Grade 5 Q&A: Chapter 13: Methods of Preserving Food

Concept Questions

Q1: Why do we need to store foodgrains like wheat, rice, and pulses throughout the year?

Answer: We need to store foodgrains like wheat, rice, and pulses throughout the year because their crops get ready only at certain times of the year. To have them available continuously, one season's crop must be stored and protected until the next season.

Q2: Why are papads, jams, and pickles prepared and preserved in many homes?

Answer: Papads, jams, and pickles are prepared and preserved in many homes to avoid having to go to the market for provisions again and again, and to enjoy seasonal fruits and vegetables all year round.

Q3: What changes are seen in food when it is spoiled?

Answer: When food is spoiled, it often develops a bad smell, and visible changes like white, black, or greenish cottonwool-like fibrous growth (fungus) may appear on it.

Q4: What are the favorable conditions for the rapid growth of micro-organisms in food?

Answer: The favorable conditions for the rapid growth of micro-organisms in food are the availability of air, moisture, and warmth.

Q5: What are the harmful effects of eating spoiled food?

Answer: Eating spoiled food can cause a stomachache, diarrhoea, vomiting, etc. The nutritional value of such food is also reduced, and sometimes, it can even threaten life.

Q6: What is 'fungus'?

Answer: Fungus is a type of micro-organism that often grows as cottonwool-like fibrous patches on spoiled food.

Q7: What is the main principle behind preserving foodstuffs?

Answer: The main principle behind preserving foodstuffs is to destroy the micro-organisms in them and then place them in conditions where micro-organisms will not grow again.

Q8: Name four methods of food preservation mentioned in the chapter.

Answer: The four methods are: Drying, Cooling, Boiling, and Placing in airtight cans.

Q9: How does 'Drying' preserve food? Give an example.

Answer: Drying preserves food by removing its water content. This method is used for foodstuffs like papads, kurdai, sandage, wheat, and daals.

Q10: How does 'Cooling' preserve food?

Answer: Cooling preserves food by placing it in a refrigerator, where micro-organisms do not get the warmth they need for growth, thus slowing down spoilage.

Q11: How does 'Boiling' preserve food? Give an example.

Answer: Boiling preserves food by destroying the micro-organisms in it. For example, boiling milk prevents it from spoiling immediately, and curries are boiled to keep them from spoiling until the next meal.

Q12: How does 'Placing in airtight cans' preserve food?

Answer: When foodstuffs are preserved in airtight containers, the micro-organisms are first destroyed, and then it is ensured that water or air will not enter the foodstuff, preventing further growth of micro-organisms.

Q13: What are 'preservatives'? Give two examples.

Answer: Preservatives are certain substances added to jams and pickles to preserve them for a long time. Examples include sugar, salt, asafoetida (hing), mustard, oil, and vinegar.

Q14: What should you check when buying food in sealed bags or boxes?

Answer: When buying food in sealed bags or boxes, you should always check the expiry (Use before) date printed on it.

Q15: Why do spices have strong tastes and flavours, and how are they used in food?

Answer: Spices have strong tastes and flavours and are therefore used in very small quantities to add variety to the taste of our foods. They can be dried and stored for a long time, and mixed and powdered to make different masalas.

Application-Based Questions

Q16: The papads you stored have become soft and moist. What is the solution?

Answer: The papads have become soft and moist because they have absorbed moisture, which allows micro-organisms to grow. The solution is to **dry them again thoroughly in the sun** to remove the moisture, and then store them in an airtight, dry container.

Q17: Fruits like mangoes, amlas, guavas, and vegetables like peas, onions, tomatoes, and fenugreek are available in plenty only in certain seasons but are needed all year round. What is the solution to have them available throughout the year?

Answer: The solution is to use various food preservation methods. For fruits, they can be made into jams, pickles, or dried. Vegetables can be dried (like fenugreek leaves), pickled (like onions, tomatoes), or frozen (like peas) to be used throughout the year.

Q18: Semolina (shevaya) does not get spoiled for a very long time, but kheer made from it spoils easily. Why is this so?

Answer: Semolina (shevaya) is a dry foodstuff with very low moisture content, which inhibits the growth of micro-organisms. Kheer, on the other hand, is made with milk, sugar, and often other ingredients, creating a moist and nutrient-rich environment that is highly favorable for the rapid growth of micro-organisms, causing it to spoil quickly.

