Food Chemistry

494 9 Food Contamination

Nitrosamine formation is also possible from pri-
mary amines:

(9.8)

from diamines:

(9.9)

and from tertiary amines:

(9.10)

(9.11)

Table 9.15.Nitrosamines in food

Food product CompoundaContent μg/kg

Frankfurter

(hot dog) NDMA 0–84

Fish (raw) NDMA 0–4

Fish, smoked and

pickled with nitrites

or nitrates NDMA 4–26

Fish, fried NDMA 1–9

Cheese (Danish, Blue,

Gouda, Tilsiter,

goatmilk cheese) NDMA 1–4

Salami NDMA 10–80

Bacon (hog’s hind leg)

smoked meat NDMA 1–60

Pepper-coated ham,

raw and roasted NPIP 4–67

NPYR 1–78

aNDMA: N-Nitrosodimethylamine, NPIP: N-nitro-

sopiperidine, NPYR: N-nitrosopyrrolidine.

Nitrosamines are detected in variable amounts

in many foods (Table 9.15). The most common

compound is dimethylnitrosamine, which is also

a most powerful carcinogen. Some activity has

been ascribed to nitrosopiperidine and nitrosopy-

rrolidine. In meat products cured and treated with

pickling salt, 30% of the samples contained ni-

trosodimethylamine (NDMA; 0.5–15 μg/kg) and

13% nitrosopyrrolidine (NPYR; > 0 .5μg/kg).

About 25% of the cheese samples analyzed were

contaminated (0.5–4.9μg/kg).

Nitrosopyrrolidine is formed from the amino acid

proline by nitrosation followed by decarboxyla-

tion at elevated temperatures, such as in roasting

or frying:

(9.12)