MANGOES AROUND THE YEAR-TEXT

MANGOES AROUND THE YEAR

ENVIRONMENTAL STUDIES 

CBSE-V

Children in this lesson we are going to learn about Spoilage and wastage of food,preservation of food(drying and pickling).

Food spoilage means the original nutritional value, texture, flavour of the food are damaged, the food become harmful to people and unsuitable to eat.

There are three types of microorganisms that cause food spoilage -- yeasts, moulds and bacteria. 

yeasts and moulds can thrive in high acid foods like fruit, tomatoes, jams, jellies and pickles.

Bacteria are round, rod or spiral shaped microorganisms. Bacteria may grow under a wide variety of conditions. There are many types of bacteria that cause spoilage.

Fungal Spoilage: Blue mould rot in tomato caused by Penicilliumi spp,

Watery soft rot in apple caused by Sclerotinia sclerotiorum.

Bacterial Spoilage: Soft rot in tomato caused by Erwinia carotovora.

Enzymes:

Enzymes are proteins found in all plants and animals. If uncooked foods are not used while fresh, enzymes cause undesirable changes in colour, texture and flavour. Enzymes are destroyed easily by heat processing.

Oxidation by air:

Atmospheric oxygen can react with some food components which may cause rancidity or color changes.

Microorganisms, specifically bacteria, molds, and yeasts, can cause food to spoil. For example, microorganisms that break down fats in unsalted butter can cause it to become rancid. Bacteria that breaks down protein in meat (proteolytic bacteria) and results in foul odors.

Biji returned the bread:

Aman’s Biji went to the market to buy bread. The shop was very crowded. The shopkeeper picked up a packet of bread and gave it to Biji. She looked at it and returned it immediately.

How does food get spoilt?

The whole class can do this experiment together. Take a piece of bread or roti. Sprinkle a few drops of water on it, and put it in a box. Close the box. See the bread or roti everyday until you find some changes on it.

Make this table on a chart paper and put it up in the classroom. Fill up the chart every day after discussing the changes seen.

So children the fod gets spoiled easily.bacteria and fungi grow well at room temperature in the presence of moisture. Cereals and pluses do not get spoiles easily as there is no moisture in them.

Spolit food it unfit for consumption. It taste bad and can causes disease.

Therefore, it has to be prevented from spoilage. This prevention is termed as preservation.

PRESERVATION OF FOOD:

Food can be presrved by the following methods. We can stored food by this following five methods.

1. Cooling Or Refrigeration

2. Jellying

3. Pickling

4. Drying Or Dehydration

5. Tetra packing

6. Canning

1. Cooling Or Refrigeration: food spoiling bacteria do not grow in cold temperature. So, this is a common way of preservation.

2. Jellying: fruits like strawberries, mangoes and pine apples are preserved by this method. The fruit pulp is a boiled in sugar syrup. Sugar acts as a preservative. Jams and fruits are preserved in this way.

3. Pickling: seasonal fruits like mangoes, lime, amla and garlic are preserved by pickling. For this we add `salt, vinegar and oil are used as preservatives in pickles.

4. Drying Or Dehydration: the food can also be preserved by drying in the stem. Spices like chillies and ginger, papadas and food grains are preserved by drying in the sun. Dry means removing the moisture content of the food which promotes the growth of bacteria.

5.Tertra packing : this method is similar to canning but is used for liquids. Here, the food is heated to very high temperature and then packed in terapacks .

Ex: milk, juice, oil, and ghee are stored in this way.

6. Canning: in this process the food is heated temperature to kill the food spoiling bacteria and then stored in air tight cans or bottles.

Food preserved helps in preventing wastage of food from the spoiling. It also helps us to store food and use it when it required whole the year. All preserved foods have a shelf life. While buying and using preserved food, we should check the expiry date mentioned at the label of the product.

Summer treat – Mamidi tandra:

Chittibabu and Chinnababu live in Atreyapuram town in Andhra Pradesh. The brothers spend the summer holidays playing in the mango garden, when the trees are full of fruits. They also like to eat unripe mangoes with salt and chilly powder.

