Beverages
David S. Seigler
Department of Plant Biology
University of Illinois
Urbana, Illinois 61801 USA
seigler@life.illinois.edu
http://www.life.illinois.edu/seigler
Outline - Beverage plants
Importance
o historical
o economic
o recreational
Chemistry
Botanical
Most important crops
o coffee
o cacao
o tea
o others
Reading
• CHAPTER 13 IN THE TEXT
Introduction
• Many plant materials are used for beverages.
For example, the juices of many fruits are
drunk.
• Popular beverage plants include roselle or
flor jamaica or roselle (Hibiscus sabdariffa,
Malvaceae), rooibos tea (Aspalathus linearis,
Fabaceae), tamarind (Tamarindus indica,
Fabaceae), and a number of herbal teas.
Roselle or flor jamaica, Hibiscus
sabdariffa, Malvaceae
Field of rooibos in South Africa
B. E. van Wyk and N. Gericke, People’s Plants, Briza, Pretoria, 2000
B. E. van Wyk and N. Gericke, People’s
Plants, Briza, Pretoria, 2000
Rooibos tea
Tamarind (Tamarindus indica, Fabaceae)
Bentley and Trimen, Medicinal Plants
Chamomile, Anthemis nobilis, Asteraceae
Stimulating beverages
• However, coffee, tea, cacao, and other
stimulant-containing beverages are
extremely popular and widely
consumed.
• Interestingly, the history of use of these
plants among most Europeans only
dates to the 1500s and 1600s.
• Tea and coffee are consumed daily by at least
1/3 of the world's population.
• Table of beverages and the compounds they
contain p. 314. Also see table on page 317.
• Many of the beverages we drink contain
caffeine. These give the consumer a general
feeling of well being. One of these beverages
is consumed by most people in the world on a
daily basis.
Coffee, Coffea arabica or C. canephora
(Rubiaceae)
• The dried, fermented fruits of Coffea
arabica or C. canephora (Rubiaceae)
are second only to petroleum in the
value of the material traded annually on
the international market.
• See coffee diagram on p. 317.
Growing of coffee seedlings
Coffee plantation in
Venezuela. Note the
legume shade trees.
Mature coffee in Kenya
Courtesy Dr. Abraham Krikorian
Drying coffee in Kenya
Courtesy Dr. Abraham Krikorian
• Coffee has up to 3% caffeine by weight.
• Coffee probably originated in Ethiopia. The
leaves, which also contain caffeine, were
originally chewed. At some point, however,
people started using the fruits.
• The plant was taken to the Arabian peninsula
about the 6th century. The Arabs were the
first to "brew coffee".
• Coffee drinking didn't spread to Europe until
the 1600's.
• This beverage became an important aspect
of social and political development in England
about 1650.
• There were 3000 coffee houses in 1675;
these institutions served as forums for
political and religious debate. The king tried to
have them closed, but was not very
successful.
• The Arabs monopolized the coffee
trade. They killed the seeds before
marketing them.
• Eventually, however, the Dutch acquired
live seeds from Mocha, the traditional
source of Arabic coffee. They started
plantations in Sri Lanka and the East
Indies and broke the Arab monopoly.
• Coffee was taken to the West Indies about 1723.
From a tree taken from Paris to Martinique in
1723, coffee spread through the western
hemisphere.
• Brazil leads the world in coffee production.
• Coffea arabica accounts for about 90% of
world's trade in coffee.
• Importantly, the coffee from Coffea arabica
has the best flavor.
• C. arabica is a self-compatible polyploid.
• Coffea canephora accounts for another 9%.
C. liberica accounts for about 1%. Both are
more productive and more disease resistant.
• Coffea canephora and C. liberica are selfincompatible diploids.
• C. canephora is used often to make instant
coffee. This species is preferred in some
parts of Africa.
• The fruit of coffee is a type of berry (inferior
ovary).
• The seeds are removed from the fruits and
are the part used to prepare the beverage.
Coffee fruits are often called "beans".
• Coffee is usually cultivated in tropical and
subtropical latitudes. It prefers rich soils and
high rainfall, with a seasonally dry period.
• A plant produces fruit after 3 years and until
the plant is about 40 years old.
• The plants are often shaded in plantations,
but open orchards are used as well. Many of
the shade trees are legumes and fix nitrogen.
• The best coffee usually comes from areas
with cool nights.
• Coffee is seldom harvested mechanically.
