Introduction

Introduction

Food is required for our good health, maintenance, growth, and development. Food contains several kinds of substances or constituents. Each one is important for some function or the other. These food constituents which are needed by us for our growth and maintenance are called nutrients.

Components of FOOD

Our foods have seven components. These are:

1. Carbohydrates
2. Fats
3. Proteins
4. Vitamins
5. Minerals
6. Water
7. Roughage (or Dietary fibers)

Function of Food

For providing proper growth of the body.

For performing various body functions.

For repairing damaged or injured body cells.

For manufacturing various cell parts.

For protecting against diseases and infections.

For providing energy to perform various activities like walking, taking, etc.

Classification of Food

Carbohydrates

Carbohydrates contain hydrogen and oxygen. Carbohydrates give the energy to work and play. They are one of the important nutrients needed by all living organisms. Carbohydrates give quick energy. The main carbohydrates are:

Functions: Carbohydrates provide energy. During respiration, these react with oxygen, get oxidized, and produce energy.

Type and Sources

Glucose : Grape Juice, Blood sugar

Fructose : Honey, Fruits

Starch : Rice, Potato, Sweet Potatoes

Test for Starch

Preparation of iodine solution

It can be prepared by taking 5 grams of iodine and dissolving it in 100 ml of distilled water then add 10 grams of potassium iodide. The solution should be stirred thoroughly.

Procedure

Take a slice of bread or a boiled potato. Place a drop of iodine solution on each. On application of iodine solution, both bread and potato become blue-black. This indicates that bread and potato contain starch.

Proteins (Building Blocks)

Protein contains nitrogen in addition to carbon, hydrogen, and oxygen. They are needed to make new cells for growth and to replace old cells. Hairs, nails, skin, and muscles mostly comprise proteins.

Function:

Build new cells and help in growth.

Help to maintain tissue and do necessary repairs in our body.

Provide energy (when needed).

Help in making hormones.

Sources:

Plant sources: nuts, such as cashew nut, groundnut, almonds, and beans, such as soybean, peas, cereal maize, and pulses.

Animal Sources: fish, egg, milk, cheese etc.

Fats : Fats are also compounds of carbon, oxygen, and hydrogen. One gram of fats gives more than double the energy one gram of carbohydrates provides.

Function of Fats:

Fats are concentrated sources of energy.

Fats transport essential fatty acids and fat-soluble vitamins inside the body.

Fats insulate our body against cold.

Fats add flavor to food.

Fats protect our delicate organs.

Sources:

Plants Sources : Nuts, soybeans, seeds of mustard, sunflower, sesame etc.

Animals Sources: Milk, cheese, butter, ghee, egg yolk, and meat.