Joint International Conference on Long-term Experiments ...

The fat cooked out of some of the bacon samples was analyzed and was found to contain
from 19 to 92 ppb N-nitrosopyrrolidine. All values in Table 2 were confirmed by combined
GLC-MS, except Sample 16, which had a low concentration.
Table 2. N-Nitrosopyrrolidine (ppb) found in commercial bacon
Sample Raw Fried Fat cooked out
1 0 67 92
2 0 91
3 0 74, a 64 a 111," 129*
4 0 30
5 0 119, 139
6 0 129, c 104 c
7 0 33, 33, 33 47
8 0 34 48
9 0 10
10 0 16, 13 24
11 0 10
12 0 28, 29
13 0 42, 51
14 0 28,30 55,44
15 0 22, 20 19
16 0 7, d 7 d
17 0 23, b 19 c
18 0 13, 12, 13
19 0 8
20 0 42,34 49,44
21 0 36, c 29 c
22 0 65, 59, 72, 64
a
Held at 72°F for 8 hr.
b
Held at 72°F for a total of 34 hr.
c
Held at 72°F for 36 consecutive hr.
d
Not confirmed.
No nitrosamines were found in the raw bacon. One sample of dry-cured bacon (not shown
in the table) was analyzed; no nitrosamines were found in either the fried or the raw product.
It is evident that pan-frying does induce the formation of N-nitrosopyrrolidine in bacon, but
the actual mode of formation during the cooking process has not been definitely established.
It may be through the formation of nitrosoproline from proline and nitrite and subsequent
decarboxylation to nitrosopyrrolidine, or by direct interaction of pyrrolidine, which could
arise from proline or putrescine and nitrite.
Four bacon samples were also analyzed after having been kept at room temperature
(72°F) for 34-36 hr, before frying. It has been suggested that bacterial action on meat tissue
could result in higher concentrations of polyamines. In the presence of nitrite these could, in
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