322 Chapter 17
almost infi nite number of possible formula-
tion combinations allows the designing of the
sausages according to needs: sometimes
strong - tasting and fi rm sausages are required,
while other times milder and softer are
needed.
Microbes also exert a substantial effect on
the sensory properties of meat, although the
hygienic quality of sausages has improved
tremendously. It is not possible to cover the
microbial effects exclusively. Salt (NaCl)
decisively infl uences the microbial pattern in
meat, as it strongly reduces the proteolytic
metabolism of the fl ora. The inhibitory effect
of salt is based on its content in the water
phase of the product. In countries where the
product has a high fat content and phosphate
is not added, the salt content in the water
phase ranges from 4% to 5%; but with lower
fat and higher levels of water (with phos-
phates), the content in the water phase
could be even as low as 2.5%. It should be
remembered that about 10 percentage units
of lean meat water is strongly bound to the
polar parts of proteins and thus not included
in the free water phase of the product (3% –
6% units of the product water, depending on
the lean meat content of product; Hamm
1972 ).
Nitrite also has a very strong inhibitory
effect on microbes, but the effect is strain
specifi c. The effect is especially important
against the most pathogenic bacteria within
the contents used in cooked meat products.
As the pK a - value of the effective form,
nitrous acid (HNO 2 ) is 3.4, nitrite is more
effi cient at lower pH values, but on the other
hand, low pH values increase the degradation
of nitrite (Honikel 2007 ).
The nutritional quality of sausages directly
refl ects the formulations of the sausages,
which can be most variable. As the maximum
temperature used in cooking is 72 – 74 ° C,
meat proteins do not lose their nutritive
value, but on the contrary, collagen turns
digestible via denaturation (Bailey and Light
1989 ). Since sausage does not lose liquid bystuffed into natural or artifi cial casings and
linked (Fig. 17.5 ). Then the sausages are
moved to a smoking chamber, where they
fi rst are dried at 50 – 60 ° C. Excessively high
temperatures or long times must not be used
in order to avoid temperatures > 60 ° C, which
may reduce smoke absorption or cause fat
separation in the surface layer. Immediately
after drying, sausages are smoked at 65 – 70 ° C
until the desired surface color and aroma
have been reached, and the temperature is
about 50 ° C (B ø gh - S ø rensen et al. 1981 ).
Then the sausages are cooked in steam (75 ° C)
until a core temperature of 72 – 73 ° C is
reached (Fig. 17.6 ).
Quality Aspects of the
Finished Product
Quality includes taste and fl avor, structure,
color, nutritional value, and microbial quality.
The taste and fl avor of sausage is a combina-
tion of the savory taste of cooked cured meat
and spices. The fl avor is infl uenced by the
formulation (what meat animals have been
used, what the proportions are, and especially
the content of fat from the various sources).
An integral part of the fl avor is the effect of
nitrite, which is based not on the direct taste
of the salt itself but on an indirect effect on
various components of the meat (Pegg and
Shahidi 2000 ). Much chemical research has
been performed on the effects of nitrite on
fl avor, but this extremely complex system is
still far from fully elucidated.
The sensory and nutritional quality is
mainly based on lean meat content, fat
content, and the amount of water added. In
addition, if other foodstuffs are added, they
may improve the overall nutritional quality,
or as extenders, they may dilute the nutri-
tional density and taste. The use of phos-
phates facilitates the use of less lean meat and
more water and fat, thus exerting a negative
effect on nutritional value (unless low - fat/
low - sodium products are targeted). The