- Edible fruits or seeds of pod-bearing plants : family leguminosae
- Legumes : Alternate name for pulses
- Gram : Dry legume seeds with husk
- Dhal : Split decorticated grains
- Over 13,000 plants belong to family leguminosae
Nutritive value and composition
- Energy :
- 340 cal/100g
- 100 cal/30g (per serving)
- Deficient in Sulphur containing amino acids e.g. methionine
- Pulses are rich in lysine. Cereals lack in lysine.
- (FAO) Soybean contains adequate tryptophan.
- contain mainly globulins, a few albumins.
- high protein content-20-40%
- Carbohydrate :
- 55-60% carbohydrates
- Include-starch, fibre
- 5% lipid by dry weight.
- Most of the pulses contain, high amount of PUFA – Linoleic acid, linolenic acid
- Undesirable changes due to oxidative rancidity during storage
- Loss of protein solubility
- Off-flavor development
- Loss of nutritive quality
- Important sources of Ca, Mg, Zn, Fe, K, and P
- Around 80% of Phosphorus – in form of phytate
- Phytin complexes with proteins & minerals & render them biologically unavailable
- Excellent source of Thiamine, folic acid & pantothenic acid.
- Fairly rich in Niacin.
- Contain small amount of Vitamin A-carotene.
- Germinated legumes contain some Vitamin C.
Digestibility of Pulses
- Chick pea protein has high digestibility
- Lentils such as Rajmah – low digestibility due to albumin-which is not easily digestible
- Factors that reduce digestibility of pulse proteins-
- Pulse proteins have high molecular weight & compact molecules
- Some proteins complex with carbohydrate & influence digestibility
- Some proteins complex with phytin
Processing of pulses
- Important to improve nutritive value
- Various processing methods:
Decortication or Milling
- Dry pulse seeds have a fibrous seed coat (husk) which is indigestible & may have a bitter taste.
- Dhals-dehusked & split pulses.
- Yield of dhal during milling-around 82 %
- Protein digestibility improves.
- Removal of husk reduces fibre content.
- Improves appearance, texture, cooking quality & palatability.
- Keeping quality is improved.
During dehusking germ gets removed causing loss of some thiamine content.
- Whole pulses are soaked in cold water-overnight
- Or in warm water -60-700C for 4-5 hours.
- Makes the pulse tender
- Hastens the process of cooking
- Improves nutritive value of pulses.
- Dormant enzymes are activated.
- Starch, proteins -> simple substances
- Provide more essential amino acids
- Phytic acid amount is reduced. Availability of proteins & minerals increases.
- Riboflavin, niacin, choline & biotin content increases
- Vitamin C is synthesized during germination.
- Decreases cooking time
- Improves taste & texture, add variety to diet.
- Increases digestability, palatability & nutritive value
- Toxic substances can be eliminated by fermentation
- Availability of EAA increases
E.g. idly making.
- Nervous disease
- Cause-excessive consumption of pulse kesari dhal for long period.
- Group affected- young men 15-45years old
- Lathyrism develops only when the consumption of this dhal is in high amounts (300 g/day) for six months& the diet does not contain adequate quantity of cereals.
- Contain 28%protein.
- 1st stage –Difficulty in walking
- Final stage-Bending of knees & extreme stiffness of lower limbs, patient has to crawl.
- Toxin can be reduced by parboiling. Special hot & cold water treatment for prolong time.
- Disease-Hemolytic anemia
- Occurrence-when individual deficient in G-6PD (Glucose-6 Phosphate Dehydrogenase) consumes broad beans or by inhaling the pollen grains.
- Deficiency of G-6PD affects the metabolism of glutathione in red blood cells. Red blood cell is more prone to injury & destruction.
- In severe cases of favism-death may occur within 24-48 hours of onset of attack. Children are more vulnerable. If the victim survives acute stage, recovery takes four weeks.
Other Harmful Substances
- Trypsin inhibitors
- Thiocyanates, isothiocyanates present in soybean, lentil, groundnut etc. are called goitrogens.
- They interfere with Iodine uptake by thyroid gland.
- Excessive intake of these foods with marginal intake of Iodine from food & water may lead to Goiter.
- Trypsin Inhibitors-
- A protein found in many pulses, suppresses the release of amino acids
- stimulates th
- e production of extra trypsin by the pancreas & brings about its loss of activity.
- are condensed polyphenolic compounds.
- Tannins bind with Iron & interfere with iron absorption .
- They also bind proteins & reduce their availability.
- Removal of seed coat reduces tannins.
- Black & red seed coat – More tannin content
- White coat beans- less tannin content
- They are also proteins which combine with products of digestion & thus impair the efficiency of absorption of nutrients.
- Role of pulses in cookery:
- Give bulk to the diet
- Give satiety-due to high protein & fibre
- Rich in protein & B-vitamins
- Give variety to diets :
- Used in salads-e.g. sprouts
- Used in sweets & deserts-e .g. Laddu, Mysore Pak
- chivada, chutney making
- In snacks-bhajji, pharsan, potato vada.
- Fermented pulses in-idly, dosa.
- Soybean-useful pulse & an oilseed
- 1st produced in China
- Now U.S.A. is the no. 1 producer
- Is used to produce textured vegetable protein-TVP-also known as nutrinuggets , to replace the meat.
- So many products are available,-Soya curd-also known as Tofu
- Soybean milk, Soy sauce
- Infant formula-for lactose intolerant babies
- Bengal gram-long time consumption decreases serum cholesterol by increasing fecal excretion of bile acids.
- Provide high fibre-decreases rise in blood sugar, so good for diabetics.
- Guar gum-a gel derived from cluster bean.
- decreases plasma cholesterol.
- decreases cholesterol absorption of liver.
- Increases insulin sensitivity.
- Acts as soluble fibre.
- Able to form a viscous gel in small intestine.
- Pulses in human nutrition-
- Protein malnutrition is common in underdeveloped & developing countries.
- Pulse protein is a cheaper source of protein.
- By a suitable combination of pulses, rice and oil seeds a formula can be prepared with a high quality protein, an amino acid profile as close as to that of good animal proteins.