/g,14.50mg/g,239.5μ g/g,814.05μg/g.They are1.26,1.29,6.78,12.09times more than the content in corn germ oil respectively. Besides, the stability of oil from corn DDGS is better than corn germ oil.The POV can stay stable in first6days and8weeks during the accelerated storage study and room temperature storage study while the other only4days and6weeks.we make a research of the effect of extracting oil from corn DDGS,we get the results that water content and the value of b are extremely significantly related to the before (p=0.000). The content of oil decreases to1.03%,the content of protein increases to28.54%and the value of b decreases to8.32.The water activity decreases to0.61.After the removal of the oil,the results of the GC/MC tells us that the flavor material species changes less but the content much. The phenethyl alcohol remain the main flavor material,the content of adehyde,ketone,alcohol in small molecular increase and1,3-butanediol increases most of all, which from10.53%to19.12%when2,4-decadienal decreases from15.94%to4.84%.The results indicates that the solvent extraction is effective and the oil’s quality is good with abundant lipid-classes.The quality of corn DDGS after defatting increases and the application in the area of feed industry expands.