Corn starch,
cornstarch,
cornflour or
maize starch is the
starchStarch or amylum is a carbohydrate consisting of a large number of glucose units joined together by glycosidic bonds. This polysaccharide is produced by all green plants as an energy store...
of the corn (
maizeMaize known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable...
) grain obtained from the
endospermEndosperm is the tissue produced inside the seeds of most flowering plants around the time of fertilization. It surrounds the embryo and provides nutrition in the form of starch, though it can also contain oils and protein. This makes endosperm an important source of nutrition in human diet...
of the corn
kernelA seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
.
History
Thomas Kingsford is credited to have been the inventor of corn starch in the 1840s, while he was working as the superintendent of a wheat starch factory in
Jersey City, New JerseyJersey City is the seat of Hudson County, New Jersey, United States.Part of the New York metropolitan area, Jersey City lies between the Hudson River and Upper New York Bay across from Lower Manhattan and the Hackensack River and Newark Bay...
. Until 1850, corn starch was used primarily for starching laundry and industrial uses.
Use
It is used as a
thickening agentThickening agents, or thickeners, is the term applied to substances which increase the viscosity of a solution or liquid/solid mixture without substantially modifying its other properties; although most frequently applied to foods where the target property is taste, the term also is applicable to...
in soups and liquid-based foods, such as sauces, gravies and custard. It is sometimes preferred over
flourFlour is a powder which is made by grinding cereal grains, other seeds or roots . It is the main ingredient of bread, which is a staple food for many cultures, making the availability of adequate supplies of flour a major economic and political issue at various times throughout history...
because it forms a translucent mixture, rather than an
opaqueOpacity is the measure of impenetrability to electromagnetic or other kinds of radiation, especially visible light. In radiative transfer, it describes the absorption and scattering of radiation in a medium, such as a plasma, dielectric, shielding material, glass, etc...
one. As the starch is heated, the molecular chains unravel, allowing them to collide with other starch chains to form a mesh, thickening the liquid (
Starch gelatinizationStarch gelatinization is a process that breaks down the intermolecular bonds of starch molecules in the presence of water and heat, allowing the hydrogen bonding sites to engage more water. This irreversibly dissolves the starch granule...
).
It is usually included as an
anticaking agentAn anticaking agent is an additive placed in powdered or granulated materials, such as table salt, to prevent the formation of lumps, easing packaging, transport, and consumption....
in powdered
sugarSugar is a class of edible crystalline carbohydrates, mainly sucrose, lactose, and fructose, characterized by a sweet flavor.Sucrose in its refined form primarily comes from sugar cane and sugar beet...
(10X or
confectioner's sugarPowdered sugar, also known as confectioners' sugar or icing sugar, is very fine sugar. When intended for home use, it typically contains a small amount of anti-caking agent....
). For this reason, recipes calling for powdered sugar often call for at least light cooking to remove the raw corn starch taste.
Baby powderBaby powder is an astringent powder used for preventing diaper rash, as a deodorant, and for other cosmetic uses. It may be composed of talc or corn starch. Talcum powder is harmful if inhaled since it may cause aspiration pneumonia or granuloma. Drugs such as cocaine are sometimes cut with...
often uses cornstarch.
When using corn starch, first mix it with cold water (or another liquid) until it forms a smooth paste, and then add it to whatever is being thickened. If it is added directly into the cooking food it will form lumps that are then difficult to mash out for a smooth mixture. An easy way to make certain that all the lumps are gone from the corn starch/water mixture is to put the two into a jar with a screw on lid and vigorously shake the sealed jar until the lumps are gone. This also works with a flour/water mixture. This method also allows for better portion control when slowly adding it to a soup, sauce, or gravy.
Corn starch, in certain scientific experiments, can be used as a
Non-Newtonian fluidA non-Newtonian fluid is a fluid whose flow properties differ in any way from those of Newtonian fluids. Most commonly the viscosity of non-Newtonian fluids is not independent of shear rate or shear rate history...
.
A common substitute is
arrowrootArrowroot, or obedience plant , Bermuda arrowroot, araru, ararao, is a large perennial herb found in rainforest habitats...
, which replaces corn starch on a 1:1 ratio.
