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 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. 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 adhesives, 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—see dust explosion. 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 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 in liquid-based foods (e.g.,

s, gravies, custard), 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, rather than opaque 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 (icing or confectioner's sugar). A common substitute is arrowroot 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 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 used for 3D printing) and may be used in the manufacture of airbags. 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. 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 gloves. 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 for 30 to 48 hours, which ferments it slightly. The germ 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, the cereal germ, the fibers and the corn gluten mostly in hydrocyclones and centrifuges, 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. Finally, the starch may be modified for specific purposes.

Risks

Like many other powders, corn starch is susceptible to dust explosions. 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, further grinding then drying, masa 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 countries. Distinct in these countries from cornmeal. * 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