Chapter 5 Preservation of Food Textbook Solutions

NIOS Home Science Class 10 Chapter 5

INTEXT QUESTIONS 5.1

1. Choose the correct answer to complete the incomplete statements below:

i) Food spoilage is due to

a) micro-organisms and enzymes

b) micro-organisms and excess production

c) enzymes and excess production

d) all the above

Ans: a) micro-organisms and enzymes

ii) Non- perishable food items are those which

a) do not spoil at all

b) take long time to spoil

c) spoil easily

d) spoil according to where they are kept

Ans: b) take long time to spoil

iii) Preservation of food means

a) to keep food safe

b) to retain quality of food

c) to prevent decomposition of food

d) all the above

Ans: c) to prevent decomposition of food

iv) Shelf life of food is related to

a) freshness of food

b) quality of food

c) decomposition of food

d) time limit for which food can be used

Ans: d) time limit for which food can be used

v) The main reason for preserving food is to

a) improve its colour and taste

b) increase its shelf life

c) make costly food available

d) change its texture

Ans: a) improve its colour and taste

INTEXT QUESTIONS 5.2

1. Which of the following will not help to arrest the action of micro-organisms on tomatoes :

(a) put them in boiling water

(b) put them in a freezer

Ans: (c) leave them on the shelf.

2. List four ways of delaying action of micro-organisms on apples.

Ans:

(a) Do not remove the peel
(b) Pack apples in polythene or aluminium foil
(c) Keep in the refrigerator
(d) Make jam

3. Define the terms preservation and shelf life.

Ans: Preservation is a process by which food items are prevented from getting spoiled for a short or long

period of time. The time for which a food can be kept fresh is called its ‘shelf life’. It is also known

as the stability of food during storage.

INTEXT QUESTIONS 5.3

1. Fill in the blanks using appropriate words.

(1) Papad is an example of preservation by…………………

Ans: Dehydration

(2) Refrigeration reduces the activity of …………………. and………………….

Ans: enzymes and microorganisms

(3) Dehydration is based on the principle of removal of…………..

Ans: moisture

2. Write True and False against the following statements:

(i) Addition of spices to pickles allows the microorganisms to grow quickly.

Ans: False

(ii) When making squashes, we make use of an acid and a lot of sugar for preservation.

Ans: True

(iii) Sterilization increases the activity of enzymes and microorganisms.

Ans: False

3. Write down the steps you will follow to preserve cauliflower by the dehydration method.

Ans:

(i) Clean and dry the plates and tin for drying and storing cauliflower.
(ii) Wash and cut cauliflower. Remove stems and any decaying portions.
(iii) Put the cauliflower pieces in boiling water. Take off when they are a little soft.
(iv) Take it out from water and spread it on a clean cloth in the sun. Cover with a thin cloth.
(v) When pieces are dry, cool and stored in tins.

4. Match the following

i Jam	a. Spices
ii Papad	b. Sugar
iii Pickle	c. Citric acid
iv Milk	d. Removal of moisture
v Dried-methi	e. Pasteurization
vi Squash	f. Oil, salt
	g. reducing temperature

Ans: i) b ii) a iii) f iv) e v) d vi) c

5. In your garden, you have plenty of lemons. List the products you can prepare to preserve them. Describe the process of preparing any one preserved product using lemons.

Ans: Individual answer.

6. Match the following:

Foods	Preservatives
i Apple jam	a. Citric acid
ii Lemon pickle	b. Potassium Metabisulfite
iii Potato chips	c. Sodium Benzoate
iv Squash	d. Salt
	e. Sugar

Ans: i) e ii) d iii) b iv) a

TERMINAL EXERCISE

1. Write whether the following statements are true (T) or false (F). Give reasons for your answer.

(i) Oranges can be kept for a long time without getting spoiled.

(ii) While dehydrating fenugreek (methi) leaves, these should be put in potassium metabisulfite for 5-10 minutes.

Ans:

(i) False, oranges can be kept for some time without getting spoiled.

(ii) False, it is not treated with potassium metasulphite; instead, it is dried by keeping it in sunlight.

2. Write down the steps in preserving pudina (mint) leaves by the dehydration method.

Ans: Dehydrating mint

Remove the stems and wash the mint leaves thoroughly.
Put on a cloth in the sun, cover it with a muslin cloth.
Keep it in the sun till it is dry.
Cool to room temperature and store in air-tight containers.

3. Match the statements in Column A with those in Column B

Column A	Column B
(a) Natural preservative	(i) potassium metabisulfite
(b) Chemical preservative	(ii) sunlight
(c) Dehydration	(iii) removing microorganisms
(d) Increasing temperature	(iv) salt
	(v) citric acid
	(vi) vinegar

Ans:

Column A	Column B
(a) Natural preservative	(iv) salt
(b) Chemical preservative	(i) potassium metabisulfite
(c) Dehydration	(ii) sunlight
(d) Increasing temperature	(iii) removing microorganisms