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Malaysian J Pathol 2013; 35(2) : 111 – 121
The history and science of chocolate
Roberto VERNA
Sapienza University of Roma, Italy
Abstract
This article gives an account of the origins, evolution and properties of chocolate. Chocolate is
processed from the pod or cabosside of the cacao plant, grown in the tropical belt. The origins of
chocolate are traced back to the Maya people who were probably the first to cultivate the cacao
plant. The early chocolate drink, considered a “drink of the Gods” was mixed with cinnamon and
pepper, tasting bitter and strong, and was most appreciated for its invigorating and stimulating effects
than for its taste. Imported from the Americas, the softened version soon spread in Europe. From
the 1800s to the 20th Century, it evolved from a drink to its current pleasurable varieties (such as
fondant, Gianduja, milky and white chocolate), gaining much momentum in industry and also made
great impact as a romantic item and art form. Important components in chocolate are flavonoids
(antioxidants), cocoa butter, caffeine, theobromine and phenylethylamine, whereas the presence of
psychoactive substances account for its pleasurable effects. Caffeine, theophylline and theobromine
constitutes the methylxanthines, known to enhance the action of cAMP, which plays an important
role in the transmission of intracellular signals. Chocolate is noted to have anti-inflammatory,
neuroprotective and cardioprotective effects, and improves the bioavailability of nitric oxide, which
action improves the pressure, platelet function and fluidity of blood.
Key words: chocolate, antioxidant, theobromine, methylxanthines, nitric oxide, endothelium
SPECIAL ARTICLE
Address for correspondence and reprint requests: Professor Roberto Verna, Professor of Clinical Pathology, Sapienza University of Roma, Viale Regina
Elena, 324 – 00161 Roma, Italy. E-mail: roberto.verna@uniroma1.it
Almost everyone, especially children, love
chocolate. But do we know what it really is?
In addition to its tasty flavor, do we know its
origins, evolution and properties? In this paper,
I will try to share some useful information on
what it is.
From tree to chocolate
Cacao is grown in a tropical belt straddling the
equator - between 10 and 20 degrees north to
south, in the area called the “cocoa belt”. The
tree can be very tall - up to 12 meters. It starts
bearing after about 5 years, but takes 10 years
to reach maximum yield.
Its fruit, called a pod or cabosside, can take a
color ranging from brown/yellow to purple, and
contains 20 to 40 seeds or cocoa beans. Each plant
produces 20 to 50 cabossides a year, with about
10 cabossides needed to produce a kilogram of
cocoa (Fig. 1a and b).
The taste of the cocoa bean depends
not only on the variety of plant, but also
on the soil, environmental temperature and FIG. 1. (a) Cocoa tree (b) Cabossides
(b)
(a)
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112
the amount of sunlight and rain received.
After a process of fermentation and drying in the
sun, the beans are packed for local consumption
or manufacture into cocoa and chocolate. In
processing into cocoa or chocolate, the seeds are
first roasted to the characteristic color of cocoa.
Finally, the shell is removed from the roasted
seeds which are then ground into a fine grain
or powder. Hotter roasting will produce a cocoa
liquor and subsequently, with additional heat
and pressure, cocoa butter and cocoa powder. To
produce a very silky texture, a long process of
mixing and heating is finally carried out.
The origins: Maya and Aztecs
The origins of chocolate are very old, usually
traced back to the Maya people, who were
probably the first to cultivate the cacao plant, in
400 AD. The plant we know today is the result
of crossing and selection that had already started
35,000 years ago. The consumption of cocoa then
was different from what it is today: the dried
cocoa beans were ground and dissolved in water,
with cinnamon and pepper added to enhance the
flavor which was decidedly bitter and strong.
The drink took the name of xocolatl. It can be
inferred that the drink was most appreciated for
its invigorating and stimulating effects than for
its taste, effects well known to the ancients.
When, in 1200 AD, the Aztec domination
of the Maya began, the drink was particularly
appreciated by Emperor Montezuma who is
said to be so enamoured of it that he consumed
dozens of cups a day (Fig. 2). Cocoa beans were
considered so valuable that they were used as
currency and kept in safes along with gold and
precious stones.
According to ancient records, the Aztecs
believed that the god Quetzalcoatl came to Earth
on rays of light from the Star of the Morning,
bringing from heaven the cocoa tree for mankind.
