Chapter 5 - Food Safety
1. Complete the following statements by using the correct option from those given below.
(Irradiation, dehydration, pasteurization, natural, chemical)
(a) Drying the food grains from farms under the hot sun is called ______.
Ans: dehydration
(b) Materials like milk are instantly cooled after heating up to a certain high temperature. This method of food preservation is called ______.
Ans: pasteurization
(c) Salt is a ______ type of food preservative.
Ans: natural
(d) Vinegar is a ______ type of food preservative.
Ans: chemical
2. Answer the following questions in your own words.
(a) How is milk pasteurized?
Ans: Pasteurization involves heating the milk up to a certain temperature. Milk is heated at 80 °C for 15 minutes and cooled quickly. This destroys the microbes present in the milk and helps for a longer duration.
(b) Why should we not consume adulterated food materials?
Ans:
(i) The health of all people, young and old, poor or rich, is endangered by food adulteration.
(ii) Different types of adulterants affect our health in different ways.
(iii) Some adulterants cause abdominal discomfort or poisoning.
(iv) Some may affect the functioning of some organs if consumed over a long period of time. It may cause cancer.
(c) What precautions do your parents take to keep foodstuffs safe?
Ans: Parents take the following precautions in order to keep the food safe:
(i) Perishable foods like milk, fruits and vegetables, cooked food, etc. are stored in proper places where they will not be spoiled.
For example, they keep food in a refrigerator.
(ii) Foods like papads are protected and preserved by drying under the sun.
(iii) Foods like water and milk are boiled.
(iv) Airtight containers are used to store food.
(v) They also add various natural preservatives like pickles, jams, murabba, petha, etc.
(vi) These methods prevent the growth of microorganisms in food and keep it safe.
(d) How does food spoilage occur? Which are the various factors spoiling the food?
Ans: Food is said to be spoiled if there is a change in its color, texture, quantity, taste, or nutrient content. Food spoilage occurs for many reasons:
(i) When food grains produced on farms are damaged due to improper handling, storage, and transportation.
(ii) When food is not handled properly.
For example: Overcooked food.
(iii) Improper storage of food may lead to food spoilage.
For example: Storing in a dump place
(iv) Acidic foodstuffs like milk can be spoiled due to chemical reactions.
(v) Some foodstuffs are spoiled due to contamination by microorganisms or insects from the air, water, or soil.
(e) Which methods of food preservation would you use?
Ans: The following methods can be used for food preservation:
(i) Freezing or refrigerating: Food like cooked food, dairy products, and poultry products can be stored in a refrigerator as the growth of microorganisms is slowed down and the food remains safe for a longer period of time.
(ii) Boiling: Boiling destroys the microbes present in food and enables it to be kept for a longer period of time.
(iii) Drying: Drying foodstuffs removes the moisture content from foods, preventing them from getting spoiled.
(iv) Airtight containers: No moisture from the environment enters the foodstuffs, which remain safe for a longer period of time.
(v) Preservation: Pickles contain preservatives like salt and oil to keep the food stuff unspoiled. Jams and jellies have added sugar as a natural preservative.
3. What shall we do?
(a) There are vendors selling uncovered sweetmeats in open places in the market.
Ans: We should avoid eating uncovered foods, as they are not safe. They contain microorganisms from the surroundings, which may spoil the food.
(b) A ‘pani-puriwalla’ is serving the pani puri with dirty hands.
Ans: We should not consume these panipuris. They may make us ill. There might be bacteria present on his dirty hands that may enter our system and make us ill.
(c) We have purchased a large quantity of fruits and vegetables.
Ans: Fruits and vegetables are perishable; hence, we should store them at a low temperature in airtight containers.
(d) We need to protect foodstuffs from pests like rats, cockroaches, wall-lizards, etc.
Ans: We should store the food in a proper place with a proper lid so that pests do not spoil it.
4. Find the odd-man-out.
(a) salt, vinegar, citric acid, sodium benzoate.
Ans: salt.
(b) lakhi dal, brick dust, methanyl yellow, turmeric powder.
Ans: turmeric powder.
(c) banana, apple, guava, almond.
Ans: almond.
(d) storing, freezing, settling, drying.
Ans: settling.
