Cornstarch or starch is a carbohydrate added to many food products and is the most important food thickening agent used by the food industry.
From Wikipedia: “Corn starch, cornstarch, cornflour or maize starch or maize is the starch derived from the corn (maize) grain or wheat. The starch is obtained from the endosperm of the kernel. Corn starch is a popular food ingredient used in thickening sauces or soups, and is used in making corn syrup and other sugars.”
“Cornstarch was discovered in 1840 by Thomas Kingsford, superintendent of a wheat starch factory in Jersey City, New Jersey. Until 1851, corn starch was used primarily for starching laundry and other industrial uses.”
“The corn is steeped for 30 to 48 hours, which ferments it slightly. The germ 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, the cereal germ, the fibers and thec orn 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.”
“Cornstarch is used as a thickening agent in liquid-based foods (e.g., soup, sauces, 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 mixture, rather than an opaque 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 gelatinization).
It is usually included as an anti-caking agent in powdered sugar (10X or confectioner's sugar). Baby powder often includes cornstarch among its ingredients. ...
A common substitute is arrowroot, which replaces cornstarch on a 1:1 ratio. ...
Food producers reduce production costs by adding varying amounts of cornstarch to foods, for example to cheese and yogurt. This is more common in the United States of America where the Congress and the Department of Agriculture subsidize and reduce its cost to food manufacturers.”
Names and varieties:
“Called cornstarch in the United States and Canada. Called cornflour in the United Kingdom, Ireland, Israel and some Commonwealth countries. Not to be confused with cornmeal.
Often called maizena in the Netherlands, Belgium, France, Germany, Finland, Austria, Italy, Portugal, Morocco, Brazil, Norway, Denmark, Slovakia, Sweden, Switzerland, Spain, South Africa and Latin America, after the brand.”
Possible risks of heating:
“According to research (2004), when starches are heated at high temperatures (for example, when baked, roasted, grilled, or deep-fried) in the presence of the amino acid asparagine, acrylamide can form. Acrylamide is a probable carcinogen for humans.*”
Note (italics): * = Translation from a German Wikipedia entry.