They learned from Quetzalcoatl to toast and grind
the seeds to obtain a nutritious paste, soluble in
water. They added spices to produce the drink
“tsocolatl”, or “bitter water”, believed to confer
them wisdom and universal knowledge.
Drink of the Gods
According to mythological origins (winners
always write history the way they want it), cocoa
originated from the sacrifice of an Aztec princess,
who preferred death by the enemy to revealing
the riches of her kingdom. From her blood sprung
the delicate cacao plant, with mystical meanings
and aphrodisiac properties, to be given as a drink
to priests and warriors.
Today, the cocoa plant is grown in several
countries, mainly, Ivory Coast, Ghana, Indonesia,
Nigeria, Brazil, Cameroon, Ecuador, Dominican
Republic and Papua New Guinea. Other countries
cultivating it are Madagascar, Malaysia, Mexico,
some Caribbean islands, such as Granada, and
Cuba, and some Pacific islands, like Samoa.
In 1502, the first meeting of Western
civilization with cocoa occurred: Christopher
Columbus landed on the island of Guanaja,
Honduras, and received the gift of a cup of
chocolate (Fig. 3). Columbus at first, then Cortes,
FIG. 2. Montezuma drinking chocolate
FIG. 3. Columbus and Montezuma
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CHOCOLATE
discovered in the Americas the cocoa plant, but
only Cortes brought the seeds to Europe. From
this moment onwards, due to frequent trade with
the American colonies of the Spanish, chocolate
began to be introduced in the old continent as a
beverage.
At first the Spaniards followed the recipe of
the Aztecs, with further addition of chilli and
hot spices. Then, with the addition of sugar,
cinnamon and vanilla, the cocoa taste became
sweet and soft.
Table 1 summarises the early chronology of
chocolate drinks.
Imported from the Americas, in the European
courts, the softened version (compared to the
original strong and spicy beverage) soon spread,
initially as a medicine and stimulant.
Starting from 1660, the drinking of hot sweet
chocolate spreaded across Europe: Belgium,
Germany and Switzerland, and also Austria and
Italy. Venetian and Florentine masters gave life
to the art of chocolate preparation. In England,
there were Chocolate Houses for the wealthier
classes.
In 1662, Cardinal Brancaccio pronounced
that drinking hot chocolate did not break the
fasting period, spurring spread of the drink in
monasteries and the European courts.
In 1753, the Swedish naturalist, Carl von
Linné, named the cocoa tree
Theobroma cacao:
Food of the Gods.
From 1750 to 1790, the Arcadia devoted
attention to chocolate with poems, such as
Metastasio,
Baruffaldi and
Parini, but the real
consecration of the drink was only after the
middle of the eighteenth century, in France
becoming fashionable among the European
aristocracy.
The chocolate industry
Table 2 summarises the evolution of the chocolate
industry. In this, the conching process deserves
special mention. Conching is mixing cocoa with
various ingredients, such as milk, vanilla and
extra cocoa butter for a very long time (12 to 48
hours) at a controlled temperature to maintain the
liquid texture. After this, the chocolate is kept
melted in tanks at 45 - 50°C (Fig. 4a and b).
The art in chocolate
The theme of chocolate has been addressed
several times in the seventh art, cinema. The films
include:
Chocolat,
Like water for Chocolate,
Hot Chocolate,
Chocolate Factory,
Lessons in
Chocolate and
Bianca (Fig. 5).
But art is also the transformation of a material
(chocolate) to particular aesthetic forms (Fig. 6).
The main pictorial representation is by Jean
Étienne Liotard, the Nice chocolate maker
(Fig. 7). Giancarlo Bononi and Michel Mandurino
combined the theme of Caravaggio with that of
Cioccoshow in a photo exhibition (Fig. 8).
Varieties of chocolate
Fondant. This is the most expensive chocolate.
With the intense and persistent aroma of cocoa
TAbLE 1: Early chronology of the chocolate drink
Liquid chocolate, bitter and spicy
300-900 A.D
Mayans melted cocoa into a bitter drink, probably
making and consuming it warm with corn
1375-1521
Aztecs melted cocoa into a bitter drink, probably drunk
cold with spices
Liquid chocolate, bitter and cold
1565
Published in Venice “Historia del Mondo Nuovo”
in which Italian traveler, Girolamo Benzoni, stated
that bitter cacaute was “food more for pigs than
humans”.
