Coffee bean anatomy: Uncovering the secrets of its structure

The external structure of coffee beans

Coffee beans are one of the common foods in our daily life. They usually appear brown or black. From the outside, coffee beans are oval in shape and slightly flat. Its surface is smooth and has a certain luster.

The internal structure of coffee beans

When we cut coffee beans, we can see that they have a complex and delicate internal structure. First, we can see a hard shell or exocarp that surrounds the entire coffee bean. This hard shell is usually reddish brown or yellowish brown and is relatively hard.

Under the hard shell is a softer and stickier pulp layer (meSOCarp), which is mainly composed of water, sugar and other organic substances. The pulp layer is usually light yellow or white and gradually becomes sweeter during the ripening process.

The most important and innermost layer is the so-called "seed" - the coffee endosperm. This is what we usually call coffee beans. The coffee endosperm is composed of two main parts: a thin silver skin on the outside and a green or yellow-green endosperm on the inside.

Key components in coffee bean structure

Now that we know the overall structure of coffee beans, let's look at some of their key components. First, the shell is mainly composed of cellulose and lignin, which makes it relatively hard and difficult to digest.

The pulp layer is rich in water and sugars, especially glucose and fructose, which explains why unprocessed coffee beans have a somewhat sweet taste.

The most important and famous thing is that the endosperm contains a lot of caffeine. In addition, the endosperm also contains a variety of nutrients such as amino acids, proteins, and oils.

There are differences between different types of coffee beans

While all coffee beans have a similar basic structure and composition, there are still some differences between different types of coffee beans. First, the color of the coffee beans can vary. For example, Arabica beans are usually lighter in color, while Robusta beans are darker.

In addition, the content of amino acids and sugars in the endosperm may also be different. These differences directly affect the flavor characteristics of different types of coffee.

in conclusion

By dissecting coffee beans, we can better understand their complex and delicate internal structure. From the outer skin to the endosperm, each part carries specific functions and nutrients. This unveiling of the mysteries of coffee bean structure provides us with more knowledge about making, roasting and tasting delicious coffee.