The Maillard reaction is a chemical reaction between an amino acid and a reducing sugar, usually requiring the addition of heat. Like caramelization, it is a form of non-enzymatic browning. The reactive carbonyl group of the sugar interacts with the nucleophilic amino group of the amino acid, and interesting but poorly characterized odor and flavour molecules result. This reaction is the basis of the flavouring industry, since the type of amino acid determines the resulting flavour. A chemical reaction is a process that results in the interconversion of chemical substances [1]. The substance or substances initially involved in a chemical reaction are called reactants. ... In chemistry, an amino acid is any molecule that contains both amino and carboxylic acid functional groups. ... A reducing sugar is a type of sugar with a ketone or aldehyde group. ... In physics, heat is defined as energy in transit. ... Caramelization is the oxidation of sugar, a process used extensively in cooking for the resulting nutty flavor and brown color. ... BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIiiiCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEe Category: ... In chemistry, a carbonyl group is a functional group composed of an atom of carbon double-bonded to an atom of oxygen. ... In chemistry, a nucleophile (literally nucleus lover) is a reagent which is attracted to centres of positive charge. ... In chemistry, especially in organic chemistry and biochemistry, an amino group is an ammonia-like functional group. ... In chemistry, an amino acid is any molecule that contains both amino and carboxylic acid functional groups. ... Flavouring (CwE) or flavoring (AmE) is a product which is added to food in order to change or augment its taste. ... In chemistry, an amino acid is any molecule that contains both amino and carboxylic acid functional groups. ...

In the process, hundreds of different flavour compounds are created. These compounds in turn break down to form yet more new flavour compounds, and so on. Each type of food has a very distinctive set of flavour compounds that are formed during the Maillard reaction. It is these same compounds that flavour scientists have used over the years to create artificial flavours.

Although used since ancient times, the reaction is named after the chemist Louis-Camille Maillard who investigated it in 1910s. Louis Camille Maillard (February 4, 1878 - May 12, 1936) was a French physician and chemist. ... // Events and trends The 1910s represent the culmination of European militarism which had its beginings during the second half of the 19th Century. ...

Products with Maillard reactions

The Maillard reaction is responsible for many colors and flavours in foodstuffs:

• caramel made from milk and sugar
• the browning of bread into toast
• the colour of beer, chocolate, coffee, and maple syrup
• self-tanning products
• the flavour of roast meat
• the color of dried or condensed milk

6-acetyl-1,2,3,4-tetrahydropyridine (1) is responsible for the biscuit or cracker-like odor present in baked goods like bread, popcorn, tortilla products. 2-acetyl-1-pyrroline (2) flavours aromatic varieties of cooked rice. Both compounds have odor thresholds below 0.06 ng/L ^[1]. A piece of caramel confectionery. ... A glass of cows milk Milk most often means the nutrient fluid produced by the mammary glands of female mammals. ... Magnified view of refined sugar crystals. ... European sweetbread (strucla) Four loaves French bread has a somewhat rigid crust Breads and Bread Rolls at a bakery Continental Italian Bread Tin Vienna Bread Bread in a traditional oven, in Portugal, with hot coal in front For other uses, see Bread (disambiguation). ... A classic two-slot toaster Toast is bread that has been browned by exposure to dry heat. ... Beer is an alcoholic beverage produced through the fermentation of cereal sugars, and which is not distilled after fermentation. ... Chocolate most commonly comes in dark, milk, and white varieties, with cocoa solids contributing to the brown coloration. ... Coffee in beverage form. ... A sugarshack where sap is boiled down to maple syrup. ... Self Tanning, (also know as sunless tanning, or UV free tanning) is commonly used in reference to applying a skin safe chemical to the skin surface to provide a tan coloration which resembles the color of a common UV-based tan. ... Roasting is cooking with dry heat, whether an open flame, oven, or other heat source. ... Powdered milk is a powder of a substance that when mixed with water creates a milk drink. ... This article needs to be cleaned up to conform to a higher standard of quality. ... European sweetbread (strucla) Four loaves French bread has a somewhat rigid crust Breads and Bread Rolls at a bakery Continental Italian Bread Tin Vienna Bread Bread in a traditional oven, in Portugal, with hot coal in front For other uses, see Bread (disambiguation). ... POPCORN is a telephone acronym for the number 767-2676, which, for all area codes in Northern California, serves as a telephone-based speaking clock service. ... Traditional tortilla making. ... Species Oryza glaberrima Oryza sativa Rice refers to two species (Oryza sativa and Oryza glaberrima) of grass, native to tropical and subtropical southeastern Asia and to Africa, which together provide more than one fifth of the calories consumed by humans. ... The nanogram is an SI unit of mass (symbol ng) defined as: 1 ng = 1 × 10-12 kilogram (1 × 10-9 gram) A nanogram is one billionth (1/1,000,000,000) of a gram. ... The liter (spelled liter in American English and litre in Commonwealth English) is a unit of volume. ...

The process

1. The carbonyl group of the sugar reacts with the amino group of the amino acid, producing N-substituted glycosylamine and water
2. The unstable glycosylamine undergoes Amadori rearrangement, forming ketosamines
3. There are several ways for the ketosamines to react further:
   • Produce 2 water and reductones
   • Diacetyl, acetol, pyruvaldehyde and other short-chain hydrolytic fission products can be formed
   • Produce brown nitrogenous polymers and melanoidins

In chemistry, a carbonyl group is a functional group composed of an atom of carbon double-bonded to an atom of oxygen. ... In chemistry, especially in organic chemistry and biochemistry, an amino group is an ammonia-like functional group. ... In chemistry, an amino acid is any molecule that contains both amino and carboxylic acid functional groups. ... Glycosylamine is a compound consisting of an amine with a glycosidic linkage to a carbohydrate. ... Diacetyl is a natural by-product of secondary or malolactic fermentation. ... Methylglyoxal, also called pyruvaldehyde or 2-oxo-propanal (CH3-CO-CH=O or C3H4O2) is the aldehyde form of pyruvic acid. ... Hydrolysis is a chemical process in which a molecule is cleaved into two parts by the addition of a molecule of water. ...

Factors

Pentose sugars react more than hexoses, which react more than disaccharides. Different amino acids produce different amounts of browning. A pentose is a monosaccharide with five carbon atoms. ... A hexose is a monosaccharide with six carbon atoms. ... A disaccharide is a sugar (a carbohydrate) composed of two monosaccharides. ...

Since the Maillard reaction produces water, having a high water activity environment inhibits the reaction. Water activity or aw is the relative availability of water in a substance. ...

See also

• Baking
• Advanced glycation endproduct

Wikibooks Cookbook has more about this subject: Baking Baking is the technique of cooking food in an oven by dry heat applied evenly throughout the oven. ... This article needs to be cleaned up to conform to a higher standard of quality. ...

External links

• Course website on Maillard reaction
• Nice diagram

References

• ↑  An Expeditious, High-Yielding Construction of the Food Aroma Compounds 6-Acetyl-1,2,3,4-tetrahydropyridine and 2-Acetyl-1-pyrroline Tyler J. Harrison and Gregory R. Dake J. Org. Chem.; 2005; 70(26) pp 10872 - 10874; (Note) DOI: 10.1021/jo051940a Abstract