N-[N-[3-(3-hydroxy-4-methoxyphenyl)propyl]-L-α-aspartyl]-L-phenylalanine 1-methyl ester useful as a sweetener with a high potency of sweetness, is provided in the crystalline form having a high stability and a good purity which is favorable as a commercial product

Crystals of aspartame derivative

Commercially favorable crystals of N-[N-[3-(3-hydroxy-4-methoxyphenyl)propyl]-L-α-aspartyl]-L-phenylalanine 1-methyl ester, which is useful as a sweetener with a high degree of sweetness, having a high stability and a good purity.

Aspartame derivative crystals

A cleaning method for separating and highly purifying a natural crystalline or amorphous substance which is a non-electrolyte or weak electrolyte from a slurry comprising the crystalline or amorphous substance and a mother liquor having a strong electrolyte dissolved therein. It attains a high cleaning efficiency. In the cleaning method, the electrical conductivity of the washings resulting from the cleaning of the crystalline or amorphous non-electrolyte or weak electrolyte is continuously measured. Thus, the degree to which the crystalline or amorphous substance has been cleaned is detected without the need of conducting sampling.

Method of and apparatus for cleaning crystalline or amorphous substance

PROBLEM TO BE SOLVED: To obtain the subject crystal capable of being readily separated, cleaned and dried by crystallizing a uniform aqueous crystallization system, incorporated with a specific amount of a ketone so as to make the formed crystal become a network structure which has gaps and is capable of draining, by conduction cooling while avoiding fluidity. SOLUTION: In this method for crystallizing α-L-aspartyl-L-phenylalanine methyl ester from an aqueous solution by conduction cooling while avoiding the fluidity of a crystallization system, a ketone such as 2-propanone (acetone), 2-butanone, methyl isobutyl ketone, 2,5-hexanedione is used as a 3-8C ketone. At least 0.1wt.% of the ketone based on the total of the crystallization system is present, the solution is cooled to a temperature not less than 10 deg.C in a uniform state before the start of crystallization and the crystallization is carried out by selecting the amount of the ketone and temperature so as to make the formed crystal become a network structure which has gaps and is capable of draining. Consequently, the objective crystal such as a low-calorie sweetener, having improved solid-liquid separation by centrifugal separation, capable of being efficiently cleaned and dried is obtained.

Marinas Petras Wilhelm Rickers

Papers

Crystallization of alpha-l-aspartyl-l-phenylalanine methyl ester