Transcript Sugar and Stimulants

Sugar and Stimulants
Outline and Readings
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Sugar
Coffee
Tea
Chocolate
• p. 55 sugar
• Chap 16.
Sugar
• What we call “sugar” is sucrose, a disaccharide
made of glucose plus fructose.
– “sugar” is actually a more generic term for a
whole series of simple carbohydrates
• The name “carbohydrate” comes from the
approximate composition: a ratio of 1 carbon to
2 hydrogens to one oxygen (CH2O). For
instance the sugar glucose is C6H12O6.
• Carbohydrates are composed of rings of 5 or 6
carbons, with –OH groups attached. This
makes most carbohydrates water-soluble.
• Glucose, a monosaccharide or simple sugar, is
the primary food molecule for generating
energy. Other compounds get converted to
glucose, then get broken down into carbon
dioxide.
Oxidation of Glucose
• Energy from chemical bonds is transferred in the form of electrons. The
process is called oxidation and reduction.
• Cells oxidize glucose to form carbon dioxide and water. The cell removes
high energy electrons from glucose (in a series of steps), which converts it
to carbon dioxide. The energy stored in the electrons is used to make
ATP, the cell’s energy molecule. The electrons (now low energy) are
given to oxygen molecules, converting them to water.
• By passing the electrons through a series of steps before their final
destination in water, the cell can harvest the energy efficiently. In
contrast, burning releases the energy all at once, so it can’t be captured
easily.
Sugar in Animals and Plants
• Sugar is a source of the food calories we
need, and we are genetically programmed to
enjoy eating it: we have a taste receptor for
sweetness.
– So are most animals (even insects), although
cats have lost their sweetness taste receptor
and are pretty indifferent to sweet things.
• In plants, sucrose is used to transport sugar
through the phloem from the leaves to other
tissues.
• In most plants, the sucrose gets converted to
starch for storage, or converted to glucose
to be used as food.
• However, sugar cane (and sugar beets)
stores the sucrose.
Sugar Cane in the Ancient World
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Sugarcane (Saccharum officinarum) is a
monocot, a tropical perennial grass with C4
photosynthesis.
Sugar cane originated in New Guinea, probably
as a hybrid of several different species.
• people chewed the stalks for the sweet taste
Spread throughout East Asia (including India)
and the Pacific Islands as much as 5000 years
ago
• the Indians learned how to crystallize
sugar from the sugarcane sap
– Basic method: pound the sugar cane stalks to
extract the juice, then boil it to concentrate the
sugar. It crystallizes out, far purer than the
original sap.
• In 350 BC: Alexander the Great noticed
“honey obtained from reeds” during his
conquest of western India, and brought it
home to Greece.
Sugar, Islam, and the Crusades
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Muslim traders and conquests following 632 AD spread sugarcane cultivation as
far west as Spain. Also, they developed methods for large scale industrial
production of sugar.
In Europe, the only sweetener was honey. During the Crusades (1100's),
Europeans came across "sweet salt", and by 1200 sugar was considered a
necessary (but expensive) commodity in Europe.
– It was still an expensive spice, however. In 1319 AD it went for the equivalent of $50
per pound.
Sugar in Europe
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Europeans started growing it on Cyprus and
on various islands in the Atlantic: Canaries,
Cape Verde Islands, Madeira. All these
islands were discovered, or re-discovered, by
the Portuguese in the 1400's as they
attempted to work their way around Africa
under the leadership of Prince Henry the
Navigator.
In August 1492, on his first voyage to the
still-undiscovered New World, Christopher
Columbus stopped at the Canary Islands to
pick up fresh food and water. He intended to
stay only 4 days, but he became romantically
involved with the governor of the island,
Beatriz de Bobadilla y Ossorio, and stayed a
month. When he finally left, she gave him
some sugarcane cuttings, which became the
first European plant to reach the Americas.
Sugar in the New World
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Sugarcane likes tropical climates, and the Caribbean
worked very well. Unfortunately, smallpox, yellow
fever, and malaria were rampant: these are all Old
World diseases. Disease and hard work killed off the
enslaved native population. This created a huge
market for African slaves, who had more natural
resistance to the diseases.
