1. Acrylamide in Food –State of the Art
Dr. Rüdiger Weißhaar

2. 1997 - The Hallandsas Tunnel in Sweden:
Chronology (1)
The Hallandsas Tunnel in Sweden:
Acrylamide from groutings streamed into ambient waters
Dead fish and paralyzed cows
Acrylamide in private wells
Agricultural products from the whole area were discarded

3. 1997 –2001 Acrylamide biomarker analysis
Chronology (2)
1997 –2001 Acrylamide biomarker analysis
Acrylamide-Hb-Adduct: not only in exposed workers, but also in unexposed control persons
Elevated AA-Hb-Adducts in rats fed with fried feed
Acrylamide: A cooking carcinogen ? M. Tornqvist et al. ,Chem. Res. Toxicol. (2000)

4. Chronology (3)
Development of a LC-MS-MS-method and broad survey of common food products in Sweden.
24. April 2002: Swedisch National Food Administration informed international authorities about the finding of acrylamide in many types of heat processed foods.
Since April 2002: Worldwide survey and research about acrylamide in food.

5. Toxicological aspects (1)
Acrylamide is neurotoxic for humans
NOAEL for peripheral neuropathy: 500 µg/kg bw/d
Estimated intake (Germany): 0,6 µg/kg bw/d
Young people consuming high amounts of potato chips and french fries: 3,5 µg/kg bw/day)
There are no indications for any neurotoxic effect of foodborne acrylamide, because of the high margin between exposure and NOAEL

6. Toxicological aspects (2)
Acrylamide induces tumors in rats and mice
Acrylamide and Glycidamide are genotoxic
There is no treshold level known for the action of acrylamide on DNA
IARC classification for acrylamide:
Probably carcinogenic to humans
Reevaluation of a population based study in Sweden (Mucci et al., 2003): No effect of fried food on the risk for three frequent types of cancer

7. Toxicological aspects (3) J. Schlatter BAG Switzerland 2002
Dose inducing tumors in animals
Average human intake
Margin of Exposure =
Margin of Exposure
benzo[a]pyrene
nitrosoamines
aflatoxines
1 000
acrylamide

8. Toxicological aspects (4)
WHO Expert Consultation
„The consultation recognized the presence of acrylamide in foods as a major concern in humans based on the ability to induce cancer and heritable mutations in laboratory animals

9. LC-MS-MS-Method Extraktion with water
Purification of water extract (precipitation, SPE)
LC-MS-MS (ESI)
No enrichment step for acrylamide !

10. GC-MS-Method / Derivatisation with bromine
Extraktion with water
Bromination of water extract
Extraction of dibromopropionylamide with ethylacetate
Evaporation of solvent (enrichment step)
GC-MS (characteristic dibromine pattern)

11. Detection methods
Distribution of detection techniques used in proficiency tests (2002)

12. Method performance (simple matrices)
LOD RSD
GC-MS µg/kg 4-8%
LC-MS-MS µg/kg 2-10%
(0,2-1 µg/kg)*
*High sophisticated (high price) LC-MS-MS-systems
optimized for low-mass-range detection

13. Presuppositions for acrylamide formation
Free asparagine
Free reducing sugar (e.g. glucose, fructose)
Low water activity
Product temperature > 100°C

14. Mechanism of acrylamide formation

15. Formation of acrylamide in potato products
Asparagine is a nitrogen reservoir for the potato.
Level of reducing sugars is the limiting factor.
Fresh potatoes only have low levels of reducing sugars.
Levels of reducing sugars increase during storage.
Dramatic increase of reducing sugars takes place, if storage temperatures are below 8°C or if potatoes become green.

16. Acrylamide in French fries at different frying temperatures
100
200
300
400
500
600
700 2 4 6 8 10 12 14
Minutes
µg/kg Acrylamide
190°C
180°C
170°C
Optimum range
Recommendation: Maximum frying temperature 175°C

17. Cereal products: Asparagine is the limiting factor !
wheat flour rye flour
Flour was mixed with water and precursors and heated under controlled condicions:
I: no precursor added
II: + 5% glucose/fructose
III: + 1% asparagine

18. Acrylamide increases with dough maturing time
Wheat and rye flour was pasted with water. The resulting doughs were stored at 25°C for different times and then heated under controlled condicions.
wheat flour rye flour

19. Effect of ammonium hydrogencarbonate
Wheat and rye flour was pasted with water. To a portion, ammonium-hydrogencarbonate was added. Doughs were heated under controlled condicions.
wheat flour rye flour

20. Ammoniumhydrogencarbonate: mode of action
Wheat flour was pasted with water and different additives. Doughs were heated under controlled condicions.
I: no additive
II: + asparaginic acid
III: + NH4HCO3
IV: + asparaginic acid
+ NH4HCO3
V: + lactic acid

21. Ammonium salts: mode of action (hypothesis)
CH3 – CH(OH) – COO– NH4+
microbiological ? Δ T ? H2O
CH2 = CH – COO– NH4+
Δ T H2O
CH2 = CH – CO NH2

22. Acrylamid levels in Food
Food Classes N
Range [µg/kg]
Median
[µg/kg]
Signal
Value
N > Signal Value
min.
max.
potato chips
192
140
3640
819
1000 76
french fries 98
< 10
2779
151
570 11
biscuits, cakes 38
1090
190
660 4
Coffee powder 30
115
1685
343
370 14
crisp bread 32 15
1714
133
610 8
breakfast cereals
846 65
260
others
308
4594 16
Lebensmittelüberwachung Baden-Württemberg, May 2003-April 2003

23. Data base on Acrylamide levels in Food
As a joint DG SANCO- DG JRC initiative a monitoring data base on acrylamide levels in food was launched in April 2003.
Data from official, private, industrial and research laboratories.
Contact:

24. Proficiency Tests at EU level
Two proficiency test for official food control ´laboratories at EU level are planned in 2003:
A test with „simple“ matrices (crisp bread, butter cookies) organized by JRC-IRMM, running now.
A second proficiency test, jointly organized by the
JRC-IRMM and the German BfR with „difficult“ matrices (cocoa powder, coffee powder) in autumn 2003.

25. ... Thank you very much for your friendly attention