Vacuum
packing
From Wikipedia, the free encyclopedia
Vacuum packing or vacuum packaging is a method of packaging
that removes air from the package prior to sealing. It can involve both rigid
and flexible types of packaging. The intent is usually to remove oxygen from
the container to extend the shelf life
of foods and, with flexible package forms, to reduce the volume of the contents
and package.[1]
Vacuum packing reduces atmospheric
oxygen, limiting the growth of aerobic bacteria or fungi, and preventing the evaporation
of volatile components. It is also commonly used to store dry foods
over a long period of time, such as cereals, nuts,
cured meats,
cheese,
smoked fish,
coffee,
and potato chips (crisps). On a more short term basis, vacuum packing can also be
used to store fresh foods, such as vegetables, meats, and liquids, because they
inhibit bacterial growth.
Vacuum packing greatly reduces the
bulk of non-food items. For example, clothing and bedding can be stored in bags
evacuated with a domestic vacuum cleaner
or a dedicated vacuum sealer. This technique is sometimes used to compact household waste,
for example where a charge is made for each full bag collected.
Vacuum packaging products using plastic bags,
canisters,
bottles,
or mason jars
are available for home use.
Vacuum packaging delicate food items
can be done by using an inert gas, such as nitrogen. This helps prevent
crushing fragile items and delicate foods such as potato chips.
External
sealers
External vacuum sealers involve a
bag being attached to the vacuum-sealing machine externally. The machine will
remove the air and seal the bag, which is all done outside the machine.
Chamber
sealers
Chamber sealers require the entire
product to be placed within the machine. Like external sealers, a plastic bag
is typically used for packaging. Once the product is placed in the machine, the
lid is closed and air is removed. Then, there is a heat seal inside the chamber
that will seal the bag, after sealing the bag the chamber is refilled with air
by the automatic opening of a vent to the outside. This oncoming pressure
squeezes all remaining air in the bag. The lid is then opened and the product
removed. Chamber sealers are typically used for higher-volume packaging, and
also have the capability to vacuum seal liquids
Preventing
freezer burn
When foods are frozen without
preparation, freezer burn can occur. It happens when the surface of the food is
dehydrated, and this leads to a dried and leathery appearance. Freezer burn
also ruins the flavor and texture of foods. Vacuum packing reduces freezer burn
by preventing the food from exposure to the cold, dry air.
Sous-vide
cooking
Vacuum packaging also allows for a
special cooking method, sous-vide. Sous-vide, French
for under vacuum, involves poaching food that is vacuum sealed in a
plastic bag.
Food
safety
In an oxygen-depleted environment, Anaerobic organisms can proliferate, potentially causing food safety problems.
Vacuum packing is often used in combination with other packaging and food
processing techniques.
The entire wiki article can be found at: http://en.wikipedia.org/wiki/Vacuum_packing
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