NIOS Class 12 Home Science Chapter 7 Purchase and Storage of Food

NIOS Class 12 Home Science Chapter 7 Purchase and Storage of Food Solutions to each chapter is provided in the list so that you can easily browse throughout different chapters NIOS Class 12 Home Science Chapter 7 Purchase and Storage of Food and select need one. NIOS Class 12 Home Science Chapter 7 Purchase and Storage of Food Question Answers Download PDF. NIOS Study Material of Class 12 Home Science Notes Paper 321.

NIOS Class 12 Home Science Chapter 7 Purchase and Storage of Food

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Also, you can read the NIOS book online in these sections Solutions by Expert Teachers as per National Institute of Open Schooling (NIOS) Book guidelines. These solutions are part of NIOS All Subject Solutions. Here we have given NIOS Class 12 Home Science Chapter 7 Purchase and Storage of Food, NIOS Senior Secondary Course Home Science Solutions for All Chapter, You can practice these here.

Purchase and Storage of Food

Chapter: 7




Classify the following foods as perishable (P), semi-perishable (SP) and nonperishable (NP).

1. Bhindi.

2. Urad dal.

3. Suji.

4. Besan.

5. Jaggery.

6. Wheat.

7. Milk.

8. Banana.

9. Rice.

10. Tomatoes.

11. Apples.

12. Pappad.

13. Moong dal.

14. Sugar.

15. Cooking oil.

16. Wheat flour.

17. Green peas.

18. Spinach.


BhindiSujiUrad dal 
BananaBesanMoong dal
Green peasWheat flourSugar
SpinachCooking oil


Q. 1. Define the following terms:

(i) perishable.

(ii) semi-perishable.

(iii) non-perishable.

Ans: Most foods can be classified into one of the three categories, making it easy to sort them ready for proper storage. The three categories are: perishable, non-perishable, semi-perishable.

(i) Perishable foods: Perishable foods are those foods which deteriorate quickly when not stored properly. Perishable foods usually require refrigerated storage.

Dairy products and eggs, meat and poultry, seafood, cooked foods and leftovers, fruits and vegetables are include in perishable foods.

(ii) Semi-perishable foods : Semi-perishable foods are those that do not require refrigeration, but still have a limited shelf life. They include things like potatoes, onions, pumpkins and salamis. Frozen foods, though basically perishable, may be classified as semi- perishable provided that they are properly stored at freezer temperatures.

(iii) Non-perishable foods: Technically speaking there is no such thing as non-perishable foods, as all goods deteriorate overtime. But some commodities deteriorate so slowly that they are called non-perishable. Examples of non- perishable goods are: wheat, rice, cooking oil, pulses, spices etc.

Q. 2. Mention common quality indicators for the perishable, semi-perishable and non-perishable food items.

Ans: The term quality is used not only the relative goodness or degree of excellence of something that is being commented on but also the quality of the product in relation to the expectations of the customer.

Quality dimensions are product specific characteristics of the product characteristics, which they believe, indicate the usefulness of the product in fulfilling purchase motives. To the consumers it can mean that food is safe, but also wholesome, tasty and nutritious.

Foods may be classed in this connection as perishable, semi-perishable, and non-perishable. Those foods classed here as

• Perishable are those which readily “spoil,” that is, those that are affected by mould and bacteria on account of the moisture that they contain, and also those that lose flavour and freshness quickly. Those most easily affected should be kept the coldest; those in the.

• Semi-perishable group do not deteriorate so rapidly, although a low temperature is desirable with all of these.

• Under the non-perishable foods are classed those that are not subject to bacteria or mould in ordinary circumstances. These should be kept dry, however, and never in a heated place. In a sense, no food material is non-perishable. Insects sometimes develop in the cereal products, for instance, and the material is thus rendered unfit for food.

Common quality indicators for food items:

1. Quality Changes: Browning, Drying out, Rancidity, Dissolving, Separations, Ice crystal damage in frozen foods, Expired dates on commercially manufactured foods.

2. Safety Changes: Bacteria, viruses, moulds, or parasites present in the food in large enough numbers to overwhelm an individual’s immune system. Discard food with off-odours, visible slime, and soft mouldy food, canned foods with off odours, colour, or texture. Discard these so animals do not consume them.


Select the correct answer:

1. Rice can be kept for a long time since its moisture content is:

(a) high.

(b) medium.

(c) low.

because ______________.

Ans: (c) low.

Quality and nutritive value of food deteriorates during storage, therefore foods should not be held for long periods beyond their established shelf-life. When food is stored too long, there is the risk of two things happening:

(i) color, flavour, aroma, texture or appearance deteriorates to a level where people will not consume the food, and 

(ii) nutrient deterioration may be severe enough to render the food an unreliable source of specific nutrients.

Rice is low in water content and microorganisms do not attack it readily.

2. Bacteria is a/an:

(a) enzyme.

(b) rodent.

(c) microorganism.

because _____________.

Ans: (c) microorganism. 

Bacteria are microscopic (very tiny) organisms that are unicellular (made up of a single cell).It exists either as independent (free- living) organisms or as parasites (dependent upon another organism for life).

3. Fruits and vegetables remain fresh if the temperature is

(a) warm.

(b) cool.

(c) hot.

because _____________.

Ans: (b) cool.

