Chocolate with improved and enriched aroma, and a process of its production

A raw material cacao for chocolate may be improved and enriched in its aroma, thereby providing a chocolate whose consumption results in increased mental concentration, and which has an improved cacao aroma and reduced sweetness. The chocolate of the invention is produced by using the improved and enriched cacao nibs produced by an alkali-treatment of cacao beans. The process for producing the chocolate using cacao nibs of improved and enriched aroma comprises removing shells and germs from raw or semi-roasted cacao beans to prepare cacao nibs, adding an alkali thereto and stirring for reaction thereof with the alkali, subsequently drying and roasting the same and finally grinding and pulverizing the alkali-treated cacao nibs to prepare a cacao mass to be used for producing the chocolate in the conventional way. The alkali is preferably calcium hydroxide.

BACKGROUND OF THE INVENTION 
The invention relates to a chocolate of reduced sweetness and to a process 
of producing the same, in which the flavor of main raw cacao material for 
the chocolate is improved to enrich the cacao. 
For the purpose of producing a chocolate, there have been neither ideas nor 
practices for treating the material cacao with alkali. Heretofore, the 
cacao has been treated with alkali for another purpose, that is merely to 
improve an aroma, color, dispersibility in water and the like of cocoa 
powder. 
Further, there have been several cases of the alkali-treatment of cacao 
other than production of cocoa powder. For example, an attempt of treating 
the cacao with an aqueous solution of weakly alkaline salt for the purpose 
of sterilization is disclosed in the Japanese Patent Publication No. 
291233/1990. An attempt of neutralizing organic acids with ammonia for the 
purpose of improvement in aroma of cacao beans of low grade is disclosed 
in the Japanese Patent Publication No. 56975/1986. An attempt of 
increasing water-dispersibility of chocolate for food materials used in a 
pudding or jelly is disclosed in the Japanese Patent Publication No. 
10094/1986. 
On the other hand, a roasting process of cacao in which an alkali, a 
reducing sugar, amino acids and tannin are added to a cacao mass or nibs 
of specified pH is disclosed in the Japanese Patent Publication No. 
31493/1978. According to this process, composition of raw cacao beans must 
be determined prior to adding a required amount of the above additives, 
resulting in a complicated process which cannot sufficiently improve the 
aroma of cacao. 
This prior art had different purposes from that of the present invention in 
which a further rich aroma may be extracted from cacao beans of high grade 
to increase cacao aroma and to produce a chocolate of reduced sweetness. 
Further, in the prior art neither convenient operation nor enough 
development of aroma may be achieved. 
SUMMARY OF THE INVENTION 
Accordingly, an object of the invention is to improve the aroma of a main 
raw cacao material for chocolate. Another object of the invention is to 
produce a chocolate of reduced sweetness having a richer aroma of the 
improved cacao. 
The above and other objects, features and advantages of the invention will 
be apparent from the following descriptions. 
In order to achieve the above objects, the invention provides a method of 
improving and enriching an aroma of cacao nibs useful for chocolate, which 
comprises treating the cacao nibs of raw or semi-roasted cacao beans with 
an alkali. 
Further, the invention provides a process for producing a chocolate using 
cacao nibs of improved and enriched aroma, which comprises removing shells 
and germs from raw or semi-roasted cacao beans to prepare cacao nibs, 
adding an alkali thereto and stirring for reaction thereof with the 
alkali, subsequently drying and roasting the same, and finally grinding 
and pulverizing the alkali-treated cacao nibs to prepare a cacao mass 
which is used for producing the chocolate in the conventional way. 
According to the invention, there is further provided a chocolate produced 
from the cacao nibs of improved and enriched aroma, which comprises the 
cacao mass prepared by the process as described in the above and other 
conventional raw materials for chocolate.

EMBODIMENTS 
In accordance with the invention, an alkali to be used for the 
alkali-treatment of said cacao-nibs may be potassium carbonate, sodium 
carbonate, potassium bicarbonate, sodium bicarbonate, ammonium hydroxide, 
ammonium carbonate, magnesium oxide, magnesium carbonate or the like. 
Calcium hydroxide is especially preferred, which has never been utilized 
for the alkali-treatment of cacao. 
Types, sizes and conditions of cacao beans to be used in the present 
invention, such as an extent of fermentation, a water content, an organic 
acid concentration and the like are not critical and may be every types of 
material cacaos for conventional chocolates. The present invention is not 
intended to improve a lower grade of cacao or worst beans of insufficient 
fermentation, but be intended to positively extract aroma of a higher 
grade of cacao. Better results may therefore be achieved with the higher 
grade of cacao beans. 
