Question

Why fats and oils should be stored properly in airtight containers

Answer 1

Racidity is a process of slow oxidation of oil and fat present in food material resulting in the change of smell and taste.
For eg when some potato wafers are fried in oil and stored in ordinary container their smell and taste become too bad after few days. If the wafers are stored in packets containing nitrogen gas they do not become rancid and remain safe for Co. Consumption purpose for longer time.