The best coffee comes from berries picked
just when ripe.
• The seeds are separated from the outer
portion of the fruit by either a wet or dry
process. In the dry process, the fruits are
dried and the outer portion abraded away.
• See diagrams p. 319 and 321.
• In the wet process, the fruits are depulped by
a machine and the seeds washed.
• The wet seeds are allowed to ferment
for 12-24 hours. After fermentation, the
seeds are dried for about a week.
• The remaining endocarp and the seed
coats are removed mechanically.
• Roasting is also essential to
development of flavor of the final
product. The temperature and time of
roasting are important.
• In recent years instant and freeze dried coffee
have become extremely popular and account
for a large part of the market.
• Much instant coffee is made by flash drying.
• "Aroma components" are added to give the
product enhanced flavor and odor.
• Decaffeinated coffee is also important.
• In 1981, this form of the beverage
accounted for about 17% of the coffee
drunk in the U.S.
• The caffeine is removed from green
coffee beans by solvent extraction,
water extraction, or steam extraction.
• Methylene chloride is often used as the
extraction solvent.
• There are many serious disease
problems with coffee. These have made
it difficult to grow Coffea arabica in
many parts of Africa and these diseases
now have been introduced into Brazil.
Cacao, Theobroma cacao (Malvaceae)
(formerly Sterculiaceae)
• Cacao is native to the Americas.
• Although considered as a beverage in this
lecture, eating chocolate is more important
than the beverage today.
• The plant, Theobroma cacao is a small tree.
• Cacao was a quite different beverage to the
Indians of Central America than it is to us
today.
• See diagram p. 325.
Cacao flowers,
Theobroma cacao,
Malvaceae
Courtesy Axel Walther
Cacao fruits, Theobroma
cacao, Malvaceae
Courtesy Axel Walther
Cacao fruit, Theobroma cacao, Malvaceae
Courtesy Axel Walther
• When Columbus and his men landed in
Nicaragua, they reported seeing the Indians
drinking a strange beverage. Cortez reported
on the importance of cacao in the Aztec court.
Quetzlcoatl gave cacao to the Indians.
• Cacao was cultivated in Mexico by about the
7th century.
• The beans were roasted and mixed with
ground achiote, Bixa orellana (Bixaceae).
Red pepper was also added. The whole
mixture was cooked into a paste and made
into tablets. The drink was made by putting
these tablets into water. This beverage was
often thickened by adding atole.
• Not surprisingly, Europeans didn't like this
drink too much. They added sugar and left
out the chili peppers. In the middle 1600's,
chocolate drinks were extremely popular in
Europe. The Spanish had a monopoly on the
chocolate trade.
• The Dutch broke the Spanish monopoly by
establishing plantations in southeast Asia in
1670.
• Cacao was introduced into Africa in 1878 and
today most cacao is produced in Africa.
• The pods are harvested, opened, and the
seeds and pulp removed. The seeds are
allowed to ferment for 4 to 7 days. Water loss
causes them to shrink from the seed coats.
• See diagram p. 325.
• The pulp is liquified by microbes, and the
seeds inside are then dried and polished.
Subsequently, the seeds are shipped.
Cacao seeds undergoing fermentation
Courtesy Axel Walther
Drying cacao seeds
Courtesy Axel Walther
• As for coffee, roasting is an important part of
development of cacao flavor. The chocolate
flavor only develops during this part of the
processing.
• The seed coats are removed.
• The seed coats and seeds can be extracted
to produce a lipid known as cocoa butter
(about 30% of the cotyledons). This
substance is used in other food products and
in pharmaceuticals.
• The seeds contain theobromine, a compound
with similar properties to caffeine.
• Chocolate is made by making the nibs or
cotyledons into a paste. In the Dutch process,
the cocoa butter is separated and dry cocoa
powder produced. The acids are neutralized
with alkalai. About 90% of all cocoa is
produced this way.
• The English devised adding milk to cocoa as
a beverage.
• The Swiss started adding milk to the cocoa to
make milk chocolate. Cocoa butter is readded to make the product more creamy.
Tea, Camellia sinensis, Theaceae
• Tea is drunk by a larger number of
people than coffee, but does not have
as high dollar value.
• Most tea is consumed locally and
comparatively small quantities enter
international trade.
• The exact origin of tea, Camellia sinensis
(Theaceae), is obscure, but the plant appears
to have arisen in China.
