The eating up of metals by the action of air, moisture or chemical on the metal’s
Surface is called corrosion. If the surface of a metal is attacked by air, water it is said to corrode.
RUSTING OF IRON METAL:
Iron reacts with oxygen in the presence of moisture to form a reddish-brown chemical
PREVENTION OF RUSTING:
Painting of iron articles
Oiling and greasing of machine parts
Galvanising iron pipes used for water supply.
Coating of Iron with chromium.
RANCIDITY
Rancidity is the process where fats and oils in food get oxidized on exposure to air. This results in food spoilage.
PREVENTION OF RANCIDITY:
Adding anti-oxidants to foods containing fats and oils prevents Rancidity.
The two common anti-oxidants used in foods to prevent the development of rancidity are BHA (ButylatedHydroxy-Anisole) and BHT (ButylatedHydroxy-Toluene).
Packaging fat and oil containing foods in nitrogen gas prevents rancidity.
Keeping food in a refrigerator can hold back rancidity.
Storing food in air-tight containers can avoid rancidity.
Storing foods away from light can avoid rancidity.
