TECHNOLOGY OF CEREALS ASSIGNMENT

PIGEON PEAS

(cajanus cajan)

» Pigeon peas is one of the oldest food crops and ranks fifth in importance among edible legumes of the world.

» India alone contributes over 96% of the present world pigeonpea production.

» It is commercially important in countries of East Africa, the Caribbean, and Latin America.

» It is mostly consumed in the form of dal.

» Pigeon peas are very popular in Gujarat. More than 30,000 tonnes of pigeon peas are produced every year in the district of Bharuch and more than 20,000 tonnes in nearby Narmada district

» An erect woody, annual shrub or small tree, 1–4 m tall with a deep taproot (to 2 m).

» Young stems are angled. Leaves trifoliate, alternate, set in a spiral around the stem; leaflets lanceolate, 2–10 cm long and 2–4 cm wide; discolourous - green above, greyish-green below.

» Lateral petioles 2–3 mm long, terminal one 10–20 mm.

» Flowers usually yellow, sometimes with purple or red streaks or plain red;

» Pods flat, acuminate, pubescent , 5–9 cm long, 12–13 mm wide, containing 2–9 oval to round seeds dark brown in colour.

» TEMPERATURE- Pigeon pea plant is very heat-tolerant. Prefers hot moist conditions. Will grow at temperatures above 35°C under adequate soil conditions of moisture and fertility. Does not tolerate frost.

» WATER- pigeon pea plant is one of the most drought tolerant legume crops, with a wide range of rainfall tolerance, but prefers more than 625 mm.

» SOIL- Tolerates a wide range of soils, from sands to heavy black clays. Tolerates a wide range of pH, but the most favourable range is pH 5.0 to 7.0. It is sensitive to salt spray, high salinity and to water logging.

» DISEASES- The crop mostly suffers from wilt, stem rot and sterility mosaic diseases. The wilt and stem rot may be controlled by using resistant varieties, providing well drained soil conditions and adopting a nice crop rotation. The sterility mosaic may be controlled by using three to four spraying of Metasystox 0.1% solution when the first attacked plant is visible in the field.

» INSECTS AND PESTS- There are several insects which are found to attack the crop like pod borers, tur pod fly, plume moth, hairy caterpillar, leaf hopper, bean fly, etc., but the pod borers are found to cause a considerable loss to the crop. Most of the insects can be killed by spraying of 0.2 to 0.3 per cent solution of Endosulfan 35 EC or Nuvacrone40 EC soon after they are visible in the field. The spraying should be repeated for their complete control.

» It is a rich source of proteins, carbohydrates and certain minerals.

» The cotyledons contain about 90% protein, 95% fat, 86% carbohydrates, and 83% minerals.

» Although the germ is rich in proteins, fats, and minerals, its contribution is negligible on a total seed weight basis.

» The nutrient composition of immature seed varies significantly depending on the degree of maturity and the seed moisture content at the time of analysis.

» Generally , the immature seed contains more moisture, but less proteins, carbohydrates, fats, fibre.

» PROTEIN – the protein content of pigeonpeas ranges from 15.5 to 28.8%. The genetic makeup and environmental factors such as application of fertilizers, season of growth, degree of maturity, location influence the protein content.

» The proteins of the seeds have been fractionated into albumins, globulins, prolamins, glutelins, and nonprotein nitrogen.

» Pigeonpea proteins are deficient in methionine, cystine and tryptophan and rich in lysine.

» CARBOHYDRATES – pigeonpeas seeds contain 57.3 to 58.7% total carbohydrates of which major proportion is contributed by starch.

The reducing and non reducing sugars

and crude fibre constitute most of the

other carbohydrates.

Verbascose and stachyose are present in

appreciable amounts.

The pectic substances are known

to influence the

cooking quality of beans.

LIPIDS – the total lipid content ranges from 0.6 to 3.8%. More than 95% of the total lipids are stored in the cotyledons in the lipid containing vesicles.

Palmitic acid in the saturated fatty acid group and linoleic acid and oleic acid in the unsaturated fatty acid group are the principal fatty acids.

MINERALS – pigeonpeas are good sources of dietary minerals such as calcium, phosphorus, magnesium, iron, sulphur and potassium.

Phosphorus is largely present as phytic acid.

VITAMINS – pigeonpeas is a relatively good source of water soluble vitamins especially thiamin, riboflavin, and choline.

Although it contains carotene, it is generally considered low in vitamin A content.

ANTINUTRITIONAL FACTORS – pigeonpea seeds contain several antinutritionalfactors such as protease inhibitor, phenolic compounds, phytate, lectins and saponins. The dark red seeds contain high amounts of polyphenols, most of which are present in the seed coat. Protease inhibitors can be inactivated by moist heat and polyphenols can be easily removed by dehusking the seed.

» Pigeonpea seeds are processed and utilized mainly as dehuskedsplits in Asia. The splits, whole seeds are cooked in water often with spices.

» The splits are cooked in water and consumed with boiled rice or used to prepare traditional products such as sambar and khichdi.