Liquid chocolate, sweet and hot
1585
In Oaxaca, Mexico, nuns in a convent mixed sugar with
cocoa and consumed it hot and sweet, as a drink.
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Table 2. Evolution of the chocolate industry
1815
Conread Van Houten of Amsterdam island made cocoa butter from cocoa mass
1832
Franz Sacher in Vienna invented his famous cake
1847
Fry produced the first solid chocolate bar with cocoa beans, sugar and cocoa butter
1865
Production of pasta gianduja in Turin, brainchild of Michael Prochet and Isidore
Caffarel
1875
Milk chocolate made by Swiss Daniel Peter with condensed milk powder from
Nestle Henry
1875
Fry created a chocolate bar flavoured with mint
1879
Rudolph Lindt in Switzerland produced the first dark chocolate, by “conching”
1900
Milk chocolate becomes a food for everyone: claimed by Swiss chocolate factories,
Lindt & Sprüngli, Tobler Suchard
1905
Cadbury sells ‘Dairy Milk’ chocolate
1907
Hershey in America invented ’Kisses ‘
1914
In France appeared Banania: cocoa powder, sugar and chopped banana.
1922
Buitoni in Italy produced the ‘Kiss’.
1923
In the United States, Frank Mars invented the ‘Milky Way’.
1925
Callebaut produced the first chocolate cover.
1925
In New York was established the Cocoa Exchange for trading the raw material, and
the United States became a global player in the production of chocolate
1943/5
American troops in Europe distributed their chocolate bars
1950-1975 In France were founded Valrhona (1950) and Maison du Chocolat by Robert Linxe.
Returned the French to supremacy in quality chocolate.
1956
Birth of ‘Mon Cheri’, the first Boer chocolate industrially produced.
1963
Rud Läderach, in the laboratory of Ennetbühls, invented “hollow” preprints for
pralines
1964
On April 20, release of the first jar of Nutella
1974
Here came Kinder Eggs
1984
Raymond Bonnat and Voiron created the first collection of dark “Grands Crus de
Cacao”.
1988
Valrhona Guanaja realized the first finger, a cru chocolate,1989 Lindt sold in Italian
supermarkets a tablet with 70% cocoa
1993/95
First Salon du Chocolat in Paris, first edition of Eurochocolate in Perugia
1998-2000 Amedei and Domori distributed in Italy tablets from crus.
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CHOCOLATE
and looking bright and shiny, it melts in your
mouth leaving a pleasant bitter after taste. Should
be smooth to the touch - silky, never grainy.
The percentage of cocoa is one of the main
characteristics determining its quality. The best
ones contain at least 70% cocoa.
Gianduja. Brown in colour, this is born
from the union of hazelnuts, cocoa and sugar.
Sometimes, milk, almonds or walnuts are added.
Gianduja was first made in Turin in the mid-19th
century.
Milky. Contains not less than 20-25% cocoa, in
addition to cocoa butter, sugar, milk powder and
lecithin. A good milk chocolate should have a
shiny appearance. The scent must be intense and
persistent. It has first the smell of vanilla and
milk and finally the cocoa must prevail. A good
milk chocolate is crisp, but dissolves quickly in
the mouth to a slightly mushy paste. Finally, the
taste should be sweet with a slight bitter note
from the cocoa.
White. This contains cocoa butter, sugar, milk
powder and vanilla. It tastes sweet and nice and
can also be used to prepare other edibles like
mousse, cream and desserts (Fig. 9). Besides
edible products, the chocolate can be used for
other applications, such as cosmetics, due to the
properties of cocoa butter (Fig. 10).
FIG. 5. Posters of movies on the theme of chocolate
FIG. 4. (a) Conching machine (b) Rudolph Lindt
(b)
(a)
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FIG. 6. Items made of chocolate
FIG. 7. Jean Etienne Liotard. The chocolate maid
FIG. 8. A Caravaggio theme with chocolate
FIG. 9. Varieties of chocolate
FIG. 10. Alternative uses of chocolate
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CHOCOLATE
Chocolate in science and health
So far, we have traced the history of chocolate, but
let us not forget science and issues of health.
Chemical and physical properties
These are mainly due to cocoa butter, which
is yellow in colour and contains three main
triglycerides with oleic acid – a monounsaturated
fatty acid: POP (20%), POSt (40%) and StOSt
(25%) (P = palmitic acid (saturated); O =
oleic acid (monounsaturated); S = stearic acid
(saturated)) - and smaller amounts of others
containing linolenic and arachidonic acids.1
Brittle below 20°C, soft between 30-32°C, the
butter melts at just below body temperature. It
has exceptional nutritional properties for the skin,
purifying, soothing and moisturizing (Fig. 11).
