Method for preparation of purified glycerides; and, products

Abstract

A method of preparing purified ester compositions is provided. The process can be utilized to isolate and purify monoglycerides and propylene glycol monoesters, to advantage. It can also be used to isolate preferred diester products. The invention also concerns equipment for conduct of the processes, provision of preferred food additives, and provision of preferred food industry compositions. The process generally involves use of liquid-liquid extractions, to advantage.

What is claimed is:  
     
         1 . A method of preparing a purified target ester-containing food composition; said method including steps of: 
 (a) providing a crude ester composition at least including: 
 (i) target ester selected from the group consisting of: 
 (A) C 3 -diol target esters of fatty acids;  
 (B) C 3 -triol target esters of fatty acids; and,  
 (C) mixtures of (i)(A) and (i)(B); and,  
 
 (ii) contaminating ester selected from the group consisting of: 
 (A) C 3 -diol contaminating esters of fatty acids;  
 (B) C 3 -triol contaminating esters of fatty acids; and,  
 (C) mixtures of (ii)(A) and (ii)(B);  
 
   (b) extracting the crude ester composition of step (a) with an aqueous alcohol phase to selectively extract, into an extractant phase, a first one of: 
 (i) selected target ester; and,  
 (ii) selected contaminating ester;  
 relative to a second one of:  
 (iii) selected target ester; and,  
 (iv) selected contaminating ester;  
   (c) treating the extractant phase from step (b) with a crude triglyceride phase to form: 
 (i) a purified extractant phase; and,  
 (ii) a triglyceride phase; and,  
   (d) separating the purified extractant phase resulting from step (c) from the triglyceride phase resulting from step (c).    
     
     
         2 . A method according to  claim 1  wherein: 
 (a) said step of providing a crude ester composition comprises providing a crude ester composition containing: 
 (i) monoglyceride as the target ester; and,  
 (ii) a mixture of triglycerides and diglycerides as contaminating ester;  
 
 (b) said step of extracting comprises preferentially extracting target ester into said extractant phase, relative to crude contaminating ester; and,  
 (c) said step of treating comprises reducing a diglyceride presence in the extractant phase, relative to monoglyceride presence.  
 
     
     
         3 . A method according to  claim 2  wherein: 
 (a) said step of providing a crude ester composition includes providing a crude ester composition comprising: 
 (i) at least 20%, and no more than 70%, monoglyceride, by wt., based on a total weight of monoglycerides, diglycerides and triglycerides, in the crude ester composition; and,  
 (ii) at least 15%, by wt., diglycerides, based on a total weight of monoglycerides, diglycerides and triglycerides in the crude monoester composition; and,  
 
 (b) said steps of extracting, treating and isolating are conducted sufficiently to provide a purified extractant phase having: 
 (i) a monoglyceride presence of no less than 90%, by wt., based on a total wt. of monoglycerides, diglycerides and triglycerides in the purified extractant phase; and,  
 (ii) a diglyceride to triglyceride weight ratio of no greater than 1:1.  
 
 
     
     
         4 . A method according to  claim 3  including a step of: 
 (a) adding a crude triglyceride mixture to the crude ester composition prior to said step of extracting; said step of adding a crude triglyceride being conducted such that the resulting composition contains more triglycerides than diglycerides, by weight.  
 
     
     
         5 . A method according to  claim 3  wherein: 
 (a) said step of providing a crude ester composition includes providing a crude ester composition comprising at least 30%, by wt., of monoglycerides and at least 25%, by wt., of diglycerides, based on total weight of monoglycerides, diglycerides and triglycerides in the crude monoester composition.  
 
     
     
         6 . A method according to  claim 4  wherein: 
 (a) said step of extracting with an aqueous alcohol extractant comprises extracting with extractant containing: 60% to 90% ethanol, by weight; and, 10% to 40% water, by weight.  
 
     
     
         7 . A method according to  claim 6  wherein: 
 (a) said step of extracting comprises conducting a multi-stage, counter-current extraction.  
 
     
     
         8 . A method according to  claim 7  wherein: 
 (a) said steps of treating and separating together comprise conducting a multi-stage counter-current wash of the extractant phase with crude triglyceride.  
 
     
     
         9 . A method according to  claim 8  wherein: 
 (a) said step 4(a) of adding a crude triglyceride mixture to the crude ester composition comprises adding, as the crude triglyceride mixture, a triglyceride-containing phase from said step of conducting a multi-stage, counter-current wash.  
 
