Phospholipid compositions and their preparation

Abstract

The invention provides improved processes for extracting and preparing polar lipids (in particular, desirable phospholipids) from krill and other biological sources. The inventors have discovered processes through which it is possible to extract phospholipids to give high phospholipid content and a reduction of undesired components.

1 . A process for preparing a composition which is rich in polar lipids from a biological material containing those lipids, comprising steps of:
 (a) mixing the biological material with a first solvent system in which the polar lipids are soluble, thereby preferentially extracting the polar lipids into a liquid phase of a slurry;   (b) washing the biological material with a second solvent system in which the polar lipids are poorly soluble; and   (c) mixing the extracted and washed material from steps (a) and (b) with a third solvent system which partitions neutral lipids and polar lipids,   
       wherein steps (a) and (b) can be performed in either order before step (c), and wherein the solvent systems include organic solvent component(s) selected from the group consisting of: water, acetic acid, heptane, acetone, isobutyl acetate, anisole, isopropyl acetate, 1-butanol, methyl acetate, 2-butanol, 3-methyl-1-butanol, butyl acetate, methylethyl ketone, tert-butylmethyl ether, methylisobutyl ketone, cumene, 2-methyl-1-propanol, dimethyl sulfoxide, pentane, ethanol, 1-pentanol, ethyl acetate, 1-propanol, ethyl ether, 2-propanol, ethyl formate, propyl acetate, and formic acid. 
     
     
         2 . The process of  claim 1 , wherein step (a) is performed before step (b). 
     
     
         3 . The process of  claim 1 , wherein the process uses only two different organic solvent components. 
     
     
         4 . The process of  claim 3 , wherein the only organic solvent components used in the process are (i) an alcohol and (ii) a ketone or an ester. 
     
     
         5 . The process of  claim 4 , wherein the alcohol is ethanol, the ketone is acetone, and the ester is ethyl acetate. 
     
     
         6 . The process of  claim 1  comprising steps of: (a) mixing krill material with ethanol to extract phospholipids into a liquid phase of a slurry; (b) washing phospholipids extracted in step (a) with an aqueous solution of ethanol in which the phospholipids are poorly soluble, to provide a precipitate which includes the phospholipids; and (c) dissolving and re-precipitating the washed phospholipids from step (b) using acetone, to separate the phospholipids from neutral lipids. 
     
     
         7 . The process of  claim 6 , comprising the further step of: (d) removing residual acetone and ethanol from the composition and/or removing residual water from the composition. 
     
     
         8 . A process for preparing phospholipids from krill material containing those phospholipids, wherein the process uses a plurality of solvent systems to provide a composition in which the phospholipids form at least 90% by weight of the composition, and wherein each of the solvent systems consists of solvent components selected from the group consisting of acetic acid, heptane, acetone, isobutyl acetate, anisole, isopropyl acetate, 1-butanol, methyl acetate, 2-butanol, 3-methyl-1-butanol, butyl acetate, methylethyl ketone, tert-butylmethyl ether, methylisobutyl ketone, cumene, 2-methyl-1-propanol, dimethyl sulfoxide, pentane, ethanol, 1-pentanol, ethyl acetate, 1-propanol, ethyl ether, 2-propanol, ethyl formate, propyl acetate, formic acid, and water. 
     
     
         9 . The process of  claim 8 , wherein each of the solvent systems consists of solvent components selected from the group consisting of ethanol, acetone, and water. 
     
     
         10 . The process of  claim 8 , wherein krill phospholipids make up at least 95% by weight of the composition.