Please read:

A personal appeal from

Wikipedia founder Jimmy Wales

Popcorn
From Wikipedia, the free encyclopedia

Jump to: navigation, search

For other uses, see Popcorn (disambiguation).
Popcorn

Popcorn on the cob, freshly

harvested.

Popped popcorn, ready for eating.

Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
(unranked): Commelinids
Order: Poales
Family: Poaceae
Genus: Zea
Species: Z. mays
Subspecies: Z. m. averta
Trinomial name
Zea mays averta

Popcorn or 'popping corn' is corn which expands from the kernel and puffs up when heated.
Corn popping was originally discovered by Native Americans in North America. Popcorn
became a popular snack food during the Great Depression and for watching movies.

Corn is able to pop because, unlike other grains, its kernels have a hard moisture-sealed hull and
a dense starchy filling. This allows pressure to build inside the kernel until an explosive "pop"
results. Some strains of corn are now cultivated specifically as popping corns.

There are many techniques for popping corn. Commercial large-scale popcorn machines were
invented by Charles Cretors in the late 19th century. Many types of small-scale home methods
for popping corn also exist, with the most popular in the USA being prepackaged. Popcorn has
both advocates and detractors. Some consider it to be a health food while others caution against
it for a variety of reasons. Popcorn can also have non-food applications, ranging from holiday
decorations to packaging materials.

Contents
[hide]

 1 History
 2 How popcorn pops
o 2.1 Methods of popping
o 2.2 Expansion and yield
 3 As a food
o 3.1 Nutritional value
o 3.2 Health risks
 4 Other uses
 5 See also
 6 References
 7 Additional reading
 8 External links

[edit] History
Popcorn was first discovered thousands of years ago by Native Americans in North America.
One of the oldest forms of corn, evidence of popcorn from 3600 B.C. was found in New Mexico.
The English who came to America in the 16th and 17th centuries learned about popcorn from the
Native Americans.

During the Great Depression popcorn was comparatively cheap at 5-10 cents a bag and became
popular. Thus, while other businesses failed, the popcorn business thrived and became a source
of income for some struggling farmers. During World War II, sugar rations diminished candy
production, causing Americans to eat three times more popcorn than they had before.[1]

At least six localities (all in the Midwestern United States) claim to be the "Popcorn Capital of
the World": Valparaiso, Indiana; Van Buren, Indiana; Marion, Ohio; Ridgway, Illinois; Schaller,
Iowa; and North Loup, Nebraska. According to the USDA, most of the maize used for popcorn
production is specifically planted for this purpose; most is grown in Nebraska and Indiana, with
increasing area in Texas.[2]

As the result of an elementary school project, popcorn became the official state snack food of
Illinois.[3]

[edit] How popcorn pops

Kernel and popped popcorn

Each kernel of popcorn contains a certain amount of moisture and oil. Unlike most other grains,
the outer hull of the popcorn kernel is both strong and impervious to moisture, and the starch
inside consists almost entirely of a hard, dense type.[4]

As the oil and the water are heated past the boiling point, they turn the moisture in the kernel,
which has a moisture-proof hull, into a superheated pressurized steam. Under these conditions,
the starch inside the kernel gelatinizes, softening and becoming pliable. The pressure continues
to increase until the breaking point of the hull is reached: a pressure of about 135 psi (930 kPa)[4]
and a temperature of 180 °C (356 °F). The hull ruptures rapidly, causing a sudden drop in
pressure inside the kernel and a corresponding rapid expansion of the steam, which expands the
starch and proteins of the endosperm into airy foam. As the foam rapidly cools, the starch and
protein polymers set into the familiar crispy puff.[4]
Special varieties are grown to give improved popping yield. Some wild types will pop, but the
cultivated strain is Zea mays averta, which is a special kind of flint corn.

[edit] Methods of popping

Although small quantities can be popped in a stovetop kettle in a home kitchen, commercial sale
of freshly popped popcorn employs specially designed popcorn machines, which were invented
in Chicago, Illinois by Charles Cretors in 1885. Cretors successfully introduced his invention at
the Columbian Exposition in 1893. (At this same world's fair, F.W. Rueckheim introduced the
first caramel corn; his brother, Louis, slightly altered the recipe and introduced it as Cracker Jack
popcorn in 1896.[5])

