WATER IN MILK AND DAIRY PRODUCTS^299(b)
Figure 7.3 The ‘basal plane’ of ice (combinations of two planes of slightly different elevations)
viewed from above. The closed circles represent oxygen atoms of water molecules in the lower
plane and the open circles oxygen atoms in the upper plane, (a) seen from above and (b) from
the side (from Fennema, 1985).
small fraction of the water in high-moisture foods. ‘Vicinal’ or monolayer
water is bound to the first layer sites of the most hydrophilic groups.
Multilayer water occupies the remaining hydrophilic sites and forms a
number of layers beyond the monolayer water. There is often no clear
distinction between constitutional, monolayer and multilayer water since
they differ only in the length of time a water molecule remains associated
with the food.
The addition of dissociable solutes to water disrupts its normal tetra-
hedral structure. Many simple inorganic solutes do not possess hydrogen
bond donors or acceptors and therefore can interact with water only by
dipole interactions (e.g. Figure 7.5 for NaCl). Multilayer water exists in a
structurally disrupted state while bulk-phase water has properties similar to