Corn starch, maize starch, or cornflour (

British English British English (BrE, en-GB, or BE) is, according to Lexico, Oxford Dictionaries, "English language, English as used in Great Britain, as distinct from that used elsewhere". More narrowly, it can refer specifically to the English language in ...

) is the starch derived from corn (

maize Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. The ...

) grain. The starch is obtained from the endosperm 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 learn ...

. 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 flavor, moisture, and visual appeal to a dish. ''Sauce'' is a French wor ...

s or soups, and to make corn syrup and other sugars. Corn starch is versatile, easily modified, and finds many uses in industry such as adhesives, in paper products, as an anti-sticking agent, and

textile Textile is an umbrella term that includes various fiber-based materials, including fibers, yarns, filaments, threads, different fabric types, etc. At first, the word "textiles" only referred to woven fabrics. However, weaving is not the ...

manufacturing. It has medical uses as well, such as to supply glucose for people with glycogen storage disease. Like many products in dust form, it can be hazardous in large quantities due to its

flammability A combustible material is something that can burn (i.e., ''combust'') in air. A combustible material is flammable if it ignites easily at ambient temperatures. In other words, a combustible material ignites with some effort and a flammable mat ...

—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 o ...

. When mixed with a fluid, corn starch can rearrange itself into a

non-Newtonian fluid A non-Newtonian fluid is a fluid that does not follow Newton's law of viscosity, i.e., constant viscosity independent of stress. In non-Newtonian fluids, viscosity can change when under force to either more liquid or more solid. Ketchup, for ex ...

. 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. Covering the northern third of the island of Great Britain, mainland Scotland has a Anglo-Scottish border, border with England to the southeast ...

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 the 19th century made of intricately woven and delicate wool. Although known as the Paisley pattern, the teardrop motif originated in Persia and India, becoming popular in Europe—and ...

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 the ...

in liquid-based foods (e.g., soup,

s, gravies, custard), usually by mixing it with a lower-temperature liquid to form a paste or slurry. It is sometimes preferred over flour 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 scattering of light. On a macroscopic scale (one in which the dimensions ...

, rather than

opaque Opacity or opaque may refer to: * Impediments to (especially, visible) light: ** Opacities, absorption coefficients ** Opacity (optics), property or degree of blocking the transmission of light * Metaphors derived from literal optics: ** In lingu ...

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

powdered sugar Powdered sugar, also called confectioners' sugar, or 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, p ...

(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 oft ...

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 used for preventing diaper rash and for cosmetic uses. It may be composed of talc (in which case it is also called talcum powder) or corn starch. It may also contain additional ingredients like fragrances ...

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

bioplastic Bioplastics are plastic materials produced from renewable biomass sources, such as vegetable fats and oils, corn starch, straw, woodchips, sawdust, recycled food waste, etc. Some bioplastics are obtained by processing directly from natural bi ...

s and may be used in the manufacture of

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

. Adhesive 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. Latexes are found in nature, but synthetic latexes are common as well. In nature, latex is found as a milky fluid found in 10% of all flowering plants (angiosperms ...

, including condoms, 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 ...

s. Corn starch has properties enabling supply of glucose to maintain blood sugar levels for people with glycogen storage disease. Corn starch can be used starting at age 6–12 months allowing glucose fluctuations to be deterred.

Manufacture

The corn is steeped 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 embryo ...

is separated from the endosperm 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'' du ...

, the

cereal germ Cereal germ or Wheat germ: The 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. Ce ...

, the fibers and the corn gluten 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, hydrocy ...

s and

centrifuge A centrifuge is a device that uses centrifugal force to separate various components of a fluid. This is achieved by spinning the fluid at high speed within a container, thereby separating fluids of different densities (e.g. cream from milk) or ...

s, and then dried. (The residue from every stage is used in animal feed and to make corn oil 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 on 27 June 2015, initiated the

Formosa Fun Coast explosion On 27 June 2015, a dust fire occurred at Formosa Fun Coast, a water park in Bali District, Bali, New Taipei City, Taiwan. Staff of an outdoor "color powder party" sprayed clouds of corn starch towards the participants, which ignited. The fire l ...

in Taiwan, despite warnings on the packaging indicating that the material is flammable.

Names and varieties

* Called ''corn starch'' in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

and

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

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

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

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 Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...

Ireland Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Grea ...

Israel Israel (; he, יִשְׂרָאֵל, ; ar, إِسْرَائِيل, ), officially the State of Israel ( he, מְדִינַת יִשְׂרָאֵל, label=none, translit=Medīnat Yīsrāʾēl; ), is a country in Western Asia. It is situated ...

and some Commonwealth countries. Distinct in these countries from cornmeal.

References

External links

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