Crystallization of allulose under reduced pressure

A process for the preparation of a solid allulose material comprising crystalline allulose, the method comprising the steps of

• (a) providing in an evaporating crystallizer an aqueous mother liquor containing dissolved allulose;
• (b) maintaining until the end of crystallization the aqueous mother liquor within the evaporating crystallizer at a crystallization temperature within a range of from 20 to 55° C.;
• (c) maintaining until the end of crystallization the vapor phase above the aqueous mother liquor within the evaporating crystallizer at a crystallization pressure within a range of from 40 to 200 mbar;
• and
• (d) inducing crystallization of allulose from the aqueous mother liquor at the crystallization temperature and at the crystallization pressure in a supersaturated state thereby obtaining the solid allulose material as a precipitate, and a supernatant;
• wherein crystallization is induced at a supersaturation coefficient y of the aqueous mother liquor of at most 1.05, including reducing the crystallization pressure from a first crystallization pressure to a second crystallization pressure.