Components of Food
1. Food-it is the group of edible substances which
provide energy to the living beings and repairs the old
tissues and builds the new tissue.
2. Components of food –the various components of
Nutrients-these are organic or inorganic substances
required for the survival of a living being. They include
carbohydrates, fats, proteins, vitamins and minerals.
Diet-It is the amount of food taken by a person at a time.
Balanced diet- A diet containing all the nutrients and
other components in proper proportion is called balanced
Energy-Energy is the capacity to do work.
Deficiency diseases-The deficiency of one or more
nutrients food for a long time may cause certain diseases /a
disorder is known as deficiency diseases.
Malnutrition-If a person does not get adequate food or if
his/her diet does not contain all the nutrients, he or she
Various food components are grouped in three
1. Energy giving food- carbohydrates and
2. Body building food-proteins
3. Protective foods-vitamins and minerals
Carbohydrates-these are the compounds made up of
three elements carbon, hydrogen and oxygen. The
main carbohydrates found in our food are in the form
of glucose, other sugars and starch.
Sources of carbohydrates-these include cereals such as
wheat, maize, rice, jawar, bajra, potatoes, sugar, honey,
bread, jaggery, sugarcane, sugar –beet,
Functions of carbohydrates:
Carbohydrates such as starch and sugar provide most
of the energy to our body.
It is the cheapest source of energy for the body.
Test for Starch/ Sugar
Test for the presence of starch: add a few drops of
weak iodine solution in a test tube containing potato
or wheat flour. The occurrence of blue black colour
shows the presences of starch.
Test for the presences of sugar: Add a few drops of
benedict’s solution into a test tube containing crushed
pieces of bananas, grapes or apple and heat it. The
formation of red precipitate shows the presence of
glucose sugar in the given food item.
Sources of fats- some of the sources of fats are
Function of fats-Fats also gives us energy. Fats
give much more energy as compared to
Test of fats-Wrap the food item in a piece of paper
and crush it. Now, straighten the paper.
Appearance of an oily patch through which light is
faintly visible shows the presence of fat.
Proteins-these are the complex compounds made up of
carbon,hydrogen,oxygen,nitrogen and sulphur.
Sources of proteins-whole cereals such as wheat, ground-
nuts, beans, pulses, fish eggs, meat, milk cheese, etc.
Function of proteins-Proteins are needed for the growth
and repair of the body, they are also called body building
Test of proteins-Take some solution or solution of mash
of the food item in the test-tube. Add a few drops (2-
3drops) of solution of copper sulphate to the test-tube.
Now add 10 drops of solution of caustic soda to this test-
Appearance of a violet colour indicates presence of Proteins
in the food item.
Vitamins-They are a group of organic compounds
essential in small amounts for maintaining normal health
Functions-Vitamins help in protecting our body against
diseases. They also help in keeping our eyes,bones,teeth
and gums healthy.
Vitamins are of different kinds known by different names.
Some vitamins such as vitamin A, vitamin D, and Vitamin E
and vitamin K are fat soluble. Where as Vitamin B complex
(such B1 ,B6 ,B12 etc.) and vitamin C are water soluble.
Minerals-minerals are inorganic compounds (metal and
non metal elements) required in small quantities.
Functions-Minerals form the chief building materials of
structures such as bones and teeth. Each mineral is
essential for proper growth of body and to maintain good
Roughage-Roughage is also called dietary fibres. They
consist of indigestible plant carbohydrates called cellulose
present in plants.
Source-Salad,vegetables,fresh fruits, whole grains and
pulses, beans etc.
Functions-Roughage is an essential component of our
food and add to its bulk. Roughage does not provide to our
body. Roughage helps our body get rid of undigested food
and so help to prevent constipation.
Water-water is very essential component of our body
A major portion of our body is formed of water.
It helps our body to absorb nutrients from food.
It is essential for most of the life processes or body
It also helps in throwing out some wastes from body as
urine and sweat.
Source-We drink water directly as well as we receive water
from milk, tea, fruits, vegetable, cold drinks etc.