386 Chapter 22
shorten fermentation time, which is fre-
quently one day or less. Even when these
products undergo a shorter ripening period
than dry fermented sausages, fermentation of
raw sliceable semidry sausages lasts longer
if no heat treatment is applied (Incze 2007 ).Air - Drying or Smoking
After the fermentation stage, sausages are
either air dried or smoked. Drying is a key
operation, especially for dry fermented
sausage production; the drying rate should be
as low as possible. A crucial aspect is avoid-
ing the pronounced surface coagulation of
proteins so that water diffusion from the
center outward is hindered (Andr é s et al.
2007 ). Drying kinetics and duration vary,
depending on temperature and air velocity.
These parameters are less important than for
the fermentation stage and range from 10 ° to
15 ° C for 4 to 12 weeks for French, Italian,
Spanish, Argentinean, and Greek dry fer-
mented sausages. Higher drying tempera-
tures (16 – 18 ° C) were reported for dry
sausages produced in Greece and East
Europe, accompanied by shorter ripening.
The RH during fermentation varies from a
minimum of 63% to 75%, to maximum
values of 86% to 95% in dry fermented sau-
sages, leading to variable a w in traditional
sausages at the end of drying (Lebert et al.
2007 ). At the beginning of drying, RH can be
as high as 98%, which leads to a distinctive
surface colonization by mold and yeasts. It
was reported that yeasts are the predominant
organisms on the surface (95%) during the
fi rst two weeks, and then molds and yeasts
are present in equal amounts (Samelis
and Sofos 2003 ). On the surface of dry fer-
mented sausages, mold growth is desirable as
it prevents excessive drying, protects from
oxidative reactions, and contributes to fl avor
development (Spotti and Berni 2007 ).
Selection of fungal starter cultures among the
naturally occurring molds on the sausages ’are added to the meat batter and thoroughly
mixed in the bowl chopper. Mixing should
be suffi cient to uniformly distribute ingredi-
ents; over - mixing must be avoided. After
thorough mixing, the meat batter should be
either immediately stuffed or kept under
refrigeration and protected from air to enable
optimal color development and microbiota
stabilization. Stuffi ng of the meat batter into
natural or synthetic casings is carried out
under vacuum, thus preventing abnormal
color or fl avors. The casing diameters (and
the sausages) vary considerably; small diam-
eters (35 – 40 mm) are generally used for
spreadable sausages, while sliceable sau-
sages are usually marketed in large - diameter
casings. For mold - fermented raw sausages, a
small diameter is required to ensure a suffi -
cient oxygen supply for the full development
of aroma (Spotti and Berni 2007 ).
Fermentation
Stuffed sausages are placed in ripening
chambers under controlled temperature, rela-
tive humidity (RH), and air speed conditions,
depending on the sausage type to be pro-
duced. For traditional fermented sausages,
natural and less controlled conditions are
applied (Lebert et al. 2007 ). Conditions of
fermentation vary in terms of temperature
and duration (Tables 22.2 and 22.3 ). In
general, the higher the fermentation tempera-
ture, the faster the lactic acid production. In
Europe, fermentation may be carried out at
relatively high temperatures (18 – 24 ° C) for 1
to 2 days for German and Italian dry fer-
mented sausages, while fermentation for 7
days has been reported for Greek, Argentinean,
and certain Italian dry sausages. Fermentation
at lower temperatures (10 – 17 ° C) for approxi-
mately one week is usually used for tradi-
tional French, Spanish, and Portuguese dry
fermented sausages. For semidry sausages,
particularly in the United States, temperature
is usually raised slowly to over 35 ° C to