Processing of Pulses

(Puffed, Flaked & Flour)

By,Karthi

Introduction Pulses – part of Legume family.

High in protein, fibre, & minerals (Zn, Iron, phosphorous, vitamins)

Low in fats

The pulses are nutritionally important since they usually provide the bulk of the

diet. They are also a relatively cheap source of energy, protein, and important

vitamins and minerals.

Processing of pulses is important in improving their nutritive value.

Processing techniques include puffing, flaking and milling.

Soaking in water is the first step in preparing pulses for consumption.

Soaking reduces anti-nutritional factors present in pulses.

Soaking reduces the oligosaccharides of the raffinose family, which are responsible for

flatulence after pulse consumption.

Soaking also reduces the amount of phytic acid in pulses.

Puffing Processing

During puffing, grains are exposed to a

very high steam pressure, which causes

the grains to burst open.

Puffed grains and pulses may be further

processed by toasting, coating, or mixing

with other ingredients.

Sand roasting method:

Pulses are exposed to hot sand, while temperature of sand is about 250°C.

Due to sudden thermal gradient, the moisture inside the grains vaporizes and tries to

escape through the micropores, expanding the starchy endosperm in size in this process .

Bengal gram can also be puffed when the preliminary roasting of grains with sand at

170°C for 75 s & then soaked in water for 5 seconds and impacted between a roller and a

hot plate for de-husking and splitting.

Under these conditions the bulk volumes of grains doubled during puffing

Gun puffing is a process in which the milled grains are introduced in to the gun or high

pressure chamber after preheating, and then a superheated steam is introduced to the closed

rotating chamber

The steam pressure is critical - final texture - puffed product, as too low pressure would result

in product lacking crispiness and too high pressure would shatter the pulses.

Sufficient time is allowed for the superheated steam to cook the grain in semi-plastic state and

in the end, the pressure is suddenly released for obtaining the crispy puffed grain.

The temperature ranging from 240°C to 270°C with corresponding exposure time of 7 to 9.7 s was found to be optimum for higher expansion ratio (8.5 to 10) and better colour of the product

Flaked products

Before flaking, grains and pulses are softened by being partially cooked in steam.

They are then pressed or rolled into flakes which are subsequently dried.

Such partially cooked pulses / cereals may be used as quick cooking or ready to eat

foods.

Both flaked and puffed grains are eaten crisp and need to be packaged in moisture-proof

containers.

The moisture content must be below 7 per cent, otherwise the product becomes soggy and

tough.

Flaked pulses is a thin crispy snack. It is mainly used

as Breakfast cereal.

It can easily be soaked in cold or hot water.

The sample to be Graded, sorted & soaked in hot

water for about 12 to 18 hours and then roasted with

fine sand in roaster.

Soaked sample is flattened between rollers in a

flaking machine until wafer thin.

The pulses are pressed into fine flakes and bran is

powdered and drops down through sieves.

Flattened/flaked pulses are mechanically dried.

Depending on the weight of the rollers flakes of

varying thickness from translucent to thick and

opaque are manufactured.

Flour processing

Milled products Grains and pulses are milled to

produce flours which are used to

produce many types of food.

Three main types of mill are

available:

Plate mill

Roller mill

Hammer mill.

The choice of mill will depend on

the raw material

Reference

Popping and Puffing of Cereal Grains: A Review, Gayatri Mishraa*, D.C. Joshib and Brajesh Kumar Pandaa Journal of Grain Processing and Storage | July-December, 2014 | Vol 1 | Issue 2 | Pages 34-46 © 2014 Jakraya Publications (P) Ltd

Improving the value of Australian pulses through puffing Author: S. P. Mukhopadhyay, J. A. Wood, P. D. Prenzler, C. L. Blanchard and A. J. Saliba S. P. Mukhopadhyay1,2, J. A. Wood1,3, P. D. Prenzler1,2, C. L. Blanchard1,4, A. J. Saliba5

Thank you