The seeds of leguminous plants are known as legumes or pulses. Pulses when decorticated and split are known as dhal. Pulses are the main source of protein for vegetarian. Even though pulses do not contain all essential amino acids necessary for growth, when taken in combination with cereals or other vegetables their nutritional value improves. Soya beans are an exception to this rule because the biological value of its protein content is very good.
Pulses contain the same amount of calories as cereals but the protein content varies from cereals. The protein content of pulses are twice that of cereals (20 - 25%) and almost equal to that of meat and poultry. But the quality of protein content is inferior to animal protein.
Pulses are lacking in amino acid methionine than the animal protein but the lysine content is more. This limitation can be over come by combining pulses with cereal. Quality of protein improves in this combination of cereal and pulse. Common examples of this food combination are idli, dosa, khichadi, and chapathi with pulses.
Pulses contain negligible amount of fat with exception of soya bean. Soya bean has about 19.5gms of fat for 100 gms. Unsaturated fats are the major types of fat present in pulses. Among the vitamins pulses contain fair source of thiamine, riboflavin and nicotinic acid. The iron content is high in pulses, about 8- 10 mg per 100 gms. Pulses and legumes also contain potassium, phosphorous, manganese and magnesium.
Whole pulses contain insoluble and soluble fibre. Insoluble fibre guard against constipation so reduces the risk of the colon and rectum cancer. Soluble fibre help in lowering blood cholesterol levels and thus reduces the risk of cardiovascular diseases. The starches and carbohydrates content of pulses are complex type and are digested and absorbed slowly. This helps to a steady release of glucose into the blood and is useful for diabetics to control their blood sugar levels. Soya beans, because of its the phytoestrogen content, believed to have a role in protecting breast cancer, osteoporosis and menopausal symptoms.
Nutritive value of pulses and legumes per 100 gms
Pulses and legumes
Bengal gram whole
Bengal gram dhal
Black gram dhal
Green gram whole
Green gram dhal
Germination and fermentation
The germination of pulses increases its nutritional content. The germinated pulses have high vitamin C content than the normal seed. Other vitamins that show an increase are B complex vitamins and folic acid. Tannin and phytates, those adversely affect the bioavailability of nutrient, are broken down on germination. Like wise the chlorophyll content also increases when the sprouted shoots change from yellow to green. Fermentation of the dhal to make idli, dosa, and dhokla also enhances the B vitamins and decreases the phytate content and trypsin inhibitors.
Draw back of pulses
Soyabeans and its products can cause food allergy. This can result in headaches and indigestion in susceptible people.
People who are suffering from gout preferably should avoid beans and peas due their high content of purine.
Pulses can cause flatulence.
Kesari dhal contains a toxic factor beta oxalylamino alanine ( BOAA) which results in paralysis when it is consumed as the staple for long periods of time. This toxin can be removed by boiling this dhal at 60Â° C for several hours and discarding the steeping water.