– But, the death rate was very high: more than 4 million
slaves were brought into the British West Indies
starting around 1700, but there were only 400,000
slaves when slavery ended in 1838.
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The combination of slavery, good climate, and
improved production methods drastically increased
the availability of sugar, and lowered the price.
Sugary foods really caught on after 1700: in 1700, the
British consumed 4 pounds of sugar per person in a
year. By 1800 it was 36 pounds per person.
By 1750, sugar was the most valuable commodity in
European trade.
Triangular Trade
• Triangular trade: profit on every leg!
– Trade goods (cloth, metal pans, guns, etc.) shipped from
England (later, Boston) to west Africa and used to buy slaves.
– Slaves shipped across the Atlantic to the Caribbean, where
they were sold to sugar plantations This was the Middle
Passage, and 15% or more died on the way.
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– sugar (often in the form of molasses) shipped to
England (or later, Boston). The sugar was refined, and
the molasses was distilled into rum.
In 1763, at the end of the Seven Years’ War (French and
Indian War), France chose to give Britain control of Canada
(“a few acres of snow”) in exchange for the Caribbean
islands of Guadaloupe and Martinique.
The American Revolution (1780's) was greatly helped by
the fact that the British considered the sugar-growing
Caribbean islands far more valuable than their North
American colonies. Thus, they put many troops and
resources in the Caribbean and not in North America.
Sugar Beets
• Sucrose is also found in beets, but not in large
amounts.
– The same beet (Beta vulgaris) as the vegetable, but
not red.
• During the time of Napoleon (1807), the British
blockaded French ports, so no sugar could be
imported from the Caribbean. This led to the
development of the sugar beet industry in France.
• Selective breeding increased the sucrose
concentration by a lot: 15-20% sucrose.
• In the continental United States, sugarcane only
grows in Florida, Texas, and Louisiana. However,
sugar beets are much hardier. Thus, most US sugar
is made from sugar beets.
• Today, about 30% of world sugar comes from sugar
beets.
Planting and Harvesting of Sugarcane
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Sugarcane is a hybrid that does not breed true, so
commercial crops are reproduced from vegetative
cuttings.
It is a perennial, but after several cuttings it doesn't
produce as well, so the roots are removed and new
cuttings planted.
Sugarcane is harvested by cutting close to the ground:
highest concentration of sugar there, and then stripping
off the leaves, which interfere with processing.
Mechanical harvesting (aided by improved plant
varieties) only got started in the 1950's. Even now, half
of the world’s sugarcane is cut and stripped by hand. It
is very labor-intensive.
Sugar Mill
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Cane must be processed within 24 hours or the
sucrose content drops. Thus, the sugarcane is pressed
in a mill close to the fields.
Sugar mills chop and shred the cane, then press it to
extract the juice.
Lime is added to remove impurities (which float to
the top and are skimmed off).
The clarified liquid is concentrated by heating it to
evaporate water. The juice crystallizes into a sticky
dark brown sugar, which is then shipped to a refinery
for purification.
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In colonial days (1650-1850) the British had a high tax
on importing refined sugar, so the Caribbean sugar
plantations shipped the unrefined sugar to England.
The remaining plant material is dried and burned to
heat the evaporation pans. Sugar mills produce more
energy than they use.
Refining Sugar
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Unlike most foods, sugar is a single chemical
compound, sucrose. The more refined sugar is, the
fewer contaminants (other compounds) are mixed in
with the sugar.
One bit of chemistry: pure compounds form crystals,
which are just regular arrays of the molecules stacked
up together. When crystals for, other compounds are
excluded from the crystal structure. So, crystallization
is the basic method for purifying sugar.
The sugar refinery condenses the juice by boiling it
until sugar crystals form.
Pure refined sugar involves dissolving the sugar in
water, then clarifying it by adding lime. This process
precipitates out impurities and colored material.
