Caramelization is a process of browning of sugar used extensively in cooking for the resulting sweet nutty flavor and brown color. The brown colors are produced by three groups of polymers: caramelans (C₂₄H₃₆O₁₈), caramelens (C₃₆H₅₀O₂₅), and caramelins (C₁₂₅H₁₈₈O₈₀). As the process occurs, volatile chemicals such as diacetyl are released, producing the characteristic caramel flavor. Like the Maillard reaction, caramelization is a type of non-enzymatic browning. Unlike the Maillard reaction, caramelization is pyrolytic, as opposed to being a reaction with

amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha ...

s. When caramelization involves the

disaccharide A disaccharide (also called a double sugar or ''biose'') is the sugar formed when two monosaccharides are joined by glycosidic linkage. Like monosaccharides, disaccharides are simple sugars soluble in water. Three common examples are sucrose, ...

sucrose 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 refi ...

, it is broken down into the monosaccharides

fructose Fructose, or fruit sugar, is a ketonic simple sugar found in many plants, where it is often bonded to glucose to form the disaccharide sucrose. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorb ...

and

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, usi ...

Process

Caramelization is a complex, poorly understood process that produces hundreds of chemical products, and includes the following types of reactions: * equilibration of

anomeric In carbohydrate chemistry, a pair of anomers () is a pair of near-identical stereoisomers that differ at only the anomeric carbon, the carbon that bears the aldehyde or ketone functional group in the sugar's open-chain form. However, in order for ...

and ring forms *

sucrose inversion Inverted sugar syrup, also called invert syrup, invert sugar, simple syrup, sugar syrup, sugar water, bar syrup, syrup USP, or sucrose inversion, is a syrup mixture of the monosaccharides glucose and fructose, that is made by hydrolytic sa ...

to fructose and glucose * condensation reactions * intramolecular bonding * isomerization of aldoses to

ketose A ketose is a monosaccharide containing one ketone group per molecule. The simplest ketose is dihydroxyacetone, which has only three carbon atoms. It is the only ketose with no optical activity. All monosaccharide ketoses are reducing sugars, be ...

s * dehydration reactions * fragmentation reactions * unsaturated

polymer A polymer (; Greek ''poly-'', "many" + '' -mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic and ...

formation

Effects of caramelization

The process is temperature-dependent. Specific sugars each have their own point at which the reactions begin to proceed readily. Impurities in the sugar, such as the

molasses Molasses () is a viscous substance resulting from refining sugarcane or sugar beets into sugar. Molasses varies in the amount of sugar, method of extraction and age of the plant. Sugarcane molasses is primarily used to sweeten and flavour foods ...

remaining in

brown sugar Brown sugar is unrefined or partially refined soft sugar. Brown Sugar may also refer to: Arts, entertainment, and media Films * ''Brown Sugar'' (1922 film), a 1922 British silent film directed by Fred Paul * ''Brown Sugar'' (1931 film), a 1931 ...

, greatly speed the reactions. Caramelization reactions are also sensitive to the chemical environment, and the reaction rate, or temperature at which reactions occur most readily, can be altered by controlling the level of acidity ( pH). The rate of caramelization is generally lowest at near-neutral acidity (pH around 7), and accelerated under both acidic (especially pH below 3) and basic (especially pH above 9) conditions.

Uses in food

Caramelization is used to produce several foods, including: *

Caramel sauce Caramel ( or ) is an orange-brown confectionery product made by heating a range of sugars. It can be used as a flavoring in puddings and desserts, as a filling in bonbons, or as a topping for ice cream and custard. The process of caramelization ...

, a sauce made with caramel * '' Confiture de lait'' and ''

Dulce de leche ''Dulce de leche'' (; pt, doce de leite), also known as caramelized milk, milk candy or milk jam in English, is a confection from Latin America prepared by slowly heating sugar and milk over a period of several hours. The resulting substance, w ...

'', caramelized, sweetened milk * Caramel candies * Creme Caramel, and the similar crème brûlée, a custard dish topped with sugar caramelized with a blowtorch * Caramelized onions, which are used in dishes like French onion soup. Onions require 30 to 45 minutes of cooking to caramelize. * Caramelized potatoes * Caramelized pears *

Cola Cola is a carbonated soft drink flavored with vanilla, cinnamon, citrus oils and other flavorings. Cola became popular worldwide after the American pharmacist John Stith Pemberton invented Coca-Cola, a trademarked brand, in 1886, which was ...

, of which some brands use caramelized sugar in small amounts for color

References

External links

Caramelization
at Science of Cooking {{Cooking Techniques Cooking techniques Culinary terminology de:Karamellisieren

Process

Effects of caramelization

Uses in food

See also

References

External links