Abstract: The invention relates to a novel crystalline anhydrous lactitol, a process for the preparation thereof, and the use thereof. The novel crystalline anhydrous lactitol belongs to the monoclinic crystal system and has the unit cell constants: (a)=7.614 .ANG., (b)=10.757 .ANG., (c)=9.370 .ANG., and .beta.=108.2.degree.. Its melting point is between 149.degree. C. and 152.degree. C., water content below 0.5% and lactitol content more than 99%; it has a low hygroscopicity.

Abstract: A crystalline lactitol monohydrate having lattice cell constants a=7.815.+-.0.008 .ANG., b=12.682.+-.0.008 .ANG., and c=15.927.+-.0.008 .ANG., and a melting range between 90 and 105.degree. C., and a water content between 4.85 and 5.15% as well as a process of preparing said crystalline lactitol monohydrate by evaporating the aqueous solution of lactitol to a concentration between 75 and 88% by weight, cooling the resultant mixture at a temperature ranging between 30.degree. and 75.degree. C., subsequently separating the lactitol monohydrate crystals from the mother liquor, and subsequently drying with air having a temperature between 120.degree. C., and a relative humidity between 0 and 40%, for a time period less than 24 hours.