Components of Food
Nutrients: The components of food are called nutrients.
➤ The major nutrients in our food are named carbohydrates, proteins, fats, vitamins, and minerals. In addition, food contains dietary fibres and water which are also needed by our body.
The tests for presence of carbohydrates, proteins, and fats
You will need solutions of iodine, copper sulphate, and caustic soda. You will also need a few test tubes and a dropper.
➤ Test for carbohydrates present in food items. There are many types of carbohydrates. The main carbohydrates found in our food are in the form of starch and sugars. We can easily test if a food item contains starch.
Test for Starch
➠ Take a small quantity of a food item.
➠ Put 2-3 drops of dilute iodine solution on it.
➠ Observe if there is any change in the colour of the food item.
➠ A blue-black colour indicates that it contains starch.
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| Source: NCERT, Testing for starch |
Test for Protein
➠ Take a small quantity of a food item.
➠ Grind or mash a small quantity of the food item.
➠ Put some of this in a clean test tube, add 10 drops of water to it and shake the test tube.
➠ Now, using a dropper, add two drops of solution of copper sulphate and ten drops of solution of caustic soda to the test tube.
➠ Shake well and let the test tube stand for a few minutes.
➠ A violet colour indicates presence of proteins in the food item.
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| Source: NCERT, Testing for protein |
Test for Fats
An oily patch on paper shows that the food item contains fat.
WHAT DO VARIOUS NUTRIENTS DO FOR OUR BODY?
➤ Carbohydrates mainly provide energy to our body. Fats also give us energy. In fact, fats give much more energy as compared to the same amount of carbohydrates. Foods containing fats and carbohydrates are also called ‘energy-giving foods’
Sources of Carbohydrates
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| Source: NCERT, Sources of carbohydrates |
Sources of Fats (Plants)
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| Source: NCERT |
Sources of Fats (Animals)
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| Sources: NCERT |
➤ Proteins are needed for the growth and repair of our body. Foods proteins are often called ‘bodybuilding foods’
➤ Vitamins help in protecting our body against diseases. Vitamins also help in keeping our eyes, bones, teeth, and gums healthy.
Vitamins are of different kinds known by different names. Some of these are Vitamin A, Vitamin C, Vitamin D, Vitamin E, and K. There is also a group of vitamins called Vitamin B-complex.
Our body needs all types of vitamins in small quantities.
➨ Vitamin A keeps our skin and eyes healthy. Sources ➪ Papaya, carrot, mango, milk
➨ Vitamin C helps the body to fight against many diseases. Sources ➪ Guava, orange, tomato, lemon, amla
➨ Vitamin D helps our body to use calcium for bones and teeth. Sources ➪ Milk, fish, egg
➤ Our body also prepares Vitamin D in the presence of sunlight.
➤ Minerals (iodine, phosphorous, iron, calcium) are needed by our body in small amounts. Each one is essential for the proper growth of the body and to maintain good health.
➨ Some sources of iodine ➪ Ginger, Fish, etc.
➨ Some sources of phosphorous ➪ Mik, banana, etc.
➨ Some sources of iron ➪ Jackfruit, banana, etc.
➨ Some sources of iron ➪ Milk, egg, etc.
Dietary Fibres
Dietary fibres are also known as roughage. Roughage is mainly provided by plant products in our foods. Whole grains and pulses, potatoes, fresh fruits, and vegetables are the main sources of roughage. Roughage does not provide any nutrients to our body, this helps our body get rid of undigested food.
Water
Water helps our body to absorb nutrients from food. It also helps in throwing out some wastes from the body as urine and sweat.
A balanced diet provides all the nutrients that our body needs, in the right quantities, along with an adequate amount of roughage and water.
DEFICIENCY DISEASES
Diseases that occur due to lack of nutrients over a long period are called deficiency diseases.
➨ If a person does not get enough proteins in his/her food for a long time, he/she is likely to have stunted growth, swelling of face, discolouration of hair, skin diseases and diarrhoea.
➨ If the diet is deficient in both carbohydrates and proteins for a long period of time, the growth may stop completely. Such a person becomes very lean and thin and so weak that he/she may not even be able to move.
Some diseases/disorders caused by deficiency of vitamins and minerals
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References
- NCERT Science Class 6
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