Transcript Legumes

Legumes
David S. Seigler
Department of Plant Biology
University of Illinois
Urbana, Illinois 61801 USA
[email protected]
http://www.life.illinois.edu/seigler
Legumes - Outline
• Importance:
all cultures - ancient - e.g., lentils
fix nitrogen
• Botanical
Fabaceae
fruit a legume or pod
• Properties
physical
nutritional
protein: must be detoxified
steps in domestication, indehiscent
pods
Major legumes
Near East:
lentils
garbanzos
broad beans
peas
New World:
Phaseolus spp.
peanuts
China:
soybeans (Glycine max)
Vigna spp.
Africa:
Vigna unguiculata
pigeon peas
Reading
• Chapter 6 - Legumes
• seeds of members of the Fabaceae
p. 137-138
Introduction
• Second only to the grasses in their
importance to humans and our domestic
animals.
• Every major civilization has been based on a
legume as well as a cereal grain.
• Legumes are by definition all members of the
Fabaceae or Leguminosae.
• This is a large family with perhaps 18,000
species.
Courtesy Dr. Ted Hymowitz
The legume
• The Fabaceae consists of three subfamilies.
• Almost all important crop legumes are in the
subfamily Faboideae (Papilionoideae).
• Fruit a legume. Commonly known as "pods".
• A single carpel that splits along two longitudinal
margins at maturity to release its seeds.
• Many important legumes in table on
page 143.
• Diagram of legume flowers and fruits p.
137-138.
• World production... see page 144.
Nitrogen fixation
• The roots of most legumes form associations
with bacteria that can fix atmospheric
nitrogen.
• These Rhizobium species live in nodules on
the roots.
• They provide “free” fertilizer.
• Flowering plants cannot use atmospheric
nitrogen but must absorb nitrate or
ammonium nitrogen through the roots.
• Nitrogen cycle on pg. 140.
Nodules on Lupinus texensis roots
Nutritional value
• Legumes rich in protein (nitrogen).
• See table on pg. 142 for nutritional
composition.
• Many are in the 20-30% range.
• Legumes also contain some fats but usually
less starches than cereal grains.
Nutritional value
• Amino acid composition different from that of
cereal grains.
• Legume seeds have more of some amino
acids than cereal grains.
• Seeds of almost all legumes are toxic if eaten
uncooked because of proteins or peptides
that inhibit digestive enzymes.
Important points
• Legumes fix nitrogen
• Legumes rich in protein
• Legumes easily stored and harvested
Ancient cultivars
• Near East and Europe: peas, broad beans,
lentils, and garbanzos.
• New World: common beans, lima beans, and
peanuts
• South East Asia and China: soy beans, mung
beans (Vigna aureus) and adjuki bean (Vigna
mungo).
• Africa: black-eyed pea, pigeon pea.
Domestication of legumes
• Lentils are one of oldest domesticated
legumes
• Wild small-seeded legumes used.
• By 6000 B.C., lentils, peas, vetch (Vicia sp.),
bitter vetch (Vicia ervilia), and garbanzos
were already cultivated.
• In Africa Vigna by 2000 B.C.
• In the Americas, Phaseolus coccineus in
Tamps. by 5000 B.C. wild harvested.
• By 4000 B.C., P. vulgaris and P. lunatus
were cultivated in Peru.
• Many domesticated legumes have lost
the ability to reseed themselves.
• Pods of cultivars are indehiscent.
Lentils (Lens culinaris)
• Among the most ancient of cultivated
crops.
• 8000-9000 years in the Near East.
• Lentils found in archaeological sites
before that, but as is the case for cereal
grains, it is difficult to sort out what is
cultivated and what is not.
Lentils (Lens culinaris)
• Lentils especially high in protein.
• Lentils drought resistant.
• By 2200 B.C., they appear in Egyptian tombs.
Lentils, Lens culinaris
• Lentils particularly important in India
today. Many different kinds of "dhal".
• In the U.S. mostly cultivated in
Washington and Idaho in the Palouse
Prairies.
Peas (Pisum sativum)
• Peas are also an extremely old crop
from the Near Eastern center.
• Peas go back at least 9000 years.
• They may have also come from Ethiopia
and Central Asia.
Peas (Pisum sativum)
• In the Middle Ages in Europe, dried peas
made up a major part of the diet of peasants.
• Still very important there, especially in
Eastern Europe.
• People didn't eat "green peas" until about the
1700's.
• Peas are the fourth most important legume
crop world wide.
The Complete Book of Fruits &
Vegetables, F. Bianchini, F.
Corbetta, M. Pistola, Crown
Publishers, New York, 1973
Peas, Pisum sativum
and
Garbanzos, Cicer
arietinum
Pea fields in Washington
Broad beans (Vicia faba)
• Broad beans domesticated in the Near
Eastern Center.
• Cultivation of these beans goes back to
Egyptians, Romans, and Greeks.
• The only common bean in Europe before
1492.
• Production spread to Asia at some time in the
past and today China is the world's largest
producer of broad beans.
Broad beans (Vicia faba)
• The Spanish brought broad beans (habas) to
the New World.
• Grow best in a cool climate. Canada
produces more than the U.S.
• Cause a genetic disorder "favism" in some
people that eat them.
Broad beans, Vicia
faba
Garbanzos or chick peas, Cicer arietinum
• Also from Near Eastern Center (Northeast
Africa).
• Cultivated 7400 years ago.
• By 2000 B.C. introduced into India.
• India now grows 79% of world's crop.
