Something to Know
A. Fill in the blanks.
1. Micro-organisms like bacteria and Fungi spoil the food.
2. Insects make their home in dark and moist places.
3. Enzymes can be harmful because they can cause spoilage of fruits and vegetables.
4. Snacks, like biscuits and chips, should be stored in air tight jars.
5. The growth of micro-organisms slows down at low temperature.
B. Write True or False for the following statements.
1. Growth of bread moulds, on bread, indicates that it has got spoiled. True
2. Vinegar is used as a preservative. True
3. It is safe to drink unpasteurised milk. False
4. We can eat more than the required quantity. False
5. We may eat spoiled food rather than wasting it. False
C. Tick (✔) the correct option.
1. A natural insect repellent, found in our kitchens, is-
(a) salt
(b) sugar
(c) turmeric powder (✔)
(d) wheat flour
Answer – (c) turmeric powder (✔)
2. Dry foods, like cereals and nuts, are preserved by-
(a) adding salt and sugar
(b) vacuum packing (✔)
(c) dehydration
(d) pasteurisation
Answer – (b) vacuum packing (✔)
3. Fruits and vegetables get ripened due to the action of-
(a) enzymes (✔)
(b) bacteria
(c) fungi
(d) insects
Answer – (a) enzymes (✔)
4. The least perishable food item, from the following, is-
(a) milk
(b) biscuits (✔)
(c) meat
(d) curd
Answer – (b) biscuits (✔)
5. The chances of spoilage of food can be reduced by keeping the food
(a) moist
(b) warm
(c) at low temperatures (✔)
(d) in open containers
Answer – (c) at low temperatures (✔)
D. Answer the following questions in brief.
1. State two factors that contribute to the fast growth of micro-organisms.
Answer – Two factors that contribute to the fast growth of micro-organisms are:
Moisture
Warmth
2. What is likely to happen to curd if it is not stored in the refrigerator?
Answer – Curd will become sourer and not suitable to be eaten if it is not stored in the refrigerator.
3. What do you understand by food preservation?
Answer – Food preservation is the process of treating, or handling, food to stop or slow down, its spoilage or decay.
4. How can we protect our food from insects, worms and rats?
Answer – We can protect our food from insects, worms and rats by keeping the cupboards, shelves and containers clean and dry.
5. Why does food stay fresh for a longer time when stored in a refrigerator?
Answer – Food stays fresh for a longer time when kept in refrigerator because low temperature reduces the chances of growth of fungi and bacteria.
E. Answer the following questions.
1. Give any three reasons for spoilage of food.
Answer – Three reasons for spoilage of food are:
(i) Micro-organisms
(ii) Enzymes,
(iiI) Insects, worms and rats.
2. How is food preservation useful to us?
Answer – Food preservation is helpful to us in following ways:
It helps to maintain nutritive value of food.
It increases the shelf life of food, thus, increasing its supply.
It makes seasonal foods available throughout the year.
It decreases the wastage of food by preventing spoilage of food.
3. Why is it important to check the manufacturing and the expiry date of packaged food items before consuming them?
Answer – It is important to check the manufacturing and the expiry date of packaged food items before consuming them because if its expiry date is crossed, it means that the food item is no longer fit to be consumed.
4. Explain the following methods of food preservation:
(a) Dehydration
Answer – It is a process of removing water from the food stuff to preserve vegetables like onion, and cauliflowers, since micro-organisms need water to grow.
(b) Canning and Bottling
Answer – It involve cooking food, sealing it in sterile cans or jars and boiling the containers to kill or weaken any remaining bacteria. Fruits, vegetables and meat products are generally canned.
(c) Pasteurisation
Answer – It is the process of heating food followed by immediate cooling, to limit the growth of micro-organisms. Milk is generally pasteurised.
5. Rakesh bought two raw papayas. He kept one papaya in the refrigerator and other papaya on the kitchen shelf. Which will ripen first and why?
Answer – The papaya which is kept on the kitchen shelf will ripen first because enzymes are more active at room temperature than at low temperature in refrigerator.
Value Based Question
Amit’s father organised a party on his birthday. Many food items were prepared for the guests. A good amount of food was left over after the party. Amit asked his parents to distribute that food among the children in the nearby slums. They immediately packed the food and went to distribute it. The children were quite happy while eating that food. Amit felt satisfied by sharing the food items with those children.
