Chemical factors - Chelators

Chelators are substances with two or more binding sites that bind particular ions, such as calcium, to build very stable complexes.

Chelating properties are of subordinate importance. But, as acids can also be chelators and bind calcium in complexes, they gain importance as they increase the deteriorating effects of the acids.

An example of an acid with calcium-chelating capacity is citric acid (C6H8O7), which is commonly added to soft drinks. For the neutralisation of such acids, more minerals (from saliva or dissolved from teeth) are needed than for simple acids (such as HCI), leading to an extended demineralisation and erosion process.
Citric acid can form complexes with calcium ions. An example of one of the most relevant complexes: tricalcium dicitrate tetrahydrate (Ca3C12H10O14*4H2O). Please note that for simplification reasons, H-atoms and H2O are not shown.
Citric acid is often used as a food additive, as flavouring and as a preservative. Commonly found in acidic beverages, citric acid is also used in meat and pastry preparations.