文档介绍：WATER
Water Functions
ponent of food.
Universal solvent (salt, vitamins, sugar, gases, pigment)
Capable of ionizing (H3O+, OH-)
Affects the texture
Chemical reactions (hydrolysis of protein = n amino acids)
Stabilizing the colloids by hydration
Necessary for anisms growth
Hydrogen Bond
The bond is formed due to the affinity of electro-positive hydrogen atoms for electro-negative atoms such as O. Binding energy of hydrogen bond is about 10% of covalent bond.
H-bond strength = 10 Kcal/mol.
H
+
d
O
-
d
H
+
d
H
+
d
H
+
d
H
+
d
O
-
d
O
-
d
H
+
d
H
+
d
H
+
d
O
-
d
THE EFFECTS OF HYDROGEN BONDS OF WATER
H2S
34
-86
-16
H2O
18
0
100
Compounds
MW
MP(C)
BP(C)
CH4
16
-184
-164
Water is a good dissolving solvent - Why?
Physical action of dispersion of solute molecule due to the high-activity of water molecules at the surface of the solute.
The high di-electric constant of water (80x that of vacuum) diminishes the effectiveness of attractive forces that tend to hold the solute molecules together.
Hydration of the solute by a plex such as the "hydrogen bond“
Dissolving of ions by high di-electric constants of water
  F = Q1 x Q2 / DR2
EFFECTS OF DIELECTRIC CONSTANTS ON SOLUBILITY
DIELECTRIC CONSTANT
The Capacity of Condenser of a Material
D=
The Capacity of Condenser of Vacuum Condition
 
The forces of electrostatic attraction tending to bine charges of opposite sign are given by Coulomb's Law.
F = Q1 x Q2 / DR2
where: Q1, Q2 are magnitude of charges
R= Distance between charges
D = Dielectric constant of the medium separating charges
KINDS OF WATER - DEGREE OF WATER BINDNESS
Monolayer Water is bound in food - restricted in its movement due to charges, hydrogen bond, physical entrapment. Hard to remove from food. Never be able to remove pletely.
Multilayer Water - additional layer of water around food particle. Not as hard to remove as the monolayer.
Mobile or Free Water - consisted with ideal solution