Patent ID: 6407227
Filing Date: 2002-06-18
Classification: C07H

Abstract:
A process for the crystallization of lactitol from an aqueous lactitol solution having a lactitol purity of no less than 80% (on DS content), comprising crystallizing structurally pure crystalline lactitol forms selected from the group consisting of anhydrous, monohydrate, dihydrate and trihydrate by cooling said lactitol solution from a temperature at or slightly below the highest temperature of the stability area of the respective crystalline lactitol form to a temperature at or slightly above the lowest temperature of the stability area of said crystalline lactitol form, said stability areas being defined, respectively, within the temperature limits of 100Â° C. and 0Â° C. by the intersections of the solubility lines defined by the following equations (1) to (4):anhydrous: s/%=59.6+0.3003t/Â° C.â€ƒâ€ƒEq.(1) monohydrate s/%=50.2+0.4346t/Â° C.â€ƒâ€ƒEq.(2) dihydrate: s/%=39.7+0.6332t/Â° C.â€ƒâ€ƒEq.(3) trihydrate: s/%=33.4+1.1482t/Â° C.â€ƒâ€ƒEq.(4) whereins is the solubility % (w/w) of each respective lactitol form calculated from the mass of lactitol and water as follows: weight of lactitol/(weight of lactitol+weight of water)Ã—100%; t is the temperature in Â° C.; and by maintaining the supersaturation of said lactitol solution at a level of 1 to 8% (w/w) above the solubility line of the respective lactitol form crystallizing in said area.