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Chewing gum is a type of confection traditionally made of chicle, a natural latex product, or synthetic rubber known as polyisobutylene, which is a non-vulcanisable form of the butyl rubber (isoprene-isobutylene) used for inner tubes or to line tubeless tires. For reasons of economy and quality, many modern chewing gums use rubber instead of chicle. Chicle is nonetheless still the base of choice for some regional markets, such as in Japan.

Contents 1 Types 2 Manufacturing 3 Use in military 4 Effects on health 4.1 Stomach acid 4.2 Dental health 4.3 Possible carcinogens 4.4 Swallowed gum 5 Bans on chewing gum 6 References 7 External links

[edit] Types

Chewing gum is available in a wide variety of flavors such as mint, wintergreen, cinnamon and various types of fruits. Mintier flavors are often chewed for fresher breath. There is no standard type of gum, as it can be formed in many different shapes and sizes. Some examples include:

• Gum balls - shaped like a ball and coated. These are most often sold in gum ball machines. In the United Kingdom, these are often referred to as 'Screwballs', as they are found at the bottom of a Screwball ice cream treat. In the US, they are known as "gum balls".
• Bubblegum - formulated with film-forming characteristics for blowing bubbles.
• Sugarfree gum - made with artificial sweeteners.
• Candy & Gum combinations - predominantly bubblegum found in the center of some types of lollipop, such as Charms Blow Pops.
• Center-filled gum - Pellet or ball gum formed around a soft or liquid centre.
• Cut & Wrap gum - refers to the name of the machine that wraps this type of gum, usually in the form of a chunk, cube or cylindrical shape.
• Dragée gum or "pellet gum" - a pillow-shaped coated pellet, often packed in blister packs.
• Functional gum - a chewing gum with a practical function. Vibe Energy Gum, for example, uses gum as the delivery system for Caffeine, Ginseng, Guarana and Green Tea.
• Medicated gum - a chewing gum acting as a delivery system to introduce medicinal substances into the saliva and thus into the bloodstream faster than pills.
• Powdered gum - free-flowing powder form or powders compressed into unique shapes.
• Stick gum - a rectangular, thin, flat, slab of gum.
• Ribbon gum or tape gum - very similar to stick gum in shape, but much longer, coiled up in a cylindrical container often shaped like a hockey puck. The chewer tears off a piece of the desired size. (See Bubble Tape)
• Tube gum or spaghetti gum - very soft bubble gum which can be squeezed from a tube or can be found in a pouch. (See Big League Chew)

[edit] Manufacturing

The approximate manufacturing methods are fairly constant between brands. The gum base is melted at a temperature of about 115 °C(240 °F), until it has the viscosity of thick maple syrup, then filtered through a fine mesh screen. Then it is further refined by separating dissolved particles in a centrifuge, and further filtered. Clear base, still hot and melted, is then put into mixing vats. Other ingredients that may be added include: powdered sugar (the amount and grain size of which determines the brittleness of the resulting gum), corn syrup and/or glucose (which serve as humectants and coat the sugar particles to stabilize their suspension and keep the gum flexible), various softeners, food colourings, flavourings, preservatives and other additives.

The homogenized mixture is then poured onto cooling belts and cooled with cold air. Extrusion, optional rolling and cutting, and other mechanical shaping operations follow. The chunks of gum are then put aside to set for 24 to 48 hours.

Coated chewing gums then undergo other operations. The chunks are wrapped with optional undercoating for better binding with outer layers then are immersed into liquid sugar. The pellets are then coloured and coated with a suitable glazing agent, usually a wax. The coating/glazing/colour on gum is sometimes derived from animal-based sources such as resinous glaze derived from an insect or beeswax.

While gum was historically sweetened with cane sugar, xylitol, corn syrup or other natural sweeteners, a large number of brands now use artificial sweeteners such as aspartame, sucralose, or Acesulfame potassium. Non-coated varieties of gum are often covered in sweetened marble dust to prevent the wrapper from sticking to the product.

[edit] Use in military

The United States military have regularly supplied soldiers with chewing gum since World War I because it helped both to improve the soldiers' concentration and to relieve stress.^[1] As of 2005, the U.S. military is sponsoring development of a chewing gum formulation with an antibacterial agent that could replace conventional oral hygiene methods in the battlefield. This product is not expected to be available for use for some time to come.^[2]

Recently, the U.S. armed forces have been providing troops with caffeinated gum to keep soldiers alert for extended periods of time without experiencing fatigue or drowsiness. Each stick of gum has approximately 100 mg of caffeine in it, about the same amount in an average cup of coffee.^[3] Although chewing gum is provided in the U.S. military MREs, it is often strongly discouraged for a troop to be seen chewing gum while standing in formation.

Recaldent chewing gum was introduced into New Zealand Defence Force ration packs in May 2007 by New Zealand Defence Dental Services to aid oral health care for service personnel in the field. Chewing gum also aids in relief of stress.^[4]

[edit] Effects on health

[edit] Stomach acid

The consumption of chewing gum is discouraged by some doctors, because chewing it too frequently has been said to increase the production of stomach acid to abnormal levels over a long period of time.^{[citation needed]}

[edit] Dental health

Sugar-free gum sweetened with xylitol has been shown to reduce cavities and plaque by starving microorganisms in the mouth. The same effect has not been shown for the sweetener sorbitol. The addition of calcium lactate has been shown to increase recalcification. Chewing gum sweetened with sugar can have a negative effect on oral health, because it can degrade the enamel on teeth.

[edit] Possible carcinogens

Concern has arisen about the possible carcinogenicity of the vinyl acetate (acetic acid ethenyl ester) used by some manufacturers in their gum bases. The Canadian government has classified the ingredient as a "potentially high hazard substance."^[5] Currently the ingredient can be hidden in the catch-all term "gum base".

[edit] Swallowed gum

One old wives' tale says that swallowed gum will remain in a human's stomach for up to seven years, as it is not digestable. According to several medical opinions, there seems to be little truth behind the tale. In most cases, swallowed gum will pass through the system as fast as any other food, but can be a little slower.^[6] There have been a few cases where swallowing gum has required medical attention, but these cases are more or less related to chronic gum swallowers. One young boy swallowed several pieces each day and had to be hospitalized,^[7] and another little girl required medical attention when she swallowed her gum and four coins, which got stuck together in her esophagus.^[6] As long as the mass of gum is small enough to pass out of the stomach, it will likely pass out of the body easily.

[edit] Bans on chewing gum

Many schools do not allow chewing gum because students often dispose of it by sticking it to desks, chairs, floors, or similar flat surfaces. In addition, gum chewing sometimes makes an audible smacking noise, which is often quite loud in a quiet classroom.

The 12-year-old nation-wide ban on chewing gum in Singapore was lifted in 2004 after pressure from US manufacturers, but gum can still only be bought from pharmacies on production of an ID card. Pharmacists face a fine of $2,940 for ignoring the regulations.^[8]

[edit] References

[edit] External links

• Study on Evaluation of Adhesive Properties of Chewing Gum
• Snopes Article on Seven Year Chewing Gum Indigestion
• Straight Dope article on "disintegrating gum syndrome": Does passionate kissing cause your chewing gum to disintegrate?.