Method of preparing dry, concentrated salts of ascorbate 2-polyphosphate

Abstract

A method of preparing dried, concentrated ascorbate 2-polyphosphate salts is provided wherein a starting aqueous solution containing the desired 2-polyphosphate species (as well as contaminating inorganic phosphates) as sodium and potassium salts is subjected to a sequential precipitation technique to first remove the contaminants, followed by recovery of the desired species. In preferred practice, the inital starting solution is first supplemented with calcium chloride and sufficient calcium hydroxide to adjust the pH from about 6-8, thereby causing precipitation of the inorganic contaminants. At this point the ascorbate 2-polyposphate species are recovered from the supernatant and dried. The latter preferably involves washing the precipitated organophosphate salts with an aqueous organic solvent, concentration, addition of a non-solvent such as ethanol to induce precipitation, and subsequent drying. The resulting product is a concentrated salt form of ascorbate 2-polyphosphate that is a free-flowing, dried powder which can be readily handled, stored and used as an active vitamin C supplement in food or pharmacological systems.