Question

Why cans or Jars are at immediate risk of spoiling once opened?​

Answer 1

Explanation:

As the food cools, a vacuum seal is formed that prevents any new bacteria from getting in. Since the food in the container is commercially sterile, it does not spoil. Once the container is opened, however, bacteria can enter and begin growing in the food.

Answer 2

Answer:

There is a term called rancidity. It means, when a food which contains fats and oils when exposed to air gets spoiled (gets rancid). Therefore cans and jars are used alongwith nitrogen sprayed inside it to pack the foods. So, once the cans or jars are opened, the nitrogen gets out and the food undergoes oxidation.

**Nitrogen is sprayed because it creates an inert atmosphere which prevents oxidation of the food.