Question

what is rancidity?how can it be prevented

Answer 1

Rancidity is the process in which the oil and fat containing food gets spoil when comes in contact with air moisture etc.
We can prevent it by storing food in refrigerator or air tight containers.

Answer 2

Rancidity is a term generally used to denote unpleasant odours and flavours in foods resulting from deterioration in the fat or oil portion of a food. Three different mechanisms of rancidity may occur. These are oxidative, hydrolytic, and ketonic. OxidativeRancidity.
we can prevent by storing food in refrigerators.