POP, POSt and StOSt are the abbreviations of
triglycerides which make up cocoa butter, but
they can also be added from other compounds
(generally called cocoa butter substitutes) to
cocoa to make chocolate (Fig. 12), e.g., made
from illipe butter, Borneo tallow (or Tengkawang
Shorea spp) (Fig. 13), palm kernel oil (Elaeis
guineensis, Elaeis olifera), fat and stearin of
Shorea robusta, shea butter (Butyrospermum
parkii), cocum butter (Garcinia indica), kernel
oil of mango (Mangifera indica). In chocolate for
making ice cream and similar frozen products,
coconut oil can be added, but the nutritional
value is not the same.
Energy and nutritional content of chocolate
The composition of the various chocolate varieties
are summarized in Table 3, while the energy
and micronutrients are briefly accounted below:
Pure chocolate = 2080 kilojoules (kJ) or 495
kilocalories (kcal)/100 gm
Milk chocolate = 2160 kilojoules (kJ) or 515
kilocalories (kcal)/100 gm
White chocolate = 2260 kilojoules (kJ) or 540
kilocalories (kcal)/100 gm
Flavonoids. These are antioxidants that act
against aging (not present in white chocolate).
Cocoa butter. Confers exceptional nutritional
properties for skin. Purifies??, soothes and
moisturizes even the driest chapped skin.
Magnesium. Stimulates the growth of skin cells.
Invigorates and improves mood.
Caffeine. Stimulant and tones skin.
Theobromine. Stimulates heart muscle and
nervous system. Higher concentration in dark
chocolate. This micronutrient has the greatest
impact on health, but the concentration varies
with the variety of chocolate.
Phenylethylamine. Stimulates good humor, and
is found in the brains of lovers!
FIG. 11. Cocoa butter
FIG. 12. Main triglycerides in chocolate
FIG. 13. Shorea spp. (origin of illipe butter)
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The combination of caffeine, theobromine and
phenlethylamine makes you think of a good
sweet chocolate, an aphrodisiac and also a base
of many cosmetics.
Beneficial effects of chocolate
Along with caffeine and theophylline, theobromine
constitutes the methylxanthines (Fig. 14 ) which
are known to enhance the action of cAMP.
In fact, they inhibit phosphodiesterases that
hydrolyze cAMP to 5 ‘ AMP. Methylxanthines,
however, has different concentrations in different
chocolates (Table 4).
TAbLE 3: Nutritional values per 100 grams of different chocolates
Fondant
Milky
White
Protein (gr)
3.2
7.6
7.5
Lipid (gr)
33.2
33.3
37
Carbohydrate (gr)
60.3
57
52
Pure Lecithin (gr)
0.3
0.3
0.3
Teobromine (gr)
0.6
0.2
/
Ca (mg)
20
220
250
Mg (mg)
80
50
30
P (mg)
130
210
200
Fe (mg)
2
0.8
Traces
Cu (mg)
0.7
0.4
Traces
Vitamin A (IU)
40
300
220
Vitamin B1 (mg)
0.06
0.1
0.1
Vitamin B2 (mg)
0.06
0.3
0.4
Vitamin C (mg)
1.14
3
3
Vitamin D (IU)
50
70
15
Vitamin E (mg)
2.4
1.2
Traces
Kcal
495.2
514.2
538.0
TAbLE 4: Methylxanthine concentrations in different chocolates
Cacao product
Methylxanthines (mg/g)
Cacao bean
14-53
Baker’s chocolate
16
Semisweet chocolate
9
Milk chocolate
2
Hot chocolate
0.4
White chocolate
0.05
FIG. 14. Methylxanthines
Earl Wilbur Sutherland was the first to
identify the role of cAMP (Fig. 15), and was
awarded the Nobel Prize (Physiology/Medicine)
in 1971. Sutherland, in addition to influencing
my scientific work (Fig. 16), pioneered a great
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CHOCOLATE
FIG. 15. Mechanism of action of cAMP
!