CLEANING

SOAKING

SEASONING

DEHUSKING AND SPLITTING

GRADING

PACKING

» Cooking improved the PER of pigeonpeaproteins, but prolonged cooking destroys the amino acids, changes the protein structure, and reduces the digestibility.

» Cooking is known to reduce the levels of protease inhibitors, hemagglutinins, volatile compds like HCN and reduce polyphenols.

» Precooking and cabinet drying of pigeon pea considerably reduced the reconstitution or cooking time. While unprocessed raw pigeon pea required 85 min for cooking by open pan boiling method. The corresponding pre-cooked and cabinet dried sample required 20 min.

» Also, frozen storage before conventional drying reduced the reconstitution time. The reconstitution time for precooked, frozen and cabinet dried Pigeon pea was only 14 min. The frozen storage before drying accelerated the rate of drying. This may occurred as a result of migration of moisture at the surface in the form of ice crystals which is expected to evaporate faster than the matrix moisture.

» Frozen storage is also expected to cause channels in the matrix of the grain, which will also help in the mass transfer in the conventional hot air drying methods.

» Sensory characterization of whole legumes as affected by different processing method was analyzed.

» The mean score values for colour and aroma for raw pigeon pea were more as compared to other treatments, whereas the values for taste and texture were rated more for precooked, frozen and cabinet dried pigeon pea by the panelist.

» As the sensory characteristics are important in consumer point of view, the prepared product must possess good sensory attributes on the basis of overall acceptability. The mean score values for overall acceptability indicates that precooked, frozen and cabinet dried pigeon peas were liked more than raw one.

» Canning of green seeds of pigeonpea is a common practice in African countries.

» The colour of canned peas and brine is important for acceptability by consumers.

» The final product should exhibit an attractive green colour along with an acceptable flavour.

» There can be a change in colour from green to brown during heat processing is due to enzymatic or nonenzymatic browning.

» Browning inhibitors such as sulphites can be used to control these changes.

» Frozen green peas are usually consumed after cooking separately or mixed with other vegetables.

» Green pigeonpea seeds are nutritionally superior to mature seeds of dal since they are harvested at a stage where the concentration of desired nutrients such as sulphur amino acids are higher.

» Because sugars in peas are so rapidly converted to starch, special procedures are used to ensure rapid delivery to processing plants. Processors manage the harvesting and packing operation. Because peas have to be picked within a day or sometimes less of reaching maturity, scheduling is very important. Processor fieldmen manage the planting operation using a combination of planting dates and varieties of different maturity to ensure that peas mature in sequence and that too much does not mature at once.

» Diseases such as pea wilt can be a problem, but breeders have developed resistant varieties which have effectively kept it at bay. Other diseases such as root rots are controlled by following a careful crop rotation to prevent buildup of the fungi which cause the problem

Pigeon peas provide an excellent source of fiber, protein and sodium. Peas are also low in fat content, making them an ideal food for heart healthy diets.

Nutritional ValuePer 100 gm

Raw Cooked

Energy (Kcal) 343 121

Protein (g) 21.7 6.8

Total fat (g) 1.49 0.4

Carbohydrates (g) 62.78 23.2

Fibres (g) 15 8

» FOLIC ACID - Folic acid is essential for fetaldevelopment and can help to prevent neural tube birth defects .

» PROTEINS - Legumes such as pigeonpeas provide essential nutrients, fibre and protein for vegetarians as well as those who wish to merely limit their meat consumption.

» CARBOHYDRATES - Toor dal is also an excellent source of carbohydrates, body breaks them down into glucose, or blood sugar. Blood sugar is then used to provide energy to your brain, body and nervous system.

» FIBRE - Legumes such as toor dal are a healthy source of dietary fiber, which can help to prevent chronic diseases.

GOOD

» A fine paste made of pigeon pea when applied regularly helps treating bald patches.

» Juice prepared from its leaves with a pinch of salt is said to an effective remedy in jaundice treatment.

» Swelling could be reduced by poultice made from seeds.

» Inflammation of internal organs and swelling can be treated using pigeon pea.

» When mixed with water, it is known to ease intoxicating effects.

BAD

» Anything in excess is bad for health. The same idea holds true in case of pigeon peas as well. Too much consumption is known to cause hyper acidity.

» Patients suffering from heart diseases and gastric ulcers are thus advised to refrain including pigeon pea in their meals.

» COMPOSITE FLOURS- synergistic effects of pigeonpeason the protein quality of various cereals have been reported. The incorporation of pigeonpeas to the extent of 15% in cereals diets based on ragi, pearl millets or wheat improved the PER of cereal diets significantly.

» WEANING FOODS- infant formulations blending pigeonpeas have been developed primarily for children suffering from malnutrition.

» BAKERY PRODUCTS- protein rich biscuits have been prepared from protein hydrolyzates of pigeonpeas. The protein content of the biscuits ranged from 9.5 to 15.5%.

REFERENCE- CRC HANDBOOK OF WORLD LEGUMES BY D.L. SALUNKHE.