The clarified liquid goes through several cycles of
being concentrated by heating under a partial vacuum
until the sugar crystallizes, extracting the crystals by
centrifugation, then redissolving them. Done under
very clean conditions.
More Sugar Refining
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The liquids left over after crystallization is
molasses. Still contains some sucrose, but also
various minerals, proteins, and other nutrients.
– Molasses can be fermented into heavy beers like
stout, or distilled into rum.
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In pre-modern times, sugar was separated from
molasses by pouring the dissolved sugar into
conical molds with a hole in the bottom. Over
several days, the remaining molasses drained
out the narrow end. The sugar could also be
washed by pouring sugar water on the top end
and letting it drain. You end up with a sugar
loaf. 10 inches in diameter, 30 inches tall,
weigh 35 pounds or so.
Modern methods involve using a centrifuge to
rapidly separate the crystals from the liquid.
Stimulants
• Coffee, tea, and chocolate all contain caffeine, a chemical
compound that stimulates the central nervous system.
– Tea also contains theophylline and chocolate also contains theobromine.
These compounds are similar in their chemical structure and their
effects to caffeine.
• Caffeine speeds the heartbeat, raises blood pressure, relieves
drowsiness and restores alertness. Because of this, they are
widely used throughout the world.
– 90% of adult Americans consume caffeine daily.
– Even in pre-historic times, people chewed plants for the caffeine
• United States v. Forty Barrels and Twenty Kegs of CocaCola. A 1911 Supreme Court case that tried to get caffeine
labeled as a deleterious and habit-forming substance. It was
rejected by the courts. Also, bills were introduced in the
House of Representatives to accomplish the same thing; they
failed.
– Caffeine is legal almost everywhere in the world.
– The US Food and Drug Administration (FDA) classifies caffeine as
“generally recognized as safe” as a food additive.
Caffeine Effects
• Caffeine binds to the adenosine receptors in the brain.
What adenosine receptors do isn’t clear: they seem to
slow mental activity, promote sleepiness, and
increase blood flow in the brain.
– Caffeine acts as an inhibitor of the adenosine receptor
neurons
• People develop tolerance and dependence on
caffeine: it takes increasing doses to get the same
stimulation. This is because the number of adenosine
receptors is greatly increased in people who routinely
use caffeine: “up-regulation”.
• When caffeine is withdrawn from an addict, the extra
adenosine receptors cause the blood vessels in the
brain to dilate, leading to headaches and nausea.
Coffee
• Coffee comes from the seeds of a shrub that
is native to Ethiopia in eastern Africa. There
are two species grown commercially: Coffea
canephora (called robusta) and Coffea
arabica, plus a few others in minor usage.
– C. arabica accounts for 85% of commercial
coffee; C. canefora is stronger and harsher, and is
mostly used for instant and decaffeinated coffee.
• Most arabica plants are self-pollinating and
highly inbred. Thus, they vary little from
plant to plant and can be grown from seed.
• In contrast, C. canephora is selfincompatible so it must be outcrossed. As a
result, every seedling is genetically different
from every other, and useful varieties must
be propagated vegetatively.
History of Coffee
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The (probably mythical) origin story: Kaldi the Ethiopian
Goatherd noticed the energizing effects of raw coffee berries
on his goats and tried them out. He took the berries to a local
holy man, who disapproved and threw them into the fire.
When the beans started roasting, they smelled so good that
Kaldi and the holy man raked them out of the fire, ground
them up and put them in hot water: the world’s first cup of
coffee.
Coffee was probably used in Ethiopia after about 100 AD, by
eating whole berries or by crushing and mixing them with fat.
It was energy food for warriors.
The first real evidence of coffee brewing as we know it today
is from the mid-1400’s, in Sufi monasteries in Yemen
(southern part of Arabian peninsula).
– Very helpful for staying awake during long religious
ceremonies
– From there it spread to the rest of the Muslim world:
Egypt, North Africa, Turkey, Middle East, Persia.
More History
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Coffee reached Europe through trade between Venice and the
Ottoman Empire. It became fashionable among wealthy Venetians
about 1600 AD.
