Crystallography365

Blogging a crystal structure a day in 2014

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Helen Maynard-Casely

The sour taste – Malic acid

What does it look like?

Oxygen are red, carbon brown and hydrogen pink atoms. Image generated by the VESTA (Visualisation for Electronic and STructural analysis) software http://jp-minerals.org/vesta/en/

Oxygen are red, carbon brown and hydrogen pink atoms. Image generated by the VESTA (Visualisation for Electronic and STructural analysis) software http://jp-minerals.org/vesta/en/

What is it?

One last Halloween-inspired post – who out there tried their hand at apple bobbing? As you dunked your head and finally got a bite of a nice green apple, what was the first (watery) taste sensation? For most people, biting into a crisp green apple gives a sour sensation to begin with. This comes from the malic acid within the apple. Also rhubarb has a high concentration of malic acid, which gives the rather tart taste we're used to. Malic acid is an organic substance made by all living organisms and is an intermediatary in the citric acid cycle.

Where did the structure come from?

This structure was determined by van der Sluis and Kroon in 1985 and is refcode DLMALC11 in the Cambridge Structural Database. Malic acid has also been studied under high pressure! This study was looking for polymorphs of the molecule.

Tags: sour   food   molecular