Handbook of Meat Processing

Drying 225

The oxygen itself and the initiation of

aerobic microbe activity makes the inner

part rancid and green, with a bad odor. That

is why the meat products must be dried

slowly in order to avoid case hardening. The

air holes remaining in the sausage batter

during stuffi ng mechanically weaken the

product. Such products become hollow more

easily.

The chopped products always have fat

particles. Case hardening, air holes, and form

The loss of volume causes tensile strength
in the outer layer; therefore, at fi rst, this layer
stretches plastically, and later, elastically.
Too rapid drying makes denaturation in the
external layer, so this layer becomes irrevers-
ibly hard (case hardening). The layer should
shrink during further drying, but it is unable
to do so. The external layer will be separated
from the inner layers, causing hollows and
breakages. Therefore, air gets into the deeper
part of the product.

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

8.0

8.5

0 5 10 15 20 25 30 35 40 45 50

days

salt content in % compared to the

fat-free material

outer layer intermediate part central part

Figure 11.6. The salt content in the layers of salami during drying.

0

10

20

30

40

50

60

70

80

90

100

0 102030405060708090100

the distance from center in % of radius

tensile-strength kPa

dried 3 months dried 2 months dried 1 month

Figure 11.7. The change of tensile strength of the layers of salami during drying.