Method for extracting cocoa procyanidins

Abstract

A cocoa extract which is rich in procyanidin monomers and oligomers is made by extracting de-fatted, unroasted, unfermented cocoa beans with organic solvents. The yield of procyanidins in an extract varies with type of solvent used, reaction temperature, reaction pH and whether or not the solvent is an aqueous solution. Extraction parameters can be optimized to increase procyanidin yield, and different conditions result in the preferential extraction of the higher or lower oligomers. A preferred extraction method is counter-current extraction method.

What is claimed is:  
     
         1 . An improved method for extracting cocoa polyphenols including cocoa procyanidins from partially or fully defatted cocoa solids, prepared from cocoa beans that have not been roasted, which method comprises a single extraction, at atmospheric pressure or under pressure, with a solvent selected from the group consisting of an organic solvent capable of solubilizing the cocoa polyphenols, or aqueous mixtures thereof, to which solvent or aqueous-solvent mixture is added an edible acid in an amount sufficient to lower the pH to about 2 to about 4.  
     
     
         2 . The method of  claim 1 , wherein the cocoa solids are prepared from unfermented or underfermented cocoa beans and wherein the organic solvent is selected from the group consisting of methanol, ethanol, isopropanol, acetone, methyl acetate, or ethyl acetate and wherein the aqueous solvent mixture contains up to about 50% water by volume.  
     
     
         3 . The method of  claim 2 , wherein the aqueous-solvent mixture is a mixture of isopropanol and about 50-70% water.  
     
     
         4 . The method of  claim 2 , wherein the aqueous-solvent mixture is a mixture of isopropanol and about 20% water.  
     
     
         5 . The method of  claim 4 , whereby the monomers and oligomers up to and including hexamers are preferentially extracted.  
     
     
         6 . The method of  claim 2 , wherein the aqueous-solvent mixture is a mixture of acetone and about 80% to about 100% water.  
     
     
         7 . The method of  claim 2 , wherein the aqueous-solvent mixture is a mixture of acetone and about 50% to about 70% water.  
     
     
         8 . The method of  claim 2 , wherein the organic solvent is ethanol.  
     
     
         9 . The method of  claim 8 , whereby the extraction of cocoa procyanidin oligomers higher than the heptamers is enhanced.  
     
     
         10 . A method of extracting cocoa polyphenols including cocoa procyanidin monomers and oligomers from partially defatted or fully defatted cocoa solids, prepared from cocoa beans that have not been roasted, comprises the step of extracting the cocoa solids, at atmospheric or under pressure, with a non-acidified organic solvent capable of solubilizing cocoa polyphenols or non-acidified aqueous mixtures thereof.  
     
     
         11 . The method of  claim 10 , wherein the cocoa beans are unfermented or underfermented cocoa beans.  
     
     
         12 . The method of  claim 2  or  11 , wherein the cocoa beans have a fermentation factor of 275 or less.  
     
     
         13 . The method of  claim 2  or  11  wherein the cocoa beans are slaty, purple, or purple brown cocoa beans, or mixtures of slaty and purple cocoa beans, purple and brown cocoa beans, or slaty, purple and brown cocoa beans.  
     
     
         14 . The method of  claim 2  or  11 , wherein the unfermented or underfermented cocoa beans contain at least about 1% up to about 15% by weight of total cocoa procyanidins per gram of defatted cocoa solids.  
     
     
         15 . The method of  claim 14 , wherein the weight of the total cocoa procyanidins is about 4-7%.  
     
     
         16 . The method of  claim 10 , wherein the organic solvent is methanol, ethanol, isopropanol, acetone, methyl acetate, or ethyl acetate and wherein the aqueous mixture contains up to 50% water.  
     
     
         17 . The method of  claim 10 , wherein the solvent is about 50 to about 70% acetone or about 95 -100%.  
     
     
         18 . The method of  claim 1  or  10 , wherein the extraction is carried out at a temperature of from 0° C. up to the boiling point of the solvent or aqueous solvent used.  
     
     
         19 . The method of  claim 10 , wherein the solvent is methanol and wherein the extraction is carried out at room temperature, wherein the solvent is ethanol and the extraction is carried out at about 20° to about 50° C., or wherein the solvent is isopropanol and the extraction is carried out at about 70° C.  
     
     
         20 . The method of  claim 10 , wherein the solvent is an aqueous acetone mixture and wherein the extraction is carried out at about 50° C. up to the boiling point of the mixture at the extraction pressure used.  
     
     
         21 . A method for selectively extracting low molecular weight cocoa procyanidin oligomers from partially or fully defatted cocoa solids, prepared from cocoa beans that have not been roasted, which method comprises the step of extracting, at atmospheric pressure or under pressure, the cocoa solids with methyl acetate or ethyl acetate.  
     