• The first book on tea was written in 780 B.C.
Tea came to Japan in 593 B.C.
• The Mongols got tea from the Chinese and
traded it across Asia. The Russians got tea in
this way.
Tea, Camellia sinensis,
Theaceae
Tea plantations and
harvesting in Kenya
(upper) and Indonesia
(lower)
Courtesy Dr. Abraham Krikorian
Tea harvesting in Sri Lanka
Courtesy Dr. Guido Holzkamp
• Europeans first got into tea when the
Portuguese brought it back from China.
• In the 1700's tea had become an important
item of trade. Both the British and Dutch
bought tea in the Orient and sold it in Europe.
• People drank tea predominately in the
English colonies in America until the Boston
Tea Party; then coffee became a more
popular beverage.
• Tea is of course still very popular in England.
• The British started planting tea in India about
1818. Sri Lanka has been the second most
important tea producer, but tea production
there only started after the coffee rust wiped
out coffee in 1880.
• Because of the hand labor, tea is not grown
extensively in the U.S. or most other
countries in the Western Hemisphere (some
is grown in Argentina).
• The plants are evergreen; they require lots of
rainfall and a constant cool temperature.
• Only the two or three youngest leaves are
used for good quality tea.
• For green tea the leaves are dried fairly
quickly to stop most enzyme activity.
• For black teas, the leaves are allowed to
wither, and rolled or twisted (broken) and then
allowed to ferment for several hours. This
modifies the tannins and polyphenols in the
leaves.
• The tea is then fired or heated to stop further
enzyme action.
• Oolong teas are semifermented.
• See outline of tea manufacture p. 329.
Tea leaves moving into
processing area and a
tea “breaking”
machine
Courtesy Dr. Guido Holzkamp
Tea ovens and tea grading
machine
Courtesy Dr. Guido Holzkamp
Yerba maté (Ilex paraguayensis,
Aquifoliaceae)
• Maté is a common beverage of southern
South America. The Indians of much of South
America used maté at one time.
• As it true for tea, the leaves of yerba maté are
used. The leaves and small twigs are heated
over a fire and then allowed to stand for a
period of time. The leaves, small twigs, and
stems are crushed and used to make a tea
like beverage.
Yerba maté, Ilex
paraguaiensis,
Aquifoliaceae
Yerba maté in flower
• Maté is traditionally drunk from a gourd,
or maté, filled with plant material. Hot
water is added. The "straw" is called a
bombilla.
Ilex vomitoria,
native to the
southeastern U.S.
was used to
prepare “black
drink” and used
ceremonially by
Indians of the
Southeastern U.S.
Guaraná,
Paullinia cupana (Sapindaceae)
• The seeds of Paullinia cupana (Sapindaceae)
are used to make a beverage called guaraná.
• This plant was originally from the Amazonian
region of Brazil.
• Guaraná is rich in caffeine. The ground
seeds are made into a paste that sets up like
a brick.
Guaraná, Paullinia
cupana, Sapindaceae
R. Bentley and H. Trimen, Medicinal Plants, London,
• A small amount of this material is rasped off
and mixed with hot water to make the
beverage guaraná.
• Guaraná is second only to coffee as the most
popular drink in Brazil.
• A soft drink prepared with this material is
similar to cola flavors.
Kola, (Cola nitida, Sterculiaceae)
• Kola, a relative of cacao (Cola nitida,
Sterculiaceae) is used to prepare the flavor of
cola beverages.
• The seeds of the plant are also fermented in
the manufacture of the flavoring.
• Cola is native to West Africa where it has
been used for a long time.
Cola, Cola acuminata, Sterculiaceae
Cola fruits, Cola nitida,
Sterculiaceae
Cola seeds, Cola acuminata, Sterculiaceae
• The pulp of the fruits is also eaten in many
African countries. The seeds are dried and
ground to make a beverage in West Africa.
This plant also contains caffeine.
Kava kava, (Piper methysticum, Piperaceae)
• Kava kava (Piper methysticum, Piperaceae)
is an important beverage plant in the South
Pacific. It as an integral part of social and
religious life there.
Roots of kava kava
Courtesy Dr. Sid Glassman
Pulverizing kava kava roots
Courtesy Dr. Sid Glassman
Macerating kava
kava roots in water
Courtesy Dr. Sid Glassman
Wringing “juice” from
kava kava roots
Courtesy Dr. Sid Glassman