food preservation is the process of treating food to preserve the natural characteristic and appearance of food and stop or slow down its spoilage

drying

it is used to reduce the amount of water activity in order to prevent bacterial growth

refrigeration

it slows down the growth and reproduction of microorganisms

freezing

it stops bacterial action temporarily

A frozen product retains its freshness, texture and flavour

freeze-drying or lyophilisation

food is frozen and placed in a strong vacuum

it removes all moisture

smoking

it has a drying effect and raises the salt concentration

salting

the salt draws out moisture and creates an environment inhospitable to bacteria

adding sugar

water is withdrawn

pickling

the additions of acids lowers the pH of foods

pasteurisation

the food is heated to a high enough temperature to kill some bacteria and to disable certain enzymes

biopreservation

it uses beneficial bacteria to enhance the safety of foods