Foods after preparation
should be stored at proper conditions to prevent spoilage and loss of nutritive
value in it. There are various methods of storing numerous food items at
Food preservation is
known “as the science which deals with the process of prevention of decay or
spoilage of food thus allowing it to be stored in a fit condition for future
use”. Preservation ensures that the quality, edibility and the nutritive value
of the food remains intact.
Different methods are
used to preserve the foods. A single method or combination of methods can be
Drying is the oldest method of
food preservation. This method reduces water content which prevents
bacterial growth. Sun and wind are both used for drying.
Freezing is keeping prepared food
stuffs in cold storages. Freezing at low temperature prevents microbial
growth, slowing of oxidation reactions.
Smoking is the process that
cooks, food exposing it to the smoke from burning wood. Various methods
of smoking are used like hot smoking, cold smoking, smoke roasting and smoke
baking. Smoking is the process that cooks, food exposing it to
the smoke from burning wood. Various methods of smoking are used like hot
smoking, cold smoking, smoke roasting and smoke baking.
Vacuum packing creates a vacuum by making
bags and bottles airtight. Since there is no oxygen in the created vacuum
bacteria die. Usually used for dry fruit.
Salting and Pickling Salting removes moisture
from foods like meat. Pickling means preserving food either in salt solution or
vinegar. Salt kills and inhibits growth of microorganisms at 20% of
Sugar is used in syrup form to
preserve fruits in crystallized form. Example: Candied peel and ginger.
Canning and bottling means sealing cooked
food in sterile bottle and canes. The container is boiled and this kills or
weakens bacteria. Once the cane or bottle is opened the food is again at risk
Jellying is preserving food by
cooking in a material that solidifies to form a gel. Fruits are
generally preserved as jelly. Sugar is also added.
Pasteurization is a process that kills
bacteria in liquid food. In this method moderately high (62°C to 100°C)
temperatures are used (for about 15 to 30 minutes) to inactivate certain
enzymes and kill certain other microorganisms especially in milk. Pasteurized
products need refrigeration after exposure to air.
Pulsed Electric Field
Processing is a new method of preservation that uses brief pulses as
strong electric field to process cells.
High pressure food
preservation is a method that presses foods inside a vessel by exerting
70,000 pounds per square inch or more of pressure.