JPH084458B2 - Method of removing methylxanthine from cocoa material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION For some time, cacao beans contain a small amount of caffeine (1,3,7trimethylxanthine) and a significant amount of theobromine (3,7dimethylxanthine). Was known. This relationship is dependent on the particular type of cocoa cocoa and varies from a ratio of theobromine to caffeine of about 2 to 1 to a ratio of theobromine to caffeine of about 10 to 1. Furthermore, theobromine was found to be about 100 times less water soluble than caffeine. Therefore,
Efficient removal of these methylxanthines from cocoa must primarily address methods of removing the majority of the relatively insoluble theobromine and at the same time removing the relatively lesser amount of the more soluble caffeine. The present invention
Cocoa cocoa or cocoa beans (cacao nib) that removes methylxanthine consisting of theobromine and caffeine
It is aimed at an improved processing method of. Such xanthines are members of a broad chemical class known as purines. The purine system is composed of imidazole and pyrimidine rings fused together. The rings of the purine molecule are numbered starting from the nitrogen atom in the upper left corner of the pyrimidine ring, proceeding counterclockwise to the 6th position (counterclockwise) and then from the 5th position of the pyrimidine Turn clockwise 7 and 8 in the imidazole ring
And 9 positions are given. Dihydroxypurine is known as xanthine and is numbered in the same way. This nomenclature system is used throughout this specification.

Various methods have been previously proposed to achieve such removal of methylxanthine from cocoa materials. One such conventional method involves extraction of these methylxanthines by using a chlorinated hydrocarbon solvent such as chloroform, ethylene dichloride or tetrachloroethane. Such a solvent extraction method is described in U.S. Pat. No. 1,073,44.
No. 1, No. 1,855,026 and No. 1,925,326. However, the use of such extraction solvents is discouraged, especially when food is involved. This is because residues of these solvents are not desirable in food products. Another method of removing theobromine from cocoa beans involves extracting with water and then aliquoting this aqueous extract with an adsorbent. Although this method does not involve the use of unfavorable chemicals, such as chlorinated hydrocarbon solvents, it does have the difficulties associated with the use of such adsorbents which adversely affect the taste of the final depurinated cocoa product. There is. Moreover, the rate of removal of theobromine is limited.

Yet another conventional method of extracting methylxanthine from a cocoa material is a cocoa material swollen by treatment with a relatively small amount of water, a food-acceptable solvent gas,
For example, comprising contacting with supercritical nitrous oxide or carbon dioxide. However, this method requires long processing times and often does not achieve a sufficient percentage reduction of theobromine content. Furthermore, removal of methylxanthine from supercritical gases presents a problem, as is usually the case when reuse of supercritical gases is desired.

Yet another method of removing caffeine from coffee is disclosed in US Pat. No. 4,474,821 as a countercurrent extraction method using multiple extraction vessels in a countercurrent operation. However, in the method of this patent, an extraction solvent consisting of ethyl acetate and water is used and the ethyl acetate-water azeotrope is finally removed by differential pressure steam stripping. In the method of this patent, a turbulent flow of extraction solvent is used to obtain an accelerated decaffeination rate, which reduces caffeine extraction time. This conventional method, like other extraction methods using organic solvents, has the disadvantage that most of the product or water extract requires exposure to the solvent.

