Tannins belong to the secondary plant substances. We get them from a variety of fruits and vegetables. Here we explain how they work and why they are important for a healthy diet.
What are tannins?
Tannins belong to the group of so-called polyphenols. In the chemical sense, these are compounds with a tanning effect. This means that they are used to “precipitate” proteins. This means that they break down proteins into their components – for example into the individual amino acids.
The textile industry, for example, makes use of this property: it uses tanning agents to change the consistency of leather, for example. Among other things, tanning makes the leather more durable and firmer, explains Spektrum magazine.
Vegetable tanning agents: They are found here
Vegetable tannins belong to the secondary plant substances. They are also called tannins and are found in many different plants and parts of plants. According to the spectrum, they are part of:
leaves (tea)
seeds (coffee)
fruits (berries)
Wooden
Tannins are acidic. They are therefore often referred to as tannic acids. They create, for example, the typical tart, sour taste of blueberries or sloes.
Tannins also have an astringent (tightening) effect on mucous membranes and cause a furry feeling on the tongue. You’ve probably noticed this effect before when you ate unripe berries.
This is how tanning agents work
Tannins in plants act as natural defenses against microbial pathogens and pests. For a long time, however, they were considered undesirable ingredients in human nutrition.
According to the knowledge magazine Spektrum, this is because they can form complexes with proteins in the digestive system. These complexes can interfere with the body’s processing of vitamins and minerals.
This can lead, for example, to the body no longer being able to absorb enough iron from food. This can lead to an iron deficiency.
Healthy diet: These foods contain tannins
If you eat a balanced and healthy diet, you often consume tannins. For this reason alone, they are of a certain importance for nutrition. The following foods contain relevant amounts of vegetable tanning agents:
Grain
legumes
Many types of fruit:
apples
bananas
blackberries
cranberries
Grapes
peaches
pears
plums
raspberries
strawberries
Green tea and black tea
red wine
Coffee