Cretors' invention introduced the first patented steam-driven popcorn machine that popped corn
in oil. Previously, vendors popped corn by holding a wire basket over an open flame. At best, the
result was a hot, dry, unevenly cooked confection. The Cretors' machine popped corn in a
mixture of one-third clarified butter, two-thirds lard, and salt. This mixture could withstand the
450 °F (232 °C) temperature needed to pop corn and it did without producing much smoke. A
fire under a boiler created steam that drove a small engine; that engine drove the gears, shaft, and
agitator that stirred the corn and powered the attention-attracting clown – the Toasty Roasty
Man. A wire connected to the top of the cooking pan allowed the operator to disengage the drive
mechanism, lift the cover, and dump popped corn into the storage bin beneath. Exhaust from the
steam engine was piped to a hollow pan below the corn storage bin and kept freshly popped corn
uniformly warm for the first time ever.[6]

An in-home hot-air popcorn maker.

A very different method of popcorn-making can still be seen on the streets of some Chinese
cities today. The corn is poured into a large cast-iron canister- sometimes called a 'popcorn
hammer'- that is then sealed with a heavy lid and slowly turned over a curbside fire in rotisserie
fashion. When a pressure gauge on the canister reaches a certain level, it is removed from the
fire, a large canvas sack is put over the lid, and the seal is released. With a huge boom, all of the
popcorn explodes at once and is poured into the sack.[7][8][9]

Individual consumers can also buy and use specialized popping appliances that typically generate
no more than a gallon of popped corn per batch. Some of these appliances also accept a small
volume of oil or melted butter to assist thermal transfer from a stationary heating element, but
others are "air poppers" which rapidly circulate heated air up through the interior, keeping the
unpopped kernels in motion to avoid burning and blowing the popped kernels out through the
chute.[10] The great majority of popcorn sold for home consumption is now packaged for use in a
microwave oven in a Popcorn bag.[11]

[edit] Expansion and yield

Popping results are sensitive to the rate at which the kernels are heated. If heated too quickly, the
steam in the outer layers of the kernel can reach high pressures and rupture the hull before the
starch in the center of the kernel can fully gelatinize, leading to partially popped kernels with
hard centers. Heating too slowly leads to entirely unpopped kernels: the tip of the kernel, where
it attached to the cob, is not entirely moisture-proof, and when heated slowly, the steam can leak
out of the tip fast enough to keep the pressure from rising sufficiently to break the hull and cause
the pop.[12]

Producers and sellers of popcorn consider two major factors in evaluating the quality of popcorn:
what percentage of the kernels will pop, and how much each popped kernel expands. Expansion
is an important factor to both the consumer and vendor. For the consumer, larger pieces of
popcorn tend to be more tender and are associated with higher quality. For the grower,
distributor, and vendor, expansion is closely correlated with profit: vendors such as theaters buy
popcorn by weight and sell it by volume. For both these reasons, higher-expansion popcorn
fetches a higher profit per unit weight.

Popcorn will pop when freshly harvested, but not well: its high moisture content leads to poor
expansion and chewy pieces of popcorn. Kernels with a high moisture content are also
susceptible to mold when stored. For these reasons, popcorn growers and distributors dry the
kernels until they reach the moisture level at which they expand the most. This differs by variety
and conditions, but is generally in the range of 14–15% moisture by weight. If the kernels are
over-dried, the expansion rate will suffer and the percentage of kernels that pop at all will
decline.

Two explanations exist for kernels which do not pop at proper temperatures, known in the
popcorn industry as "old maids". The first is that unpopped kernels do not have enough moisture
to create enough steam for an explosion. The second explanation, according to research led by
Dr. Bruce Hamaker of Purdue University, is that the unpopped kernel may have a leaky hull.
Popcorn varieties are broadly categorized by the shape of the kernels, the color of the kernels, or
the shape of the popped corn. While the kernels may come in a variety of colors, the popped corn
is always off-yellow or white as it is only the hull (or pericarp) that is colored. "Rice" type
popcorns have a long kernel pointed at both ends; "pearl" type kernels are rounded at the top.
Commercial popcorn production has moved mostly to pearl types.[13] Historically, pearl popcorns
were usually yellow and rice popcorns usually white. Today both shapes are available in both
colors, as well as others including black, red, and variegated. Commercial production is
dominated by white and yellow.[14]

"Mushroom"-shaped popcorn, left, is less fragile and less tender than "butterfly"-shaped, right.

