IJUP08 - Universidade do Porto

Influence of beer antioxidative properties on the formation of the
heterocyclic amine PhIP in grilled beef
A. Melo 1 ,M. Costa 1 , R. Eça 1 , I.M.P.L.V.O. Ferreira 1 , O. Pinho 1,2
1 REQUIMTE- Serviço de Bromatologia, Faculdade de Farmácia da Universidade do Porto, Rua
Anibal Cunha 164, 4099-030 Porto; Portugal
2 Faculdade de Ciências da Nutrição e Alimentação, Universidade do Porto, Rua Dr. Roberto Frias,
4200-465 Porto – Portugal
PhIP (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine) is an heterocyclic aromatic
amine belonging to a class of mutagens found in food. It is formed during the heating of
food (meat, fish) that contains creatine, free amino acids and carbohydrates. PhIP was first
isolated and identified from fried ground beef by Felton [1].
In several publications it was stated that the presence of antioxidants reduces the content of
heterocyclic aromatic amines, including PhIP, in meat. Since radical reactions play an
important role in the formation of heterocyclic aromatic amines, it was hypothesised that
antioxidants should reduce the content of these mutagenic substances in grilled meat.
Consequently, the addition of ingredients rich in antioxidants is considered a promising
measure to reduce heterocyclic aromatic amines exposure [2-4].
The aim of this study was to investigate the influence of beer, which is expected to have
antioxidative properties, on the occurrence of PhIP in grilled beef, one of the most
common heterocyclic aromatic amines found in grilled meat.
Beef samples were grilled in a teflon-coated frying pan, without adding oil. Before grilling,
samples were marinated with beer during 1 h, 2h, 4h and 6h. Control beef samples were
not marinated. The heat source was a gas cooker, and the temperature, on the surface,
ranged from 180 to 200ºC.
Extraction and purification of PhIP was performed by coupling of LLE with diatomaceous
earth as solid support and two SPE steps with propylsulfonic acid (PRS) and C18.
Separation and quantification of PhIP was performed by liquid chromatography with diode
array and fluorescence detection. Fluorescence detector was set at excitation 307 nm and
emission.
The marination time affected the PhIP formation. Higher content of PhIP was found in
control beef samples. There was an effective decrease of PhIP levels along the marination
with beer. Further work has to be done to clarify the complex reaction mechanisms for the
formation of PhIP. A reduction of the daily human exposure to this and other heterocyclic
aromatic amines must be the primary aim. Consequently, changes in cooking habits are
needed.
References:
[1] Felton, J.S., Knize, M.G., Shen, N.H., Lewis, P.R., Andresen, B.D., and Happe J. (1986),
Carcinogenesis (7), 1081–1086.
[2] Vitaglione, P. and Fogliano, V. (2004), Journal of Chromatography B (802), 189-199.
[3] Lan, C.M., Kao, T.H. and Chen, B.H. (2004), Journal of Chromatography B (802), 27-37.
[4] Murkovic, M., Steinberger, D., Pfannhauser, W. (1998), European Food Research and Technology (207),
477-480.
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