. FLAVOUR TRANSFER AND PYROLYSIS
Background
Early work undertaken at GRGDC showed that many
flavour
compounda and difterent humectants transferred to
smoke on
an 'efficient' basis.
At that time tquatLons were develop.2d by Sir
Charles Ellin
and others to ansess the 'amount of tobacco burnt
in puffing'.
It wiss assumed that the tobacco burnt in the
inter-puff or
smoulder periods contributei to the side-stream
smoke. The
theory of filtration of smoke by the tobacco rod
was also
developed so that the deliveries of nLcotIne and
flavour
compounds could be assessed after taking these
into account.
on this basis it was concluded that the transfer
of
materials was efficient if approzinately 101 to
121 of the
amount of the tobacco was found itt the
main-stream smoke.
This value will appear to be low to those not
experienced in
tobacco/smoke chemistry but it must be remembeced
thats
Only one third (approximately) of a cigarette in
burnt in
'puffing'. Since
(a) in an untipoel Ciq3Cette About 1/3 is 1,eft A3
the hutt
(23 mm), ani 1/3 is burnt in the smoulder piriod.
ExperL-
ments have shown the unburnt tobacco rod Is a very
efficient
filter, Particularly for 'hot' smoke. Since 50% of
the
usable tobacco rod is burnt in th,.v smoulder
periol any
material filtered out by the tobacco will
contribute
primarily to the uLde-stream smoke and not the
main-stream.
(b) The samo arguments apply to filt-c cigarettes
in that case the
'butt' will be filter plun a short length of
tobacco rod.
Transfer of Nicotine Flavouts and Other Materials
to Main-
stream Smoke
(a) Early Studies
This approach is Illustrated, for example, in
early P&D
reportst
e.g. RD 247-R, RD 286-R.
Although the work in dated, nicotine Is a good
example to
chooso in that t he cecent work lends general
support to the
argument outlined above and Is (a) more
sophisticated and (b)
Is supported by the Pyrolysis Studies of 3chmeltz,
Wenger,
Hoffman and Tso. (J. Agric. Food Chem. 1979, 27,
602).
The other use
ful reference is to the work of Dick
Baker i CD
Product Lormation mechanisms inside a burning
cigarette, (Prog. cc
Energy Combust. Scl. 1981, 7, 135-153).
BATCo document for Province of BritiSh Columbia 9
November 1999


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Although, as you would expect, Schmeltz and
11offmann do not
present 3 totally clear picture the large majority
of compounds
like ary1nitrites and aromatic hydrocarbons, founJ
an pyrolysis
were not found in cigarette smoke containing 141-
labelled
nicotine.
Vollowing on from the work on nicotine it nhould
also be
possible to present the work on humectants (RD
403-R) and
courarin (RD 505-R) in the same way. Incidentally,
I understand
that the follow-up study on glycerol in relation
to acrolein
Is no longer valid since the G.C. mothoA is now
suspect (RD
463-R).
(b) Recent Studies
Plore recent studies using radioactive tracers and
modern
analytical techniques have baen reportel in RD
1782-C and
RD 1842.
The results in these reports are bAsed on total
radioactivity
and, in at least one case, the prime objective was
not transfer
to smoke. Since some of the transfer values were
not quoted I
enclose a copy ot a note by John Green.
Further more definitive stu(ii!?s are in
nro:)r-!.9s -3n.1 it would
probably b-~ better to refer to further wock in
progreas rather
than submit the two detailed reports mintionel
above. rhis
further work fnc1q1!-s radionctive studl,!-n on a
range of flavour
compounds selected an the basis of boiling point
and structure.
Attachments
(1) Copy of paper by Dick Baker
(2) Copy of paper by Schmeltz et al.
(3) Memo from J. D. Green.
SRE/LAP
23 narch, 1964
BATCo document for Province of British Columbia 9
November 1999