Tannic acid belongs to hydrolyzed tannins, which can be hydrolyzed to acid and glucose. It is one of the earliest studied tannins and has strong biological and pharmacological activities. Tannic acid is mainly rich in plants such as Chinese five seeds, Turkish seeds, tara pods, pomegranates, sumac leaves, sumac, and witch hazel trees. Among them, Wuzi is a special forest product in China, which is mainly distributed in Qinling Mountains, Bashan Mountains, Wudang Mountains and other regions with unique climate and soil conditions.
What is tannic acid?
Tannic acid is an unique form of tannin as well as a polyphenol. Its weak acidity (pKa is about 6) results from a lot of phenolic teams in its framework. The chemical formula of commercial tannic acid is generally C76H52O46, which represents decagalloyl glucose, yet in fact it is a combination of polyglycidyl glucose or polyglycidyl quinoate and also gallic acid number. The part of each molecule varies from 2 to 12, depending upon the plant source utilized to remove tannic acid. Business tannins are normally removed from any one of the following plant components: tara capsules, gallnuts from lacquer trees or Quercus infectia or Sicilian lacquer leaves.
According to the meanings of external referrals such as the International Pharmacopoeia, the Codex Alimentarius, and the FAO – WHO monograph on tannin, just tannins drawn out from the above plants can be considered as tannin. Often the extract of chestnut or oak is also described as tannin, however this is the incorrect use of the term. It is a yellow to light brown amorphous powder.
Although tannic acid is an unique kind of tannin (plant polyphenol), both terms can in some cases (mistakenly) be utilized interchangeably. The long-lasting abuse of these terms as well as their look in academic short articles have actually exacerbated the confusion. This is particularly common in green tea and also black tea, both of which contain many different sorts of tannins, not simply tannins.
Tannic acid is not the suitable requirement for tannin evaluation of any kind of type, due to the fact that its structure is not clearly specified.