Patent ID: 8367864

Claim:
A process for preparing a composition comprising at least one dimeric, double metal salts of group IA and group IIA of (−)-hydroxycitric acid selected from the group consisting of: Formula I; Formula II; and Formula III, or any mixture thereof, as given below: wherein X is IIA group metal: Be, Mg, Ca, Sr, Ba, or Ra; wherein Y is IA group metal: Li, Na, K, Rb, Cs, or Fr; and wherein the relative molar ratio of IIA group metal to IA group metal is from at least about 1:3.5 to at least about 1:4.5, comprising the steps of: a. preparing a liquid (−)-hydroxycitric acidilactone concentrate mixture; b. partially neutralizing 2 molar equivalents of the liquid (−)-hydroxycitric acid/ lactone concentrate mixture with 4 molar equivalents of a group IA metal hydroxide under conditions wherein the reaction temperature is maintained from at least about 27° C. to at least about 33° C. to yield a partially neutralized liquid (−)-hydroxycitric acid/lactone concentrate mixture; c. reacting the partially neutralized liquid (−)-hydroxycitric acid/lactone concentrate mixture of step b with one (1) molar equivalent of a IIA metal hydroxide to yield a fully neutralized liquid (−)-hydroxycitric acid/lactone concentrate mixture; d. hydrolyzing the lactone component of the fully neutralized liquid (−)-hydroxycitric acid/lactone concentrate mixture of step c by heating the mixture to at least about 60° C. until the pH of the mixture is stable from about pH 8.8 to about pH 9.2 to yield a (−)-hydroxycitric acid dimeric double metal salt solution; and e. isolating the dimeric, double metal salts of group IA and group IIA of (−)-hydroxycitric acid from the (−)-hydroxycitric acid dimeric, double metal salt solution of step d, thereby preparing the composition comprising at least one dimeric, double metal salts of group IA and group IIA of (−)-hydroxycitric acid selected from the group consisting of: Formula I; Formula II; and Formula III, or any mixture thereof, as given below: