Dr.
J. S. Khan
Senior Deputy Advisor
S & T Missions Division
CSIR
Pulses
along with cereals play an important role in the Indian dietary habits. The
annual production is around 14 million tonnes which has remained stagnant since
last three decades. At the current level of production, the per capita
availability of pulses is around 30 gms as against the requirement of 70 gms per
day for an optimal diet. Production stagnation on one side and population growth
on the other have progressively put heavy pressure on their availability. This
has led to escalation of prices of most of the pulses, making them out of reach
of poor people. This situation calls for an increased agricultural production
and minimised post harvest losses that occur drring handling, transport, storage
and processing.
Pulse
milling is an important agro-based industry in India next only to rice and wheat
milling. Unlike wheat or rice milling, processing of pulses to produce dhal is
unique and indigenous to India. This is because substantial quantity of pulses
(more than 10 MT) is consumed in this country as dhal (dehusked split pulse).
Further in most cases traders also operate as millers and farmers are at a
serious disadvantage as they are compelled to sell their produce to them. There
are about 6000 dhal mills in the country, only 8 to 10 per cent of which, are
located in the rural areas, where pulses are largely produced. In general the
processing centres are located far away from actual pulse producing centres
resulting in unavoidable transportation costs.
There
are a large number of small scale processors in the country milling 1-5 quintals
of pulses almost every day either for trade or as a family occupation. However,
their products are inferior in quality and yield, as compared to that from large
commercial plants. The limitiations of the existing small scale pulse milling
industry could be summarised as follows :
a)
Low yield of full dhal, (generally less than 60 percent) due to more brokens
(about 20 to 30 percent) wich makes the process cost intensive.
b)
Unsatisfactory dehusking (less than 90 percent) resulting in lower consumer
acceptance
c)
Difficulty in maintenance and repair of machines in rural areas.
d)
Improper pre-milling treatments leading to product with poor consumer
acceptance.
This
suggests that special attention is required to set up improved small scale
milling units in rural area, right at the production centres. To achieve this
objective, the improved pulse milling machinery (hand operated pulse dehusker
mini dhal mill and versatile dhal mills have been developed and propagated by
CFTRI.
The
husk is tightly attached to the cotyledons in pulses. Hence, a pretreatment for
loosening of the husk prior to milling is essential. This is generally achieved
by pitting, oiling and \ or
moistening the grains followed by sun drying. These treatments have been found
to be most effective where the duration and intensity of sunshine is more and
the humidity is low, for most part of the year, which is higly conducive for
drying of pulses. It is perhaps for this reason that major pulse processing
centres are located in relatively drier areas.
HAND
OPERATED PULSE DEHUSKER
It
is an abrasion type machine which performs the operations of dehusking and
splitting the pulse simultaneously without causing much breakage and powdering.
Separation of husk and brokens is done manually by winnowing and sieving. This
unit can dehusk 40-60 kg preconditioned pulse per hour and can dehusk bold
pulses like Tur, Bengal gram, peas, soyabean, khesari etc. Generally the yield
of head dhal is around 75-80 per cent with a dehusking efficancy of 98-80 per
cent. This is a manually operated unit and does not require power.
MINI
DHAL MILL
CFTRI
designed Mini Dhal Mill dehusks conditoned pulses. Run by a single phase 1 HP
motor, the unit yields 77-80 per cent dhal, with a dehusking of 97-99 percent. A
specially designed grader is also employed toseprate a large quantity of pulse
after premilling treatment. This grader has a capacity of 100-150 kg wet
pulse/hr and is run by 0.5 HP single phase motor. Bold pulses like Tur, Bengal
gram, Field bean, etc. can be dehusked easily with the mill.
Preconditioned
grains are fed to the machine with clearance adjusted to suit the grain size.
Grains are dehusked and split simultaneously. Husk is aspirated off and the
reciprocating sifter seperates brokens. Dehusked dhal is collected separately
and unhusked whole grain is recyled.
Versatile
Dhal Mill
Mini
Dhal Mill developed by CFTRI had become very popular for milling of pulses in
rural areas of pulse producing states. However, because of its ability to dehusk
only near-spherical and bolder pulses as also the need for wet premilling
treatment, there appeared to be a requirement for a larger capacity unit to mill
most pulses preferably using dry pre-milling treatment. A Versatile Dhal Mill,
has therefore, been developed to meet these rquirements. This mill has a
capacity of 250-300 kg per hr. with a power requirement of 15 HP. The mill can
convert all types of pulses to dhals (hence the term Versatile Dhal Mill) using
dry pre-milling treatment preferred by the millers and also popular among the
consumers. Two units of Versatile Dhal Mills are being installed as commercial
unit to popularise the mill.
Gota
Separator :
During
the processing of Tur, a mixture of de-husked, whole grain (gota) and un-husked
pulse is obtained. In traditonal mills this mixture is recycled many times to
increase the proportion of de-husked grains, which results in 1 to 2 per cent
loss of dhal as powder. A mechanised 'Gota Separator' unit has recently been
developed to separate gota from whole pulse based on bouncing principle. An
industrial level unit has been fabricated and demonstrated. Two such units are
being installed in the commercial dhal mills predominantly in the tur processing
areas, for popularisation.
The
above machinery for pulse milling are bing promoted by Technology Mission on
Oilseeds Pulses and Maize, Department of Agriculture and Cooperation, Ministry
of Agriculture, Government of India through Council of Scientific &
Industrial Research (CSIR). These machines provide very good opportunity for
self employment through enterpreneural activities. The industry and investors
should take advantage of these machines.