374 Chapter 21
few days, maybe weeks — without organolep-
tic faults. The reason for this limitation is that
the mold layer sticks suffi ciently to the casing
surface if the inside moisture can evaporate
when it reaches the surface. Should this not
be the case, as when the sausages are in pack-
ages impermeable to water vapor or even
when they are tightly packaged in a box, the
moisture coming out from inner layers makes
the mold layer wet, loosening it so that it
comes off, which gives an unattractive
appearance. One more disadvantage of sen-
soric nature also has to be mentioned: in
some cases Kocuria strains grow together
with yeasts as the fi rst microbes at the begin-
ning of ripening, even if technological pro-
cesses were controlled. This layer does not
disappear, yet if it is covered by a sound layer
of molds, it cannot be seen and does not
smell, and if moisture can evaporate from the
surface, no problems evolve. If, however, no
evaporation can take place because of
improper packaging, a characteristic unpleas-
ant odor appears, caused by the wet layer of
these microorganisms.
The usual compromise is to apply a per-
forated fi lm pouch through which moisture
can evaporate, which maintains the mold
layer for a while. Another possibility is to
wrap the rods in cellophane, through which
moisture can also evaporate. Neither type of
packaging gives the possibility for longer
storage, however, and a further weight loss
also has to be calculated.
Peeled, sliced sausage (either in vacuum
or modifi ed atmosphere) is a reliable method
of packaging with a long shelf life. Although
vacuum packaging ensures longer shelf life,
slices stick together and are not easy to take
apart, so MAP is generally the preferred
choice.Shelf Life
Unlike the case of cooked meat products, the
shelf life of dry sausages has practically no
limitation of a microbial nature, since low a wbe found in artifi cially inoculated meats; if
mycotoxic mold was the test strain, toxin for-
mation is infl uenced by several factors, out
of which genetics, food composition, tem-
perature, relative humidity (or a w of medium),
competitive inhibition, and eventual inhibi-
tory substances are most important. In this
respect, it was found that Penicillium chrys-
ogenum as starter culture may sometimes
produce toxin (Spotti and Berni 2007 ); in the
absence of carbohydrate, toxin production
does not take place, the presence of sulfhydril
groups inactivates patulin (Hofmann et al.
1971 ), and a combination of suboptimal tem-
perature, the presence of competing molds
and intensive smoking inhibits mold growth
and toxin production (Incze and Frank 1976a,
b ).
Due to concerns regarding a potential
mycotoxin presence in mold - covered tradi-
tional meat products, research as a further
step concentrated on selecting mold strains
that are suitable from a technological point
of view (good growth under given circum-
stances, good appearance), produce neither
mycotoxin nor antibiotics, and have no cel-
lulase activity that would cause detrimental
changes in cellulose casing. These require-
ments are not easy to meet, for which reason
only a few molds have been found suitable
for use as mold starters, and these are widely
utilized.
Packaging of
Mold - Ripened Sausages
Although mold cover renders several advan-
tages as mentioned, a basic disadvantage has
to be calculated, too. While dry sausages
without mold are ideal meat products for
packaging, ensuring long shelf life, and sau-
sages from good raw material that are smoked
and thoroughly dried can be stored for a long
time at ambient temperature in vacuum or
modifi ed atmosphere (MAP with CO 2 and
N 2 ), no such packaging can be applied to
sausages with mold on them — or only for a