DESCRIPTION OF THE INVENTION The present invention is a substance present in cocoa materials that does not use any process that adversely affects the depurinated end product and minimizes the amount of end product exposed to organic solvents. The present invention is directed to a method of removing all methylxanthines. The present inventors have found that about 40 ° C
We have found that extraction of cocoa material with water heated to a temperature in the range of about 60 ° C does not remove all of the methylxanthines present in the cocoa material, even after repeated such water extractions. . This is especially the case for theobromine removal, the residual theobromine not being removed being of the order of 1% to 3%.
However, we have found that after one or more extraction steps with water at about 45 ° C to about 55 ° C, about 90 ° C to about 105 ° C.
It has been found that greatly improved theobromine removal is achieved when several extraction steps with water at ° C are carried out. We use such a low temperature water extraction followed by a sequence of significantly higher temperature water extraction steps, resulting in a much higher percentage than would be obtained when using either of these extraction temperatures alone. It has been found that all theobromine removal can be obtained. Obviously, about 45 ℃ ~ 55 ℃
The water extraction with the cocoa bean mixture content is such that the subsequent successive water extraction steps at about 90 ° C to about 105 ° C remove residual theobromine that was not previously removed at either temperature alone. And perhaps change the structure. Not all theobromine is removed when a continuous hot extraction step is used without first performing a cold extraction. Similarly, not all of theobromine is removed using low temperature extraction without subsequent sequential high temperature extraction steps. This surprising and unexpected result is shown in Tables 1 and 2 based on data obtained from water extraction of cocoa beans using various temperatures and multiple extraction steps. The data in these tables were used in making the curves in Figures 2 and 3 of the drawings, which form a part of this specification.

The data shown in Tables 1 and 2 were obtained as follows.

Example 1 Four sets of 450 g each of raw, screened and degerminated cocoa beans obtained from a bag of uniform populations were prepared. For each set, the beans were placed in a 100 mesh stainless steel cylindrical filter tube, which was then placed in a jacketed stainless steel extraction sump maintained at a constant temperature by an external circulating water bath. Add 1400 ml of water to the extraction reservoir and use a recirculation pump operating at a speed of about 500 ml per minute for 20 minutes to recirculate the water from bottom to top of the extractor to continuously stir the water in the cocoa beans. did. After the first extraction, seven more extractions were carried out, each time adding 1100 ml of water to restore the initial volume of liquid in these extractions. Each of the four sets had a specific purpose, as will be seen below.

Four extraction sets were performed as follows: 1-a In the first set, all eight extractions were performed.
It was carried out at 55 ° C.

1-b In the second set, all eight extractions
It was carried out at 95 ° C.

1-c In the third set, three extractions were performed at 55 ° C, followed by five extractions at 95 ° C.

1-d In the fourth set, three extractions were performed at 55 ° C, followed by five extractions at 105 ° C. (The extractor was kept at a suitable positive pressure to achieve a temperature of 105 ° C.) The results of these four extraction methods are shown in Table 1.

The meaning of the above results is clear when examining the curves shown in FIG. The 55 ° C. curve shows a uniform increase in the cumulative amount of theobromine extracted, the curve ending well below the dashed line after eight extractions. This dashed line is the standard AO
It represents the theoretical amount of theobromine obtained using the AC analysis method. The 95 ° C curve becomes significantly flatter after four extractions 8
After the extraction of the number of times, it ends substantially at the level of the broken line. However, the curve marked 55 ° C at the lower end and 55 ° C + 95 ° C at the upper end ends well above the dashed line, at 3
It is shown that there is a substantial increase in theobromine removal when 5 extractions are performed after 95 extractions.

Example 2 The procedure of Example 1 was repeated for the three extraction sets and the three extraction sets were carried out as follows: 2-a In the first set, 95 ° C after one extraction at 55 ° C. The extraction was performed 7 times.

2-b In the second set, two extractions were performed at 55 ° C followed by six extractions at 95 ° C.

2-c In the third set, extraction was performed 3 times at 55 ° C and then 5 times at 95 ° C.

The extraction times are 1 and 7 times, or 2 and 6 times.
It can be said that the results are comparable for one, or three and five. Acceptable results are obtained if the initial extraction temperature is not higher than about 55 ° C and not lower than about 45 ° C.

Example 3 The procedure of Example 1 was repeated for the seven extraction sets and the seven extraction sets were carried out as follows: 3-a In the first set, three extractions at 40 ° C followed by 95 ° C were performed. The extraction was performed 5 times.

3-b In the second set, extraction was performed 3 times at 50 ° C and then 5 times at 95 ° C.

3-c In the third set, extraction was performed 3 times at 55 ° C and then 5 times at 95 ° C.

3-d In the fourth set, three extractions were performed at 60 ° C followed by five extractions at 95 ° C.

