Canola oil having increased oleic acid and decreased linolenic acid content

Abstract

An endogenous oil extracted from Brassica seeds is disclosed that contains, after crushing and extraction, greater than 86% oleic acid and less than 2.5% α-linolenic acid. The oil also contains less than 7% linoleic acid. The Brassica seeds are produced by plants that contain seed-specific inhibition of microsomal oleate desaturase and microsomal linoleate desaturase gene expression. Such inhibition can be created by cosuppression or antisense technology. Such an oil has a very high oxidative stability in the absence of added antioxidants.

What is claimed is:  
     
         1 . An endogenous oil obtained from Brassica seeds, said oil having an oleic acid content of greater than about 80%, an α-linolenic acid content of less than about 2.5% and an erucic acid content of less than about 2%, said oleic acid content, linolenic acid content and erucic acid content determined after hydrolysis of said oil.  
     
     
         2 . The oil of  claim 1 , further comprising a linoleic acid content of from about 1% to about 10%, said linoleic acid content determined after hydrolysis of said oil.  
     
     
         3 . The oil of  claim 1 , wherein said oleic acid content is from about 84% to about 88% and said α-linolenic acid content is from about 1% to about 2%.  
     
     
         4 . The oil of  claim 3 , further comprising a linoleic acid content of from about 3% to about 7%, said linoleic acid content determined after hydrolysis of said oil.  
     
     
         5 . The oil of  claim 1 , wherein said seeds are  Brassica napus  seeds.  
     
     
         6 . A Brassica plant containing at least one recombinant nucleic construct, said at least one construct comprising: 
 a) a first seed-specific regulatory sequence fragment operably linked to a wild-type microsomal delta-12 fatty acid desaturase coding sequence fragment; and    b) a second seed-specific regulatory sequence fragment operably linked to a wild-type microsomal delta-15 fatty acid desaturase coding sequence fragment,    wherein said plant produces seeds, yielding an oil having an oleic acid content of about 86% or greater and an erucic acid content of less than about 2%, said oleic acid content and erucic acid content determined after hydrolysis of said oil.    
     
     
         7 . The plant of  claim 6 , wherein said plant contains first and second recombinant nucleic acid constructs, said first construct comprising said delta-12 desaturase coding sequence fragment and said second recombinant nucleic acid construct comprising said delta-15 desaturase coding sequence fragment.  
     
     
         8 . The plant of  claim 6 , wherein said delta-12 desaturase coding sequence fragment comprises a full-length Brassica delta-12 desaturase coding sequence.  
     
     
         9 . The plant of  claim 6 , wherein said delta-15 desaturase coding sequence fragment comprises a full-length Brassica delta-15 desaturase coding sequence.  
     
     
         10 . A Brassica plant containing at least one recombinant nucleic acid construct, said at least one construct comprising: 
 a) a first seed-specific regulatory sequence fragment operably linked to a wild-type microsomal delta-12 fatty acid desaturase coding sequence fragment; and    b) a second seed-specific regulatory sequence fragment operably linked to a wild-type microsomal delta-15 fatty acid desaturase coding sequence fragment,    wherein said plant produces seeds yielding an oil having an oleic acid content of 80% or greater, an α-linolenic acid content of about 2.5% or less and an erucic acid content of less than about 2%, said oleic acid content, linolenic acid content and erucic acid content determined after hydrolysis of said oil.    
     
     
         11 . The plant of  claim 10 , wherein said first and second regulatory sequence fragments are linked in sense orientation to said delta-12 and delta-15 desaturase coding sequence fragments, respectively.  
     
     
         12 . The plant of  claim 10 , wherein said plant contains a first recombinant nucleic acid construct comprising said delta-12 desaturase coding sequence fragment and a second recombinant nucleic acid construct comprising said delta-15 desaturase coding sequence fragment.  
     
     
         13 . The plant-of  claim 10 , wherein said delta-12 desaturase coding sequence fragment comprises a full-length Brassica delta-12 desaturase coding sequence.  
     
     
         14 . The plant of  claim 10 , wherein said delta-15 desaturase coding sequence fragment comprises a full-length Brassica delta-15 desaturase coding sequence.  
     
     
         15 . The plant of  claim 10 , wherein said plant produces seeds yielding an oil having an oleic acid content of about 84% to about 89%, an α-linolenic acid content of about 1% to about 2% and an erucic acid content of less than about 2%, said oleic acid content, linolenic acid content and erucic acid content determined after hydrolysis of said oil.  
     
     
         16 . The plant of  claim 15 , wherein said oleic acid content is from about 86% to about 89% and said α-linolenic acid content is from about 1% to about 1.7%.  
     
     
         17 . A method of producing an endogenous oil from Brassica seeds, comprising the steps of: 
 a) creating at least one Brassica plant having a seed-specific reduction in microsomal delta-12 fatty acid desaturase gene expression and a seed-specific reduction in microsomal delta-15 fatty acid desaturase gene expression;    b) crushing seeds produced from said plant; and    c) extracting said oil from said seeds, said oil having an oleic acid content of about 86% or greater and an erucic acid content of less than about 2%, said oleic acid content and erucic acid content determined after hydrolysis of said oil.    
     
     
         18 . The method of  claim 17 , wherein said seed-specific reduction in delta-12 desaturase expression is created by cosuppression.  
     
     
         19 . The method of  claim 17 , wherein said seed-specific reduction in delta-12 desaturase expression is created by antisense suppression.  
     
     
         20 . The method of  claim 17 , wherein said seed-specific reduction in delta-15 desaturase expression is created by cosuppression.  
     
     
         21 . The method of  claim 17 , wherein said seed-specific reduction in delta-15 desaturase expression is created by antisense suppression.  
     
     
         22 . A method of producing an endogenous oil from Brassica seeds, comprising the steps of: 
 a) creating at least one Brassica plant having a seed-specific reduction in microsomal delta-12 fatty acid desaturase gene expression and a seed-specific reduction in microsomal delta-15 fatty acid desaturase gene expression;    b) crushing seeds produced from said plant; and    c) extracting said oil from said seeds, said oil having an oleic acid content of about 80% or greater, an α-linolenic acid content of 2.5% or less and an erucic acid content of less than about 2%, said oleic acid content and erucic acid content determined after hydrolysis of said oil.    
     
     
         23 . The method of  claim 22 , wherein said seed-specific reduction in delta-12 desaturase expression is created by cosuppression.  
     
     
         24 . The method of  claim 22 , wherein said seed-specific reduction in delta-12 desaturase expression is created by antisense suppression.  
     
     
         25 . The method-of  claim 22 , wherein said seed-specific reduction in delta-15 desaturase expression is created by cosuppression.  
     
     
         26 . The method of  claim 22 , wherein said seed-specific reduction in delta-15 desaturase expression is created by antisense suppression.