Vacuum sealer with food sealed on wooden table and rolls of plastic for sealing

Vacuum packing is a method of packaging that removes air from the package prior to sealing. This method involves placing items in a plastic film package, removing air from inside and sealing the package. Shrink film is sometimes used to have a tight fit to the contents. The intent of vacuum packing is usually to remove oxygen from the container to extend the

shelf life Shelf life is the length of time that a commodity may be stored without becoming unfit for use, consumption, or sale. In other words, it might refer to whether a commodity should no longer be on a pantry shelf (unfit for use), or no longer on a ...

of foods and, with flexible package forms, to reduce the volume of the contents and package. Vacuum packing reduces atmospheric oxygen, limiting the growth of

aerobic bacteria Aerobic means "requiring air," in which "air" usually means oxygen. Aerobic may also refer to * Aerobic exercise, prolonged exercise of moderate intensity * Aerobics, a form of aerobic exercise * Aerobic respiration, the aerobic process of cell ...

fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...

, 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 Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of ...

coffee Coffee is a drink prepared from roasted coffee beans. Darkly colored, bitter, and slightly acidic, coffee has a stimulating effect on humans, primarily due to its caffeine content. It is the most popular hot drink in the world. Seeds of ...

, and potato chips (

crisps A potato chip (North American English; often just chip) or crisp (British and Irish English) is a thin slice of potato that has been either deep frying, deep fried, baking, baked, or air frying, air fried until crunchy. They are commonly serve ...

). On a more short-term basis, vacuum packing can also be used to store fresh foods, such as vegetables, meats, and liquids, because it inhibits 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 A vacuum cleaner, also known simply as a vacuum or a hoover, is a device that causes suction in order to remove dirt from floors, upholstery, draperies, and other surfaces. It is generally electrically driven. The dirt is collected by either a ...

or a dedicated vacuum sealer. This technique is sometimes used to compact

household waste Municipal solid waste (MSW), commonly known as trash or garbage in the United States and rubbish in Britain, is a waste type consisting of everyday items that are discarded by the public. "Garbage" can also refer specifically to food waste, a ...

, for example where a charge is made for each full bag collected. Vacuum packaging products, using plastic bags, canisters,

bottle A bottle is a narrow-necked container made of an impermeable material (such as glass, plastic or aluminium) in various shapes and sizes that stores and transports liquids. Its mouth, at the bottling line, can be sealed with an internal stop ...

s, or

mason jar A Mason jar, also known as a canning jar or fruit jar, is a glass jar used in home canning to preserve food. It was named after American tinsmith John Landis Mason, who patented it in 1858. The jar's mouth has a screw thread on its outer perime ...

s, are available for home use. For delicate food items that might be crushed by the vacuum packing process (such as potato chips), an alternative is to replace the interior gas with nitrogen. This has the same effect of inhibiting deterioration due to the removal of oxygen.

Sealing techniques

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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. A

heat sealer A heat sealer is a machine used to seal products, packaging, and other thermoplastic materials using heat. This can be with uniform thermoplastic monolayers or with materials having several layers, at least one being thermoplastic. Heat sealing ...

is often used to seal the pack.

Single vacuum chamber machines

Single 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 low-to-medium-volume packaging. This style of vacuum machine is also capable of sealing liquids due to equal pressure in the chamber and the bag eliminating the risk of the liquid being sucked out of the open edge of the bag.

Double vacuum chamber machines

XtraVac Double Chamber Vacuum Packaging Machine

Double chamber sealers require the entire product to be placed in a plastic bag within the machine. Once the product is placed in the machine on the seal bar, the lid is closed and air is removed. Then a seal bar inside the chamber seals the product in 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. Double chamber sealers are typically used for medium-volume packaging, and also have the capability to vacuum seal liquids. The lid generally swings from one side to another, increasing production speed over a single chamber model. Double chamber vacuum packaging machines generally have either spring-weighted lids or fully automatic lids. Double chamber vacuum packaging machines are commonly used for: * Fresh meat * Processed meat * Cheese (hard and soft) * Candy and chocolate

Rotary belt type vacuum sealer (rolling vacuum sealer)

Rotary belt type vacuum packaging machine or vacuum sealer features the same function as the double chamber vacuum packaging machine as a 'vacuum bag sealer'. But the rotary belt vacuum packaging machine is more convenient, as the belt rotates automatically while the bags are placed to the sealing bar and vacuum sealing process completed. The vacuumed and sealed bags are automatically unloaded, which obviously is more convenient. The packaging plate of the machine is adjustable to 4 degrees, which allows the vacuum packaging of food with soup and liquid. Rotary belt type packaging machines are commonly used for: * Fresh meat * Processed meat * Seafood * Pickles * Cheese (hard and soft) * Candy and chocolate * Any other packs that needs vacuum sealing, and the size of the pack is not too big.