Coffee drinking was initially prohibited by both Muslim and
Christian (Ethiopian Orthodox) religious leaders, but the bans were
reversed after important political leaders started to enjoy it.
– Various priests wanted Pope Clement VIII to ban it, but after trying a
cup, he baptized it, making it an acceptable drink for Christians.
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After this, it spread rapidly throughout Europe, and coffeehouses
became popular gathering places, sources of intellectual
stimulation.
– The insurance company Lloyd’s of London was founded in a
coffeehouse.
– Political leaders didn’t like this. Charles II of England called
coffeehouses “seminaries of sedition”.
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Not everyone liked this. Here’s part of a petition from 1645: ...the
Excessive Use of that Newfangled, Abominable, Heathenish
Liquor called COFFEE [...] has [...] Eunucht our Husbands, and
Crippled our more kind Gallants, that they are become as
Impotent, as Age
Coffee Leaves Africa
• In the 1600’s, the Arabs monopolized the coffee
trade, by dipping the beans in boiling water to kill
them before selling them.
• The Dutch managed to obtain some live plants in the
late 1600’s, and found that they grew well in
Indonesia (the island of Java) and Ceylon (Sri
Lanka). The trees also grew well in greenhouses in
Amsterdam and Paris.
• Coffee came to the Americas after a ship’s captain
talked the botanist in Paris out of some cuttings: the
botanist was reluctant to disfigure the King’s coffee
tree.
• From there, cultivation moved to other parts of the
Caribbean and South America.
• Today, the largest coffee producers are Brazil and
Vietnam.
Growing Coffee
• Originally, coffee was grown in the shade of open
forests. However, in recent times, coffee is grown
industrially in open sun, with high fertilizer and
pesticide usage. This results in higher yield and more
rapid ripening, but probably lower quality.
• Coffee plants are killed by frost, but they grow best at
high elevations, where the plants grow more slowly and
acquire more flavor.
– C. canefora can grow at lower elevations, and it is
resistant to rust.
• The plants start producing berries at about 3 years, and
they can be productive for about 40 years.
• Coffee berries are the fruits of the coffee bush. The
berries contain the “beans”, which are actually the seeds.
Each berry contains 2 seeds.
Processing Coffee
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Ripe berries are picked, and the flesh is removed.
The beans are coated with a sticky layer of
mucilage, which is removed by soaking the beans
and allowing naturally-occurring enzymes to
degrade the mucilage for several days.
– This is called “fermenting”, but it is entirely different
from the fermenting used to produce alcoholic
beverages.
– Fermenting helps develop the proper taste.
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The beans are then washed (which produces a large
amount of waste water), and dried. The result is
green coffee beans.
The green beans are then graded and sold for
export.
The green beans need to be roasted: most coffee is
sold in the roasted state, not green. This is done at
about 200oC, for about 15 minutes. Roasting
promotes many chemical reactions in the beans,
causing them to develop their flavor, color, and
aroma.
Decaffeinated and Instant Coffee
• Instant coffee is made by dehydrating brewed coffee.
– The original process involved spraying the coffee in a fine mist in a dry
tower. Water evaporated from the droplets as they fell to the ground.
– Freeze-drying is a more recent process that retains the flavor better: the
brewed coffee is frozen, then dried under a vacuum.
• About 20% of coffee consumed in the US is decaffeinated. There are
several decaffeination processes.
– Invented by a German, Ludwig Roselius, who believed his father had died
from too much coffee drinking.
– Originally, green coffee beans were steamed, then soaked in methylene
chloride. This removed the caffeine without affecting the flavor much.
However, methylene chloride was found to be carcinogenic and banned.
– Another method involves soaking the beans in liquid carbon dioxide, which
can only be done under pressure.
– The Swiss Water method involves soaking the beans in water that in
saturated with all the compounds present in coffee except caffeine. This
causes the caffeine to diffuse out of the beans, while the other compounds
stay inside.
Coffee Rust
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Coffee rust, a fungal pathogen, is native to Africa. It
was first reported in 1861.
wiped out the coffee plantations in Ceylon between
1867 and 1869, and spread from there to India and
other Asian countries.