For the alkali-treatment of the cacao nibs, an amount of the alkali, 
particularly calcium hydroxide as added, may be in the range of from 0.2 
to 3.0% by weight relative to the cacao nibs preferably in the range of 
from 1.0 to 2.0% by weight. With an amount of lower than 0.2%, a 
sufficient effect of reducing a bad odor or developing a favorable aroma 
cannot be expected, while a strong alkali-odor may be developed with an 
amount of higher than 3.0%, resulting in disruption of aroma balance. 
The reaction of the alkali, particularly calcium hydroxide, with the cacao 
nibs is preferably carried out in the presence of water. The condition of 
reaction may be preferably at a temperature in the range of from 
40.degree. to 210.degree. C. and under a pressure in the range of from 1 
to 5 atm. In the course of the reaction, not only the nibs may simply be 
mixed with the alkali but also the reaction may advantageously be 
accelerated by applying pressure and temperature in the presence of water. 
After the alkali-treatment, the cacao nibs may be dried, roasted, ground 
and milled to produce a cacao mass in the conventional manner. Thereafter, 
a general process may be employed to produce chocolate. 
In accordance with the invention, it is critical that the alkali-treatment 
should be conducted before the roasting step. By performing the 
alkali-treatment before the roasting process the alkali may be reacted 
with a precursor of an aroma ingredient to generate an aroma during the 
roasting step and to maintain a favorable pH value for promoting the 
Maillard reaction, namely an aroma-developing mechanism. If the 
alkali-treatment is carried out after the roasting step to the contrary, 
the aroma ingredient itself is reacted with the alkali to change a good 
aroma generated in the roasting process into a different flavor due to the 
alkali-treatment, so that the better cacao aroma and the enhancement of 
mental concentration cannot be achieved. 
In accordance with the present invention, the raw material cacao for 
chocolate may be improved and enriched in its aroma, thereby providing the 
chocolate with the increased mental concentration and the improved cacao 
aroma. This fact is supposed to occur because the alkali, particularly 
calcium hydroxide, causes a hemicellulose, which constitutes a tissue of 
cacao beans as well as a protein and a starch to hydrolyze accompanied 
with the precursor of aroma such as amino acids and sugars being released, 
resulting in an increased amount of the aroma. 
The use of the cacao beans thus alkali-treated in the chocolate may 
increase the aroma ingredient of cacao and decrease an unfavorable odor, 
thereby producing a superior chocolate with reduced sweetness and higher 
preference. 
Further, it has been found from the results of experiments that the 
improved and enriched flavor contributes to the enhancement of mental 
concentration. Consequently, the chocolate produced by using the cacao 
nibs with the improved and enriched aroma may increase its mental 
concentrating effect. 
In accordance with the present invention, the raw material cacao for 
chocolate may be improved and enriched in its aroma, thereby providing the 
chocolate with the increased mental concentration, the improved cacao 
aroma and the reduced sweetness. The chocolate produced by using the cacao 
nibs with the improved and enriched aroma can increase its mental 
concentrating effect. 
(Example 1: Production of Cacao Nibs Treated with Calcium Hydroxide) 
Cacao nibs were added with 1.5% of calcium hydroxide to be stirred at 
130.degree. C. under 1 atm for 20 minutes for subsequent dry and roast 
treatments to produce the cacao nibs treated with calcium hydroxide. 
(Experiment 1) 
The chocolate according to the invention is characterized by the enriched 
favorable aroma together with the reduced bad odor as compared with the 
conventional type of chocolate. In fact, a result of gas-chromatographic 
analysis for the cacao mass treated with alkali with respect to Example 1 
as compared with untreated cacao mass is shown in FIG. 1. It has been 
found that a content of pyrazine or aroma ingredient of cacao was 
increased more than doubly, while a content of volatile organic acids or 
origin of the bad odor was suppressed to the level of about a quarter of 
that of the conventional type. 
(Example 2: Production of Chocolate Using Cacao Nibs Treated with Calcium 
Hydroxide) 
The cacao nibs prepared by the process of Example 1 was ground to form a 
cacao mass to be thoroughly mixed with sugar, a whole powder milk and a 
portion of cocoa butter, for roll-milling thereof and subsequent addition 
with the remaining cocoa butter, emulsifier and flavor and a further 
concinnating process so as to prepare a chocolate body to be finally 
shaped into a chocolate product. 
(Comparative Example 1) 
The process of Example 2 was repeated except for using the conventional 
ingredients instead of those in Example 2 to produce a chocolate product. 
(Experiment 2) 
A preference test of chocolate was carried out to two hundred panelists of 
high school girls with using the chocolates of Example 2 and Comparative 
Example 1 as samples. The results are shown in FIG. 2. 
