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Vegetable tannins are also known as tannins. They are found in the outer parts of plants and their natural role is to protect against pests. The name tannins comes from the Old Latin, and more precisely from the word tannum and freely translated means oak bark. When it comes to properties, tannins are assessed very differently. What effect do tannins have? Where can tannins be found?
Already in the Middle Ages, craftsmen discovered the unusual properties that were hidden in tree trunks, which they began to use in the process of tanning animal skins. It turned out that tannins have the ability to change the structure of proteins found in the skins, the process made the material more susceptible to cutting and dyeing. During the Industrial Revolution, when processing leather, tannins were replaced with a chromium solution.
Tannins – action
Tannins are primarily designed to protect plants from external pests. They can be found in leaves, roots and fruits, but their greatest concentration is in the bark. Tannins have a discouraging effect on small vertebrates and insects, causing poisoning them, additionally they protect fruits and leaves against fungal pathogens and bacteria, this feature is due to the properties of changes in the structure of proteins in the organism of microorganisms. If you experience a bitter-tart taste when eating, it may indicate the presence of tannins.
Tannins are divided into two groups:
- condensed tannins otherwise known as proanthocyanides
- hydrolysing tannins, i.e. tannins containing a small particle of sugar
For a long time it was believed that tannins, which by their properties, can harm living organisms. Tannins were thought to slow down the digestive process and also block the body from properly absorbing the nutrients. Currently, studies are conducted which initially show that tannins can also have a positive effect on the body’s work. According to scientists, tannins can have a negative effect on the body if consumed in too much, the type of tannin is also important. Condensed tannins are considered antioxidants that protect the body against free radicals. Research has also shown that tannins reduce oxidative stress and its effects.
According to researchers, tannins have astringent properties, i.e. they are an effective weapon in the fight against bacteria. A single tannin or more is able to fight pathogens invading the body, for example, tannic acid can be effective in treating oral herpes, various types of skin rashes, gingivitis, and even the effects of diaper dermatitis. There is a group of tannins in the field of cancer treatment because it is believed that tannins can inhibit not only the growth of free radicals but also tumors.
Thus, tannins can have a positive and negative effect on the body:
- tannins fight bacteria and pathogenic fungi
- inhibit the development of free radicals
- can limit tumor growth
On the other hand, the negative impacts include:
- stomach pain
- headaches
- a disturbance in the work of the intestines
- weakness
- nausea
- in allergy sufferers, tannins can even cause anaphylactic shock
Tannins – occurrence
Plants, including herbs, have been used for a long time to strengthen the body both from the inside and the outside. That is why, according to some, tannins are considered the perfect recipe not only for perfect health, but also for beauty. Where can tannins be found? They are found in large amounts in legumes, for example in red beans, and in addition they are found in high concentration in blackberry leaves, in St. John’s wort, in cinquefoil, and in turnip greens. Tannins are also fruits, including strawberries, grapes, blueberries, cranberries. Tannins are found in large amounts in walnuts and hazelnuts.