3-e In the fifth set, three extractions were performed at 70 ° C followed by five extractions at 95 ° C.

In the 3-f sixth set, three extractions were performed at 80 ° C followed by five extractions at 95 ° C.

In the 3-g seventh set, each extraction was carried out eight times at 95 ° C.

 The results of these seven extraction methods are shown in Table 3.

The meaning of the above results is clear when examining the curves shown in FIG. In FIG. 3, each plotted point is marked with a g number indicating the cumulative amount of extracted theobromine. The temperature of each curve is also displayed. Two temperatures are shown for each except the 95 ° C curve. The first temperature applies to the lower part of the particular curve (three extractions),
And the second temperature applies to the upper part (5 additional extractions). This experiment shows that the initial temperature is 50 ° C ± 5
The maximum extraction occurs at ° C.

Preferred Conditions for Carrying Out the Invention Convenient starting points for carrying out the method of the invention (10)
(Figure 1), using well-known standard procedures,
It consists of preparing a large amount of raw cocoa beans obtained from cacao cocoa. Practically speaking, the method of the present invention separates substantially all water-soluble materials, including caffeine and theobromine, from the original raw cocoa beans, thereby extracting an aqueous extract of cocoa beans and a large amount of wet cocoa. It consists of a series of water extraction steps to produce beans. This water extraction is carried out by successive steps at two completely different temperatures: (1) beans are first extracted with water at about 45 ° C to about 55 ° C. (2) This is followed by extraction with water at about 90 ° C to about 105 ° C about 4 to 5 times. After each extraction, substantially all the liquid is drained from the extraction vessel and then water is added.

The moist cocoa beans (27) remaining after the water extraction step, from which substantially all of the methylxanthine and most of the water-soluble materials have been removed, are gradually dried (28). After the water content in the beans reaches a point below about 4%, the beans are stored and finally ground (29) to obtain the product known as raw cocoa mass (30). Re-grind this mass to obtain a pumpable liquid. This reground cocoa mass (3
1) is ready to be blended with the solids of the water soluble material (26) originally extracted from the beans.

The water extract obtained from the extraction process is filtered by a filter press (13) or centrifugal clarifier to remove small particles. The filtered extract is then subjected to an ultrafiltration step (14) with a separation membrane having a cutoff molecular weight of about 10,000 or about 20,000. The filtrate (15) from this membrane contains more than 97% of the water originally present in the water extract and contains caffeine, theobromine and molecules below the cut-off value of the membrane. The remaining material is an ultrafiltration retentate (23) containing soluble cocoa material with a molecular weight greater than 20,000.
Water is only 3% of its original volume and contains very small amounts of caffeine and theobromine.

The small amounts of the two major methylxanthines remaining in the residue, namely dimethylxanthine and trimethylxanthine, are carried out by adding an equal volume (first 3%) of water to the residue (diafiltration ( 24) minimized. Then another equal volume of water is added and the process of diafiltration (24) is repeated at least 4 times. The filtrate from the diafiltration step is added to the main filtrate (15). The final volume of filtrate is about 109-115% of the initial volume of extract. about
The residue, which contains 10% cocoa solids, is approximately
Concentrate in evaporator until reduced to 1/2 or 1/3 volume. This solution, called the final UF residue (25), is more ready for processing.

The material remaining after the filtration step (15) contains water-soluble substances having a molecular weight of less than 20,000 and is subjected to a concentration process (16). In this concentration process (16),
At least 80% of the water contained is removed by reverse osmosis, a well-known physical method commercially available for solid concentration and desalination of seawater. The concentrated filtrate (17) containing caffeine, theobromine, cocoa solids and water-soluble low molecular weight substances is subjected to countercurrent extraction (18) with methylene chloride. This countercurrent extraction is based on the partition coefficient of the two methylxanthines between water and methylene chloride. The methylene chloride is recirculated and redistilled at a constant rate, utilizing the specific gravity of the methylene chloride solvent to circulate through the distribution column from top to bottom. The distribution column used in the countercurrent extraction process is maintained at a temperature of about 30 ° C to about 38 ° C. The concentrated filtrate is pumped from the bottom into the distribution column at a rate equal to the distillation rate of methylene chloride. In order to obtain better than 97% removal of caffeine, 6 volumes of methylene chloride must be redistilled for each volume of concentrated filtrate, but for theobromine extraction 18% for the same efficiency. Needs capacity. This result can be obtained by increasing the number of reactive columns in series, by recycling the concentrated filtrate in the same column as needed, or by proportionally reducing the concentrated filtrate flow rate. .