Manufacture
The corn is steeped for 30 to 48 hours, which ferments it slightly. The
germThe germ of a cereal is the reproductive part that germinates to grow into a plant; it is the embryo of the seed. Along with bran, germ is often a by-product of the milling that produces refined grain products. Cereal grains and their components, such as wheat germ, rice bran, and maize may be used...
is separated from the
endospermEndosperm is the tissue produced inside the seeds of most flowering plants around the time of fertilization. It surrounds the embryo and provides nutrition in the form of starch, though it can also contain oils and protein. This makes endosperm an important source of nutrition in human diet...
and those two components are ground separately (still soaked). Next the starch is removed from each by washing. The starch is separated from the
corn steep liquorCorn steep liquor is a by-product of corn wet-milling. It is an important constituent of some growth media. It was used in the culturing of Penicillium during research into penicillin, by American microbiologist Andrew J. Moyer. It is an excellent source of organic nitrogen. ....
, the
cereal germThe germ of a cereal is the reproductive part that germinates to grow into a plant; it is the embryo of the seed. Along with bran, germ is often a by-product of the milling that produces refined grain products. Cereal grains and their components, such as wheat germ, rice bran, and maize may be used...
, the fibers and the
corn glutenCorn gluten meal is a byproduct of corn processing that has historically been used as an animal feed. It can also be used as an organic herbicide.- Herbicide :...
mostly in hydrocyclones and
centrifugeA centrifuge is a piece of equipment, generally driven by an electric motor , that puts an object in rotation around a fixed axis, applying a force perpendicular to the axis...
s, and then dried. (The residue from every stage is used in
animal feedFodder or animal feed is any agricultural foodstuff used specifically to feed domesticated livestock such as cattle, goats, sheep, horses, chickens and pigs. Most animal feed is from plants but some is of animal origin...
and to make
corn oilCorn oil is oil extracted from the germ of corn . Its main use is in cooking, where its high smoke point makes refined corn oil a valuable frying oil. It is also a key ingredient in some margarines. Corn oil is generally less expensive than most other types of vegetable oils. One bushel of corn...
or other applications.) This process is called wet milling. Finally the starch may be
modifiedModified starch, also called starch derivatives, are prepared by physically, enzymatically, or chemically treating native starch, thereby changing the properties of the starch. Modified starches are used in practically all starch applications, such as in food products as a thickening agent,...
for specific purposes.
Amylophagia
AmylophagiaAmylophagia is a condition involving the compulsive consumption of excessive amounts of purified starch. It is a form of pica and is often observed in pregnant women. Amylophagia is distinct from a traditional diet containing a great deal of starchy staples such as potatoes, rice etc...
is a condition involving the compulsive consumption of excessive amounts of purified starch, often corn starch.
Names and varieties
- Called corn starch in the USA.
- Called cornflour in the United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
, IrelandIreland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...
and CommonwealthThe Commonwealth of Nations, normally referred to as the Commonwealth and formerly known as the British Commonwealth, is an intergovernmental organisation of fifty-four independent member states...
countries, except in Canada, where it is also known as corn starch. Not to be confused with cornmealCornmeal is flour ground from dried maize or American corn. It is a common staple food, and is ground to fine, medium, and coarse consistencies. In the United States, the finely ground cornmeal is also referred to as cornflour. However, the word cornflour denotes cornstarch in recipes from the...
.
- Called maize starch in Europe.
- Often called maizena in the Netherlands, Belgium, France, Italy, Portugal, Norway, Denmark, Sweden, Switzerland, Spain, South Africa, Latin America and Indonesia, after the brand.
See also
- Amylomaize
Amylomaize was a term coined by Robert P. Bear of Bear Hybrids Corn Company in Decatur, Illinois to describe his discovery and commercial breeding of a unique cornstarch with high amylose content, also called high amylose starch...
, high amylose starch
- Waxy corn
Waxy corn was found in China in 1909. As this plant showed many peculiar traits, the American breeders long used it as a genetic marker to tag the existence of hidden genes in other maize breeding programs...
, waxy maize starch
- Corn syrup
Corn syrup is a food syrup, which is made from the starch of maize and contains varying amounts of maltose and higher oligosaccharides, depending on the grade. Corn syrup is used in foods to soften texture, add volume, prevent crystallization of sugar, and enhance flavor...
- Corn ethanol
Corn ethanol is ethanol produced from corn as a biomass through industrial fermentation, chemical processing and distillation. Corn is the main feedstock used for producing ethanol fuel in the United States and it is mainly used as an oxygenate to gasoline in the form of low-level blends, and to a...
- Modified starch
Modified starch, also called starch derivatives, are prepared by physically, enzymatically, or chemically treating native starch, thereby changing the properties of the starch. Modified starches are used in practically all starch applications, such as in food products as a thickening agent,...