Calcium tartrate
Calcium tartrate, exactly calcium L-tartrate, is a byproduct of the wine industry, prepared from wine fermentation dregs. It is the calcium salt of L-tartaric acid, an acid most commonly found in grapes. Its solubility decreases with lower temperature, which results in the forming of whitish crystalline clusters as it precipitates. As E number E354, it finds use as a food preservative and acidity regulator. Like tartaric acid, calcium tartrate has two asymmetric carbons, hence it has two chiral isomers and a non-chiral isomer. Most calcium tartrate of biological origin is the chiral levorotatory isomer.
