Now a days, the use of canned food items is increasing. Before packaging milk or other food items in cans or bottles, milk or the food items are heated at 60°C for 30 minutes and then cooled down. This process is repeated 2 – 3 times and it kills the harmful micro-organisms present in them. This technique of killing germs is called pasteurization. Air is removed from the cans after pasteurized food items are packaged in cans because the micro-organisms cannot grow in the absence of air. The date mentioned on the cans before which the food item must be consumed is known as expiry date. We must always see the expiry date of canned food items before buying them. Such food items must be consumed before their expiry date.