– They were replaced by tea plantations. This switched the
British from coffee drinkers to tea drinkers.
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Rust also knocked out most of the Indonesian coffee
production, where rubber replaced coffee as the main
cash crop.
Spread to South America (Brazil) in 1970.
Coffee is the obligate host for this organism, so its
spread is helped by monoculture: growing nothing but
coffee in the fields (i.e. sun-grown).
Some chemical control, especially by copper
compounds. But mostly controlled by catching the
infection early and destroying the infected plants.
Current work: breeding resistant varieties.
Tea
• Tea is thought to be the most widely
consumed beverage in the world.
– “Herbal tea” or “tisane” are terms used for any
number of dried plant mixtures that are
prepared by soaking in boiling water. Most of
them contain no real tea.
• The tea plant, Camellia sinensis, seems to
have originated in Southeast Asia, where
China, Burma (Myanmar), Tibet, and India
intersect.
• Shen Nung, the semi-legendary second
Emperor of China (about 2727 BC), invented
Chinese agriculture and medicine. He is said
to have been drinking a bowl of boiled water,
when some tea leaves fell in. He noticed the
pleasant taste and stimulating effect: the first
cup of tea.
Growing Tea
• The tea plant is a shrub that is generally kept pruned
to 3-4 feet tall, for easy harvesting. Historically, it
was grown from seed, but today it is propagated
vegetatively to maintain genetic uniformity in high
quality varieties.
• Tea itself is made from the leaves and buds of the
tea plant. Specifically, the bud and top two leaves
are used to make the best teas. The plants are
usually plucked twice a year, often by hand.
Processing Tea
• Although all tea comes from the same plant, it can
be processed four (or more) different ways, to
produce green tea, black tea, oolong tea, and white
tea.
• The basic processes used in tea processing are:
– Withering is done as soon as the leaves are harvested,
to remove water from the leaves. Blowing hot dry air
on the leaves for 12-24 hours does this.
– Oxidation involves letting the leaves sit in a climatecontrolled room for several days, during which
enzymes in the leaves break down the chlorophyll
and do other chemical conversions. Sometimes
called “fermentation”, but no microbes are involved.
– After oxidation, the leaves are subjected to fixation,
but heating them briefly. Fixation stops the oxidation
process.
– Rolling breaks open the cells, releasing the flavors.
Types of Tea
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The differences in the types of tea come
from whether they are allowed to wither
before drying, and whether they are
allowed to oxidize.
Black tea, the main type used in the US, is
withered for 12-24 hours, then fermented
for 2-4 weeks.
– In China, black tea is called red tea,
because that is the color of the brewed
tea liquid.
Oolong tea is only partly fermented, for 23 days.
Green tea is not fermented. As soon as it
is picked, the oxidation process is stopped
by steaming the leaves. Then it is rolled
and dried. The green color come from
chlorophyll.
White tea is lightly steamed to destroy the
enzymes that cause oxidation, but not
fermented.
History of Tea
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Domesticated in China very long ago, and widely consumed.
But, it was grown in inaccessible places, and odd stories about
it existed.
– Supposedly, in one village monkeys pick the tea. The
villagers stand below the tea tree and taunt the monkeys.
The monkeys respond by gathering handfuls of leaves
and throwing them at the villagers.
– Or maybe it’s trained monkeys
Spread to Korea, Japan, and the rest of East Asia by Buddhist
priests, roughly 600 C.E.
– The Japanese tea ceremony was invented by Zen
Buddhist monks, as a way of demonstrating the universal
truths that are found in simple things.
Tea existed in India, but mostly as medicine, not as a popular
drink.
Tea Comes to Europe
• Tea was brought to Europe by Dutch traders in the
1600’s, but caught on slowly.
• In 1662, Charles II of England married Catherine of
Braganza, a Portuguese princess. She grew up
drinking tea, and it became a fashionable drink at
court under her.