In popcorn jargon, a popped kernel of corn is known as a "flake". Two shapes of flakes are
commercially important. "Butterfly" flakes are irregular in shape and have a number of
protruding "wings". "Mushroom" flakes are largely ball-shaped, with few wings. Butterfly flakes
are regarded as having better mouthfeel, with greater tenderness and less noticeable hulls.
Mushroom flakes are less fragile than butterfly flakes and are therefore often used for packaged
popcorn or confectionery, such as caramel corn.[14] The kernels from a single cob of popcorn may
form both butterfly and mushroom flakes; hybrids that produce 100% butterfly flakes or 100%
mushroom flakes exist, the latter developed only as recently as 1998.[14] Growing conditions and
popping environment can also affect the butterfly-to-mushroom ratio.

[edit] As a food
Popcorn is usually served salted or sweetened. In North America, it is traditionally served salted,
although sweetened versions, such as caramel corn and kettle corn, are also commonly available.
In the United Kingdom, ready-made popcorn is available either salted or simply sweetened with
sugar. Toffee (i.e. caramel) popcorn is also available, but tends to be more expensive. Popcorn is
a popular snack at sporting events and in cinemas, where it has been served since 1912.[citation needed]
The Boy Scouts of America sell popcorn door-to-door as a primary fundraiser, similar to Girl
Scout cookies.[15]

[edit] Nutritional value

Popcorn, air-popped, no additives

Nutritional value per 100 g (3.5 oz)
Energy 1,598 kJ (382 kcal)
 Carbohydrates 78 g
Dietary fiber 15 g
Fat 4g
Protein 12 g
Thiamine (Vit. B1) 0.2 mg (15%)
Riboflavin (Vit. B2) 0.3 mg (20%)
Iron 2.7 mg (22%)
One cup is 8 grams.
Percentages are relative to US recommendations for adults.
Source: USDA Nutrient database

Air-popped popcorn is naturally high in fiber, low in calories and fat, contains no sodium, and is
sugar free.[16] This can make it an attractive snack to people with dietary restrictions on the intake
of calories, fat, and/or sodium. For the sake of flavor, however, large amounts of fat, sugar, and
sodium are often added to prepared popcorn, which can quickly convert it to a very poor choice
for those on restricted diets.

One particularly notorious example of this first came to public attention in the mid-1990s, when
the Center for Science in the Public Interest produced a report about "Movie Popcorn", which
became the subject of a widespread publicity campaign. The movie theaters surveyed used
coconut oil to pop the corn, and then topped it with butter or margarine. "A medium-size
buttered popcorn", the report said, "contains more fat than a breakfast of bacon and eggs, a Big
Mac and fries, and a steak dinner combined."[17] The practice continues today. For example,
according to DietFacts.com, a small popcorn from Regal Cinema Group (the largest theater chain
in the United States[18]) still contains 29 g of saturated fat,[19] as much as three Big Macs[20] and
the equivalent of a full day-and-a-half's reference daily intake.[21]

[edit] Health risks

Popcorn is included on the list of foods that the American Academy of Pediatrics recommends
not serving to children under four, because of the risk of choking.[22] Special "hulless" popcorn
has been developed that offers an alternative for small children and for people with braces or
other dental problems who may otherwise need to avoid popcorn.

Microwaveable popcorn represents a special case, since it is designed to be cooked along with its
various flavoring agents. One of these common artificial-butter flavorants, diacetyl, has been
implicated in causing respiratory ailments.[23]

[edit] Other uses

Scent: Popcorn smell has an unusually attractive quality for human beings. This is largely
because it contains high levels of the chemicals 6-acetyl-2,3,4,5-tetrahydropyridine and 2-acetyl-
1-pyrroline, very powerful aroma compounds that are used by food and other industries to make
products that either smell like popcorn (or bread, or other foods containing the compound in
nature), or for other purposes.

Decoration: Popcorn, threaded onto a string, is used as a wall or Christmas tree decoration in
some parts of North America,[24][25] as well as on the Balkan peninsula.[26]

Packing material: Some shipping companies have experimented with using popcorn as a
biodegradable replacement for expanded polystyrene packing material. However, popcorn has
numerous undesirable properties as a packing material, including attractiveness to pests,
flammability, and a higher cost and greater density than expanded polystyrene. A more
processed form of expanded corn foam has been developed to overcome some of these
limitations.[27]

Novelty: The world's largest popcorn ball was unveiled in October 2006 in Lake Forest, Illinois.
It weighed 3,415 pounds (1550 kilograms), measured 8 feet (2.4 m) in diameter, and had a
circumference of 24.6 feet (8 m).[28]