The non-enzymatic browning reaction of coffee roasting what happens to the caramelization reaction?

Baking basic Science-Browning reaction

Non-enzymatic browning reaction (Nonenzymatic Browning)

Non-enzymatic browning reaction is different from enzymatic browning reaction. Non-enzymatic browning reaction does not need enzyme, but its reaction needs heat energy, sugar and amino acid. There are two kinds of non-enzymatic browning reactions related to coffee roasting: caramelization (caramelization recation) and Maillard reaction (Mailard reaction).

Caramelization reaction (caramelization reaction)

The caramelization reaction is easier to explain. Caramelization is a process of oxidation, dehydration and degradation of sugar, which affects the flavor and color of coffee. The sugar we refer to here is mainly sucrose (sucrose). The sugar we use in cooking belongs to sucrose. When sucrose is heated to 160 degrees, it begins to slowly dehydrate and dissolve into a translucent liquid. When heated to 200 degrees, the compounds in the sugar begin to recombine to produce brown caramel (toffee) with a certain burnt smell and bitter taste, which is completely different from the caramel taste in the sweet caramel cake. Caramel is usually eaten with sugar, milk, or other flavor agents.

Depending on the purpose of use, the manufacturer can choose the flavor and color caused by caramelization, for example, the caramel pigment produced by ammonia method is used in coloring cola drinks.

In addition to producing odors and colors, caramelization produces organic acids (organic acids). For example, in the process of making crisp sugar, baking soda powder (baking soda) is added to react with organic acids to release carbon dioxide to form a unique taste.

A similar reaction occurs during coffee roasting. Sugar degradation also produces carbon dioxide, which increases the pressure on the fibrous tissue inside the coffee bean, which eventually causes the fiber tissue to break, forming the popping sound of the "second explosion" in the coffee roasting process. The cause of the "first explosion" phenomenon in the coffee process is different from the "second explosion". The "first explosion" is mainly caused by the pressure caused by the evaporation of water in coffee beans.

About 90% of sucrose is degraded during baking to form a variety of products, including formic acid (formic acids) and acetic acid (acetic acids).

Some experiments show that the content of acetic acid can increase by about 20 times in the early stage of baking and decrease rapidly in the later stage of baking. Although acetic acid is a weak acid, it can affect the flavor of coffee. Arabica coffee contains about twice as much sucrose as robusta coffee, so we can experience obvious aroma and acidity in Arabica coffee.

In short, caramelization produces aromas, acidity, carbon dioxide, and color during baking. The caramelization reaction and Maillard reaction work together on the final flavor of coffee.