🧪 Rancidity

 Certainly, Mayank. Here's a concise, CBSE Class 10–level explanation of Rancidity, written in a way that is exam-friendly, easily teachable, and suitable for both classroom and online instruction.

🧪 Rancidity

(Class 10 Science – Chapter: Chemical Reactions and Equations – Section 1.3.2)

📘 Definition:

Rancidity is the process in which fats and oils get oxidised, resulting in a bad smell and unpleasant taste in food.

🔍 Cause of Rancidity:

  • Rancidity occurs due to the oxidation of fats and oils when they are exposed to oxygen, light, or moisture over time.

🧠 Examples:

  • Spoiled ghee or butter giving a bad odour

  • Chips or snacks that taste bitter or stale

  • Old cooking oil left uncovered or used repeatedly

⚠️ Why is Rancidity a Problem?

  • Makes food unfit for consumption

  • Reduces nutritional value

  • Leads to food waste

🛡️ Methods to Prevent Rancidity:

Method How it helps
Use of antioxidants Chemicals like BHA and BHT slow down oxidation
Airtight packaging Prevents exposure to air and moisture
Refrigeration Slows down the chemical reactions
Nitrogen flushing Removes oxygen from packets (used in chips packaging)

🧪 CBSE Example:

Q: Why are packets of chips flushed with nitrogen gas?

✅ Answer:
To prevent rancidity by removing oxygen and slowing down the oxidation of oils present in the chips.

🧠 CBSE Exam Tip:

Q: What is rancidity? Write any two methods to prevent it.
✅ Answer:
Rancidity is the oxidation of fats and oils, leading to bad smell and taste in food.
Prevention methods:

  1. Adding antioxidants

  2. Storing food in airtight containers

Let me know if you'd like a concept map, quiz sheet, or animated explainer video script for this topic!

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