The concentrated filtrate obtained from the countercurrent extraction is here in the form of the fraction in which the methylxanthines have been extracted. Caffeine and theobromine (19) are recovered in high purity from the evaporator after the methylene chloride extraction step. The methylxanthine extracted fraction (20) is then evaporated under reduced pressure to remove substantially all of the small residual amount of solvent. Solid content is about 10
Continue evaporation until volume% is reached. This concentrated material is called the final filtrate (21).

The final filtrate and final UF residue (25) are now combined (22). The combined final solution is then subjected to normal drying techniques,
Dry (26), for example by freeze-drying or spray-drying. The powder thus obtained is added to the reground milled cocoa mass (31) and then roasted in a cocoa mash roaster (32) of known design.

The second alternative is to concentrate the combined final solution (22) and inject it directly into the cocoa mass reactor. The solution is added in several steps to evaporate the water before roasting the entire cocoa mass in the same reactor. Roasted cocoa mass has quality, flavor and sensory (fonctionalit
In y), it is equivalent to normal cocoa liquor, but substantially free of xanthine stimulants, especially theobromine.

The above overall process description is provided to illustrate one method of using the multi-stage extraction process of the present invention.

[Brief description of drawings]

FIG. 1 is a flow chart showing one method for carrying out the method of the present invention. FIG. 2 is a graph of the data shown in Table 1. Low temperature extraction and high temperature extraction are performed by taking the number of extractions on the abscissa of the Cartesian coordinates and the amount of theobromine extracted on the ordinate. FIG. 4 is a diagram consisting of a series of curves showing extraction with combined cold and hot temperatures. The temperature that fits each curve is indicated by a leader line. FIG. 3 is a graphical representation of the data shown in Table 3 and is a series of curves showing the effect of two temperature extraction systems operating at various initial stage temperatures. In Figure 1, 10 ... cacao beans, 11 ... water extraction, 33 ... cacao liquid.

Claims (7)

[Claims] 1. A method for removing theobromine and caffeine from cocoa beans, which comprises removing cocoa beans from about 45 ° C to about 55 ° C.
About 90 ℃ ~ following the process of low temperature water extraction at the temperature of
Comprising a series of hot water extraction steps at a temperature of 105 ° C., removing the extraction filtrate and then recovering a cocoa liquor substantially free of theobromine and caffeine from the cocoa mass thus obtained. Method. 2. The method according to claim 1, further comprising at least one water extraction step by low temperature set extraction and at least three water extraction steps by high temperature set extraction. the method of. 3. A process according to claim 2 further characterized in that the cold extraction is carried out at about 55 ° C and the hot extraction step is carried out at about 95 ° C. 4. A step of subjecting the removed extraction filtrate to ultrafiltration and diafiltration to obtain an ultrafiltration residue, and a cocoa liquor in which theobromine and caffeine are extracted from cocoa mass. A process according to claim 1, characterized in that the residue is added to the cocoa mass before recovery. 5. A step of removing methylxanthine from the extraction filtrate and a step of removing the thus obtained methylxanthine-extracted fraction from the cocoa mass before the cocoa mass is treated with the cocoa mass. A method according to claim 1 characterized by the step of adding. 6. An extract obtained by subjecting the extract filtrate from the ultrafiltration and diafiltration steps to a concentration and countercurrent extraction step, and then extracting the methylxanthine from the cocoa mass before processing it into a cocoa liquor. A method according to claim 4, characterized in that the component is added to the cocoa mass. 7. The method according to claim 6, further comprising performing the concentration step by reverse osmosis.