Functional groups in tannic acid are the phenolic -OH groups.
Tannic acid is a specific commercial form of tannin, a type of polyphenol. Its weak acidity (pKa around 6) is due to the numerous phenol groups in the structure. The chemical formula for commercial tannic acid is often given as C76H52O46
A sketch of its formula is found in 'Related links' below this answer.
There are two hydroxyls and tow carboxylic acid groups.
Tartaric acid is present there. Its also present in grapes. Tartaric acid is present there. Its also present in grapes.
tartaric acid is present in tamarind i.e. imli vitamin c / ascorbic acid is present in amlas
The acid present in tomatoes are tartaric acid.
carbosyl acid
citric acid
Tartaric acid is present there. Its also present in grapes. Tartaric acid is present there. Its also present in grapes.
tartaric acid
tartaric acid is present in tamarind i.e. imli vitamin c / ascorbic acid is present in amlas
Tartaric acid
NO
Tartaric Acid
The acid present in tomatoes are tartaric acid.
carbosyl acid
It is understood that tamarind contains mainly tartaric acid
citric acid
It's the carboxylic acid functional group (COOH).
The functional group in an organic acid is -COOH.