Method for producing allulose crystals

A method for producing allulose crystals, wherein the method comprises:

• a) evaporating a feed allulose syrup at a first sub-ambient pressure and a first temperature to produce a first supersaturated allulose syrup having an allulose syrup target saturation;
• b) introducing seed crystals to the first supersaturated allulose syrup and allowing the allulose to crystallize to produce a first massecuite comprising first allulose crystals and a first supersaturated mother liquor having a first target mother liquor saturation higher than the allulose syrup target saturation;
• c) evaporating the first massecuite at the first sub-ambient pressure and the first temperature to produce a second massecuite comprising second allulose crystals and a second supersaturated mother liquor having a second mother liquor target saturation lower than the first mother liquor target saturation;
• d) increasing the first sub-ambient pressure to a second sub-ambient pressure and cooling the second massecuite to a second temperature to produce a third massecuite comprising third allulose crystals and a third supersaturated mother liquor having a third mother liquor target saturation;
• e) holding the third massecuite at the second sub-ambient pressure and the second temperature for a period of time to produce a fourth massecuite comprising fourth allulose crystals and a fourth mother liquor having a fourth target mother liquor saturation;
• f) increasing the pressure to ambient and cooling the fourth massecuite to a third temperature at a cooling rate to produce a fifth massecuite comprising fifth allulose crystals and a fifth supersaturated mother liquor having a fifth target mother liquor saturation;
• g) allowing the fifth massecuite to crystallize for a crystallization time to produce a product massecuite comprising product allulose crystals at a target yield and a product mother liquor, the product mother liquor having a target product mother liquor supersaturation;
• and
• h) separating the product allulose crystals from the product supersaturated mother liquor to provide the product allulose crystals at the target yield, wherein temperatures for the evaporating and cooling are effectively controlled to reliably obtain the target yield.