Cornflour, cornstarch, maize starch, or corn starch (

American English American English, sometimes called United States English or U.S. English, is the set of variety (linguistics), varieties of the English language native to the United States. English is the Languages of the United States, most widely spoken lang ...

) is the

starch Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human diet ...

derived from corn (

maize Maize (; ''Zea mays''), also known as corn in North American English, is a tall stout grass that produces cereal grain. It was domesticated by indigenous peoples in southern Mexico about 9,000 years ago from wild teosinte. Native American ...

) grain. The starch is obtained from the

endosperm The endosperm is a tissue produced inside the seeds of most of the flowering plants following double fertilization. It is triploid (meaning three chromosome sets per nucleus) in most species, which may be auxin-driven. It surrounds the Embryo#Pla ...

of the

kernel Kernel may refer to: Computing * Kernel (operating system), the central component of most operating systems * Kernel (image processing), a matrix used for image convolution * Compute kernel, in GPGPU programming * Kernel method, in machine learnin ...

. Corn starch is a common food ingredient, often used to thicken

sauce In cooking, a sauce is a liquid, cream, or semi- solid food, served on or used in preparing other foods. Most sauces are not normally consumed by themselves; they add flavour, texture, and visual appeal to a dish. ''Sauce'' is a French wor ...

s or

soup Soup is a primarily liquid food, generally served warm or hot – though it is sometimes served chilled – made by cooking or otherwise combining meat or vegetables with Stock (food), stock, milk, or water. According to ''The Oxford Compan ...

s, and to make

corn syrup Corn syrup is a food syrup that is made from the starch of corn/maize and contains varying amounts of sugars: glucose, maltose and higher oligosaccharides, depending on the grade. Corn syrup is used in foods to soften Mouthfeel, texture, add vol ...

and other

sugar Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucose Glucose is a sugar with the Chemical formula#Molecular formula, molecul ...

s. Corn starch is versatile, easily modified, and finds many uses in industry such as

adhesive Adhesive, also known as glue, cement, mucilage, or paste, is any non-metallic substance applied to one or both surfaces of two separate items that binds them together and resists their separation. The use of adhesives offers certain advantage ...

s, in paper products, as an anti-sticking agent, and

textile Textile is an Hyponymy and hypernymy, umbrella term that includes various Fiber, fiber-based materials, including fibers, yarns, Staple (textiles)#Filament fiber, filaments, Thread (yarn), threads, and different types of #Fabric, fabric. ...

manufacturing. It has medical uses as well, such as to supply glucose for people with

glycogen storage disease A glycogen storage disease (GSD, also glycogenosis and dextrinosis) is a metabolic disorder caused by a deficiency of an enzyme or transport protein affecting glycogen synthesis, glycogen breakdown, or glycolysis, glucose breakdown, typically in m ...

. Like many products in dust form, it can be hazardous in large quantities due to its

flammability A combustible material is a material that can burn (i.e., sustain a flame) in air under certain conditions. A material is flammable if it ignites easily at ambient temperatures. In other words, a combustible material ignites with some effort a ...

—see

dust explosion A dust explosion is the rapid combustion of fine particles suspended in the air within an enclosed location. Dust explosions can occur where any dispersed powdered combustible material is present in high-enough concentrations in the atmosphere ...

. When mixed with a fluid, corn starch can rearrange itself into a non-Newtonian fluid. For example, adding water transforms corn starch into a material commonly known as oobleck while adding oil transforms corn starch into an electrorheological (ER) fluid. The concept can be explained through the mixture termed "cornflour slime".

History

Until 1851, corn starch was used primarily for starching laundry and for other industrial uses. A method to produce pure culinary starch from maize was patented by John Polson of Brown & Polson, in Paisley,

Scotland Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjac ...

in 1854. This was sold as "Patented Corn Flour". Brown & Polson were muslin manufacturers who had been producing laundry starch for the

Paisley shawl Paisley shawls were a fashionable item of women's clothing in Europe during the late eighteenth and nineteenth centuries. Many were made of intricately woven and delicate wool, as well as examples being printed onto silks, wools, and cotton. The ...

industry and would become the largest starch producers in the UK.

Uses

Although mostly used for cooking and as a household item, corn starch is used for many purposes in several industries, ranging from its use as a chemical additive for certain products, to medical therapy for certain illnesses.

Culinary

United States Food Admininstration corn products poster

Corn starch is used as a

thickening agent A thickening agent or thickener is a substance which can increase the viscosity of a liquid without substantially changing its other properties. Edible thickeners are commonly used to thicken sauces, soups, and puddings without altering their ...

in liquid-based foods (e.g.,

s, gravies,

custard Custard is a variety of culinary preparations based on sweetened milk, cheese, or cream cooked with Eggs as food, egg or egg yolk to thicken it, and sometimes also flour, corn starch, or gelatin. Depending on the recipe, custard may vary in con ...

