Magnesium Malate

Magnesium malate is the magnesium salt of malic acid, formally magnesium 2-hydroxybutanedioate, C4H4MgO5 with a molecular weight of 156.38 (CAS 869-06-7, EINECS 212-784-3, UNII LA9X9UJA2Z). On the anhydrous 1:1 salt the theoretical elemental magnesium content is 15.5% (24.305 divided by 156.38), which puts it close to magnesium citrate at roughly 16.2% and far below magnesium oxide at 60.3%. Buyers should note that hydrated and buffered trade grades sold under the same name assay materially lower, so the figure that matters is the one on the Certificate of Analysis for the lot, not the theoretical value. Registry numbers 6150-86-3 and 24561-63-5 also circulate in the literature for hydrated or alternative-stoichiometry forms. The malate counter-ion is what distinguishes this salt commercially. Malic acid, C4H6O5, MW 134.09 (DL-form CAS 6915-15-7, additive number E296), is the predominant organic acid of apples and many stone fruits and carries a clean, rounded sourness rather than the sharp bite of citric acid. In practice that means magnesium malate dissolves appreciably better than magnesium oxide or carbonate and brings a mild fruit-acid character that formulators can work with in effervescent tablets, stick packs and flavoured beverage powders instead of masking. In dry blends it behaves as a conventional free-flowing mineral powder and takes direct-compression cuts well. This is a manufactured salt, produced by reacting malic acid with a magnesium source, not an extract of fruit, and the label should not imply otherwise. It is vegan and vegetarian suitable and free from milk, egg, soy, fish, crustacean, gluten and nut allergens. There is no pharmacopoeial monograph for magnesium malate, so specification is by agreement: magnesium by titration or ICP-OES, malate by HPLC or ion chromatography, with lead, cadmium, mercury and arsenic by ICP-MS and a full microbiological panel per lot. Magnesium malate appears among the permitted mineral sources for food supplements in major markets, including the EU list under Directive 2002/46/EC; confirm the current position for your destination market before label copy is finalised.