SUBMITTED BY

BHUKYA JITHENDER REG:2050215003

M.TECH( Food Processing Engineering.)

SUBMITTED TO DR. S.P CHOLERA Assistant Professor

Department Of Food Processing Enginering

presentation ON

Grain structure of major cereals, pulses and oilseed

CEREAL GRAINS

Wheat Rice Maize Oats Rye Barley

CEREALS Cereals are plants that yield edible grains.

They are consumed worldwide and make up a majority of the worlds calories and

50% of protein consumption.

Rice is the world’s most important food with

wheat not far behind. Over 90% of rice is grown in Asia where it is consumed.

In the U.S., corn is the leading grain but most is used for animal production while

wheat is used directly for human consumption.

Physical Characteristics of Grain

Starchy endosperm- main part of the grain or kernel.

Protective outer layers- bran or hull

Embryo or germ- typically located at the bottom of the kernel.

STRUCTURE OF CEREAL GRAIN

Bran layer 14%: fibre, vitamin B, calcium, iron.

Endosperm 84%: Starch, protein, vitamin B.

Germ 2%: protein, fat, vitamins B & E, iron.

Milling of Cereal Grains

In most milling operations, the hulls are removed which are largely

indigestible by humans.

The dark-colored bran is also removed.

The germ, which is high in oil, is enzymatically active and under certain

conditions would be likely to produce a rancid condition in the grain.

Thus, the main component of interest is the starchy, proteinaceous endosperm.

Since the bran is rich in B vitamins and minerals, it is a common practice to

add these back to processed grains from which they came. This is known as

“enrichment”.

Typically cereal grains contain a moisture of 10-14% if properly dried.

When the moisture content is higher than this, they must be dried or they may Mold or

rot in storage before they can be used.

Cereal grains contain about two-thirds carbohydrate, most is in the form of digestible

starches and sugars.

The operations of milling generally remove much of the indigestible fiber and fat

from these grains

when they are to be consumed for human food.

WHEAT

Wheat is classified into one of two types –

Hard wheat is higher in protein than soft and produces a stronger dough used for bread-making. Soft wheat is better for batters and cake baking.

Wheat milling is basically a succession of pulverizing steps to break down the endosperm.

WHEAT STRUCTURE

CONVENTIONAL WHEAT MILLING

Milling is a progressive series of disintegrations followed by sieving. The disintegrations are made by rollers set progressively closer and closer together.

The first rollers break open the bran and free the germ from the endosperm. The second and third rollers further pulverize the brittle endosperm and flatten out the semi plastic germ.

The flakes of bran and flattened germ are removed by the sieves under the first few sets of rollers.

USES OF WHEAT FLOUR The uses of wheat flour in the baking industry include the making of breads, sweet

doughs, cakes, biscuits, doughnuts, crackers and the like.

Another use of wheat flour and courser milled fractions of wheat are alimentary pastes such as macaroni, spaghetti and other forms of noodles and pasta.

Alimentary pastes are mostly milled wheat flour and water. The wheat is usually hard durum and is milled to yield course particles called semolina”.

Alimentary pastes may also contain eggs, salt and other minor ingredients.

They differ from bakery doughs in that alimentary pastes are not leavened.

Alimentary pastes are usually made with 100 parts wheat flour/ 30 parts water, mixed, and extruded into thin sheets, cut into noodles or other shapes and then dried.

RICE Rice is unusual compared to other grains in that it is not ground into flours before

consumption.

Worldwide, rice is primarily consumed as an intact grain.

The milling process is designed to remove only the outer bran layer and hull without breaking the kernel.

It is often used in the U.S. as a carbohydrate source for making beer because its bland flavor.

RICE MILLING

Rice milling begins with whole grains of rice being fed by machine between abrasive disks or moving rubber belts.

These machines, known as shellers or hullers, do not crush the grains but instead rub the outer layer of hull from the underlying kernels.

The hulls are separated from the kernels by jets of air and the kernels, known as brown rice, move to another abrasive device called a rice-milling machine.