1. List the values displayed by Amit and his parents.
Answer – The values displayed by Amit and his parents are helpful, responsibility, compassion.
2. Do you think Amit and his parents did the right thing by distributing the food among the slum children?
Answer – Yes, they did the right thing, as it prevented the wastage of food.
3. Have you ever had a chance to feed a needy person? Share your experience, if any, with the class.
Answer – Yes, I had got several chance to feed the needy people. We were celebrating my sister’s birthday and good amount of food was left after party. So, I asked my parents to distribute food to poor people who have to sleep hungry. We went to their places and distributed the food. We felt satisfied and happy after this work.
Something to Do
1. Find out the recipe for preparing mango pickle. Make a list of ingredients that are added to the pickle to prevent the growth of micro-organisms.
Answer – 2 Kgs. raw Green Mangoes
1 liter Mustard Oil
400 gms. Salt
300 gms.Fenugreek/Methi Seeds
300 gms.Aniseed/Saunf
100 gms.Nigella/Kalonji/Onion Seeds
100 gms.Degi Chilli Powder or Anyother Red Chilli Powder
50 gms.Coarsely Ground Black Pepper
50 gms. Turmeric Powder
We have to follow the stepwise instructions to prepare pickle
Ingredients that are added to the pickle to prevent the growth of micro-organisms are Vinegar. White distilled or cider vinegars
2. Note down the list of ingredients mentioned on a bottle of jam, sauce and juice. Which of these ingredients prevent spoilage of these food items?
Answer – The total mass of a jam is made up of ingredients like sugar, fruit pulp, pectin, preservatives, salt, food colour and other soluble solids present naturally or added in combining form. Sodium benzoate and sodium metabisulphite are the ingredients used to prevent spoilage of these food items.
3. Discuss the following situations in groups:
(a) A large amount of sugar, rice, wheat flour and pulses are stored in a house but fruits and vegetables are bought on daily, or, weekly basis. What could be the reason for this activity?
Answer – A large amount of sugar, rice, wheat flour and pulses are stored in a house because there are unreactive to the air for a long time where as fruits and vegetables are reactive to the air and getting spoiled faster than sugar, rice, wheat. So, it is bought on daily, or, weekly basis.
(b) Mohan visited his grandparents’ village during the Summer Vacation. He saw that there were plenty of mangoes available. He wanted to take a basket full of mangoes. Is he doing the right thing? Give reasons for your answer.
Answer – No, he is not doing the right thing because he will not be able to consume basket full of mangoes. As a result of this mangoes will be spoiled due to growth of micro-organism.
Inside Questions
1. Write the places where the following food items are stored.
Fruits and Vegetables- Lower shelves of the refrigerator
Milk- Refrigerator
Biscuits, chips, pulses, uncooked rice- Air- tight jars at room temperature
Raw chicken, fish or meat- Freezer compartment in refrigerator
Onion and potatoes-
Sugar and salt- In In trays or shelves at room temperature containers at room temperature
Curd- Refrigerator
2. What happens to the milk if it is kept outside refrigerator for longer time?
Answer – Milk will curdle if kept at room temperature for longer time.
3. What are the three types of food on the basis of how long they can be kept without any treatment?
Answer- (i) Perishable foods- These food stuffs spoil very quickly in one or two days. Examples- Milk, meat, fruits and vegetables.
(ii) Semi-perishable foods- These food stuffs last for few weeks or a month before getting spoiled. Examples- Onions, potatoes, cereals, nuts.
(iii) Non-perishable foods- These food stuffs can be stored for months and years without spoiling.
Examples- Sugar, salt, oil, honey
4. Write any five methods of preservation of food and its examples.
Answer- (i) Dehydration- Vegetables like onion and cauliflowers.
(ii) Adding sugar and salt- Pickles, jams
(iii) Canning and bottling- Fruits, vegetables and meat products.
(iv) Pasteurisation- Milk
(v) Vacuum packing- cereals, nuts, coffee, cheese, potato chips
5. Which gas is filled in packets of potato chips to prevent them from becoming rancid?
Answer – Nitrogen
By Sunaina Karmakar