Food Biochemistry and Food Processing

28 Biochemistry of Fermented Meat 647

tion takes only a short time, just a few minutes; and
the ratio of bowl speed to knife speed determines the
desired particle size.

PROCESSING STAGE 2: STUFFING

The mixture is stuffed under vacuum into casings,
natural, collagen-based, or synthetic, with both
extremes clipped. The vacuum avoids the presence
of bubbles within the sausage and disruptions in the
casing. The stuffing must be adequate in order to
avoid smearing of the batter, and temperature must
be kept below 2°C to avoid this problem. Once
stuffed (Fig. 28.4), the sausages are hung in racks
and placed in natural or air-conditioned drying
chambers.

PROCESSING STAGE 3:
FERMENTATION

FERMENTATIONTECHNOLOGY

Once sausages are stuffed, they are placed in
computer-controlled air-conditioned chambers and
left to ferment for microbial growth and develop-
ment. A typical chamber is shown in Figure 28.5.
Temperature, relative humidity, and air speed must
be carefully controlled in order to have correct
microbial growth and enzyme action. The whole
process can be considered as a lactic acid solid-state
fermentation in which several simultaneous process-

es take place: (1) microbial growth and develop-

ment, (2) biochemical changes, mainly enzymatic

breakdown of carbohydrates, proteins, and lipids,

and (3) physical changes, mainly acid gelation of

meat proteins and drying.

Meat fermentation technology differs between the

United States and Europe. High fermentation tem-

peratures (35–40°C) are typical in U.S. sausages,

followed by a mild heating process, as a kind of pas-

teurization, instead of drying, to kill any trichinellae.

Figure 28.3.Detail of the batter after mixing in a vacu-

um mixer massager.

Figure 28.2.Grinding of meats and fats. There are
many sizes of grinder plates in accordance to the
required particle size.

Figure 28.4.Sausages stuffed into a collagen casing,

80 mm diameter, and clipped on both extremes.