Most fruits are highly perishable. Cold storage of fruits and vegetables was used extensively by our ancestors to keep food after the harvest season. Once harvested, fruits and vegetables must be stored under proper conditions, the most important of which are temperature and humidity. Each fruit or vegetable has its own ideal set of conditions at which it will store most successfully for the maximum length of time.In addition to proper temperature and humidity, all fruits and vegetables must be kept in a dark, aerated environment. While most vegetables like moist conditions, standing water must be avoided, as it will quickly lead to rot.


Select the correct answer:

Q. 1. Before storing, green leafy vegetables should be wrapped in

(a) brown paper.

(b) moist muslin cloth.

(c) newspaper.

(d) polythene packet.

Ans: (b) moist muslin cloth.

Q. 2. Eggs should be stored with pointed ends 

(a) straight.

(b) downwards.

(c) upwards.

(d) angled.

Ans: (b) downwards.

Q. 3. Rice can be stored using

(a) neem leaves.

(b) special ayurvedic tablets.

(c) lumps of salt and turmeric.

(d) all of the above.

Ans: (d) all of the above.

Q. 4. Perishable food items can be stored in refrigerator for

(a) one day.

(b) a week.

(c) limited time.

(d) unlimited time.

Ans: (c) limited time


Q. 1. Give three examples each of perishable, semi-perishable and non- perishable foods.

Ans: On the basis of their stability during storage, foodstuffs have been divided into non-perishable, semi-perishable and perishable foods.

1. Perishable Foods: Fruits, green vegetables, milk, eggs etc.

2. Semi-Perishable Foods: Pickles, onion, potato, biscuits etc. 

3. Non-Perishable Foods: Pulses, spices, cereals, tea, sugar etc.

Q. 2. List two points we must keep in mind while selecting the following foods:

(a) rice.

(b) vegetables.

(c) bread.

(d) meat.

(e) maida.

(f) canned food.

Ans: Whether it’s bagged or loose, organic or traditionally grown-there’s always going to be some chance, however small, that harmful bacterium may have gotten on the food. It can happen anywhere between the fields and your kitchen, during picking, transporting, or packaging the produce.

(a) Rice: Look for absence of worms and Jump forming among the grains. The older the rice, the better it tastes.

(b) Vegetables: Since raw vegetables, especially leafy greens, are minimally processed, they have surpassed meat as the primary culprit for food-borne illness. The safeguards you can take begin when you’re selecting produce at the store. Be sure to inspect fruits and vegetables before you buy them, and avoid any with visible cuts or broken skin where bacteria could enter.

(c) Bread: The packing should be unbroken. The bread feels soft and spongy on pressing. See date of manufacturing to confirm freshness.

(d) Meat: Select frozen foods and perishables such as meat, poultry or fish last. Always put these products in separate plastic bags so that drippings don’t contaminate other foods in your shopping cart. Check for cleanliness at the meat or fish counter and the salad bar. For instance, cooked shrimp lying on the same bed of ice as raw fish could become contaminated. Meat should appear bright red.

(e) Maida: ‘Flour’ listed alone always means “wheat flour”. Any other flour source will be listed as such, e.g., corn flour or rice flour. A stored food product may become infested at the processing plant or warehouse, in transit, at the store, or right in your home. Most of the stored food insects also are pests of stored grain or other commodities and may be relatively abundant outdoors. Food products that are left undisturbed on the shelves for long periods are particularly susceptible to infestation. However, foods of any age can become infested. Packages should be sealed and unbroken. Also check the freshness packaging date. Look for evidence of insects, including holes in the packaging or wrapping.

(f) Canned Food: Prevention of foodborne illness starts with your trip to the supermarket. Pick up your packaged and canned foods first. Don’t buy food in cans that are bulging or dented or in jars that are cracked or have loose or bulging lids. Look for any expiration dates on the labels and never buy outdated food. Likewise, check the “use by” or “sell by” date on dairy products such as cottage cheese, cream cheese, yoghurt, and sour cream and pick the ones that will stay fresh longest in your refrigerator

Q. 3. What are the main causes of food spoilage and factors speeding them?

Ans: To come to knowledge of why foods spoil, it will be well to note that nature abounds. in microorganisms, or living things so minute as to be invisible to the naked eye. These microorganisms are known to science as microbes and germs, and they are comprised of  bacteria, yeasts, and moulds, a knowledge of which is of the utmost importance to the physician and the farmer, as well as the housewife. In the household their influence is felt in three ways: They are the cause of the decay and spoiling of foods; they are of value in the preparation of certain foods; and they are the cause of contagious diseases. It will thus be seen that while some microbes are undesirable, others exert a beneficial action.

Foods may be classified as perishable, semi-perishable, or non-perishable, depending on how they are to spoiling. The most perishable foods are those with large concentrations of protein and/or water, which accelerate the microbial and chemical processes of decomposition. For example fish, seafood, meat, eggs, and dairy products, which all have a high protein and water content, are very perishable. Watery fruits and vegetables such as tomatoes, peaches, berries, and leafy vegetables are also highly perishable. Semi-perishable foods contain less water and include those, such as potatoes, carrots, beets, turnips, onions, and apples, that can keep for several days or even months under proper conditions. Processed nuts, cereals, dried tea leaves, pastas, and dried beans and peas are classified as non- perishable because they contain very little water and will keep for months with little loss of quality.

Some of the conditions that accelerate spoilage, such as inappropriate temperature and moisture control, also encourage the growth of pathogenic microorganisms that cause food- borne illness.

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