How is food packed in cans?

         Canning of food is one of the methods of food preservation. The food that is stored in cans has to be made sterile and free from germs to keep it fresh. Canning also involves keeping air away from food because it would bring germs to it.

         In a canning factory, the food is prepared in large containers. It is heated to destroy micro-organisms and to stop enzyme activity. Most germs-killing temperatures range from 100°C to 121°C. Meat, fish and vegetables are heated at about 120°C. The sterilizing time depends on the temperature, the container and the type of food.

         The food after heating goes to the canning machine, which is fed with a line of empty cans. The food is filled in the metal or glass containers with a liquid, such as, sauce or sucrose syrup. Air is removed from the containers and the containers are then sealed with air-tight lids. For some foods the cans and food are sterilized first by heating before the cans are filled.

         Most canned food can be kept for more than a year. The other methods of food preservation are cold storage, freezing, drying, freeze-drying and curing. All these methods are based on modern science and technology. All methods of food preservation are performed with extreme cleanliness and hygienically.