Corn syrup is a food syrup which is made from 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 die ...

of corn (called

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

in many countries) and contains varying amounts of sugars:

glucose Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, u ...

, maltose and higher

oligosaccharide An oligosaccharide (/ˌɑlɪgoʊˈsækəˌɹaɪd/; from the Greek ὀλίγος ''olígos'', "a few", and σάκχαρ ''sácchar'', "sugar") is a saccharide polymer containing a small number (typically two to ten) of monosaccharides (simple sug ...

s, depending on the grade. Corn syrup is used in foods to soften texture, add volume, prevent crystallization of sugar, and enhance flavor. Corn syrup is not the same as from high-fructose corn syrup (HFCS), which is manufactured from corn syrup by converting a large proportion of its glucose into fructose using the enzyme D-xylose isomerase, thus producing a sweeter substance. The more general term

glucose syrup Glucose syrup, also known as confectioner's glucose, is a syrup made from the hydrolysis of starch. Glucose is a sugar. Maize (corn) is commonly used as the source of the starch in the US, in which case the syrup is called "corn syrup", but ...

is often used synonymously with corn syrup, since glucose syrup in the United States is most commonly made from

corn starch Corn starch, maize starch, or cornflour (British English) is the starch derived from corn (maize) grain. The starch is obtained from the endosperm of the kernel. Corn starch is a common food ingredient, often used to thicken sauces or sou ...

. Technically, glucose syrup is any liquid starch

hydrolysate Hydrolysate refers to any product of hydrolysis. Protein hydrolysate has special application in sports medicine because its consumption allows amino acids to be absorbed by the body more rapidly than intact proteins, thus maximizing nutrient deliv ...

of mono-, di-, and higher- saccharides and can be made from any source of starch: wheat,

tapioca Tapioca (; ) is a starch extracted from the storage roots of the cassava plant (''Manihot esculenta,'' also known as manioc), a species native to the North and Northeast regions of Brazil, but whose use is now spread throughout South America ...

and potatoes are the most common other sources.

Commercial preparation

Historically, corn syrup was produced by combining

with dilute

hydrochloric acid Hydrochloric acid, also known as muriatic acid, is an aqueous solution of hydrogen chloride. It is a colorless solution with a distinctive pungent smell. It is classified as a strong acid. It is a component of the gastric acid in the dige ...

, and then heating the mixture under pressure. The process was invented by the German chemist Gottlieb Kirchhoff in 1811. Currently, corn syrup is obtained through a multi-step bioprocess. First, the

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...

α- amylase is added to a mixture of corn starch and water. α-amylase is secreted by various species of the

bacterium Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were am ...

genus '' Bacillus'' and the enzyme is isolated from the liquid in which the bacteria were grown. The enzyme breaks down the starch into

s, which are then broken into glucose molecules by adding the enzyme glucoamylase, known also as "γ-amylase". Glucoamylase is secreted by various species of the

fungus A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately fr ...

'' Aspergillus''; the enzyme is isolated from the liquid in which the fungus is grown. The glucose can then be transformed into fructose by passing the glucose through a column that is loaded with the enzyme D-xylose isomerase, an enzyme that is isolated from the growth medium of any of several bacteria. Corn syrup is produced from number 2 yellow dent corn. When wet milled, about 2.3 litres of corn are required to yield an average of 947g of starch, to produce 1 kg of glucose syrup. A bushel (25 kg) of corn will yield an average of 31.5 pounds (14.3 kg) of starch, which in turn will yield about 33.3 pounds (15.1 kg) of syrup. Thus, it takes about 2,300 litres of corn to produce a

tonne The tonne ( or ; symbol: t) is a unit of mass equal to 1000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton to distinguish it from the non-metric units of the short ton ( United State ...

of glucose syrup, or 60 bushels (1524 kg) of corn to produce one short ton. The viscosity and sweetness of the syrup depends on the extent to which the hydrolysis reaction has been carried out. To distinguish different grades of syrup, they are rated according to their dextrose equivalent (DE). Most commercially available corn syrups are approximately 1/3 glucose by weight. Two common commercial corn syrup products are light and dark corn syrup. *''Light corn syrup'' is corn syrup seasoned with vanilla flavor and salt. It is a nearly clear color. *''Dark corn syrup'' is a combination of corn syrup and refiner's syrup, caramel color and flavor, salt, and the preservative sodium benzoate. It's color is dark brown.

Uses

Corn syrup's major uses in commercially prepared foods are as a thickener, a sweetener, and a humectant (an ingredient that retains moisture and thus maintains a food's freshness). The primary ingredient in most brands of commercial "

pancake syrup Maple syrup is a syrup made from the sap of maple trees. In cold climates, these trees store starch in their trunks and roots before winter; the starch is then converted to sugar that rises in the sap in late winter and early spring. Maple t ...

" is either regular corn syrup or high-fructose corn syrup, both of which are less expensive than maple syrup. In the United States,

cane sugar Sucrose, a disaccharide, is a sugar composed of glucose and fructose subunits. It is produced naturally in plants and is the main constituent of white sugar. It has the molecular formula . For human consumption, sucrose is extracted and ref ...

quotas raise the price of sugar; hence, domestically produced corn syrup and high-fructose corn syrup are less costly alternatives that are often used in American-made processed and mass-produced foods, candies, soft drinks, and fruit drinks.

Glucose syrup Glucose syrup, also known as confectioner's glucose, is a syrup made from the hydrolysis of starch. Glucose is a sugar. Maize (corn) is commonly used as the source of the starch in the US, in which case the syrup is called "corn syrup", but ...

was the primary corn sweetener in the United States prior to the expanded use of high fructose corn syrup production in 1964. HFCS is a variant in which other enzymes are used to convert some of the glucose into fructose. The resulting syrup is sweeter and more soluble. If mixed with

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, fructose, and galactose. Compound sugars, also called disaccharides or do ...

water Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as ...

, and cream of tartar, corn syrup can be used to make

sugar glass Sugar glass (also called candy glass, edible glass, and breakaway glass) is a brittle transparent form of sugar that looks like glass. It can be formed into a sheet that looks like flat glass or an object, such as a bottle or drinking glass. Des ...

History

Corn syrup was available at grocery stores in the 19th century, as a

generic product Generic brands of consumer products (often supermarket goods) are distinguished by the absence of a brand name, instead identified solely by product characteristics and identified by plain, usually black-and-white packaging. Generally they imitat ...

sold from a barrel. In 1902, the

Corn Products Refining Company Ingredion Incorporated is an American multinational ingredient provider based in Westchester, Illinois, producing mainly starches, non-GMO sweeteners, stevia, and pea protein. The company turns corn, tapioca, potatoes, plant-based stevia, grain ...

introduced clear, bottled corn syrup under the brand name of Karo Syrup. In 1910, the company launched one of the largest advertising campaigns ever seen. This included full-page advertisements in women's magazines and free cookbooks full of recipes that called for Karo brand corn syrup. In the 1930s, they promoted a new pecan pie recipe that featured corn syrup, followed by a similar, nut-free chess pie recipe, in a bid to drive sales. Later, they promoted it as an alternative to maple syrup for waffles. As cooking in the home declined in the 21st century, so that fewer people made candies or pies at home, commercial sales of Karo tended to dominate over the retail sales.

References

External links

* {{Sugar Sugar substitutes Maize products Syrup Starch *

Commercial preparation

Uses

History

See also

References

External links