Dairy Chemistry And Biochemistry

MILK PROTEINS 181

Table 4.6 Average characteristics of casein micelles (modified from

McMahon and Brown, 1984)

Characteristic Value

Diameter

Surface area

Volume

Density (hydrated)

Mass

Water content

Hydration

Voluminosity

Molecular weight (hydrated)

Molecular weight (dehydrated)

Number of peptide chains

Number of paticles per ml milk

Surface of micelles per ml milk

Mean free distance

36

• A

7-l-

120 nm (range: 50-500 nm)

8 x lo-'' cm2

2.1 x cm3

1.0632 g cm-3

2.2 x 10-15 g

63 Yo

3.7 g H,O g-' protein

4.4 cm3 g-'

1.3 x lo9 Da

5 x 10' Da

104

10~~-10~6

5 x lo4 cm3

240 nm

100 200

Diameter (nm)

300

Figure 4.19 Number and volume frequency distribution of casein micelles in bovine milk (from
Walstra and Jenness, 1984).