The origin of caramelization of the attractive aroma of coffee

Why do you love coffee so much, in addition to caffeine and other effects, I think everyone and thousands of coffee fans often miss coffee because of its charming aroma, then how does this aroma come from? The important thing is that coffee beans are rich in a variety of raw materials, after roasting a variety of reactions, and create an attractive aroma. The two most important reactions are caramelization reaction and Mena reaction. Let's take a look at what these two reactions are all about.

1. caramelization reaction

The sugar content in coffee beans undergoes caramelization reaction at about 170~200℃, which is exactly the melting point of sucrose (185℃) and the temperature of the first explosion stage when coffee beans are roasted. The products of caramelization are divided into two parts:

(1)The dehydrated product of sugar, caramel or brown

(2)The cracking products are mainly volatile aldehydes and ketones.

In general, caramelization produces roasted aromas, caramels, and colors, as well as other aromatic compounds such as maltol, Cyclotene, furans, and so on, which can also be found in red wine, juice, cream, and other foods. However, if you caramelize too much during the roasting process, it is not a good thing. Instead, it will cause carbonization and make the coffee dry and bitter. If not caramelized enough, the aroma will be dull and lack of depth.

2. Maillard reaction

Menard reaction can be divided into three stages

1. Initial stage:

Amadori Molecular Rearrangement by Carbonylamine Condensation

II. Medium-term:

Amadori molecular rearrangement product fructosamine dehydration to HMF(hydroxymethylfurural), fructosamine deamination to reduce ketone, amino acid and dicarbonyl compounds.

III. Final Stage:

Aldol condensation, polymerization reaction to form melanin.

In addition to carbohydrates, proteins account for about 11% of the raw bean weight, and the amino acids contained in these proteins are just the raw materials for the Mena reaction. Menard reaction refers to a series of reactions between amino acids and reducing sugars (glucose, fructose, lactose, etc.) in food during heating. Mena reactions produce a wide variety of aromatic substances and pigments such as Pyridines, Pyrazines ,Oxazoles, Thiazoles, Pyrroles. Mena reaction plays an important role in the flavor of food cooking, whether it is sausage when grilling black and emitting flavor, crispy outside soft roast chicken, fragrant toast, these barbecue foods are behind the Mena reaction.

Coffee is blessed with a large and complex variety of chemicals, in addition to the above compounds, there are other organic acids, inorganic acids, plant alkaloids and so on. Not only sweet and beautiful ingredients, but also slightly bitter compounds give coffee a wider range of flavors and variations, creating a unique rich taste of coffee.

Do you know why coffee has such an attractive aroma? Do you miss coffee more?