• Around 1700, the British East India Company started
an advertising campaign to increase tea’s popularity
– Because of Catherine of Braganza, tea drinking was
acceptable for women, although coffee drinking was
not.
– Also at this time, sugar from the Caribbean became
much cheaper.
– Sweet tea became very popular. The drink of the
Industrial Revolution: the caffeine is a stimulant and the
sugar provides energy.
More Tea History
• During the late 1700’s, tea got so popular in England
that the British East India Company (BEAC) had to
pay the Chinese in silver, not trade goods.
– The solution: BEAC started growing opium in India and
shipping it to China illegally.
– The Chinese government objected, and started the Opium
Wars. Advanced British weapons dominated, and the Chinese
were forced to officially accept opium in trade for their tea.
• The Chinese did not allow the export of tea plants, or
knowledge of how to process it. The BEAC hired a
botanist, Robert Fortune, who dressed up as a Chinese
official and started looking for the tea-growing
regions.
– The people there had never seen a European, so they thought
he was just a weird looking guy from a distant province.
– Fortune smuggled live tea plants to India, where they grew
very well. India was the world’s leading tea producer up until
very recently.
Tea in America
• Tea was a popular drink in colonial days: we were a
British colony.
• Its import was a monopoly, but much smuggling
occurred. An attempt to stop the smuggling and
enforce the BEAC monopoly led to the Boston Tea
Party in 1773, where Bostonians dressed up as
Mohawk Indians boarded some ships and threw a lot
of tea overboard. It was a precursor to the American
Revolution (1776).
• After this, it became unpatriotic to drink tea in the US
for many years: coffee was drunk instead.
• Iced tea was invented in 1904, during a heat wave at
the St. Louis Exposition. Only drunk in the US.
– Also invented at this time: the ice cream cone
• The tea bag was also invented in 1904. It was cheaper
than packaging the tea in tin cans, and made brewing
the tea much easier. Originally made of silk.
Chocolate
• Comes from the cacao plant, Theobroma
cacao. Native to New World tropics.
– The coca plant, source of cocaine, is an entirely
different plant despite similar names.
• Used as a ceremonial beverage by the Mayans
and Aztecs, but very different from the
modern sweet chocolate: bitter and mixed
with hot peppers and other spices. They also
mixed it with tobacco and smoked it.
– The genus Theobroma means “food of the gods”
• Cacao beans were used as currency among the
Aztecs. There were even counterfeit beans in
circulation.
– Example: 1 turkey was worth 100 cacao beans
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Unfortunately, the Spanish conquerors destroyed
nearly all written records from these civilizations,
so most of our knowledge is archeological and not
historical.
Marriage feast in 1051 AD
(Nuttall Codex)
Chocolate and the Europeans
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Columbus originally brought it back to Spain, but it
wasn’t really understood: just some more odd looking
seeds.
When Hernan Cortez conquered Mexico in 1519, he
met (and killed) the ruler Montezuma. Cortez noted
how the beverage was prepared, and that Montezuma
drank vast quantities of it.
The Spanish added sugar was added to make it fit
European tastes. It was an expensive drink.
– However, it wasn’t as popular as tea or coffee, partly
because it had a high fat content and thus made a rather
greasy drink.
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Chocolate houses, equivalent to coffee houses, sprang
up in England in the late 1600’s.
The chocolate bar was invented in about 1828, after the
method of removing cocoa butter from cocoa powder
was invented.
Growing Cacao
• The cacao tree is a found in the understory of
tropical forests, perhaps originally from the Amazon
River basin. It likes a warm, wet, and shady
environment. Wild cacao trees still grow in South
America.
• Cacao is pollinated by tiny flies (midges). One of
the problems with commercial cacao production is
that the midges are hard to transplant, and getting
the flowers pollinated has been difficult.
– A mature tree can have 6000 flowers on it, and only produce
20 pods.
• The largest production is in western Africa,
especially the Ivory Coast, Ghana, and Nigeria.
– Indonesia also produces a lot, and South America still
produces significant quantities.
– Children are often used, and often not paid i.e. they are
slaves.