At home, their mother cooks unripe mangoes in different ways. She also makes many kinds of mango pickles. The pickles last through the year until the next mango season. One evening, while having food Chinnababu asked, “Amma, we have so many mangoes. Make some mamidi tandra (aam papad) from them.”

Their father said, “Making mamidi tandra needs four weeks of hardwork. If you both promise to help us everyday for the next four weeks, we can together make the mamidi tandra.”

Both the brothers quickly agreed to help. The next day both the children went to the market with their father. They bought a mat woven from the leaves of a palm tree, poles of casuarinas tree, string made of coconut husk, some jaggery and sugar. Amma found a sunny place in the backyard. Both the brothers made a high platform by using poles. They spread out and tied the mat on that platform.

The next day, Appa chose the most ripe mangoes.  They took out the mango pulp into a large pot. Then they strained the pulp through a fine muslin cloth, to remove the fibres from the pulp.

Then Chittibabu crushed the gur (jaggery) till there were no lumps. They added the jaggery and sugar in equal amountsto the pulp.

Chinnababu mixed the jaggery and sugar well with a big spoon. Amma then spread this pulp into a thin layer over the mat. The thin layer was left to dry in the sun. In the evening, they covered the mat with a clean saree to avoid any dust.

The next day they again took out some mango pulp. They added jaggery and sugar into the pulp. Then they spread the pulp over the previous day’s layer. This work was given to both the brothers. Both of them together spread many layers over it.

For the next four weeks they hoped that it would not rain. For four weeks, they added layer after layer until the jelly grew four centimetres thick and looked like a golden cake.

After some days Amma said, “The mamidi tandra is ready, we can

take it out and cut it into pieces tomorrow.” The next day, the mat was brought down from the platform.

Mamidi tandra was cut into smaller pieces. The brothers tasted it. It was tasty. Chhinnababu said, “Wow, how tasty! After all we have also helped in making it.”

THANKYOU,

NANDITHA AKUNURI

SUNITA IN SPACE- TEXT

SUNITA IN SPACE

ENVIRONMENTALSTUDIES

CLASS-V

CBSE

Childen we going to learn about great Sunita " Williams. She was  Born September 19, 1965. She is an American  astronaut and united states navyofficer of Indian-Slovenian descent.

Straight from the heart -What do you think the earth looks like? Make a drawing of the earth in your notebook. On your drawing show where you are. Take a look at your friends’ drawings too.

What is our earth really like?

Uzaira and Shahmir are playing with the globe. While they play they are talking to each other.

Uzaira: Do you know that Sunita Williams is visiting our school tomorrow? I have heard that she has spent more than six months in space.

Shahmir: (looking at the globe) Hmm... look here is America, Africa. Hey, where is space? Uzaira: The sky, stars, sun and moon, they are all in space.

Shahmir: Yes, I know. Sunita Williams went in a spaceship. I saw on TV that she could see the earth from there.

Uzaira: Yes, from there the earth looked like this globe.

Shahmir: If our earth looks like this globe, then where are we?

Uzaira takes a pen and places it on the globe.

Uzaira : Here we are. This is India.

Shahmir: If we were here like this, we would all fall off. I think

we must be inside the globe.

Uzaira: If we are inside, then where is the sky, the sun, the moon and the stars? We must be on the globe. And all the seas and oceans must also be on the globe.

Shahmir: (pointing towards the lower part of the globe) You mean

to say that no one stays here?

Uzaira: People live here too. Brazil and Argentina are here.

Shahmir: Are the people there standing upside down? Why don't

 these people fall off?

Uzaira: Yes, it looks strange, isn’t it? And this blue part must be the sea. Why doesn’t the sea water fall off?

If the earth is round like a globe, how is it that we do not fall off?

Do the people in Argentina stand upside down?

Talking with Sunita

When Sunita Williams came to India, thousands of children like Uzaira and Shahmir got a chance to meet her.

