Common genera and species of beans

Currently, the world's gene bank holds approximately 40,000 varieties of beans, although only a small fraction is produced in large quantities for everyday consumption.Most of the foods we call "beans", "legumes", "lentils" and "legumes" are all in the same family of legumes ("legumes"), but they come from different genera and species,Native to different homelands and distributed around the world depending on their adaptability.Many varieties are eaten either fresh (whole pods, immature beans may or may not be inside) or hulled (immature seeds, ripe fresh seeds, or ripe dried seeds).Many legumes look alike and have naturalized in various parts of the world, which often leads to similar names for different species.

Properties 

Nutrition

Raw mung beans are 90% water,7% carbohydrates, 2% protein, and contain negligible fat (table).In a 100 g (3.5 oz) reference serving, raw mung beans provide 31 food energy calories and are a moderate source of vitamin C (15% DV) and vitamin B6 (10-19% Daily Value, DV) 11% DV), with no other significant amounts of micronutrients.

Antinutrients

Many types of legumes, such as kidney beans, contain high amounts of antinutrients, which can inhibit certain enzymatic processes in the body. Phytic acid and phytates are found in grains, nuts, seeds and legumes and can interfere with bone growth and interrupt vitamin D metabolism.Edward Mellanby's pioneering work on the role of phytic acid .

Health concerns

Toxins

Some green beans contain a harmful, odorless toxin: the plant lectin lectin, which must be removed by cooking.Red kidney beans are especially toxic, but other types also pose a food poisoning risk. Many types of beans contain lectins,with kidney beans having the highest concentrations especially red kidney beans. Just 4 or 5 green beans can cause severe stomach pain, vomiting and diarrhea.The recommended method is to boil the beans for at least ten minutes; uncooked beans can be more toxic than raw beans.Cooking beans in a slow cooker at temperatures well below boiling without boiling may not destroy the toxin. One case of poisoning from butter beans used to make falafel was reported; the beans were used in place of traditional broad beans or chickpeas, soaked and ground without boiling, formed into patties, and then shallow-fried.Bean poisoning is not widely known in the medical community, and many cases may have been misdiagnosed or never reported; figures appear to be unavailable.In the case of the UK's National Poisons Information Service, which is only available to health professionals, the dangers of legumes other than red beans were not labeled as of 2008.Some parts of Africa use fermentation to remove toxins and improve the nutritional value of beans. Inexpensive fermentation can improve the nutritional impact of dried soybean flour and improve digestibility, according to research co-authored by Emire Shimelis of Addis Ababa University's Food Engineering Program.Pulses are the main source of dietary protein in Kenya, Malawi, Tanzania, Uganda and Zambia.

Bean sprouts bacterial infection

It is common to make sprouts by allowing certain types of beans (usually mung beans) to germinate under moist and warm conditions; sprouts can be used as an ingredient in cooked meals or eaten raw or lightly cooked. Bacterial contamination led to numerous outbreaks, typically Salmonella, Listeria, and E.coli, as well as undercooked sproutssome resulting in mass mortality.

Flatulence

Many edible legumes, including fava beans, navy beans, kidney beans, and soybeans, contain oligosaccharides (notably raffinose and stachyose), sugar molecules that are also found in cabbage.Anti-oligosaccharases are required for proper digestion of these sugar molecules.Since the digestive tract of a normal person does not contain any anti-oligosaccharide enzymes, the consumed oligosaccharides are normally digested by bacteria in the large intestine.This digestive process produces gases, such as methane, as a by-product, which are then released as flatulence.