• Brought to the New World by the Spanish and
Portuguese.
Garbanzos, Cicer
arietinum, Fabaceae
Soybeans (Glycine max)
• Soybeans arose in China.
• Cultivated at least 7000 years ago.
• In Chinese literature before 1000 B.C.
Soybeans (Glycine max)
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About 38% protein and 18% fats and oils.
The amino acid content is especially good.
Serve as a source of edible oils.
In the Orient, soybeans are eaten in many
different ways.
• Converted to miso, tofu, okara, soy milk, soy
sauce, curd, cheeses, and greens (sprouts).
Glycine max,
soybean, in flower
soybeans
Soybean harvest
Variation in soybeans
National Geographic
• Although soybeans were introduced to
Europe quite early, they never became
popular.
• In Pennsylvania by 1804. Benjamin Franklin
was sent a sample of seeds and both he and
Thomas Jefferson grew them.
• Until 1940's never common in the United
States.
• Coagulated soy protein called tofu.
• Most of the U.S. soybean crop is consumed
indirectly.
• Over half of our production is exported.
• Much is used in this country as "texturized
vegetable protein".
• About 15% of crop used for industrial
purposes.
• Soy beans are the most important bean crop
in the world.
Pigeon peas (Cajanus cajan)
• Pigeon peas (gandules) commonly cultivated
in the Caribbean area.
• Native to Africa and introduced into New
World by black slaves.
• Cultivated perhaps 4000 years in Africa.
• Widely cultivated in India, which grows 95%
of the world's crop.
• Pigeon peas do well on poor soils.
Pigeon peas, Cajanus
cajan
Black-eyed peas, Vigna unguiculata
• Black-eyed peas also domesticated in Africa
and brought to the Americas by black slaves.
• Other species of the genus are widely
cultivated in Asia.
• These or related species were in India by
"Sanskrit times". Romans and Greeks knew
them.
• In the U.S., mostly grown in Texas, Georgia,
Oklahoma, and the Carolinas
Asian Vigna species
• Many species of Vigna were domesticated
and cultivated in Asia.
• Black gram or urd bean (Vigna mungo).
• Mung bean (V. aureus)
• Adjuki bean (V. angularis) (and others).
• Usually included in "bean" statistics.
Adjuki bean, Phaseolus mungo
Lima bean, Phaseolus lunatus
• Lima beans may have been
independently domesticated in Mexico
and in northern South America.
• Appear to have spread southward into
other parts of South America.
• The oldest cultivated materials are from
Peru (7000-10000 years old).
Lima bean, Phaseolus lunatus
• In 1492, cultivated from Canada to Argentina.
• Usually perennials in the tropics.
• Many lima beans are highly toxic unless
prepared properly.
• This is not true in the United States and
Europe, however.
Primitive lima beans
Lima beans from San Juan, Puerto Rico
Scarlet runner bean, Phaseolus coccineus
• The scarlet runner bean (Phaseolus
coccineus) is an ancient cultivar in Mexico.
• They are still commonly eaten there.
• This species also a common bean in Europe.
Scarlet runner bean,
Phaseolus coccineus
Scarlet runner bean, Phaseolus coccineus
Common beans, Phaseolus vulgaris
• Kidney beans, pinto beans, navy beans,
black beans, green beans, wax beans,
and snap beans are all Phaseolus
vulgaris.
• Domesticated in Mexico and South
America.
• Domesticated several times.
• Fossil cultivated beans go back 7000
years in Mexico and almost as far in
Peru.
Navy beans, Phaseolus vulgaris
Kidney beans
• Beans were commonly cultivated in all parts
of the Americas in 1492.
• This species is the second or third most
important bean crop in the world.
• The American Indians commonly cultivated
beans with squash and corn. This was partly
to provide support for the beans which were
viny, but had dietary implications as well.
Peanut or groundnut (Arachis hypogaea)
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Peanuts native to central South America.
Domesticated by the Guaraní Indians.
By 2000 B.C. cultivated in Peru.
Portuguese took peanuts to several parts of
the world in the early 1500's.
• Now hard to tell that they are not native.
• They were widely cultivated in Africa.
• Brought back to the Americas by black
slaves.
Arachis hypogaea, peanut in flower
Arachis hypogaea, peanut fruits
• Peanuts important in the southeastern U.S. in
sandy soils.
• Largely replaced cotton in the South after the
boll weevil became a major pest about 1900.
• Peanuts are widely eaten in West Africa and
Asia today.
• Peanuts are the second most important
legume, but are often not eaten directly.
• Contains more oil than most legumes. Peanut
oil widely used in West Africa and France.
• Usually used to fondue because of its higher
temperature properties.
• Fruits borne under the ground.
• Much U.S. production goes into peanut
butter.
• Aflatoxin is a major problem.
Vigna (Voandzeia) subterranea, bambara
groundnut
Tamarind and Carob
• Tamarinds (Tamarindus indica) have been
used in tropical Africa and Asia for thousands
of years.
• The sticky pulp surrounding the seeds has a
sour taste and is the part used.
• Used in many types of sauces.
• See pg. 152.
Tamarindus
indica,
tamarind
Bentley and Trimen, Medicinal Plants
• Carob (Ceratonia siliqua) has also been
cultivated in the Near East for thousands of
years.
• Fruits have long been used to feed livestock.
• Carob currently used as a chocolate
substitute and as a source of "locust gum".
Courtesy Dr. Ben-Erik van Wyk
Ceratonia siliqua, carob