Food storage is both a traditional domestic skill and is important industrially. Food
is stored by almost every human society and by many animals. Storing of food has several
main purposes: Storage of harvested and processed plant and
animal food products for distribution to consumers Enabling a better balanced diet throughout
the year Reducing kitchen waste by preserving unused
or uneaten food for later use Preserving pantry food, such as spices or
dry ingredients like rice and flour, for eventual use in cooking
Preparedness for catastrophes, emergencies and periods of food scarcity or famine
Religious reasons Protection from animals or theft
History of food storage Domestic food storage
The safe storage of food for home use should strictly adhere to guidelines set out by reliable
sources, such as the United States Department of Agriculture. These guidelines have been
thoroughly researched by scientists to determine the best methods for reducing the real threat
of food poisoning from unsafe food storage. It is also important to maintain proper kitchen
hygiene, to reduce risks of bacteria or virus growth and food poisoning. The common food
poisoning illnesses include Listeriosis, Mycotoxicosis, Salmonellosis, E. coli, Staphylococcal food
poisoning and Botulism. There are many other organisms that can also cause food poisoning.
There are also safety guidelines available for the correct methods of home canning of
food. For example, there are specific boiling times that apply depending upon whether pressure
canning or waterbath canning is being used in the process. These safety guidelines are
intended to reduce the growth of mold and bacteria and the threat of potentially-fatal
food poisoning. Food storage safety
Freezers and thawing food Freezer temperature should be maintained below
0°F. Food should never be thawed at room temperature, this increases the risk of bacterial
and fungal growth and accordingly the risk of food poisoning. Once thawed, food should
be used and never refrozen. Frozen food should be thawed using the following methods:
Microwave oven During cooking
In cold water In the refrigerator
Throw out foods that have been warmer than 40 °F for more than 2 hours. If there is
any doubt at all about the length of time the food has been defrosted at room temperature,
it should be thrown out. Freezing does not destroy microbes present in food. Freezing
at 0 °F does inactivate microbes. However, once food has been thawed, these microbes
can again become active. Microbes in thawed food can multiply to levels that can lead
to foodborne illness. Thawed food should be handled according to the same guidelines as
perishable fresh food. Food frozen at 0°F and below is preserved
indefinitely. However, the quality of the food will deteriorate if it is frozen over
a lengthy period. The United States Department of Agriculture, Food Safety and Inspection
Service publishes a chart showing the suggested freezer storage time for common foods.
Refrigeration It is important to note that safe food storage
using refrigeration requires adhering to temperature guidelines:
For safety, it is important to verify the temperature of the refrigerator. Refrigerators
should be set to maintain a temperature of 40 °F or below. Some refrigerators have built-in
thermometers to measure their internal temperature. For those refrigerators without this feature,
keep an appliance thermometer in the refrigerator to monitor the temperature. This can be critical
in the event of a power outage. When the power goes back on, if the refrigerator is still
40 °F, the food is safe. Foods held at temperatures above 40 °F for more than 2 hours should
not be consumed. Appliance thermometers are specifically designed to provide accuracy
at cold temperatures. Be sure refrigerator/freezer doors are closed tightly at all times. Don’t
open refrigerator/freezer doors more often than necessary and close them as soon as possible.
Storage times for refrigerated food The United States Department of Agriculture,
Food Safety and Inspection Service publishes recommended storage times for refrigerated
food. Storing oils and fats
Oils and fats can begin to go rancid quickly when not stored safely. Rancid cooking oils
and fats do not often smell rancid until well after they have spoiled. Oxygen, light and
heat all contribute to cooking oils becoming rancid. The higher the level of polyunsaturated
fat that an oil contains, the faster it spoils. The percentage of polyunsaturated fat in some
common cooking oils is: safflower; sunflower; corn; soybean; peanut; canola; olive.
To help preserve oils from rancidification, they should be refrigerated once opened. Opened,
refrigerated cooking oils should be used within a few weeks, when some types begin to go rancid.
Unopened oils can have a storage life of up to one year, but some types have a shorter
shelf-life even when unopened. Dry storage of foods
Vegetables
The guidelines vary for safe storage of vegetables under dry conditions. This is because different
vegetables have different characteristics, for example, tomatoes contain a lot of water,
while root vegetables such as carrots and potatoes contain less. These factors, and
many others, affect the amount of time that a vegetable can be kept in dry storage, as
well as the temperature needed to preserve its usefulness. The following guideline shows
the required dry storage conditions: Cool and dry: onion
Cool and moist: root vegetable, potato, cabbage Warm and dry: winter squash, pumpkin, sweet
potatoes, dried hot peppers Many cultures have developed innovative ways
of preserving vegetables so that they can be stored for several months between harvest
seasons. Techniques include pickling, home canning, food dehydration, or storage in a
root cellar. Grain
Grain, which includes dry kitchen ingredients such as flour, rice, millet, couscous, cornmeal,
and so on, can be stored in rigid sealed containers to prevent moisture contamination or insect
or rodent infestation. For kitchen use, glass containers are the most traditional method.
During the 20th century plastic containers were introduced for kitchen use. They are
now sold in a vast variety of sizes and designs. Metal cans are used. Storage in grain sacks
is ineffective; mold and pests destroy a 25 kg cloth sack of grain in a year, even if stored
off the ground in a dry area. On the ground or damp concrete, grain can spoil in as little
as three days, and the grain might have to be dried before it can be milled. Food stored
under unsuitable conditions should not be purchased or used because of risk of spoilage.
