Each plant, of any species, shape or size, contains tannin. Its presence is the result of a natural evolution: plants are exposed to numerous risks and if threatened by any danger (animals, environments that become unhealthy, atmospheric agents, such as heavy rains or wind) they can certainly not move to seek shelter.
Without the presence of tannin, the plant life would be constantly under attack. Its task, in fact, is to protect trunks, stems, leaves and fruits from the assault of fungi, bacteria and viruses but also of herbivores and other animals that feed on these plants, which would otherwise act undisturbed, causing the plant to rot and to die.
Best Plants for Tannin Extraction
Although present in all plant species, there are some trees in which tannin is present in higher tannic concentrations. Among them:
The Chestnut Tree
The botanical name is Castanea sativa. It is rich in tannin, that can come to constitute up to 10% of its weight.
It is widespread in Southern Europe and some countries on the Black Sea shores, especially in Turkey. Put together, the chestnut forests cover more than two million hectares only in Europe.
Xenophon, an Athenian historian and mercenary, called it the bread tree because its fruit, also named chestnut, has been on the peasant table for centuries.
It grows very fast and when a trunk is cut, the remaining stump quickly develops new shoots that give life to new stems (tree shoots).
The chestnut trees can live even a thousand years, during which they reach considerable dimensions. Among the monumental European trees there are several specimens of chestnut.
The botanical name is Schinopsis balansae. It contains an exceptional amount of tannin, which can make up to 25% of the total weight of the wood.
A real super-defense that protects it from the subtropical climates of South America, particularly humid and warm, therefore favorable to the proliferation of bacteria.
Its main growing areas can be found in Argentina, in the provinces of Chaco, Formosa and Santa Fé, as well as in Bolivia and Paraguay. The word “quebracho” derives from the Spanish “Quiebra-Hacha” or “Axe-Breaker”, a name that well describes its wood, particularly durable and compact.
The bark is traditionally used as a febrifuge and as a cough remedy. This tree can live for over three hundred years.
The native populations of Argentina and Paraguay attribute mystical powers to the Quebracho and the tree is often part of many local myths and legends.
Its botanical name is Caesalpinia spinosa. It grows on the Andes, in Peru.
It is much appreciated as an ornamental tree and is used in folk medicine to relieve fever, sore throat and stomach ache.
Unlike the Quebracho and Chestnut one, Tara derived tannin is not extracted from the wood but from the fruits, the pods, once deprived of the seeds and grinded.
From its seeds, Tara gum is obtained. It’s a food thickening agent used for the production of ice creams, sausages, loaf bread, cheese spreads and many other foods.
A “Gall” is a kind of swelling growth that can develop on branches, leaves or other parts of a plant.
It is also known as cecidia. It is not a fruit, but a cell mass produced by plants as a reaction to the attack of fungi, insects or bacteria.
It is therefore a defensive strategy of the plant that isolates itself from the attack of the “enemy”.
It is not surprising then that the Galls are very rich in tannin, a variety that is defined as gallotannin.
Among the most widespread botanical species are the Turkish Gall (Quercus infectoria) and the Chinese Gall (Rhus semialata).
Tannin and Animals
Being present in every part of the plant, even in the leaves and in the fruits, tannin becomes a natural supplement in the diet of many animals, who ingest it without even suspecting its presence: mammals, birds and some reptiles, such as turtles, who regularly assume tannin through the grass of the meadows or the fruits of the trees.
Tannin has a positive effect even on animal’s health: it can improve digestive processes, in particular those of the ruminants, reduce the phenomena of diarrhea in the chickens, improve the quality of milk and meat thanks to its properties of natural growth promoter.
These benefits also extend to humans. Last time you ate a fruit or a salad, you surely ate small amounts of tannin.
Tannin in Animal Nutrition
Even farm animals can benefit from tannin. Industrial feed cannot contain all the nutrients naturally present in the berries, seeds and leaves: supplementing their diet with tannin allows to strengthen their immune system, improve their digestive processes and consequently their vitality.