WHEAT

Wheat is the major cereal crop in India. The structure of wheat, its composition and its functional properties are discussed in this presentation.

1. WHEATWHEATWHEAT

2. S C N
STRUCTURE COMPOSITION NUTRITIVE
VALUE
F
FUNCTIONAL
PROPERTIES
AGENDA

3. Wheat is the main cereal
crop in India. The major
increase in the productivity
of wheat has been observed
in the states of Haryana,
Punjab and Uttar Pradesh.
Wheat grown in central and
western India is typically
hard, with high protein and
high gluten content.

4. Endosperm
Bran
Germ
Wheat grains are ovoid in shape, rounded in both ends. The
grain is usually between 5 and 9mm in length and weighs
between 35 and 50mg.
The grain has a single cotyledon and when dissected can be
divided into three main parts.
1.
2.
3.

STRUCTURE OF WHEAT

6. BRAN : The outer layer or the seed covering is called the wheat bran and protects
the main part of the kernel. The bran comprises about 15 percent of the seed
weight.
Bran can be further divided into the pericarp which consists of epidermis,
hypodermis, cross layer, tube cells, seed coats, and hyaline layer.

Bran is nutritionally rich in protein and is
used in the production of brown and
wholemeal flours.
Protein: 4.5 grams/29 gms
Wheat bran is high in fiber and contains
lignan phytochemicals and phytic acid —
reduces the risk of colon and breast cancer.

7. EPIDERMIS: The outer layer-epidermis of the cereal consists of thin walled long
rectangular cells.
HYPODERMIS: Next to the epidermis is the hypodermis.
SEED COAT: The seed coat or testa is a thin single or double layer. The inner layer
of testa is often deeply pigmented which gives the grain its characteristic colour.
HYALINE LAYER: This layer is colourless and devoid of any cellular structure.

8. ENDOSPERM: The endosperm itself consists of cells of various sizes, shapes and
different composition. The endosperm cell consists mainly of starch and protein.
It is the potential white flour within the centre of the wheat grain. When milled, the
endosperm fractures along the cell walls, and separates from the bran layers.
This layer contains the greatest share of protein, carbohydrates, and iron, as
well as the major B-vitamins, such as riboflavin, niacin, and thiamine.

9. GERM: The germ is responsible for germination when planted in soil.

It is a rich source of B-complex vitamins, oil, vitamin E and natural plant fat.

The wheat germ is the embryo that would eventually develop into the wheat plant.
Consequently, it is often used in health foods, such as fortified bread and
wholemeal flour.
ENDOSPERM
83%
GERM
14.5%
BRAN
2.5%

10. ENERGY: Wheat is the main source of energy, mainly in North India. Hundred
grams of wheat gives 340 kcal.
CARBOHYDRATES: 80% of dry matter of wheat is carbohydrate(starch). The
two major carbohydrates present in wheat are starch and crude fibre.
The fibre constituents are cellulose, hemicellulose and pentosans which are
concentrated in the bran layers.
PROTEIN: Proteins are found in all the tissues of the cereal grain. Higher
concentrations occur in the embryo, scutellum and in the aleurone layer.
The type of protein present in the wheat are albumins, globulins, gliadins
and glutelins.
COMPOSITION OF WHEAT

11. FATS: Fats are present to the extent of 1-2%. in wheat. Fats are present in the
germ and bran part of the wheat.
MINERALS: About 95% of minerals present in wheat are phosphates and
sulphates of potassium, magnesium and calcium. A considerable part of
phosphorus in wheat are present in the form of phytin. Some mineral
elements like copper, zinc and manganese are also present in very small
quantities.
VITAMINS: Vitamins such as vitamin B6 are also distributed throughout the
wheat grain.
ENZYMES: Wheat contains amylases, proteases and lipases.

12. NUTRIENT AMOUNT
ENERGY 341 kcal
PROTEIN 12.1 g
FAT 1.7 g
CARBOHYDRATES 69.4 g
CALCIUM 48 mg
NUTRIENT AMOUNT
PHOSPHORUS 355 mg
IRON 4.9 mg
CAROTENE 29 µg
THIAMINE 0.49 mg
RIBOFLAVIN 0.17 mg
NUTRITIVE VALUE OF WHEAT FLOUR

13. FUNCTIONAL PROPERTIES OF WHEAT
The unique presence of glutelin and gliadin in the wheat makes it suitable
for certain recipes.
Glutelin gives toughness and rubberiness to gluten.Gliadin gives elasticity.
Glutenin is much larger molecule than gliadin. Greater the amount of gliadin,
softer the dough will be.
The insoluble protein gluten can be separated readily from flour by adding
water to form a stiff dough and the kneading in water to wash away other
constituents.
GLUTEN FORMATION

14. The wet gluten is cohesive, elastic mass that expands greatly on baking.
Baked gluten contains about 85% protein, 8% lipids and variable amounts
of starch.
In the presence of lipids,
water and mechanical
agitation, the protein
fraction forms a tough
elastic complex termed
GLUTEN.

15. GELATINIZATION:


The process of gelatinisation occurs when starch
granules are heated in a liquid, which results in
the liquid thickening.
In excess water, wheat starch gelatinizes at a
temperature range of about 52–85°C.
RETROGRADATION:
Retrogradation is a reaction that takes place in gelatinized starch when
the amylose and amylopectin chains realign themselves.
Freshly made chappatis is soft and elastic but on storage becomes hard and
brittle.

16. In case of stale bread, where in the crumb
becomes hard , dry and crumbly.
DEXTRINIZATION:
Dry heat also brings changes to starch
granules through a process called as
dextrinization.

If starch is subjected to dry heat, it breaks down
to form dextrins.
When these dextrins dissolve in water, they
have a sweet taste. Colour and flavour
changes occur.

17. REFERENCE:
Food science by B.Shrilakshmi, Seventh edition,
New Age International Publishers.
https://www.ifst.org.com
https://www.goenfoods.com
https://www.healthline.com

18. A Presentation by:
N.AYESHA MARZOOKA
1 st M.Sc N&D