2009_Book_FoodChemistry

600 12 Meat
12.7.2.2.1 Raw Sausages
Typical products are Cervelat sausage, salami and
the German Mettwurst. They are made of raw,
ground skeletal muscle (pH < 5.8), fat and spices.
They are cured by the addition of 2.8–3.2% of
nitrite curing salt (cf. 22.2.4) or common salt
and sodium nitrate (max. 300 mg/kg), max. 2%
of sugar (sucrose, glucose, maltose, lactose) and
other curing aids (D-gluconic acid-5-lactone,
ascorbic acid etc.). Starter cultures are normally
added to optimize ripening. The production
of raw sausage is schematically presented in
Fig. 12.32.
The grinding is preferably carried out in a cutter
in which the following steps are conducted:
cutting, distribution, mixing, very fine grinding,
and emulsification. A cutter consists essentially
of a dish rotating around a highspeed cutter head.
Products of varying texture can be produced by
varying the form and speed of the cutter, the
size of the cutting chamber (possible insertion
of stowing rings), plate speed, and cutting duration.
Operation under a vacuum has advantages.
Apart from batch cutters with a dish content of up
to 750 l, continuously operating dish cutters are
also available today.
In the case of firm types of raw sausages, frozen
material is used for grinding (−20 ◦ C) and the
temperature is kept below 4 ◦ C during the grinding
process by cooling. After the mass has been
stuffed, the sausage is ripened in air conditioned
rooms. At first, the temperature is 20–26 ◦ C(air
humidity 90–95%) to increase lactobacilii; it is
later reduced to 10–15 ◦ C (air humidity 75%).
The specific aroma is formed in the course of
ripening by microorganisms present (micrococci
and lactobacilli, often added in the form of starter
cultures). Reddening (cf. 12.3.2.2.4) also plays
a big role. The drop in pH due to lactic acid
formation (5.2–4.8) results in shrinkage of the
protein gel. The sausages become stable, firm and
suitable for slicing after vaporization of the water
released (20–40% weight loss). Ripening takes
2–3 weeks (fast processes) or 7–8 weeks (slow
processes). The raw sausage is subsequently
smoked, e. g., cold smoking at 16–28 ◦ C. The
white layer on various types of salami is due to
mold mycelia or, in cheaper products, a layer of
lime milk dip.
12.7.2.2.2 Cooked Sausages
Cooked sausages are made from cooked starting
materials. Typical products are liver sausage,
blood sausage, and jellied sausage. The production
of liver sausage is shown schematically in
Fig. 12.33. Modern plants generally use cooking
cutters in which the following steps are conducted
in one machine: preliminary grinding, cooking,
mixing, and cutting. In comparison with boiling
sausages, cooked sausages can be cut only when
cold.
Fig. 12.32. Production of raw sausage
Fig. 12.33. Production of cooked sausage (liver sausage)