ENRICHMENT

Rice can be enriched in one of two ways;

1)Coat the polished rice with the enrichment mixture (thiamin, niacin and iron) and then coat the grains with a waterproof film material.

2)Parboiling whole rice including the hulls, bran and germ in water for 10 hr at 70C.

This causes the B vitamins and minerals from the hulls, bran and germ to leach into the endosperm. The rice is then dried, milled and polished. This is often referred to as “converted rice”.

CORN

Corn is consumed as both whole kernels ( a vegetable) or as a flour.

Popcorn pops because the moisture expands upon heating and explodes because it cannot escape.

Corn can be dry-milled like wheat or wet-milled.

Wet milling is popular and is used to make corn syrups and high fructose corn syrup

GRAIN STRUCTURE OF CORN

WET MILLING OF CORN

In wet milling, corn kernels are placed in large tanks of warm water with generally an acid and sulfur dioxide as a preservative.

The softened kernels are then run through an attrition mill to break up the kernels. The pasty mass is then pumped to settling troughs. Here is where the oil rich germ floats to the top, is skimmed off to be pressed for oil.

The watery slurry is then filtered to remove the hulls.

The watery slurry now containing the starch and protein fractions is passed through high speed centrifuges to separate the heavier starch from the lighter protein fraction.

The starch is dried to yield “corn starch”.

The protein fraction is dried and referred to as corn gluten or zein which is commonly used for animal feed.

BARLEY, OATS AND RYE

Barley is also used to produce barley malt. In this process, the barley seed is allowed to germinate to a sprout.

The dried barley sprout is now called barley malt and is used in the brewing industry to help digest starchy material into sugars for rapid yeast fermentation. The malt also adds a distinctive flavor to beer.

Malt further adds flavor to breakfast cereals and malted-milk concentrates.

CEREAL PRODUCTSCereal ProductsWheat Flour, semolina (couscous), pasta,

weetabix and other breakfast cereals.Rice Ground rice, rice flour, rice wine, rice

cakes, Rice Krispies, rice paper.Maize/corn

Corn on cob, sweetcorn, maize meal, corn flour, corn oil, popcorn, cornflakes.

Oats Oatmeal, pinhead oats, rolled oats for porridge and muesli, oatmeal biscuits.

Rye Rye bread, crispbread, whiskey.

Barley Pearl barley, barley water, whiskey.

PULSES• Pulses constitute essential components of vegetarian diet. Pulses are major source of protein in Indian vegetarian diet.

• These are main source of protein providing most of the essential amino acids to a certain degree. • Economically, pulses are cheapest source of protein. Pulses are Bengal gram, pigeon pea, black gram, green gram, lentil, etc.

• Pulses are mainly consumed in the form of dehusked split pulses, as these are rich in proteins. In vegetarian diet pulses are main source of protein.

PULSES FIG

PULSE MILLING • Pulses are usually converted into Dhal by decutilating and splitting.

• Both dry and wet milling processes are employed. By and large carborundum emery rollers are used for dehusking and burr grinders for splitting.

• Decuticling is seldom complete in single pass requiring multiple passes, each pass producing 1.5 to 2% fines reducing recovery of dal.

OILSEED

• Oilseeds are rich sources of energy and nutrition.

• The oils and fats present in them are useful as food fats and industrial raw material.

• The proteins present in some oilseeds and their cakes are edible to humans while the others are useful as animal feeds.

• Oilseeds also contain carbohydrates, vitamins and minerals.

• Oilseeds and oilseed meals have an important role in relieving the malnutrition and calorie nutrition of human and animal population.

Soybeans

• Soybeans are very versatile food products used for both animal and human foods.

• Soybeans can have up to 23% fat.

• Soy protein is quite extensively used for animal feed as a protein source.

Peanuts

• Peanuts contain 25% protein and 50% oil.

• They are used mainly to produce peanut butter (50% of the crop).

• They can also be used to make flour and used for oil.