Legumes

I. Introduction

A. Fabaceae

• Faboidae (common beans-food crops, pulses)
• Caesalpiniodeae (tropical trees or shrubs-tamarind)
• Mimosoideae (Mimosa-acacia, albizia, sensitive plant, leucaena)

B. Root Nodules and Nitrogen Fixation

1. Nitrogen Cycle 

-nitrogen is essential to make proteins, nucleic acids, etc.

-often the limiting factor for plant growth/alternate legumes with other crops (e.g. soybeans and rice)

-most nitrogen on earth is in the atmosphere in an oxidized state (N₂)

-conversion of N₂ to usable forms (NH₄, NO₃, etc) requires energy and/or microorganisms 

2. Legumes and nitrogen fixation

root nodules close-up view microscopic view of bacteroids (Rhizobia)

nitrogenase leghemoglobin

C. Legume Nutrition

high nitrogen content, but...

soybean protein amino acids

D. Legume Crop Yields

the cost of nitrogen fixation reduces yields

E. Legume Toxicity

natural defense against fungal pathogens

lose weight the easy way?

protease inhibitors, etc. genetic engineering (example: amylase inhibitor) weight loss products 

Other responses to eating legumes!

alpha galactosidase pre-treatments

II. Example Legumes

A. Pulses

1. Lentils (Lens culinaris); seeds dal

2. Peas (Pisum sativum) flower  

3.Broad Bean (Vicia faba) seeds

4. Soybean (Glycine max) seeds

trypsin inhibitors

miso tofu soy sauce

TVP example

Industrial uses example

5. Common Bean (Phaseolus vulgaris) seed variety

6. Peanuts (Arachis hypogaea) b

George Washington Carver

John Harvey Kellog

B. Tamarind and Carob

1. Tamarind (Tamarind indica)products

2. Carob (Ceratonia siliqua) seeds products

C. Forage Legumes

-planted to improve soil

-cannot be sole grazing forage (same problem for us!)

-Alfalfa (Medicago sativa) root growth