Chapter-2 “Components of Food” Nutrients: The nutrients are chemical substances needed by our body for proper growth and functioning. Nutrients Carbohydrates Proteins Fats Vitamins and Minerals In addition to these nutrients, our body also requires dietary fibres (roughage) and water for its better functioning.

CARBOHYDRATES * They are the main source of energy for our body to carry out our daily activities. * Plants are the main source of carbohydrates. * The main carbohydrates found in our food are in the form of starch and sugars. * Sources of carbohydrates are chapati, bread, rice, bajra, potato, banana, sugar, rice, fruit, juice, glucose etc. * Glucose and fruit juices contain sugars whereas potato and rice are rich in starch. * They are also called ‘energy giving foods’. chapati potato rice banana bread

Test for Starch Procedure: 1. Take a small piece of chapati or a slice of bread or potato. 2. Put 2-3 drops of dilute iodine solution on it. Observation: The change of colour of solution from brown to blue black indicates presence of starch.

PROTEINS * They are essential for growth, repair and maintenance of our body. *We get proteins from plants as well as animals. *Some common foods rich in protein include pulses, beans, nuts, milk, cheese, eggs, fish etc. *They are also called ‘body building foods’. pulses nuts milk cheese eggs

Test for Protein Procedure: 1. Take some food item and crush it or grind it. 2. Put small quantity in a test tube, add 10 drops of water to it and shake the test tube. 3. Now add two drops of copper sulphate solution and ten drops of caustic soda solution to it. 4. Shake well and let the test tube stand for a few minutes. Observation: After sometimes violet colour appears which indicates the presence of protein.

FATS * Fats are also energy giving food components and make the body strong. * However, same amount of fat provides more energy than carbohydrates. * We get fats from animals as well as plants. * Some common foods containing fats are ghee, oil, butter, milk, meat, nuts, some seeds etc. * These protect internal organs against shock. ghee oil butter meat nuts

Test for Fats Procedure: 1. Take a small quantity of a food item. 2. Wrap it in a piece of paper and crush it. Take care that the paper does not tear. 3. Now straighten the paper and observe it carefully. Hold the paper against light. Observation: If you see an oily patch on the paper, it shows that the food item contains ‘fat’.

VITAMINS * Vitamins help in protecting our body against diseases. *Vitamins also help in keeping our eyes, bones, teeth , gums and skin healthy. *Different kinds of vitamins are known by different names such as Vitamin A, Vitamin C, Vitamin D, Vitamin E and Vitamin K. *In addition, there is a group of vitamins B1, B2,B6 and B12 known as Vitamin B-complex. *Our body needs all types of vitamins in small quantities. Functions of different vitamins in the body:

Kind of Vitamin Function

Vitamin A Keeps skin and eyes healthy

Vitamin B Helps in proper functioning of nerves and muscles

Vitamin C Keep blood vessels, teeth and gums healthy, heals cuts and injuries, helps body to fight against many diseases

Vitamin D Makes bones and teeth strong

Different food items and in particular fruits and vegetables provide us with required vitamins. papaya mango carrot eggs green vegetables cereals orange guava tomato amla lemon fish

Kind of vitamin Food item

Vitamin A papaya, milk, mango, carrot

Vitamin B green vegetables, eggs, milk, whole cereals

Vitamin C orange, guava, tomato, amla, lemon

Vitamin D milk, butter, eggs, fish

MINERALS * Our body also requires some elements like iron, calcium, potassium, sodium, magnesium, chlorine, iodine etc for proper growth and functioning. These are called minerals. * These are also needed by the body in very small quantities, but are extremely essential. Sources of some minerals:

Mineral Food item

Calcium milk and eggs

Potassium dal and fish

Iron green leafy vegetables, apple

Sodium and Chlorine common salt

Phosphorus banana, milk

Iodine fish, iodised salt

salt dal eggs fish green leafy vegetables milk apple banana Food items containing minerals

DIETARY FIBRES/ROUGHAGE * Indigestible fibrous material of food is known as roughage. * Roughage is mainly provided by plant products in our food. * 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. * Roughage retains water in the body by absorbing it in large quantity. * Food items like apple, orange, pear, cabbage, whole grain flour, whole pulses etc contain high amount of roughage. apple orange pear cabbage whole grain flour

WATER * It helps our body to absorb nutrients from food. * It also helps in throwing out some wastes from body as urine and sweat. * We also get water through milk, tea, juices, fruits and vegetables. * In addition, we add water to most cooked foods. milk tea juices fruits and vegetables

BALANCED DIET A diet which contains all nutrients in proper amount/proportion as is required by our body for normal growth and functioning is called balanced diet. It includes energy giving food, body building food, minerals, vitamins, roughage and water.

DEFICIENCY DISEASES Diseases that occur due to lack of nutrients over a long period are called deficiency diseases. * Lack of proteins in food for a long time may lead to- - stunted growth - swelling face - discolouration of hair - skin diseases and - diarrhoea * If food has deficiency of proteins and carbohydrates both, it causes a disease called marasmus in which the growth stops completely.

* Some diseases/disorders are caused due to lack of vitamins and minerals in

food. These are given in the table below:

Vitamin/ Mineral

Diseases/ Disorders

Symptoms Sources/Food items

Vitamin A Loss of vision

Poor vision, night blindness, sometimes complete loss of vision

Green leafy vegetables, carrot, papaya, fish-liver oil

Vitamin B1 Beriberi Weak muscles and very little energy to work

Meat, eggs, whole grains, milk

Vitamin C Scurvy Bleeding gums, wounds take longer time to heal

Citrus fruits, amla, tomato

Vitamin D Rickets Bones become soft and bent

Fish-liver oil, milk, sunlight

Calcium Bone and tooth decay

Weak bones, tooth decay Milk, meat, leafy vegetables

Iodine Goitre Glands in the neck appear swollen, mental disability in children

Iodized salt

Iron Anaemia Weakness Meat, eggs, spinach