Class 05 EVS - The Mystery of Food

Exercises

Question 1

Why do some food items last for weeks and others spoil in just a few days? Answer: Food items last longer if they are dry, kept in airtight containers, or stored in a cool place like a fridge. Items that contain a lot of moisture and are left in a warm, open place provide the perfect conditions for microbes to grow and cause spoilage within a few days.

Question 2

You are going on a field trip for two days. List five food items you will carry. How will you keep them from getting spoiled? Answer: I would carry:

1. Biscuits: They are dry and have very little moisture.
2. Khakhra: A dry, roasted flatbread that lasts long.
3. Mango Pickle: The oil and salt in the pickle prevent microbial growth.
4. Roasted Peanuts: Drying and roasting remove moisture.
5. Dried Fruits (Dates/Raisins): Dehydrated foods do not spoil easily. These items are either naturally dry or preserved with oil and salt, making them safe for a two-day trip without refrigeration.

Question 3

What if food cannot be preserved? Imagine a world without food preservation and discuss the consequences. Answer: In a world without food preservation:

1. There would be massive food wastage as leftovers and fresh produce would spoil quickly.
2. Seasonal fruits and vegetables would only be available for a very short time.
3. People would have to buy fresh food every single day.
4. It would be very difficult to transport food to different regions, leading to food shortages in areas that don't produce certain crops.

Question 4: Match the Following

Match the food item (A) with its preservation method and final product (B).

• Roti → Dehydration → Khakhra
• Papad → Dried in sun → Dried papads
• Mango → Pulping and Drying → Aam papad
• Lemon → Pickling (Adding salt/oil) → Lemon pickle
• Butter → Heating → Ghee
• Juice → Canning → Canned juice
• Chillies → Drying → Chilli powder
• Fish → Drying → Dried fish

Question 5

What are the three main things microbes need to grow? Answer: Microbes need moisture (water), air, and the right (warm) temperature to grow.

Question 6

What happens to food inside your mouth when you chew it? Answer: When you chew food, your teeth break it down into smaller pieces. This releases saliva, which mixes with the food to make it mushy and easier to swallow, and also starts the chemical process of digestion.