hydrocarbons. In the fraction of about 20
aliphatic hydrocarbons, the compound
present in the highest concentration is
methane, known also as the product of dry
distillation of wood. Much larger is the
group of polycyclic aromatic hydrocarbons
(PAH) identifi ed in numerous investigations
(Obiedzi n´ ski and Borys 1977 ). Some smoked
products contain up to 100 different PAH and
their alkylated derivatives, of molecular
weights from 116 (indene) to 302 (dibenzopyrenes).
They are generated at temperatures
above 420 ° C and, having high boiling temperature,
are present mainly in the dispersed
phase of smoke. Thus the contents of PAH
can be decreased by reducing the wood
smouldering temperature and fi ltering the
smoke.
Smoke fl avorings produced commercially
for the food industry contain only traces of
PAH. They are generally smoke extracts fi ltered
and separated from the tars or distillates
of pyroligneous liquids. Various fl avorings
of different brands are available as aqueous
solutions or in free - fl owing, dry form on salt,
yeast, or other material.
Wood smoke also contains a number of
other chemicals, including NO, NO 2 , and
NO 3 , as well as various heterocyclic compounds,
including the N - heterocyclic pyrrole,
pyrazine, and carbazole.
hydrocarbons. In the fraction of about 20aliphatic hydrocarbons, the compoundpresent in the highest concentration ismethane, known also as the product of drydistillation of wood. Much larger is thegroup of polycyclic aromatic hydrocarbons(PAH) identifi ed in numerous investigations(Obiedzi n´ ski and Borys 1977 ). Some smokedproducts contain up to 100 different PAH andtheir alkylated derivatives, of molecularweights from 116 (indene) to 302 (dibenzopyrenes).They are generated at temperaturesabove 420 ° C and, having high boiling temperature,are present mainly in the dispersedphase of smoke. Thus the contents of PAHcan be decreased by reducing the woodsmouldering temperature and fi ltering thesmoke. Smoke fl avorings produced commerciallyfor the food industry contain only traces ofPAH. They are generally smoke extracts fi lteredand separated from the tars or distillatesof pyroligneous liquids. Various fl avoringsof different brands are available as aqueoussolutions or in free - fl owing, dry form on salt,yeast, or other material. Wood smoke also contains a number ofother chemicals, including NO, NO 2 , andNO 3 , as well as various heterocyclic compounds,including the N - heterocyclic pyrrole,pyrazine, and carbazole.
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