The difference between "Mena reaction" and "caramelization" in the baking process

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"Mena reaction" wins "caramel"

The "Mena reaction" refers to a series of degradation and polymerization of monosaccharide carbohydrates (glucose, fructose, maltose, arabinose and lactose) with proteins (amino acids). The color will also become darker, discovered by French scientist Mena (Louis CamilleMaillard) in 1912.

"caramelization" only ends in the "oxidation" or "browning" reaction of sugars heated. The "Mena reaction" is broader. All kinds of monosaccharides react with amino acids at different temperatures to produce more complex aromas, which are much more complex than caramelization, because caramel components are degraded again and polymerized with amino acids to form pyrazine heterocyclic aromatic compounds with continuous increase in furnace temperature, which is the source of chocolate flavor. Then, most people mistakenly think that caramelization is the main source of coffee sweet fermentation, while ignoring the more important Mena reaction, which is easier to understand, while the name of Mena reaction is more complex and rare.

You should know that the aromas of nuts, almonds, cream and chocolate in the baking process come from the Mena reaction, not caramelization. In other words, if the coffee is caramelized without Mena reaction, it will only have a monotonous sweet and bitter taste, not a drink with all kinds of flavors.

The nuts in the SCAA flavor wheel are classified as caramelization reactions with many sweet aromas, which seems to simplify the formation of sweetness, and the addition of Mena reaction here can bring the real results closer to the facts. The "smell spectrum" under caramelization and Mena reaction can be classified into three flavors: nut rhyme, caramel rhyme and chocolate rhyme, as shown in the following table.

1. Nut rhyme: drupe and wheat teeth

Drupes: almonds, peanuts, walnuts

Wheat teeth: corn, rice and wheat, cereals, toast

2. Caramel rhyme: candy and syrup

Candy: taffy, hazelnut, licorice

Syrup: honey, maple syrup

3. Chocolate rhyme: dark chocolate and cream chocolate

Dark Chocolate: bitter Chocolate, Dutch Chocolate

Cream chocolate: Swiss chocolate, almond chocolate

The above is the "aroma spectrum" produced by caramelization and Mena reaction from medium baking to medium-deep baking, and its baking degree and molecular weight are in the following order: nutty odor → caramel odor → chocolate odor.

The nutty aroma is most pronounced in shallow baking, caramel aroma appears later, most protruding after medium baking, and chocolate aroma is later, about medium to deep baking, even deep baking. Basically, the molecular weight and baking degree of nut, caramel and chocolate are higher than those of fermented fruit acid. If you continue baking, medium-deep baking or deep baking, the compounds continue to dehydrate and polymerize, resulting in higher molecular weight, darker bean surface color and lower volatility, but higher bitterness, showing a completely different taste spectrum.