Q19: You have some leftover curry from dinner. What should you do to keep it from spoiling until the next meal or the next day?

Answer: To keep the leftover curry from spoiling, you should **boil it thoroughly** and then allow it to cool before storing it in a **refrigerator** in a clean, covered container. Boiling kills existing micro-organisms, and cooling/refrigeration slows down the growth of any new ones.

Q20: Your grandmother wants to make a large batch of lemon pickle to last the whole year. What ingredients would she need to add to preserve it effectively?

Answer: To preserve lemon pickle effectively for a long time, she would need to add **salt** and **oil** (or vinegar, depending on the recipe) as primary preservatives. Sugar and spices would also be added for taste, and they contribute to preservation by creating an unfavorable environment for microbial growth.

Higher-Order Thinking Questions

Q21: "If we know the reasons why foodstuffs go bad, we would know what to do to keep them from spoiling." Explain how understanding the science behind food spoilage empowers us to preserve food effectively.

Answer: This statement highlights the importance of scientific knowledge in practical applications. Food spoils primarily due to the rapid growth of micro-organisms (bacteria, fungi) that thrive in specific conditions (warmth, moisture, air, food). By understanding these factors, we can deliberately create unfavorable conditions for them: * **Drying:** Removes moisture. * **Cooling/Refrigeration:** Reduces warmth. * **Boiling:** Destroys existing micro-organisms through heat. * **Airtight Canning:** Prevents entry of air and micro-organisms. * **Preservatives:** Create environments (e.g., high salt/sugar concentration, acidity from vinegar) that inhibit microbial growth. This knowledge empowers us to choose the most appropriate preservation method for different foods, ensuring safety and extending shelf life.

Q22: The chapter mentions that "The nutrition value of such food is also reduced" when it gets spoiled. Why is this a concern beyond just the immediate health risks like stomachache or vomiting?

Answer: The reduction in nutritional value of spoiled food is a concern beyond immediate health risks because it contributes to **malnutrition** over time. Even if the immediate symptoms of food poisoning are avoided or mild, regularly consuming food with degraded nutrients means the body is not receiving the essential vitamins, minerals, proteins, and carbohydrates it needs for proper growth, energy, and disease resistance. This can lead to stunted growth, chronic fatigue, weakened immunity, and specific deficiency disorders, impacting overall health and well-being in the long run, especially in children.

Q23: How does the practice of making papads, jams, and pickles in the right season contribute to sustainable living and food security, especially in a country like India?

Answer: This practice significantly contributes to sustainable living and food security in India by: * **Reducing Food Waste:** It utilizes seasonal abundance of fruits and vegetables, preventing them from spoiling when supply is high. * **Ensuring Year-Round Availability:** It makes nutritious food items available even when they are out of season, improving dietary diversity throughout the year. * **Economic Benefits:** Supports local agriculture and small-scale industries involved in processing and preserving food, creating livelihoods. * **Food Security:** By storing surplus produce, it acts as a buffer against periods of scarcity or price fluctuations, enhancing household and community food security. * **Traditional Knowledge:** Preserves traditional food preparation techniques that are often energy-efficient and culturally significant.

Q24: Explain the importance of checking the 'expiry date' on packaged food items. What are the potential consequences if this is neglected?

Answer: Checking the expiry date is crucial because it indicates the period during which the food is considered safe and of good quality. Neglecting this can lead to several potential consequences: * **Health Risks:** Consuming expired food can lead to food poisoning, stomach upsets, diarrhoea, or more severe illnesses due to the growth of harmful bacteria, molds, or toxins. * **Reduced Nutritional Value:** Over time, nutrients in food can degrade, making it less beneficial even if it doesn't cause immediate illness. * **Poor Taste/Quality:** The food may lose its intended flavor, texture, or appearance, leading to an unpleasant eating experience. * **Wastage:** If food is purchased without checking the date and expires quickly, it leads to unnecessary food waste and financial loss.

References

1. Maharashtra State Board Environmental Studies (Part One) Standard Five Textbook (2015 Edition) - Chapter 13: Methods of Preserving Food, pages 64-67.
2. Maharashtra State Board 5th Standard Environmental Studies Syllabus.
3. Balbharati Environmental Studies Part 1 Textbook.