As apparent from FIG. 2, the chocolate according to the invention was 
significantly preferred in view of the taste and aroma and had the reduced 
sweetness. 
(Experiment 3) 
An enhancing test of mental concentration for chocolate was carried out to 
a panel consisting of twenty university students with using the chocolates 
of Example 2 and Comparative Example 1 as samples. 
The term "mental concentration" means one of significant psychological 
effects for improving efficiencies of study and working. A degree of the 
mental concentration may be determined by a brain wave such as 
.alpha.-wave at its time point. As shown in FIG. 3, such brain wave may be 
measured by a micro-electric current generated at the brain activity with 
using electrodes attached to the person's head. In order to measure the 
brain wave, the correlation of the shapes between brain waves such as 
.alpha.-wave of the frontal lobe (area 1 as shown in FIG. 3) and the 
occipital lobe (area 9 as shown in FIG. 3) is calculated to give a time up 
to a first peak .tau.m (see FIG. 4). In FIG. 4, as the mental 
concentration is improved, a value .tau.m decreases. 
After smelling the aroma of the chocolates according to Example 2 and 
Comparative Example 1, the brain waves of the panelists were determined 
and shown in FIG. 5. As apparent from FIG. 5, the value (.tau.m=40.0) of 
the chocolate according to the invention is lower than a value .tau.m of 
44.3 of Comparative Example. This indicates that the chocolate of Example 
1 enhances the mental concentration. With reference to two graphs as shown 
in the right of FIG. 5, the brain wave in the sleeping rest state as an 
index of unconcentrated condition and the wave in the mental calculation 
as an index of concentrated condition were measured for their m values 
wherein the brain waves were determined upon smelling neither chocolate 
aroma. By comparing these values, it will be apparent that the enhancement 
of the mental concentration by the chocolate of Example 2 approximates to 
.tau.m value 39.5 at the time of mental calculation. 
(Experiment 4) 
A proof-reading test of English Vocabulary was carried out for the 
chocolates of Example 2 and Comparative Example 1 employing a panel 
consisting of one hundred fifty five women college students. Some 
questions are raised from Table 1, in which the proof-reading test was 
carried out in such a manner that correct words were listed in the left 
while incorrect words including a single mistaken letter to be corrected 
were arranged in the right. 
After eating the chocolates of Example 2 and Comparative Example 1, the 
number of responses was recorded. The results are given in FIG. 6 wherein 
the ordinate shows the number of responses after eating the chocolate 
minus the number of responses without eating any chocolate, while the 
abscissa shows the time for response. The number of responses after eating 
the chocolate according to the present invention increases from one minute 
after the eating. The number of responses in seven minutes after eating 
the inventive chocolate increases six times that of Comparative Example 1. 
It could be understood that efficiency of working is considerably improved 
as compared with those eating the chocolate of Comparative Example 1. 
(Example 3: Production of Cacao Nibs Treated with Calcium Hydroxide) 
Cacao nibs were added with 1.0% of calcium hydroxide to be stirred at 130 
.degree. C. under 1 atm to 20 minutes for dry and subsequent roasting 
treatments to provide the cacao nibs treated with calcium hydroxide. 
(Example 4: Production of Chocolate Using Cacao Nibs Treated with Calcium 
Hydroxide) 
The cacao nibs prepared by the process of Example 3 were subjected to a 
grind to form a cacao mass to be thoroughly mixed with sugar, a whole 
powder milk and a portion of cocoa butter for roll-milling thereof and 
addition with the remaining cocoa butter, emulsifier and flavor, and 
subsequent concinnating process to prepare a chocolate body to be finally 
shaped into a chocolate product. 
(Example 5: Production of Cacao Nibs Treated with Potassium Carbonate) 
Cacao nibs were added with 1.0% of potassium carbonate and stirred at 
130.degree. C. under 1 atm to 20 minutes for dry and subjected to 
subsequent roasting treatments to provide the cacao nibs treated with 
potassium carbonate. 
(Example 6: Production of Chocolate Using Cacao Nibs Treated with Potassium 
Carbonate) 
The cacao nibs prepared by the process of Example 5 were subjected to a 
grind to form a cacao mass to be thoroughly mixed with sugar, a whole 
powder milk and a portion of cocoa butter for roll-milling and subsequent 
addition with the remaining cocoa butter, emulsifier and flavor, and a 
further concinnating process to prepare a chocolate body to be finally 
shaped into a chocolate product. 
(Experiment 5) 
A preference test of chocolate was carried out on a hundred panelists of 
high school girls using the chocolates of Example 4 and Example 6. The 
results are shown in FIG. 7. As apparent from FIG. 7, calcium hydroxide is 
superior to potassium carbonate as the alkali to be used for the 
alkali-treatment of the invention. 