To test whether grain is still good, it can be sprouted. If it sprouts, it is still good,
but if not, it should not be eaten. It may take up to a week for grains to sprout. When
in doubt about the safety of the food, throw it out as quickly as possible.
Spices and herbs Spices and herbs are today often sold prepackaged
in a way that is convenient for pantry storage. The packaging has dual purposes of both storing
and dispensing the spices or herbs. They are sold in small glass or plastic containers
or resealable plastic packaging. When spices or herbs are homegrown or bought in bulk,
they can be stored at home in glass or plastic containers. They can be stored for extended
periods, in some cases for years. However, after 6 months to a year, spices and herbs
will gradually lose their flavour as oils they contain will slowly evaporate during
storage. Spices and herbs can be preserved in vinegar
for short periods of up to a month, creating a flavoured vinegar.
Alternative methods for preserving herbs include freezing in water or unsalted butter. Herbs
can be chopped and added to water in an ice cube tray. After freezing, the ice cubes are
emptied into a plastic freezer bag for storing in the freezer. Herbs also can be stirred
into a bowl with unsalted butter, then spread on wax paper and rolled into a cylinder shape.
The wax paper roll containing the butter and herbs is then stored in a freezer, and can
be cut off in the desired amount for cooking. Using either of these techniques, the herbs
should be used within a year. Meat
Unpreserved meat has only a relatively short life in storage. Perishable meats should be
refrigerated, frozen, dried promptly or cured. Storage of fresh meats is a complex discipline
that affects the costs, storage life and eating quality of the meat, and the appropriate techniques
vary with the kind of meat and the particular requirements. For example, dry ageing techniques
are sometimes used to tenderize gourmet meats by hanging them in carefully controlled environments
for up to 21 days, while game animals of various kinds may be hung after shooting. Details
depend on personal tastes and local traditions. Modern techniques of preparing meat for storage
vary with the type of meat and special requirements of tenderness, flavour, hygiene, and economy.
Semi-dried meats like salamis and country style hams are processed first with salt,
smoke, sugar, acid, or other "cures" then hung in cool dry storage for extended periods,
sometimes exceeding a year. Some of the materials added during the curing of meats serve to
reduce the risks of food poisoning from anaerobic bacteria such as species of Clostridium that
release botulinum toxin that can cause botulism. Typical ingredients of curing agents that
inhibit anaerobic bacteria include nitrates and nitrates. Such salts are dangerously poisonous
in their own right and must be added in carefully controlled quantities and according to proper
techniques. Their proper use has however saved many lives and much food spoilage.
Like the semi-dried meats, most salted, smoked, and simply-dried meats of different kinds
that once were staples in particular regions, now are largely luxury snacks or garnishes;
examples include jerky, biltong, and varieties of pemmican, but ham and bacon for instance,
still are staples in many communities. Fish and shellfish
It is unsafe to store fish or shellfish without preservation.
Food rotation Food rotation is important to preserve freshness.
When food is rotated, the food that has been in storage the longest is used first. As food
is used, new food is added to the pantry to replace it; the essential rationale is to
use the oldest food as soon as possible so that nothing is in storage too long and becomes
unsafe to eat. Labelling food with paper labels on the storage container, marking the date
that the container is placed in storage, can make this practise simpler. The best way to
rotate food storage is to prepare meals with stored food on a daily basis.
For emergency preparation Guides for surviving emergency conditions
in many parts of the world recommend maintaining a store of essential foods; typically water,
cereals, oil, dried milk, and protein rich foods such as beans, lentils, tinned meat
and fish. A basic food storage calculator can be used to help determine how much of
these staple foods a person would need to store in order to sustain life for one full
year. In addition to storing the basic food items many people choose to supplement their
food storage with frozen or preserved garden-grown fruits and vegetables and freeze-dried or
canned produce. An unvarying diet of basic staple foods prepared in the same manner can
cause appetite exhaustion, leading to less caloric intake. Another benefit to having
a basic supply of food storage in the home is for the cost savings. Costs of dry bulk
foods are often considerably less than convenience and fresh foods purchased at local markets
or supermarkets. There is a significant market in convenience foods for campers, such as
dehydrated food products. Commercial food storage
Grain and beans are stored in tall grain elevators, almost always at a rail head near the point
of production. The grain is shipped to a final user in hopper cars. In the former Soviet
Union, where harvest was poorly controlled, grain was often irradiated at the point of
production to suppress mold and insects. In the U.S., threshing and drying is performed
in the field, and transport is nearly sterile and in large containers that effectively suppresses
pest access, which eliminates the need for irradiation. At any given time, the U.S. usually
has about two weeks worth of stored grains for the population.
Fresh fruits and vegetables are sometimes packed in plastic packages and cups for fresh
premium markets, or placed in large plastic tubs for sauce and soup processors. Fruits
and vegetables are usually refrigerated at the earliest possible moment, and even so
have a shelf life of two weeks or less. In the United States, livestock is usually
transported live, slaughtered at a major distribution point, hung and transported for two days to
a week in refrigerated rail cars, and then butchered and sold locally. Before refrigerated
rail cars, meat had to be transported live, and this placed its cost so high that only
farmers and the wealthy could afford it every day. In Europe much meat is transported live
and slaughtered close to the point of sale. In much of Africa and Asia most meat is for
local populations is raised, slaughtered and eaten locally, which is believed to be less
stressful for the animals involved and minimizes meat storage needs. In Australia and New Zealand,
where a large proportion of meat production is for export, meat enters the cold chain
early, being stored in large freezer plants before being shipped overseas in freezer ships.
Food storage facilities
See also
References
External links