How does calcium chloride act as a sequestrant (food science)? This Wikipedia page lists common sequestrants (with respect to food science). As stated on the page:


  A sequestrant forms chelate complexes with polyvalent metal ions, especially copper, iron and nickel, which can prevent the oxidation of the fats in the food.


To me, this behavior makes sense for every example listed except calcium chloride. I can certainly see chloride complexing these metal ions, but even then, I typically don't expect the chloride ion to reduce catalytic capabilities much.

I assume the calcium cation has an effect on these processes somehow, too. Otherwise, I would expect regular table salt to have the same effect, but, while discouraging bacterial growth, I don't think sodium chloride reduces the rate of oxidative rancidification.

Could it be as simple as the desiccant effect of calcium chloride keeping the polyvalent metal ions from dissolving? It would seem like a massive amount of calcium chloride would be needed to have the desired effect if that was the preservation mechanism involved.
Food Scientist here. Calcium chloride is typically used in high concentrations in pickles to keep them firm (give that desired bite) and also add a slight salty flavor without increasing sodium content. It is also used in potato chips to reduce formation of acrylamide. Calcium chloride is highly soluble in water and will dissociate into Ca2+ and 2Cl-. It is used to sequester metal cations. The metal ion complexes with the free Cl-. It has also been found that calcium ions may reduce iron absorption, and is a divalent cation that can form complexes of its own. Calcium chloride can stabilize colors, flavors, antioxidants, and also improve oxidative stability. Fats and oils readily oxidize in the presence of metal ions, so a sequestrant such as calcium chloride is used to form a complex with the metal. Additionally CaCl2 is used to stabilize gels such as those formed with alginate. Another popular sequestrant, or chelating agent is EDTA.