GEA Niro Method No. A 1 e
Revised: September 2006
The water of crystallization (%) of a powder is the difference between total moisture and free moisture.
This method may be used for any kind of dried milk products containing crystallized lactose (α-lactose-monohydrate), e.g. whey powder.
Sample total moisture (determined by Karl Fisher titration) and free moisture (determined by oven drying 87°C/6h) is measured. The water of crystallization is calculated.
4.1 As given in GEA Niro Method № A 1 c.
4.2 As given in GEA Niro Method № A 1 d.
As specified in GEA Niro Method № A 1 d.
6.1 Determine the free moisture content as described in
GEA Niro Method № A 1 c.
6.2 Determine the total moisture content as described in
GEA Niro Method № A 1 d.
Water of crystallization = % total moisture - % free moisture
The water of crystallization of whey powders provides a good indication of the ‘Degree of Crystallization’ of the lactose content.
Degree of Crystallization
%L = the content of lactose in whey powder (%), expressed as anhydride. For rapid routine test of sweet whey, the %L ≈ 74%.
GEA Niro Research Laboratory