 

Sunitasays that her friend Kalpana Chawla wanted to come to India and meet children. She came to India to fulfil Kalpana’s dream.

Sunita’s experiences of living in space! We could not sit at one place. We kept floating in the spaceship from one end to another.

Water too doesn’t stay at one place. It floats around as blobs. To wash our face or hands we had to catch these blobs and wet paper with them. 

We ate very differently there. The real fun was when all of us would float into the dining area of the spaceship and catch the floating food packets!

 In space there was no need to use a comb. My hair kept standing

all the time! Not being able to walk, we had to get used to floating around.

We had to learn to do simple things differently. To stay at one place, we had to strap ourselves there. Papers also had to be stuck to the wall of the spaceship. It was a lot of fun living in space but it was also difficult.

Isn’t it amazing?

Sunita Williams went 360 kilometres away from the earth, in the spaceship. Think how far this would be! Find out which town or city is located about 360 kilometres away from where you live. This is how far Sunita Williams went away from the earth.

Where are the lines, really!

Sunitadescribes her view of the earth from the spaceship: “The earth looks so beautiful and amazing. We could watch it for hours, from the window of the spaceship.

We could clearly see the curved shape of the earth.”Sunita’s experiences have been used to give to children a sense of the earth’s gravity.

 Actually, in the spaceship Sunita did not experience the pull of the earth because the spaceship was revolving around the earth.

When Sunita saw the earth from space she found the earth very beautiful. Many thoughts came to her mind. As she describes it, “From so far away, one can only make out the land and the sea.

Look at this photograph of the earth, taken from a spaceship. From such photographs today we know what the earth looks like. But thousands of years ago, people could only imagine what the earth looked like. Scientists tried hard to find out - how big is the earth, how does it go around?

Uzaira: See, there are lines between the different countries on this globe. Are such lines also there on the earth?

Shahmir: There must be. They are there on the map of India in this book. See, there are lines between the different states too.

Uzaira and Shahmir are looking at different countries on the globe.

Uzaira: If we go from Delhi to Rajasthan, would we find such lines made on the ground?

Shahmir: He closes one eye and moves the coin back and forth while looking at the moon. Look, I can hide the moon behind this coin.

Uzaira: Wow! Imagine hiding such a big moon behind such a small coin. Why don’t you try to do the same with a coin. How many centimetres away from the eye did you keep the coin to hide the moon.

Shahmir thinks that there are lines drawn on the ground between the states. What do you think-

Lines refer to “parallels and meridians”. Distances refer to “latitudes and longitudes”

One cannot see the different countries. Division into countries has been done by us. All the lines on the maps are made by us, they are in our minds. I wish we all think about this. Where are the lines, really?”

Have you ever looked carefully at the sky at night? Do not the

twinkling stars look magical! And sometimes the moon is silvery and

bright, while sometimes it is nowhere to be seen in the black sky.

An interesting photograph!

Aspaceship went to the moon. This photograph of the earth was clicked

from the surface of the moon. See how the earth is looking. Can

you see the surface of the moon.

Sunita was five years old she saw pictures of Neil Armstrong landing on

the moon. In 1969, Neil Armstrong was the first man to walk on the moon. Like any other child, Sunita was also fascinated.

Sunita says that when she was a young girl she really loved sports, especially swimming. She was never too interested in studies. After high school Sunitawanted to become a diver. But she could not get into that course.

 Instead, she became a helicopter pilot. One day she found out that if she studied and trained for it, she could join the Space Mission. And that is what she did!

In 2007 Sunita Williams set a new record for the longest space flight by a woman. Sunitaoften gives her own example to tell children, “If you want something, but you get something else, do not give up. Do your best, and things will work out!”

When Sunita was asked by a child what would she like to do in the future, she answered, “I want to become a school teacher!” So that she could make children understand how science and maths are closely linked to our lives.

THANKYOU,

NANDITHA

REFERENCE BOOKS

1.Antariksh Pari : Sunita Williams