308 DAIRY CHEMISTRY AND BIOCHEMISTRYKuhn isothermof amorphous lactoseWater activity8Figure 7.12 Adsorption of water by skim milk and sorption isotherms predicted by the
Braunauer-Emmett-Teller (BET), Kuhn and Guggenheim-Anderson-De Boer (GAB) sorp-
tion models (from Roos, 1997).P/P,Figure 7.13 Water vapour sorption by whey protein concentrate (A), dialysed whey protein
concentrate (B) and dialysate (lactose) from whey protein concentrate (C) (from Kinsella and
Fox, 1986).