Membrana
Caffeina
Teobromina
_
ATP
cAMP
+ PP
5’ AMP
Citoplasma
Lipasi
Fosfodiesterasi
------------
Trigliceridi
Acidi grassi!+ glicerolo
(+)
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20 years of enthusiastic scientific study on the
transmission of intracellular signals among
those I called “the cyclers”: Martin Rodbell,
Paul Greengard, Pedro Cuatrecasas, Ira Pastan,
Michael Gottesman, the first two also awarded
the Nobel Prize (Physiology/Medicine) in 1994
and 2000 respectively (Fig. 17).
Chocolate also contains psychoactive
substances (Table 5). The beneficial effects
FIG. 16. Earl W. Sutherland (in picture), Michael
Laposata (front), Roberto Verna (rear)
FIG. 17. Some famous “cyclers.” From top left: Paul
Greengard, Ira Pastan, Martin Rodbell, Pedro
Cuatrecasas, Michael Gottesman
Table 5: Psychoactive substances in chocolate
Substance
action
Dopamine
Many substances that produce pleasure trigger the release of this transmitter
in the limbic system: heroin, cocaine, alcohol, nicotine.
Serotonin
Controls mood, and gives the “antidepressant” effect of chocolate.
Anandomide
A lipid (named from a Sanskrit word that means happiness). Present in the
brain as an endogenous substance, it interacts with cannabinoid receptors.
Phenylethylamine Neurotransmitter responsible for the state of mood and pleasure. It has a
stimulant effect.
of chocolate (Tables 6 and 7) are due to the
natural components in cocoa beans, including
epicatechin and resveratrol, two powerful
antioxidants.
TAbLE 6: *Main properties of cocoa beans
beneficial to health2
Anti-inflammatory
Anti-diabetic and anti-obesity
Cardioprotective
Improves liver functions
Neuroprotective
Improves intestinal flora
Reduces stress hormone
Reduces symptoms of glaucoma and cataract
Retards progression of paradontitis
*Studies published on: http://www.greenmedinfo.com/
substance/chocolate
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CHOCOLATE
FIG. 18. NO-mediated vasodilation
Luis Ignarro, who was also awarded the
Nobel Prize in Physiology or Medicine in 1998,
defined the role of NO in erection by the male.
He demonstrated that erection is enhanced by
drugs that inhibit phosphodiesterase (Fig. 20).
Given that chocolate has the same power, would
it be useful for this purpose to eat chocolate?
REFERENCES
1. Davis TR, Dimick PS. Lipid composition of
high-melting seed crystals formed during cocoa
butter solidification. J Am Oil Chem Soc. 1989:
66:1494–8.
2. http://www.greenmedinfo.com/substance/chocolate
FIG. 19. NO, the pluripotent molecule
TAbLE 7: beneficial effects of flavonoids
• Increased capillary resistance
• Decreased permeability of vessels
• Anti-inflammatory
• Anti-allergy
• Antiviral
• Antiatherogenic
• Antiarrhythmic
• Antitumor
• Antiepatotoxic
• Immunostimulant
• Lipid-lowering
• Stimulating cognitive functions
• Modulating activity of estrogen
• Improves the bioavailability of nitric oxide
(NO), which action improves the pressure,
platelet function and increases the fluidity
of blood
Stimolo sessuale
Nervi nitrergici
Ossido Nitrico - NO
Cellule endoteliali
Rilascio
Rilascio
Attivazione
Guanilato
ciclasi
GMP
GTP
cGMP
PDEs
Sildenafil
Tadalafil
Vardenafil
Inibizione
Rilassamento del
muscolo liscio
Erezione
FIG. 20. Mechanism of erection
Vasodilation is the result of nitric oxide
(NO) derived from the endothelium. NO is a
pluripotent molecule with different effects. The
main physiological stimulus for the synthesis
of endothelial NO is friction from the flow of
blood against the surface of the blood vessel,
a process called “flow-mediated vasodilation”
(FMD) (Fig. 18).
Furthermore, a variety of agonists, such as
acetylcholine, histamine, thrombin, serotonin,
adenosine diphosphate (ADP), bradykinin,
and norepinephrine, cause vasodilation
when the endothelium is intact, overcoming
vasoconstriction or if the endothelium is
dysfunctional. Finally, NO has many other
effects, such as inhibition of platelet adhesion
and a synergistic effect with prostacyclin to
reduce the expression of tissue factor induced
by endotoxin and cytokines, the potential
prothrombotic endothelial cell and inhibition of
monocytes to the endothelium (Fig. 19).
