Method for Increasing the Yield in Lactose Production (III)

A method for the production of crystalline alpha lactose, wherein

• (i) whey is subjected to a separation process in which a protein-rich and a lactose-rich fraction is obtained,
• (ii) the lactose-rich fraction is (optionally after concentrating the main flow) subjected to demineralisation in which slowly soluble salts are precipitated,
• (iii) the demineralised residue is cooled down, optionally after further concentration, until lactose precipitates in crystalline form,
• (iv) the lactose crystals are separated from the mother liquor and evaporated,
• wherein
• (a) the first mother liquor is adjusted to a temperature of between about 62 and 67° C.,
• (b) the solution is then cooled down to between about 20 and 30° C.,
• (c) the solution is held at this temperature for a period of from 0 to 5 h,
• (d) subsequently, the solution is re-heated to between about 30 and 35° C.,
• (e) the solution is held at this temperature for a period of from 0 to 5 h,
• (f) then the solution is cooled to about 10° C. and
• (g) subsequently, the precipitated alpha lactose crystals are separated from the second mother liquor,
• (h) an amount of a carbohydrate compound is added to the second mother liquor such that the solubility product of the residual amount of lactose that is still soluble is exceeded,
• (i) the second amount of precipitated alpha lactose crystals is separated from the mother liquor, dried, and
• (j) both amounts of alpha lactose crystals are combined.