Corn syrup is a food syrup which 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 texture, add volume, prevent crystallization of sugar, and enhance flavor.
Corn syrup is not the same as 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 is often used synonymously with corn syrup, since glucose syrup in the United States is most commonly made from corn starch.
Technically, glucose syrup is any liquid starch hydrolysate of mono-, di-, and higher-saccharides and can be made from any source of starch: wheat, tapioca and potatoes are the most common other sources.
Corn syrup is obtained through a multi-step bioprocess: enzyme α-amylase is added to a mixture of corn starch and water.
α-amylase enzyme breaks down the starch into oligosaccharides, which are then broken into glucose molecules by adding the enzyme glucoamylase, known also as γ-amylase.
The glucose can then be transformed into fructose.
The viscosity and sweetness of the corn syrup depends on the extent of the hydrolysis reaction has been carried out.
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, and is nearly clear in color.
Dark corn syrup is a combination of corn syrup and refiner’s syrup, caramel color and flavor, salt, and the preservative sodium benzoate, and Its color is dark brown.
Corn syrup’s major use is as a thickener, a sweetener, and an ingredient that retains moisture and thus maintains a food’s freshness.
The primary ingredient in most brands of commercial pancake syrup is either regular corn syrup or high-fructose corn syrup.
High fructose corn syrup is a variant in which other enzymes are used to convert some of the glucose into fructose, resulting in syrup is that is sweeter and more soluble.