2. INTRODUCTION
• Biological Name: Vigna Mungo
• Family Name: Fabaceae
• Product Name: Urad dal/ Split black gram
• It originated in India, where it has been in cultivation
from ancient times.
• It is the third most important legume in India
• It is a hairy bushy herb growing upto 1-3ft.
Growth Conditions Values
Temperature 25-35 degree Celcius
Rainfall 80-100cm
Soil Black Cotton Soil
3. PRODUCTION
• Total black gram production in the world is about
2million tonnes.
• India is the largest producer as well as consumer of
black gram.
• It produces about 1.5 million tonnes of urad annually
from about 2.5 million hectares of area with an average
productivity of 400 kg per hectare.
• Black gram output accounts for about 10% of India's
total pulse production.
• Urad produced almost entirely for local consumption
and inter-state trade within India.
• Apart from India it is also cultivated in Pakistan,
Afghanistan, Bangladesh and Myanmar.
4. COMPOSITION & STRUCTURE
For Husked Seed g/100g
Moisture 10.3
Protein 23.9
Fat 1.4
Ash 3.4
Carbohydrate 60.4
Calcium 0.2
Phosphorus 0.4
Vitamin A 65IU
Vitamin B 140IU
5. PROCESSING
• Dry Milling
Harvesting from
pods
Cleaning
Rough Roller
Mill
-For scratching the surface
-Removal of waxy layer
Oil coating-
1-2% Oil
Heaped and left overnight
Sun Drying
4-6 hours
Tempering
4-5% Water
Left Overnight
Sun Drying
3-4 Days
Milling
-Roller Mills
-Dehusking and Splitting
Polishing
DRY milling of black gram
After cleaning the black grams are subjected to pricking in a rough roller mill for some scratching as well as partial removal of the waxy coating on the black grams.
The scratched grain; are then coated with 1 to 2 per cent oil in a worm mixer and then heaped over night for diffusion of the oil in the grains. The scratched and oil coated pulses are sprayed in drying yards for sun drying for 4 to 6 hours. The partially dried grains are moistened with a spray of 4 to 5 per cent water and kept over night for moisture equilibration. The wetted pulses are then dried for 3 to 4 days in the sun and tempered over nights in between these drying periods. The thoroughly dried pulses are dehusked in a roller- About 40 to 50 per cent pulses are dehusked and split in first milling operation. The husk and powder are then aspirated off. Then the split dhal is separated from the dehusked whole dhal and unhusked pulses by sieving. Both husked and unhusked whole grains are again dried in the sun and milled as above and the same process is repeated until the desired milling of pulses is achieved. The average yield of dhal is 70-71 per cent. Sometimes the last part of the unsplit grains and partially husked grains are allowed to pass through sheller and polisher machines for splitting and removal of the husk, which result in a large amount of losses due to formation of powder and brokens.
In some cases polishing is done in a buffing machine. In order to give a white finish and to protect from insect attack a coating of soapstone powder is generally given to these 'dhals’.