), usually by mixing it with a lower-temperature liquid to form a paste or slurry. It is sometimes preferred over

flour Flour is a powder made by Mill (grinding), grinding raw grains, List of root vegetables, roots, beans, Nut (fruit), nuts, or seeds. Flours are used to make many different foods. Cereal flour, particularly wheat flour, is the main ingredie ...

alone because it forms a

translucent In the field of optics, transparency (also called pellucidity or diaphaneity) is the physical property of allowing light to pass through the material without appreciable light scattering by particles, scattering of light. On a macroscopic scale ...

, rather than

opaque Opacity 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, shie ...

mixture. As the starch is heated over , the molecular chains unravel, allowing them to collide with other starch chains to form a mesh, thickening the liquid (

Starch gelatinization Starch gelatinization is a process of breaking down of intermolecular bonds of starch molecules in the presence of water and heat, allowing the hydrogen bonding sites (the hydroxyl hydrogen and oxygen) to engage more water. This irreversibly d ...

). However, continued boiling breaks up the molecules and thins the liquid. Cornstarch is usually included as an

anticaking agent An anticaking agent is an additive placed in powdered or granulated materials, such as table salt or confectioneries, to prevent the formation of lumps ( caking) and for easing packaging, transport, flowability, and consumption. Caking mechanism ...

powdered sugar Powdered sugar, also called confectioners' sugar and icing sugar, is a finely ground sugar produced by milling granulated sugar into a powdered state. It usually contains between 2% and 5% of an anti-caking agent—such as corn starch, potato ...

(icing or confectioner's sugar). A common substitute is

arrowroot Arrowroot is a starch obtained from the rhizomes (rootstock) of several tropical plants, traditionally ''Maranta arundinacea'', but also Florida arrowroot from ''Zamia integrifolia'', and tapioca from cassava (''Manihot esculenta''), which is of ...

starch, which replaces the same amount of corn starch. Food producers reduce production costs by adding varying amounts of corn starch to foods, for example to cheese and yogurt. Chicken nuggets with a thin outer layer of corn starch allows increased oil absorption and crispness after the latter stages of frying.

Non-culinary

Baby powder Baby powder is an astringent powder (substance), powder used for preventing diaper rash and for Cosmetics, cosmetic uses. It may be composed of talc (in which case it is also called talcum powder), corn starch or potato starch. It may contain a ...

may include corn starch among its ingredients. Corn starch can be used to manufacture

bioplastic Bioplastics are plastic materials produced from renewable biomass sources. Timeline of plastic development, Historically, bioplastics made from natural materials like shellac or Celluloid, cellulose had been the first plastics. Since the end of ...

s (like

PLA Pla may refer to: People * Cecilio Plá (1860–1934), Spanish painter * Conrad Pla (born 1966), Canadian kickboxer and actor * Jim Pla (born 1992), French racing driver * Joan Baptista Pla (ca. 1720–1773), Spanish composer and oboist * Josefina ...

used for

3D printing 3D printing, or additive manufacturing, is the construction of a three-dimensional object from a CAD model or a digital 3D model. It can be done in a variety of processes in which material is deposited, joined or solidified under computer ...

) and may be used in the manufacture of

airbags An airbag is a vehicle occupant-restraint system using a bag designed to inflate in milliseconds during a collision and then deflate afterwards. It consists of an airbag cushion, a flexible fabric bag, an inflation module, and an impact sensor. ...

Adhesive Adhesive, also known as glue, cement, mucilage, or paste, is any non-metallic substance applied to one or both surfaces of two separate items that binds them together and resists their separation. The use of adhesives offers certain advantage ...

can be made from corn starch, traditionally one of the adhesives that may be used to make paste papers. It dries with a slight sheen compared to wheat starch. It may also be used as an adhesive in book and paper conservation.

Medical

Corn starch is the preferred anti-stick agent on medical products made from natural

latex Latex is an emulsion (stable dispersion) of polymer microparticles in water. Latices are found in nature, but synthetic latices are common as well. In nature, latex is found as a wikt:milky, milky fluid, which is present in 10% of all floweri ...

, including

condom A condom is a sheath-shaped Barrier contraception, barrier device used during sexual intercourse to reduce the probability of pregnancy or a Sexually transmitted disease, sexually transmitted infection (STI). There are both external condo ...

s, diaphragms, and

medical glove Medical gloves are disposable gloves used during medical examinations and procedures to help prevent cross-contamination between caregivers and patients. Medical gloves are made of different polymers including latex, nitrile rubber, polyvinyl ch ...

s. Corn starch has properties enabling supply of glucose to maintain blood sugar levels for people with

. Corn starch can be used starting at age 6–12 months allowing glucose fluctuations to be deterred.