     
     
         10 . A method according to  claim 9  including a step of: 
 (a) isolating a purified monoglyceride product from the purified extractant phase.  
 
     
     
         11 . A method according to  claim 10  further including a step of: 
 (a) incorporating an emulsifying effective amount of the purified monoglyceride product into a margarine composition.  
 
     
     
         12 . A method according to  claim 10  further including a step of: 
 (a) incorporating an emulsifying effective amount of the purified monoglyceride product into a shortening composition.  
 
     
     
         13 . A method according to  claim 10  including a step of: 
 (a) modifying the purified monoglyceride product to a derivative selected from the group consisting of: acetylated monoglycerides; citric acid esters of monoglycerides; sodium salts of citric acid esters of monoglycerides; and lactic acid esters monoglycerides.  
 
     
     
         14 . A method according to  claim 1  wherein: 
 (a) said step of providing a crude ester composition comprises providing a crude ester composition containing: 
 (i) diglyceride as target ester; and,  
 (ii) a mixture of monoglycerides and triglycerides as contaminating ester; and,  
 
 (b) said step of extracting comprises selectively extracting monoglyceride contaminating ester into the extractant, relative to diglyceride target ester.  
 
     
     
         15 . A method according to  claim 14  including steps of: 
 (a) separating the extractant phase from step (1) (b) from a phase containing diglycerides and triglycerides.  
 
     
     
         16 . A method according to  claim 15  including a step of: 
 (a) selectively extracting, relative to triglycerides, diglycerides from the phase resulting from step 15(a) into an aqueous alcohol extractant phase.  
 
     
     
         17 . A method according to  claim 15  including a step of: 
 (a) incorporating an effective amount of a resulting purified diglyceride composition into shortening.  
 
     
     
         18 . A method according to  claim 1  wherein: 
 (a) said step of providing a crude ester composition comprises providing a crude ester composition containing: 
 (i) propylene glycol monoester as target ester;  
 (ii) monoglycerides; and,  
 (iii) a mixture of triglycerides and diglycerides as contaminating ester;  
 
 (b) said step of extracting comprises preferentially extracting target ester and monoglycerides into said extractant phase, relative to contaminating ester; and,  
 (c) said step of treating comprises reducing a diglyceride presence in the extractant phase, relative to monoglyceride presence.  
 
     
     
         19 . A method according to  claim 1  wherein: 
 (a) said step of providing a crude ester composition comprises providing a crude composition containing: 
 (i) propylene glycol monoester as target ester; and,  
 (ii) mixture of monoglycerides, diglycerides and triglycerides as contaminating ester;  
 
 (b) said step 1(b) of extracting comprises preferentially extracting monoglycerides into said extractant phase, relative to a triglyceride phase containing propylene glycol monoester, diglycerides and triglycerides;  
 (c) said method further including: 
 (i) a step of extracting the triglyceride phase from step 1(d) with an aqueous alcohol extractant to selectively extract propylene glycol from a triglyceride phase containing triglycerides and diglycerides; and,  
 (ii) a step of washing the extractant phase from step 19(c)(i) with crude triglycerides to form a purified propylene glycol monoester phase; and,  
 (iii) a step of isolating a purified propylene glycol monoester product from the purified propylene glycol monoester phase of step 19(c) (ii).  
 
 
     
     
         20 . A method according to  claim 19  including a step of: 
 (a) incorporating an aerating effective amount of the purified propylene glycol monoester from step 19(c)(iii) into a food mix.  
 
     
     
         21 . A method according to  claim 1  wherein: 
 (a) said step of providing a crude ester composition comprises providing a crude ester composition including citric acid esters of monoglyceride as the C 3 -diol target ester.  
 
     
     
         22 . A method of preparing a purified diglyceride food composition from a crude ester composition containing monoglycerides, diglycerides and triglycerides; said method including the steps of: 
 (a) providing a crude ester composition containing at least four times as much diglycerides as triglycerides, by wt.;    (b) extracting the crude ester composition of step (a) with an aqueous alcohol phase tuned to selectively extract, into the extractant phase, monoglycerides, to form: 
 (i) an extractant phase; and,  
 (ii) a diglycerides phase; and,  
   (c) separating the extractant phase and diglycerides phases from step 21(b);    (d) said step of extracting being conducted sufficiently to extract at least 90%, by wt., of monoglycerides in the crude ester composition without extracting more than 20%, by wt., of the diglycerides.    
     
     
         23 . A method according to  claim 21  including a step of: 
 (a) incorporating an effective amount of a resulting purified diglyceride composition into shortening.