     
         22 . The method of  claim 21 , wherein the cocoa beans are unfermented or underfermented cocoa beans and wherein the extraction is carried out at about 20° C. to about 50° C.  
     
     
         23 . The method of  claim 22 , wherein the lower oligomers consist essentially of the monomers, dimers, and trimers.  
     
     
         24 . A cocoa extract prepared by the process of  claim 22 .  
     
     
         25 . A cocoa extract consisting essentially of procyanidin monomers, dimers, and trimers.  
     
     
         26 . A method for selectively extracting higher molecular weight cocoa procyanidin oligomers from partially defatted or fully defatted cocoa solids, prepared from cocoa beans that have not been roasted, which method comprises the steps of (a) extracting, at atmospheric pressure or under pressure, the cocoa solids with ethyl acetate; (b) recovering the extracted cocoa solids; (c) extracting the recovered extracted cocoa solids with a solvent selected from the group consisting of acetone and ethanol and mixtures there of with up to 50% water, which solvent is optionally acidified to a pH of about 2 to about 4 with an edible acid; (d) separating the cocoa solids from the cocoa extract; and (e) optionally drying the cocoa extract.  
     
     
         27 . The method of  claim 26 , wherein the cocoa beans are unfermented or underfermented.  
     
     
         28 . The method of  claim 27 , wherein the extraction is carried out at about 20° C. to about 50° C.  
     
     
         29 . The method of  claim 26 , wherein the higher oligomers include at least tetramers and above.  
     
     
         30 . A cocoa extract prepared by the process of  claim 27 .  
     
     
         31 . A cocoa extract consisting essentially of cocoa procyanidin tetramers through at least decamers.  
     
     
         32 . A continuous method for extracting cocoa polyphenols including cocoa procyanidins from partially defatted or fully defatted cocoa solids using an organic solvent suitable for solubilizing cocoa procyanidins, or mixtures thereof with water, which comprises the steps of (a) contacting a series of cells containing the cocoa solids with the solvent flowing in a counter-current direction, (b) recovering the cocoa extract, and (c) drying the cocoa extract.  
     
     
         33 . The process of  claim 32 , wherein the cocoa beans are unfermented or underfermented cocoa beans.  
     
     
         34 . The process of  claim 32 , wherein the process is carried out under pressure.  
     
     
         35 . The process of  claim 32 , wherein the solvent is a lower alkyl alcohol, a lower alkyl ketone, or a lower alkyl acetate.  
     
     
         36 . The process of  claim 33 , wherein the lower alkyl alcohol is methanol, ethanol, or isopropanol, the lower alkyl ketone is acetone, and the lower alkyl acetate is methyl acetate or ethyl acetate.  
     
     
         37 . The process of  claim 32 , wherein the cocoa extract is recycled until substantially no more cocoa procyanidins are extracted from the cocoa solids.  
     
     
         38 . The process of  claim 32 , wherein the solvent is the organic solvent and the extract is ried by flashing off the solvent.  
     
     
         39 . The process of  claim 32 , wherein the solvent is the aqueous-organic mixture and the extract is dried by flashing off the solvent before drying the aqueous extract.  
     
     
         40 . The process of  claim 32 , wherein the drying of the aqueous extract is carried out by freeze drying, spray drying, flash drying, or drum drying.  
     
     
         41 . A method for recovering cocoa procyanidins and theobromine from partially defatted or fully defatted cocoa solids, prepared from unroasted cocoa beans, comprises the steps of (a) extracting the cocoa solids with ethanol at about 50° to about 70° C., (b) chilling the ethanol extract at a temperature and for a time sufficient to precipitate out the theobromine, (c) separating the precipitated out theobromine, and (d) removing the ethanol from extract to recover the dried cocoa procyanidins.  
     
     
         42 . A method of minimizing the amount of theobromine in the cocoa procyanidins extracted from partially defatted or fully defatted cocoa solids, prepared from unroasted cocoa beans, comprises the steps of (a) extracting the cocoa solids with isopropanol to produce an alcoholic extract containing cocoa procyanidins and theobromine, (b) chilling the alcoholic extract at a temperature and for a time sufficient to precipitate out the theobromine, and (c) separating the theobromine from the alcoholic extract.  
     
     
         43 . The method of  claim 41  or  42 , wherein the chilling is carried out for about 1 hour to about 12 hours at 0° to about 5° C.  
     
     
         44 . The method of  claim 41  or  42 , wherein the separating step is carried out by filtering the extract, centrifuging, the extract, or by an adsorbing the theobromine on a substrate.