What are the ingredients in coffee beans? (Part 1)

We drink coffee every day, but the ingredients in coffee beans still seem to be a mystery. Today we will reveal it to you~

There are many ingredients, and I am afraid that you may not be able to digest them all in one day, so today I will talk about the first half~

Moisture:

The moisture content of wet coffee beans with membrane is about 50%; the moisture content of dry green coffee beans is about 10%~13%; (water exists in coffee beans in a variety of different physical and chemical combinations)

Minerals :

It accounts for about 4% of the dry weight of green coffee beans.

Among them, potassium is the most abundant, accounting for about 40% of all minerals, followed by calcium, magnesium, phosphorus, sodium and sulfur.

There are many other trace elements with contents at the ppm level, such as zinc, manganese, copper, rubidium and more than 33 other elements.

The minerals contained in coffee beans cannot be used to indicate

Content of coffee or coffee powder products

carbohydrate:

The carbohydrates contained in coffee beans can be divided into polysaccharides and low molecular weight sugars.

The latter include carbohydrates such as mono-, di- and trisaccharides.

In addition, it can be divided into reducing sugar and non-reducing sugar. It also contains some derivatives, such as pectin.

Polysaccharides:

It accounts for about 40% to 50% of the dry matter.

According to the types, there are polymerized galactose, polymerized arabinose, polymerized cellulose and these are the substances that make up the coffee bean plastid and are related to the hardness of the coffee beans.

Low molecular weight carbohydrates:

Sucrose is the main free sugar in green coffee beans, and its content varies depending on variety, origin and maturity.

Generally speaking, Arabica coffee beans contain lower levels of sucrose, while Robusta coffee beans contain higher levels. Other simple sugars, including reducing sugars, can also be detected in the extract of green coffee beans.

Green coffee beans also contain glucose and fructose. The content of Arabica is lower than that of Robusta. In addition, the total reducing sugar of Arabica is also lower than that of Robusta.

Organic acids:

The non-volatile acids contained in raw Arabica coffee beans include citric acid, malic acid, oxalic acid and tartaric acid.

When brewing coffee, acidity is very important.

Under good conditions and techniques, a special flavor with refreshing acidity can be developed, which is a necessary condition for high-quality coffee.

Protein and amino acids:

In terms of crude protein, the content of green coffee beans is about 13%~16%.

If nitrogen-containing compounds such as caffeine and trigonelline are deducted, the actual protein content is approximately 8.8%~9.7%.

Green coffee beans also contain a variety of enzymes, such as lipolytic enzymes, proteolytic enzymes, carbohydrate-degrading enzymes, galactose-hydrolyzing enzymes and peroxidase.

Green coffee beans contain about 0.15%~0.25% of free amino acids.

The content of Robusta is higher than that of Arabica. These free amino acids have a greater impact on the flavor of coffee and less impact on the taste.

Chlorogenic acid:

Chlorogenic acid has at least three isomers.

Its main function is to regulate the physiological function of coffee plants, including: promoting growth, rhizome formation, antibacterial, disease and pest prevention, and becoming a precursor of lignin.

Among green coffee beans, the content of Robusta is higher than that of Arabica. The content of green coffee beans processed by wet method is about 40% lower than that by dry processing.

Fat:

The fat in green coffee beans consists of coffee oil present in the endosperm and wax present in the outer layer of the coffee beans.

Coffee oil contains not only triglycerides, but also considerable amounts of other fat components.

It forms the characteristics of coffee and is very important for coffee.

The content and composition of coffee oil in green coffee beans vary depending on the variety.

The average content of Arabica coffee beans is 15% of dry matter, with a standard deviation of 0.78%.

The content of Rbusta coffee beans is 10% and the standard deviation is 1.41%.

Let’s analyze the other half of coffee! Remember to come to class~

Article from: Coffee trainee Xiaomu