5. Complete the chart below.
| Sr. No. | Foodstuff | Adulterant |
|---|---|---|
1. | ____ | Metanyl yellow |
2. | Black pepper | ____ |
3. | ____ | Iron filings |
4. | Honey | ____ |
Ans:
| Sr. No. | Foodstuff | Adulterant |
|---|---|---|
1. | Turmeric powder | Metanyl yellow |
2. | Black pepper | Dried papaya seeds |
3. | Rava | Iron filings |
4. | Honey | Sugar, water and jaggery |
6. Explain why this happens and suggest possible remedies.
(a) Qualitative wastage of food.
Ans: Qualitative waste of food may happen because:
(i) Wrong methods of preserving food.
(ii) Excessive use of food preservatives.
(iii) Overcooking.
(iv) Washing the vegetables after cutting them.
(v) Mishandling fruits like grapes and mangoes.
Remedy:
(i) Wash the vegetables before cutting them, and handle perishable food items very carefully.
(ii) Avoid overcooking them.
(iii) Refrigerate the fruits and vegetables to maintain a conducive temperature.
(b) The cooked rice is underdone.
Ans: The cooked rice remains underdone due to a lack of water or heat.
Remedy:
Add an adequate amount of water to the vessel while preparing rice.
(c) The wheat that was bought is a bit moist.
Ans: If the wheat is not stored properly in a dry place, the moisture from the surrounding atmosphere might enter the wheat and make it moist.
Remedy:
The wheat should not be touched by a wet hand. It should be dried in the sun four to five times. Then the dried wheat should be placed in clean, dry, and airtight containers.
(d) The taste of yoghurt is too sour/slightly bitter.
Ans: The taste of yoghurt may turn sour if it is not stored at a low temperature at the time of storage. This happens because the process of microbial growth in the yoghurt continues if it remains at a high temperature.
Remedy:
Store the yoghurt at a low temperature in the refrigerator.
(e) Cut fruits have turned black.
Ans: The chemical reactions start in the cut fruits, which make them black.
Remedy:
The pieces of cut fruit should be immediately stored in airtight containers. Seasoning the fruit pieces with a little sugar or salt also prevents the blackening.
7. Give reasons.
1. Food remains safe at 5⁰ Celsius.
Ans:
(i) At a cold temperature of 5 °C, the reactions caused by microorganisms do not take place. Bacteria and fungi that spoil food are inactive at such low temperatures.
(ii) Therefore, food items remain safe at this temperature.
2. Nowadays, food is served buffet style during large gatherings.
Ans:
(i) Buffet style is introduced to prevent food waste and save food.
(ii) People are expected to consume as much food as they can.
(iii) The traditional method of serving the food results in wastage, and hence, nowadays, food is served buffet style during large gatherings.
Ans:
6. Think and answer.
(a) We prepare a variety of foodstuffs and dishes at home. Are we then autotrophic organisms?
Ans: No, We are not autotrophic; we are heterotrophic organisms. It is because we do not have chlorophyll and we cannot make our own food using sunlight. We depend on plants for grains, pulses, and vegetables. We depend on animals for meat and eggs. Thus, we are dependent on plants and animals for food.
(b) Which organisms are greater in number – autotrophs or heterotrophs? Why?
Ans: Autotrophs are greater in number. It is because autotrophs have chlorophyll, so they can make their own food through photosynthesis. They do not depend on other animals for their nutrition and survival.
(c) The number of heterotrophs found in desert regions is smaller. However, they are found in greater numbers in the sea. Why is this so?
Ans:
(i) In desert regions, the autotrophs are lesser in number, as are the heterotrophs dependent on them. The food is scarce; therefore, the number of heterotrophs also reduces.
(ii) In oceans and seas, there are multitudes of zooplankton and phytoplankton. Phytoplankton are very small, microscopic floating plants that we may not see. The food chain in the sea is dependent on these planktonic species.
(iii) Therefore, the number of heterotrophs found in desert regions is smaller, but they are found in greater numbers in the sea.
(d) What damage or harm do ectoparasitic and endoparasitic animals cause?
Ans:
(i) Parasitic organisms depend on other animals for nutrition.
(ii) Ectoparasites live on the body surface of animals and may cause intense itching, thus damaging the skin. Sucking of blood by endoparasites may lead to blood loss in animals.
For example: louse, bedbug, tick, etc.
(iii) Endoparasites live inside the bodies of other animals and may cause digestive problems in animals.
For example: tapeworms, roundworms, etc.
(e) Why is plant food not produced in any other parts of the plant except the green ones?
Ans: The chlorophyll is present only in the green parts of the plants. In these parts, photosynthesis takes place. This produces food. The non-green parts do not produce food due to a lack of chlorophyll.