Coffee bean anatomy: exploring its inner workings

Coffee bean anatomy: exploring its inner workings

Coffee beans are an indispensable part of our daily life. They provide us with delicious coffee. But have you ever wondered what the internal structure of coffee beans is like? Let's dissect coffee beans and explore their mysterious and delicate structure.

Appearance and skin

First, let's start with the appearance. A complete coffee bean is usually oval in shape and has a smooth and hard surface. This surface is called the skin, also called the pericarp.

The pericarp is made up of multiple layers of cells, the outermost of which is called the epidermis. This layer is very fragile and is removed during processing. The layer below is the endocarp, which is thicker and rich in cellulose.

Fruit pulp and sticky navel

When we peel off the skin, we can see the sticky navel and pulp covering the seeds.

The mucilage is the part that connects the seeds and the pulp. It is composed of a layer of mucus-like substance. This mucilage plays an important role in the fermentation process of coffee beans.

The pulp is the soft, juicy tissue outside the berry. It is usually red or yellow and has a rich, sweet flavor. However, during coffee processing, the pulp is removed.

Endocarp and silver peel

When we peel off the pulp, we can see the endocarp and seeds (which we call coffee beans).

The endocarp is tougher than the outer pericarp and rich in cellulose. It protects the seed from damage by the outside environment.

The silverskin is a thin, transparent layer covering the seeds that dries and cracks during roasting.

Endosperm and Germ

Finally, after we peel off the endocarp, we can see the endosperm and germ hidden in its center.

The endosperm is the main part of the coffee bean, which occupies most of the volume of the bean. The endosperm is rich in protein, fat and carbohydrates, and these nutrients provide energy for the coffee bean.

The germ is located at one end of the endosperm and is the starting point of the coffee plant. During the germination process, the germ will gradually grow and form a new plant.

Conclusion

By dissecting coffee beans, we can better understand their internal structure and the role played by each component. From the skin to the pulp, endocarp to silverskin and finally endosperm and germ, each tissue has an important and unique function. This delicate and complex structure is what gives coffee beans their unique flavor and aroma.