Question

What precautions need to be taken when foods are being canned? Why are these precautions necessary?

Why do egg whites make a stable foam when beaten?

Answer 1

Cans will be filled with the head space of 6 to 9 mm above the contents.This step is to avoid the spoilage of products inside the cans while storage.Too little headspace makes can bulged and it can cause uneven sterilization.Too high headspace will result in the filling of air in cans and it will cause corrosion of cans,spoilage of product,affect heat penetration etc.

Before seaming the canned products exhausting will be done and this is help to remove the air trapped inside the products and and reduces the chances of microbial spoilage ( aerobic bacteria).it helps to create vaccum in the can and also helps to prevent oxidation of the product.

Can seaming is an another precaution that helps to avoid the entry of microorganism inside the can and increase shelf life.

Can washing is an another step to eliminate oil, sause or other products outside the can and hence avoid corrosion, clog and sources of contamination.

Sterilization or heat processing is an another important precaution to eliminate microbes to ensure safety of the product.it helps to kill microorganism without overcooking the product.it also helps to destroy bacteria, especialy most dangerous microbe in cans such as clostridium boutilinum.

Cans will cool,label and store at preferably 10 degree celsius for long shelf life

Egg white is protein and when it is beating it will breakanddown the linkages and become unfolded ( denaturation) .The unfolded proteins then will rearrange and comes around its air molecules or air cells like a film that result in a foam formation.The air cells will expand when the foam subjected to heat .It will result in coagulation of egg and further the foam will be soldified.