gran structures and its composition

2. 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
Grainstructure of majorcereals,pulsesand oilseed

3. CEREAL
GRAIN
S
 Wheat
 Rice
 Maize
 Oats
 Rye
 Barley

4. 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.

5.  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.

6. 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.

8.  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”.

9.  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.

10. 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.

11. WHEAT STRUCTURE

12. 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.

13. 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.

14. 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.

15. 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.

16. 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”.

17. 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

18. GRAIN STRUCTURE OF CORN

19. 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.

20.  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.

21. 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.

22. CEREAL PRODUCTS
Cereal Products
Wheat Flour, semolina (couscous), pasta, weetabix and
other breakfast cereals.
Rice Ground rice, rice flour, rice wine, rice cakes,
Rice Krispies, rice paper.
Maize/c
orn
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.

23. 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.

24. PULSES FIG

25. 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.

26. 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.

27. 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.

28. 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.