Smoking 239method of smoking, the quality of smoke,
and the protection of the edible parts by the
skin. The external parts of the fi sh exposed
to the smoke, especially the skin of eel, may
contain up to fi ve times more BaP than the
fl esh. In the edible parts of fi sh smoked in a
modern automatic kiln with external smoke
generation, the contents of BaP are about
0.1 ng/g.
Some smoked foods may also be contami-
nated with nitropolycyclic aromatic hydro-
carbons. In smoked sausages, 1 - nitropyrene,
2 - nitronaphtalene, and 2 - nitrofl uorene were
found in concentrations of about 4.2, 8.4,
and 19.6 ng/g, respectively, while in roasted
coffee beans the concentrations were 2.4, 4.0,
and 30.1 ng/g.
Cured meats and bacon, as well as
smoked cured meat products, contain
several N - nitroso compounds, most of
which are carcinogenic in laboratory
animals. The contents of N - nitrosoproline,
N - nitrosohydroxyproline, and N - nitrosodime-
thylamine in smoked cured mutton after
cooking reached up to 230, 500, and 2.2 ng/g,
respectively (Dennis et al. 1984 ). The alde-
hydes of smoke can react with cysteamine
and cysteine, yielding various thiazolidine
precursors, which can be easily nitrosated.
Formaldehyde reacting with cysteamine and
cysteine yields thiazolidine and thiazolidine -
4 - carboxylic acid, respectively, which, upon
nitrosation, turn into N - nitrosothiazolidine
and N - nitrosothiazolidine - 4 - carboxylic acid.
In traditionally smoked fried bacon, the
content of N - nitrosothiazolidine may be
about 5 ng/g (Ikins et al. 1986 ). In the
presence of glycolaldehyde from smoke,
2 - (hydroxymethyl) - N - nitrosothiazolidine
and 2 - (hydroxymethyl) - N - nitrosothiazoli-
dine - 4 - carboxylic acid (HMNTCA) may be
formed. In various cured smoked products,
including smoked ham, sausages, salami,
pepperoni, and smoked poultry products, the
contents of HMNTCA ranges from about 10
to 260 ng/g (Sen et al. 1993 ). Generally, these
compounds occur in higher concentrations inrelative to BaP. The proposed TEF for BaP
and dibenzo(a,h)anthracene is 1, for benzo(a)
anthracene, benzo(a)fl uoranthene, indeno
(1,2,3 - c,d)pyrene, and benzo(k)fl uoranthene
it is 0.1, for chrysene and fl uoranthene 0.01.
Among PAH isolated from smoked products
are mainly compounds of m.w. smaller than
- In different smoked meat products, their
total mass may be from about 30 to 250 times
larger, while that of the heavy PAH about 10
times larger than that of BaP. If the specifi c
carcinogenicity of various heavy PAH con-
tained in smoked foods is taken into consid-
eration, the total carcinogenicity of all PAH
is about 10 times higher than would result
from the content of BaP alone (Scientifi c
Committee on Food 2002 ). Although many
PAH are regarded as not carcinogenic, some
of them may function in living organisms as
synergists, increasing the carcinogenicity of
other PAH.
German regulations in force since 1973
require that the content of BaP in smoked
meat products not exceed 1 ng/g. In about
75% of market samples of meat products in
Germany, the contents of BaP were not found
to be higher than the limiting value, but in
about 1% of investigated samples, even as
much as 40 ng/g were present. The actual
European limit of BaP in smoked meats and
smoked meat products is 5 ng/g wet weight
(Commission Regulation (EC) No 208/2005).
Hot smoked sausages and smoked beef
spreads usually contain below 1 ng/g, but
some black smoked products even have as
much as 55 ng/g. According to data reviewed
by Simko (2002), the content of BaP in 10
different kinds of smoked meat and meat
products ranged from 0.03 to 1.2 ng/g and
was 17.1 ng/g in dark smoked meat products.
In 1 g of fl ame - grilled sausages, 18 to 42 ng
BaP were found. This could be compared
with the contents of BaP in barbecued pork
and beef: 1.5 – 10.5 ng/g, and in charcoal -
broiled steaks 5 – 8 ng/g. Traditionally smoked
fi sh may contain from about 1 to about
60 ng of BaP/g of product, depending on the