Corn oil and protein extraction method

Abstract

The invention is a corn product removal process that successfully extracts oil and zein from dry-milled corn. Oils and zein are extracted from corn using ethanol. Corn solids are separated from the ethanol, oil and zein mixture produced in the step of extracting. Thereafter, the ethanol, oil and zein mixture are membrane filtered to restrain zein from the mixture and pass an oil and ethanol mixture. At least one of zein or oil is then selected to be separated for an output corn product.

What is claimed is:  
     
         1 . A corn product removal process, the process comprising steps of: 
 extracting oils and proteins from corn using ethanol;    separating corn solids from an extraction solution that contains oils and zein protein produced in said step of extraction;    membrane filtering said extraction solution to restrain zein from said mixture and pass the oil and ethanol mixture;    membrane filtering said oil and ethanol mixture to restrain oil and pass ethanol;    selecting at least one of zein or oil separated in said membrane filtering steps for an output corn product.    
     
     
         2 . The process of  claim 1 , wherein said step of selecting comprises selecting zein for output and further comprising a step of purifying zein concentrate obtained in said step of membrane filtering said ethanol, oil and zein mixture.  
     
     
         3 . The process of  claim 2 , wherein said step of purifying comprises evaporating any ethanol and water from said zein concentrate.  
     
     
         4 . The process of  claim 2 , wherein said step of purifying comprises precipitating zein.  
     
     
         5 . The process of  claim 4 , wherein said precipitating comprises adding cold water to said zein concentrate to lower ethanol concentration below approximately 40 percent.  
     
     
         6 . The process of  claim 1 , wherein said step of selecting comprises selecting oil for output and further comprising a step of purifying oil concentrate obtained in said step of membrane filtering said oil and ethanol mixture.  
     
     
         7 . The process of  claim 6 , wherein said step of purifying comprises evaporating any ethanol and water from said oil concentrate.  
     
     
         8 . The process of  claim 1 , wherein said separating step comprises filtration.  
     
     
         9 . The process of  claim 1 , wherein said separating step comprises centrifugation.  
     
     
         10 . The process of  claim 1 , further comprising a step of removing the ethanol solvent from the corn solids residue by application of heat.  
     
     
         11 . The process of  claim 10 , further comprising a step of recycling ethanol produced in said step of distilling into said step of extracting.  
     
     
         12 . The process of  claim 1 , wherein said step of extraction uses 60-100% ethanol and water mixtures.  
     
     
         13 . The process of  claim 1 , further comprising a step of recycling ethanol produced in any step back into said step of extracting.  
     
     
         14 . The process of  claim 1 , wherein said corn is dry grind corn.  
     
     
         15 . A corn product removal process, the process comprising steps of: 
 obtaining an oil, zein and ethanol mixture free of other corn solids from a corn input;    membrane filtering to obtain one of an oil or zein concentrate from said oil, zein and ethanol mixture.