Coffee raw beans roast color change roasted coffee beans

Raw beans constantly change color during baking, depending on the number of brown pigments and the size of molecules. Brown pigments can be classified according to the size of molecules, shallow baking will mostly produce small molecular pigments, with the deepening of baking, the total amount of pigments will increase, and the proportion of macromolecular pigments will also increase.

Most of the lightly roasted coffee beans contain small yellow pigments, which are produced by the reaction of oligosaccharide thermal decomposition with chlorogenic acid. Continue baking, oligosaccharides will be caramelized to produce caramel pigment, oligosaccharides react with amino acids to produce molasses pigment, which will produce a slightly larger reddish-brown pigment. The reaction produced by molasses pigment is called Mena reaction, which is a very important kind of food chemical reaction. The color of toast, miso and soy sauce are all the result of Mena's reaction.

If the baking continues, proteins and polysaccharides are also added to the reaction, turning into a huge dark brown pigment. This pigment is one of the elements that make up the bitterness of coffee.

The three coffee judges scored the three groups of coffee, and then summed up the final score for each group. At the end of the 19-day trial period, the scores of each group were calculated. Ratings and comments are also shown below.

The conclusion of the test shows that it is obvious that the coffee machine is clean and the taste of espresso will be greatly improved.