CHAPTER -2 ‘COMPONENTS OF FOOD’
What do different foods contain?
- 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.
- There are many types of carbohydrates.
- The main carbohydrates found in our food are in the form of starch and sugars.
Test for Starch
- Take a small quantity of a food item or a raw ingredient. Put 2-3 drops of dilute iodine solution on it. A blue-black colour indicates that it contains starch.
Test for Protein
- Take a small quantity of a food item for testing. If the food you want to test is a solid, you first need to make a paste of it or powder it. Put some of this in a clean test tube, add 10 drops of water to it add two drops of solution of copper sulphate and ten drops of solution of caustic soda. Shake well and let the test tube stand for a few minutes. A violet colour indicates presence of proteins in the food item.
Test for Fats
- Take a small quantity of a food item. Wrap it in a piece of paper and crush it. Hold the paper against light. An oily patch on paper shows that the food item contains fat.
- There are also other nutrients like vitamins and minerals
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’.
- Proteins are needed for the growth and repair of our body. Foods containing proteins are often called ‘body building 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.Minerals are needed by our body in small amounts. Few examples of minerals are iodine, phosphorous, phosphorous, iron, calcium etc.
- Vitamin A keeps our skin and eyes healthy
- Vitamin C helps body to fight against many diseases.
- Vitamin D helps our body to use calcium for bones and teeth.
- Rice has more carbohydrates than other nutrients. Thus, we say that rice is a “carbohydrate rich” source of food.
- Besides these nutrients, our body needs dietary fibres and water. 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 main sources of roughage. Roughage does not provide any nutrient to our body, but is an essential component of our food and adds to its bulk. This helps our body get rid of undigested food.
- Water helps our body to absorb nutrients from food. It also helps in throwing out some wastes from body as urine and sweat.
- For growth and maintenance of good health, our diet should have all the nutrients that our body needs, in right quantities. Not too much of one and not too little of the other. The diet should also contain a good amount of roughage and water. Such a diet is called a balanced diet.
- Some nutrients get lost in the process of cooking and preparations.
- If the vegetables and fruits are washed after cutting or peeling them, it may result in the loss of some vitamins.
- The skins of many vegetables and fruits contain vitamins and minerals.
- Similarly, repeated washing of rice and pulses may remove some vitamins and minerals present in them.
- Vitamin C gets easily destroyed by heat during cooking.
- Eat too much of fat rich foods and we may end up suffering from a condition called obesity.
- Deficiency of one or more nutrients can cause diseases or disorders in our body. 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.
- Deficiency of different vitamins and minerals may also result in certain diseases or disorders.
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