Metal carboxylate salts
A dietary source of mineral in the form of a metal carboxylate is prepared using the acid-base-like reaction. A salt of a carboxylate anion and a by-product cation is reacted in aqueous solution with a salt of a metal cation and a by-product anion under conditions which form a metal carboxylate and the by-product salt. Solutions formed in the reaction may be applied directly to a dry carrier to produce a dry dietary supplement or, alternatively, the solutions may be filtered to remove precipitated by-product salt and the filtrate used as a liquid dietary supplement. Preferably, a reducing agent, such as ascorbic acid, is added to help prevent the oxidation of divalent to trivalent form of a metal salt, when an easily oxidized divalent metal is used as starting material.
1. A process for making a metal carboxylate using the acid-base-like reaction, comprising the steps of:
(a) combining in a basic ammonium salt of a carboxylate and a water-soluble metal salt of Lewis acid property;
(b) allowing the mixture to react at a temperature between 22 and 30° C. for a period of between 0 minutes and 15 minutes; and
(c) reducing the temperature to between 0° C. and 16° C. for at least 15 minutes.
2. A process as defined in claim 1 , wherein the carboxylate moiety is selected from the group consisting of the straight-chain monocarboxylic or polycarboxylic acid possessing 1 to 20 carbon atoms, and including formic acid, acetic acid, propionic acid, 2-hydroxypropanoicacid, eicosapentaenoic acid, benzoic acid, 2-hydroxy-1,2,3-propanetricarboxylic acid, 1,2-ethanedicarboxylic acid, trans-1,2-ethenedicarboxylic acid, and hydroxybutanedioic acid.
3. A process as defined in claim 1 , wherein the water-soluble metal salt of Lewis acid property is selected from the group consisting of salts of Fe(II), Fe(III), Mg(II), Cu(II), Zn(II), Cr(III), Co(II), Co(III), Mn(II), Mo(II), Mo(III), Ca(II), and Sn(II).
4. A process as defined in claim 2 , wherein the ammonium salt of carboxylate is formed by the reaction of the corresponding carboxylic acid and ammonium hydroxide.
5. A process as defined in claim 1 , further comprising the addition of a reducing agent.
6. A process as defined in claim 5 , wherein the reducing agent is an inorganic or organic compound.
7. A process as defined in claim 6 , wherein the organic compound is a food-grade organic compound.
8. A process as defined in claim 7 , wherein the food-grade organic compound is ascorbic acid.
9. A process for forming a metal carboxylate and a by-product salt using an acid-base-like reaction, comprising the step of combining in aqueous solution a water-soluble salt having a carboxylate anion and a by-product ammonium cation and a water-soluble salt having a metal cation and a by-product anion.
10. A process as defined in claim 9 , further comprising the step of adjusting the temperature of the reaction from an initial high temperature to a low temperature so that products precipitate out of the solution.
11. A process as defined in claim 9 , wherein the by-product anion is selected from the group consisting of chloride, iodide, sulphate, and phosphate.
12. A process as defined in claim 9 , further comprising the step of adding a reducing agent to the solution.
13. A process as defined in claim 12 , wherein the organic acid is a food-grade organic compound.
14. A process as defined in claim 13 , wherein the food-grade organic compound is ascorbic acid.