Harvesting and
Fermenting
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Chocolate is made from the seeds (called
“beans”) of the cacao tree. The seeds are
contained within pods (the fruits), which
contain about 50 seeds.
• Ripe pods are harvested manually, and the
seeds plus surrounding pulp are removed,
• The seeds and pulp are allowed to “ferment”
(oxidize) for a week. They are left out in the
open or covered with banana leaves, and
stirred periodically. The chocolate flavor
only develops during fermentation: green
beans have no chocolate taste.
• After fermenting, the seeds are dried and
sent to a chocolate factory
Chocolate Factory
• At the factory, the beans are roasted to
develop the flavor and color. Most beans
are treated with alkalai (“dutched”) to
neutralize natural acids and produce off
tastes.
• The chocolate actually comes from the
fleshy cotyledon leaves of the seed. After
roasting, these “nibs” are removed from
the seed coat and embryo.
• The nibs are then ground up and heated to
melt the cocoa butter: they are up to 40%
fat. The result is a thick liquid called
chocolate liquor or cocoa mass.
– When allowed to cool, the chocolate liquor
can be sold as unsweetened baker’s
chocolate.
More Chocolate Processing
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Cocoa butter is separated from cocoa
powder by pressing the chocolate liquor.
– Cocoa butter is the main ingredient of
white chocolate, and it is also used for
cosmetics , suntan lotion, and other
things. It has very little chocolate taste
or color.
– Cocoa powder is also sold as
unsweetened cocoa, for baking.
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Chocolate bars are made by mixing
cocoa butter, cocoa powder, sugar, and
vanilla. Milk is also added, for milk
chocolate but not dark chocolate.
– The mixture is then “conched”: mixed
mechanically for several days to develop
a smooth velvety texture.
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Chocolate is often mixed with other
ingredients.
Kola
• The kola nut is made by a tree native to tropical
Africa (Kola nitrida) . It is related to the cacao
tree (native to South America).
– The fruits are pods containing 8 seeds. Processing
involves removing the seed coats and allowing a
fermentation to occur.
• Kola nuts contain caffeine, and it is chewed as a
stimulant and appetite suppressant in many West
African cultures.
– They are extremely bitter.
• Visitors to a home are offered kola nuts as part
of a ceremony. Also sometimes as part of a
wedding ceremony: gifts from a groom to the
parents of the bride.
Coca-cola
• Coca-cola was invented in 1886, in Atlanta ,Georgia. It
contained extracts from coca leaves (source of cocaine) and
from kola seeds, as well as caramel color, sugar, carbonated
water, and several other ingredients.
– After 1903, cocaine was removed from the coca leaves,
although they are still used as a flavoring.
• Recipe is locked in a bank vault and is highly secret.
– The main flavor comes from cinnamon and vanilla.
• An attempt in 1985 to improve the flavor, called New
Coke, was a spectacular failure. Many people preferred the
original flavor despite market research taste tests that
suggested the opposite. Or perhaps it was just a problem
with a change in something familiar.
Soft Drinks
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Coca-cola was just the
first example of
carbonated, caffeinecontaining beverages.
Many are marketed
around the world, with
different flavors
depending on local
tastes.
– Most don’t use kola
nuts as a source of
caffeine: it’s too
bitter.
• Most Illinoisans call
soft drinks “pop”, but
in other parts of the
country, it’s called
“soda” or “coke”.
Maté and Guaraná
• Maté is traditional South American drink, the national
drink of Uruguay and popular in Argentina and Paraguay.
It contains significant amounts of caffeine and is used as a
stimulant similar to coffee.
• Maté is made by steeping the leaves of yerba mate (Ilex
paraguariensis) in hot water. It is sucked through a steel
straw with small holes at the end to act as a sieve, from a
hollow gourd. It is often drunk in social groups, as part of
conversation.
• Guaraná is also a caffeine-containing plant native to South
America. Ground seeds are immersed in hot water to
make a tea. It is used in the Amazon forest of Brazil.
– The word “guaraná “has become a synonym for soft drinks in
Brazil. The seeds are often used as a flavoring in these drinks.