#6- Tinned or canned food
The method of canning conserves foods by sealing them in air tight containers and cooking them to a adequately high temperature to ensure that they are sterile. Because any microorganisms inside the container are killed and air is excluded, tinned foods can be kept for a long time without crumble. However their disadvantages are: they are rich in salt, color and taste of food is fake and some nutrients like vitamin B and C are lost. It will not give you enough energy for good health.