Automatic belt vacuum chamber machines

VC999 K9 Automatic Belt Vacuum Chamber Machine

Automatic belt chamber sealers require the entire product to be placed in a plastic bag or flow wrapped pouch within the machine. The product travels on the conveyor belt, it is automatically positioned in the machine on the seal bar, the lid is closed and air is removed. Then a seal bar inside the chamber seals the product in 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. Automatic belt vacuum chamber machines are typically used for high-speed packaging of large items, and also have the capability to vacuum seal liquids. The lid generally travels straight up and down. Automatic belt vacuum chamber packaging machines are commonly used for: * Fresh meat (large portions) * Processed meat * Large sausage logs * Cheese (hard and soft)

Thermoforming (rollstock) vacuum packaging machines

VC999 i-Series Thermoform Packaging Machine

Vacuum Packaging in large production facilities can be done with thermoforming machines. These are Form-Fill-Seal style machines that form the package from rolls of packaging film (webbing). Products are loaded into the thermoformed pockets, the top web is laid and sealed under a vacuum, producing vacuum packaged products. Thermoforming can greatly increase packaging production speed. Thermoformed plastics can be customized for size, color, clarity, and shape to fit products perfectly, creating a consistent appearance. One of the most commonly used thermoformed plastics is PET, known for a high-strength barrier resistant to outside tampering and an ease of molding into designated designs and shapes. Some common uses for Thermoforming in vacuum packaging include: * Fresh and marinated meat * Sausage * Cheese * Candy / chocolate * Grain * Grab-and-go snacks (beef jerky, snack sticks) * Pharmaceutical and medical products * Coins / collectables

In food storage

Food safety

In an oxygen-depleted environment,

anaerobic bacteria An anaerobic organism or anaerobe is any organism that does not require molecular oxygen for growth. It may react negatively or even die if free oxygen is present. In contrast, an aerobic organism (aerobe) is an organism that requires an oxygenat ...

can proliferate, potentially causing food-safety issues. Some pathogens of concern in vacuum packed foods are spore-forming non-proteolytic ''

Clostridium botulinum ''Clostridium botulinum'' is a Gram-positive, rod-shaped, anaerobic, spore-forming, motile bacterium with the ability to produce the neurotoxin botulinum. The botulinum toxin can cause botulism, a severe flaccid paralytic disease in humans ...

'', ''Yersenia enterocolitica'', and ''

Listeria monocytogenes ''Listeria monocytogenes'' is the species of pathogenic bacteria that causes the infection listeriosis. It is a facultative anaerobic bacterium, capable of surviving in the presence or absence of oxygen. It can grow and reproduce inside the host ...

''. Vacuum packing is often used in combination with other food processing techniques, such as

retorting In a chemistry laboratory, a retort is a device used for distillation or dry distillation of substances. It consists of a sphere, spherical vessel with a long downward-pointing neck. The liquid to be distilled is placed in the vessel and heate ...

or refrigeration, to inhibit the growth of anaerobic organisms.

Shelf life

Depending on the product, atmosphere, temperature, and the barrier properties of the package, vacuum packaging extends the

of many foods. The shelf life of meats can be extended by vacuum packaging, particularly when used with

modified atmosphere packaging Modified atmosphere packaging (MAP) is the practice of modifying the composition of the internal atmosphere of a package (commonly food packages, drugs, etc.) in order to improve the shelf life. The need for this technology for food arises from t ...

High barrier shrink vacuum bags

The amount of shelf life enhanced by a vacuum bag is dependent on the structure in the material. A standard vacuum bag is composed of a PA/PE structure where PA is for puncture resistance and PE is for sealing. The high barrier category includes the usage of more layers focused on the prevention of oxygen permeability, and therefore shelf life protection. There are two materials used in high barrier structures,

polyvinylidene chloride Polyvinylidene chloride, or polyvinylidene dichloride (PVDC), is a homopolymer of vinylidene chloride. History Ralph Wiley accidentally discovered polyvinylidene chloride polymer in 1933. He, then, was a college student who worked part-time at D ...

(PVDC) and ethylene vinyl alcohol (

EVOH Ethylene vinyl alcohol (EVOH) is a formal copolymer of ethylene and vinyl alcohol. Because the latter monomer mainly exists as its tautomer acetaldehyde, the copolymer is prepared by polymerization of ethylene and vinyl acetate to give the et ...

). Shelf life indication can be effectively measured by how many cubic centimeters of oxygen can permeate through 1 square meter of material over a 24-hour period. A standard PA/PE bag allows on average 100 cubic centimeters, PVDC allows on average over 10, and EVOH on average 1 cubic centimeter. Multi-layer structures allow the ability to use strong oxygen-barrier materials for enhanced shelf life protection. The PremiumPack structure is a good example of EVOH based high barrier shrink material.

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 changes the flavor and texture of foods. Vacuum packing reduces freezer burn by preventing the food from exposure to the cold, dry air.

Other uses

Sous-vide cooking

Vacuum packaging also allows for a special cooking method,

sous-vide Sous vide (; French for 'under vacuum'), also known as low-temperature, long-time (LTLT) cooking, is a method of cooking in which food is placed in a plastic pouch or a glass jar and cooked in a water bath for longer than usual cooking times (us ...

. Sous-vide, French for ''under vacuum'', involves poaching food that is vacuum sealed in a plastic bag.