Mineral ascorbates Mineral ascorbates Mineral ascorbates are a group of salts of ascorbic acid (vitamin C). They are composed of a mineral cation bonded to ascorbate (the anion of ascorbic acid). Mineral ascorbates are powders manufactured by reacting ascorbic acid with mineral carbonates in aqueous solutions, venting the carbon dioxide, drying the reaction product, and then milling the dried product to the desired particle size. The choice of the mineral carbonates can be calcium carbonate, potassium carbonate, sodium bicarbonate, magnesium carbonate, or many other mineral forms. Mineral ascorbates are used as dietary supplements and food additives. Ascorbate salts may be better tolerated
Chemistry of ascorbic acid performs the dual function of removing the two acetal groups and ring-closing lactonization. This step yields ascorbic acid. Each of the five steps has a yield larger than 90%. A more biotechnological process, first developed in China in the 1960s, but further developed in the 1990s, bypasses the use of acetone-protecting groups. A second genetically modified microbe species, such as mutant "Erwinia", among others, oxidises sorbose into 2-ketogluconic acid (2-KGA), which can then undergo ring-closing lactonization via dehydration. This method is used in the predominant process used by the ascorbic acid industry in China, which supplies 80% of world's ascorbic