Smoking 237during processing, concentration of salt, and
composition and quantity of smoke deposited
in the meat. Various products preserved by
curing and heavy smoking may have a shelf
life of even several months at room tempera-
ture, while mild treatment, as applied in
manufacturing of some frankfurter - type sau-
sages, yields products that can be kept only
a few days under refrigeration. By smoking
frankfurters 30 minutes at internal tempera-
tures 60 – 76 ° C, the total number of aerobic
bacteria may be reduced by about two log
cycles; higher temperature and longer pro-
cessing time is slightly more effective.
Smoke components delay the growth of
microfl ora in cold - stored frankfurters,
whereby the effect increases with the smoking
time. Natural smoking can retard the onset
of greening of frankfurters caused by
Leuconostoc mesenteroides during storage
(Anifantaki et al. 2002 ).
Numerous smoke compounds (phenols,
carboxylic acids, and formaldehyde) in con-
centrations similar to those in heavily smoked
goods are effective antimicrobial agents.
Their activity against various microorgan-
isms at different stages of development is
not equal. The phenols prolong the lag phase
of bacterial growth proportionally to their
concentration in the product. Therefore,
the amount of the smoke components depos-
ited on the meats during smoking has a sig-
nifi cant infl uence on the preservative effect.
Generally, hot smoking decreases the number
of viable microorganisms in the products by
one to two log cycles, whereby the effect
increases with the rise in processing time
and temperature. Among the most effective
antimicrobial agents of wood smoke are:
guaiacol and its methyl and propyl deriva-
tives, creosol, pyrocatechol, methylpyrocate-
chol, 2,6 - dimethoxyphenol, and pyrogallol
and its methyl ether. Formaldehyde inhibits
Cl. botulinum in concentrations of 40 μ g/cm^3.
Adding to raw minced beef 8% of liquid
smoke, containing in 1 cm^3 about 1.4 – 4.0 mg
of phenols and 20 – 70 mg of carbonyl com-meats. The products of thermal decomposi-
tion of cellulose and hemicelluloses are the
result of carmelization and the source of
fruity and fl oral scents, while the phenols
generated by decomposition of lignin con-
tribute the fl avor associated with smoke,
scorch, spices, vanillin, and clover. Various
fractions of smoke condensates separated by
chromatography reveal different fl avors,
including fruity, diacetyl - like, spicy, protein
hydrolysate - like, or that of freshly baked
bread. The desirable smoky fl avor is associ-
ated with the presence of a mixture of
syringol and 4 - methylsyringol, although 4 -
allylsyringol, guaiacol, 4 - methylguaiacol,
and trans - isoeugenol also contribute to the
typical sensory sensation. However, the mul-
titude of variations of the smoky fl avor is
probably due to the contribution of the osmic
effect of different carbonyl compounds and
their reaction products, furans, esters, short -
chain carboxylic acids, pyrazine and its
derivatives, terpenes, and other unidentifi ed
constituents, as well as various products of
interactions of smoke compounds and reac-
tive meat constituents.
The smoky taste is a result of the sensory
properties of smoke constituents, mainly
numerous phenols and carbonyl compounds,
as well as various products of the interactions
with proteins and lipids. Some results of
experiments point to the crucial role of the
fraction of smoke condensates containing
guaiacol and its four derivatives, eugenol,
phenol, 3 cresols, 4 - ethylphenol, 3 xylenols,
tyglic acid, and 4 carbonyl compounds.
The Antimicrobial Activity of
Smoke Components
The shelf life of smoked meats depends on
the time and temperature of heating during
the process, on decrease in water activity,
and on the antibacterial and antioxidant
activity of smoke components. Thus the pre-
servative effect is related to the effectiveness
of the heat pasteurization, loss of water