Question

what so u understand by the term rancidity?

Answer 1

Rancidity is a very general term and in its most general meaning, it refers to the spoilage of a food in such a way that it becomes undesirable (and usually unsafe) for consumption. When people say that a food has "gone bad," what they're usually talking about is rancidity.

Answer 2

When oil and fat containing food items are exposed to air for longer period of time, it undergoes oxidation which makes the food stale or spoiled.
It's smell, colour and taste changed. This process is called rancidity.
Some methods to prevent rancidity are:
1. By keeping the food in air tight containers
2. By keeping the food in refrigerator as it slows down oxidation
3. By packing food items in nitrogen gas. Nitrogen being an unrealized gas doesn't reacts with foods items which prevents oxidation and hence prevents the food from getting spoiled.

Hope this helps you.