D-Tartaric acid

D-Tartaric acid, also known as (S, S)-tartrate or D-threaric acid, belongs to the class of organic compounds known as sugar acids and derivatives. Sugar acids and derivatives are compounds containing a saccharide unit which bears a carboxylic acid group. D-Tartaric acid has been detected but not quantified in loquats (Eriobotrya japonica). This could make D-tartaric acid a potential biomarker for consuming these foods. D-Tartaric acid is a secondary metabolite. Secondary metabolites are metabolically or physiologically non-essential metabolites that may serve as defense or signalling molecules. In some cases, they are molecules that arise from the incomplete metabolism of other secondary metabolites.
D-Tartaric acid is a white crystalline dicarboxylic acid found in many plants, particularly tamarinds and grapes. It is an acidulant that occurs naturally in grapes. It is hygroscopic and rapidly soluble, with a solubility of 150 g in 100 ml of distilled water at 25°c. It has a slightly tarter taste than citric acid, with a tartness equivalent of 0.8–0.9. It augments the flavor of fruits in which it is a natural constituent. It is used in grapeand limeflavored beverages and grape-flavored jellies. It is used as an acidulant in baking powder and as a synergist with antioxidants to prevent rancidity.
ChEBI: D-tartaric acid is the D-enantiomer of tartaric acid. It has a role as an Escherichia coli metabolite. It is a conjugate acid of a D-tartrate(1-). It is an enantiomer of a L-tartaric acid.
D-(-)-Tartaric acid is a polycrystalline solid, widely used as food additive. It has been reported to exhibit piezoelectric effect.
Crystallise the acid from distilled H2O or *benzene/diethyl ether containing 5% of pet ether (b 60-80o) (1:1). Soxhlet extraction with diethyl ether has been used to remove an impurity absorbing at 265nm. It has also been crystallised from absolute EtOH/hexane and dried in a vacuum for 18hours [Kornblum & Wade J Org Chem 52 5301 1987]. [Beilstein 3 IV 1229.]