(Experiment 6) 
An enhancing test of the mental concentration for chocolate was carried out 
on twenty panelists of university students using the chocolates of Example 
4 and Example 6. The process of Experiment 3 was repeated. 
After smelling the aroma of the chocolates of Examples 4 and 6, the brain 
waves of the panelists were determined and shown in FIG. 8. As apparent 
from FIG. 8, the value .tau.m of 39.5 of the chocolate of Example 4 
according to the invention is much lower than a value .tau.m of 43.9 of 
Example 6. This indicates that the chocolate of Example 4 enhances the 
mental concentration. With reference to two graphs as shown in the right 
of FIG. 8, the brain wave in the sleeping rest state as an index of 
unconcentrated condition, and the wave in the mental calculation as an 
index of concentrated condition were measured for their .tau.m values 
wherein the brain waves were determined upon smelling neither chocolate 
aroma. By comparing these values, it will be apparent that the enhancement 
of the mental concentration by the chocolate of Example 4 approximates to 
.tau.m value of 39.5 at the time of mental calculation. 
(Experiment 7) 
A proof-reading test of English Vocabulary was carried out with the 
chocolates of Example 4 and Example 6 on a hundred fifty panelists of 
women college students. The process of Experiment 4 was repeated. The 
results are shown in FIG. 9. 
As apparent from FIG. 9, the number of responses in seven minutes after 
eating the chocolate of Example 4 increases to five times that of the 
chocolate of Example 6. This shows the surprisingly improved efficiency of 
working. 
(Example 7: Production of Cacao Nibs Treated with Sodium Carbonate) 
Cacao nibs were added with 1.0% of sodium carbonate to be stirred at 
115.degree. C. under 1 atm to 20 minutes for dry and were subjected to 
subsequent roasting treatments to provide the cacao nibs treated with 
sodium carbonate. 
(Example 8: Production of Chocolate Using Cacao Nibs Treated with Sodium 
Carbonate) 
The cacao nibs prepared by the process of Example 7 were subjected to a 
grind to form a cacao mass to be thoroughly mixed with sugar, a powdered 
whole milk and a portion of cocoa butter for roll-milling and subsequent 
addition with the remaining cocoa butter, emulsifier and flavor and a 
further concinnating process to prepare a chocolate body to be finally 
shaped into a chocolate product. 
(Experiment 8) 
A preference test of chocolate was carried out on a hundred panelists of 
high school girls using the chocolates of Examples 4 and 8. The results 
are shown in FIG. 10. 
As apparent from FIG. 10, calcium hydroxide is superior to sodium carbonate 
as the alkali to be used for the alkali-treatment of the invention. 
(Experiment 9) 
The enhancing test of the mental concentration for chocolate was carried 
out on twenty panelists of university students using the chocolates of 
Examples 4 and 8. The process of Experiment 3 was repeated. 
After smelling the flavors of the chocolates of Examples 4 and 8, the brain 
waves of the panelists were determined and shown in FIG. 11. As apparent 
from FIG. 11, the value .tau.m of the chocolate of Example 4 according to 
the invention is lower than the value of .tau.m of Example 8. This shows 
that the chocolate of Example 4 enhances the mental concentration. With 
reference to two graphs as shown in the right of FIG. 11, the brain wave 
in the sleeping rest state as an index of unconcentrated condition and the 
wave in the mental calculation as an index of concentrated condition were 
measured for their .tau.m values wherein the brain waves were determined 
upon smelling neither chocolate aroma. By comparing these values, it will 
be apparent that the enhancement of the mental concentration by the 
chocolate of Example 4 is equal to a .tau.m value of 39.5 at the time of 
mental calculation. 
(Experiment 10) 
The proof-reading test of English Vocabulary was carried out with the 
chocolates of Examples 4 and 8, on a hundred fifty woman panelists of 
college students. The process of Experiment 4 was repeated. The results 
are shown in FIG. 12. 
As apparent from FIG. 12, the number of responses after eating the 
chocolate of Example 4 according to the invention increases significantly 
relative to the chocolate of Example 8. This shows an improved efficiency 
of working. 
TABLE 1 
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Tests for English vocabulary 
(A Part of Questions) 
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1. sabulum sabul.backslash.em 
2. porphyrins p.backslash.erphyrins 
3. oxyrhine oxyr.backslash.nine 
4. prothesis proth.backslash.asis 
5. buddha buddh.backslash.e 
6. conquistador con.backslash.guistador 
7. exultant exulta.backslash.mt 
8. gloucester glou.backslash.eester 
9. haughty ha.backslash.wghty 
10. multiversity multi.backslash.wersity 
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