Manufacture

The corn is

steeped Steeping is the soaking of an organic solid, such as leaves, in a liquid (usually water) to extract flavours or to soften it. The specific process of teas being prepared for drinking by leaving the leaves in heated water to release the flavour a ...

for 30 to 48 hours, which ferments it slightly. The

germ Germ or germs may refer to: Science * Germ (microorganism), an informal word for a pathogen * Germ cell, cell that gives rise to the gametes of an organism that reproduces sexually * Germ layer, a primary layer of cells that forms during embry ...

is separated from the

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 liquor Corn steep liquor is a by-product of corn wet-milling. A viscous concentrate of corn solubles which contains amino acids, vitamins and minerals, it is an important constituent of some growth media. It was used in the culturing of ''Penicillium'' ...

, the

cereal germ The germ of a cereal grain is the part that develops into a plant; it is the seed embryo. 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 ge ...

, the fibers and the

corn gluten Corn gluten meal (CGM) is the principal protein of corn (maize) endosperm consisting mainly of zein and glutelin. It is a byproduct of corn processing that has historically been used as an animal feed. Despite the name, corn gluten does not contai ...

mostly in

hydrocyclone Hydrocyclones are a type of cyclonic separators that separate product phases mainly on basis of differences in gravity with aqueous solutions as the primary feed fluid. As opposed to dry or dust cyclones, which separate solids from gasses, hydro ...

s and

centrifuge A centrifuge is a device that uses centrifugal force to subject a specimen to a specified constant force - for example, to separate various components of a fluid. This is achieved by spinning the fluid at high speed within a container, thereby ...

s, and then dried. (The residue from every stage is used in

animal feed Animal feed is food given to domestic animals, especially livestock, in the course of animal husbandry. There are two basic types: fodder and forage. Used alone, the word ''feed'' more often refers to fodder. Animal feed is an important input ...

and to make

corn oil Corn oil (North American) or maize oil (British) is oil extracted from the germ of corn (maize). 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 margarin ...

or other applications.) This process is called

wet milling Wet-milling is a process in which feed material is steeped in water, with or without sulfur dioxide, to soften the seed kernel in order to help separate the kernel’s various components. For example, wet-milling plants can separate a 56-pound bu ...

. Finally, the starch may be modified for specific purposes.

Risks

Like many other powders, corn starch is susceptible to

s. It is believed that overheating of a corn starch-based powder—despite warnings on the packaging indicating that the material is flammable—initiated the Formosa Fun Coast explosion in Taiwan on 27 June 2015.

Names and varieties

* Called ''corn starch'' in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

and

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

. The term ''corn flour'' refers to cornmeal that is very finely milled; or, after wet processing with

alkali In chemistry, an alkali (; from the Arabic word , ) is a basic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The a ...

, further grinding then drying,

masa ''Masa'' or ''masa de maíz'' (; ) is a dough made from ground nixtamalized maize. It is used for making corn tortillas, '' gorditas'', '' tamales'', '' pupusas'', and many other Latin American dishes. It is dried and powdered into a flour f ...

flour. * It is called ''cornflour'' in the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...

Ireland Ireland (, ; ; Ulster Scots dialect, Ulster-Scots: ) is an island in the North Atlantic Ocean, in Northwestern Europe. Geopolitically, the island is divided between the Republic of Ireland (officially Names of the Irish state, named Irelan ...

Israel Israel, officially the State of Israel, is a country in West Asia. It Borders of Israel, shares borders with Lebanon to the north, Syria to the north-east, Jordan to the east, Egypt to the south-west, and the Mediterranean Sea to the west. Isr ...

and some

Commonwealth A commonwealth is a traditional English term for a political community founded for the common good. The noun "commonwealth", meaning "public welfare, general good or advantage", dates from the 15th century. Originally a phrase (the common-wealth ...

countries. Distinct in these countries from

cornmeal Maize meal is a meal (coarse flour) ground from dried maize. It is a common staple food and is ground to coarse, medium, and fine consistencies, but it is not as fine as wheat flour can be.Herbst, Sharon, ''Food Lover's Companion'', Third Editi ...

. * Cornflour is commonly derived from wheat in Australia. The starch is extracted from the wheat kernel, and is sometimes referred to as 'wheaten cornflour'.

References

External links

American Corn Refiners Association
{{corn Maize products Starch Edible thickening agents 1840 introductions