LEGUMES• Bean family, pea family, pulse family• Family Leguminosae • Now Fabaceae• Cicer arietinum, Pisum sativum, Arachis

hypogea, Medicago sativa, Glycine max • Widely distributed family of trees and

ornamental plants

• Members of family Fabaceae share pretty similar flower and fruit structure

• Five petaled flower is irregular, bilateral symmetry, butterfly or boat shaped

• Fruit is pod, or legume with one rows of seeds

• Seed contain two prominent cotyledons• Leaves mostly pinnately compound

• Seeds important food worldwide • Source of oil and proteins• Close to animal meat for their higher

protein• Poor man’s meat• Higher protein content due to root

nodules containing nitrogen fixing bacteria i.e.,

Rhizobium

• Rhizobium convert free atmospheric nitrogen into from that can be utilized by plants in making of proteins and other nitrogen containing compounds

• Cultivation of legumes enriches soil due to nitrogen fixing bacteria

• Since fertilizers are expensive, farmers alternate nitrogen yielding crops such as soya bean (legumes) with nitrogen demanding crops such as corn

• Excess nitrogen yielded by beans can be utilized for corn next year

• Alternating strips of corn and beans• Ecologist recommend planting fast-

growing leguminous trees to reclaim eroded or barren areas

Formation of root nodules a) In legumes root hairs curls when in contact

with Rhizobium b) Rhizobium invade the root tissue at the site

of curling c) The plant responds to invasion by forming an

infection thread of plasma membrane growing inward from the infected cell of the host

d) Cell divisions in the infected tissue leading to nodule formation

The nodule is in contact with vascular tissues of the host for nutrient exchange

Nodule Formation

IMPORTANT LEGUME FOOD CROPS

BEANS AND PEAS

Variety of shapes like kidney beans, lima beans, pinto beans, navy beans, green beans, wax beans, butter beans

LIMA BEANS (Phaseolus lunatus)

• Protein rich• May contain cyanide• Pods few cm in length

Pinto Beans

• Skin looks like pinto horse• Beige-colored seeds with brown speckles• Popular in U.S and Mexico• Rich in starch protein• Source of potassium, vitamin

Pinto Beans

kidney beans

• Commonly known as red bean• Look like human kidney• Popular diet in North America

Kidney Beans

• Creamy yellow colored beans of moderate size • Often imported from China• U.S is world’s largest producer of soybeans Soy Beans

Soy Beans

Soy Milk• Drink derived from soy beans• Obtained by grinding of soaked soybeans,

mixing with water, straining off the milk, heating it, or blending soy flour with water and heating it

• Popular in Japan and North America• Available as plain or flavored with vanilla,

strawberry, almond, coffee, chocolate

• Soy milk is interchangeable with cow’s milk in most recipes• May have beany flavor that can be masked by

using honey, maple syrup, or deactivated by using hot water

• Soy milk are ready to drink and may taste like milkshakes

SOY MILK

• Tofu and soy milk contain isoflavones, which are Phytoestrogens

• Plants esterogens weaker than humans

• Lower cholesterol level, and blood pressure

• Reduce symptoms of osteoporosis

• Increase in bone density of lumbar spine observed in women whose daily intake included soy food with 90mg of isoflavones

• Isoflavones inhibit formation and growth of tumors

• Miso -fermented food of Japan prepared from soybeans, salt and rice

• Soy oil used for cooking purposes, salad oil

• Average Americans consume 6 gallons of soy oil a year

• Industries replacing unhealthy fats with saturated fats with soybean oil

• Soy oil used for paints, inks, soaps, insecticides, cosmetics

• Lecithin common food additive is lipid extracted from soybeans

• Adding to cakes mixes, it stabilizes them

Use of soybeans should increase more in future

Beans of the future

• Research is discovering new varieties of legumes

• Phosphocarpus tetragonolobus native to Southeast Asia

• All parts are edible and highly nutritious• Cooked flowers taste like mushrooms• Tendrils supporting the vines taste like

asparargus

Phosphocarpus tetragonolobus

• Leaves eaten like spinach• Roots eaten like potatoes, but its protein

content is much higher• Seeds similar to soy beans (37% protein

content) • Apios americana (groundnut) nitrogen fixing

legume native throughout eastern North America

• Interest in domesticating this plant because 12% to 13% protein content

Apios americana

• Yam bean or Mexican turnip (Jicama) targeted for development

• Source of proteins and carbohydrates• Efficient nitrogen-fixing legume • Seeds, pods, leaves, stem contain rotenone, a

natural insecticide• Cultivated for rotenone• Roots used to cure fevers, and to treat

peeling or itching skin

TOFU

• Bean curd or soy cheese• Popular food in supermarket• Prepared by pureeing soaked soy beans with water, straining them to extract soy milk,

cooking soy milk, adding solidifier to produce curd

• Like yoghurt, can be eaten uncooked

• Tofu high in protein (7.8%)

• Source of calcium, iron, phosphorus

• Easy to digest

• Used as baby food

TOFU

Green Beans

• Widely distributed beans

• French Beans

Green Beans

• Beans oldest and common crops • Protein contents in range of 17% to 31% and

average about 25%

• Dry seeds and green beans, wax beans edible• Warm-season annuals

• Can tolerate most types of soils and can be grown worldwide

• Vicia faba broad bean Old World species• Favism• Eating broad beans or even inhaling the pollen can cause favism• Hemolytic anemia (lysis of red blood cells)

Broad beans

PEAS• Edible seeds cultivated for centuries• United States grows over five hundred

thousand tons a year on commercial basis• Green peas, split peas, Black eyed peas, chick

peas, snow peas• High proteins content (21%)

• Peas good source of vitamin-A, phosphorus, potassium, iron and calcium

• Grown during cooler seasons of year

• Famous pea is garden pea (Pisum sativum) used by Gregor Mendel for his genetics

experiments

Snow Peas

• Whitish tint of pods• Ability to grow in winter and covered with snow

Snow Peas

Black Eyed Peas

Black Eyed Peas

• Cow peas or China Peas• Light colored eye spot• High in potassium, iron, Vitamin A• Associated with good luck

Peanuts• Groundnuts• Originally native to South America• Gold and Silver jewelry recently discovered in

Peru • Archaeologist discovery showed that peanuts

played an important role in ancient time

• Spanish discovered peanuts in 16th Century in South America and brought them back to Europe

• Two varieties in U.S are larger-seeded Virginia peanut and smaller-seeded Spanish peanut

• With 45-50% oil, and 20-30% protein, peanut is highly nutritious seed

• In U.S half of peanut crop used to make peanut butter

• Peanut oil used as cooking, salad dressing, soaps, creams, plastics, and paints

• George Washington Carver introduced and promoted cultivation of peanut