Creatinine and Maillard Reaction Products as Precursors of Mutagenic Compounds Formed in Fried Beef

Abstract

Evidence of formation of mutagens from creatinine and Maillard reaction products was obtained from meat experiments and model reaction systems. Lean beef containing varying amounts of glucose after frying showed mutagenic activity with Ames test, which increased with the glucose content. Varying amounts of creatinine were formed from creatine during frying and the mutagenic activity was found to be related to the creatinine levels. In model experiments solutions of creatinine, glucose and glycine or alanine in diethylene glycol: H 2 O were refluxed for 4 h. The resulting mutagenic activity was around 12 -20 x 10 3 revertants (TA98 + S9) per ml solution depending on which amino acid was used.

Influence of amino acids on the formation of mutagenic/carcinogenic heterocydic amines in a model system

“…The quinoline/quinoxaline part of the molecule arises from pyridines or pyrazines and Strecker aldehydes, formed in the Maillard reaction (18). Surprisingly, neither IQ nor MelQ was found in any of the samples.…”

“…Amino acids act as precursors of HAs by serving as a nitrogen source in pyrazine formation (28). They also seem to provide the carbon and, in some cases, the methyl group at position 4 (18). According to the hypothesis, glycine is a precursor of IQ, MelQx and 7,8-DiMeIQx, while alanine might give MelQ and 4,8-DiMeIQx.…”

“…Jagerstad et al (18) suggested that IQ compounds may be produced via the Maillard reaction from creatin(in)e, amino acids and hexoses present in foods of animal origin (see Scheme 1). This hypothesis has been confirmed by heating creatin(in)e, amino acids and sugars in various model systems, resulting in the formation of IQ, 2-amino-3-methylimidazo [4,5- (4, and PhIP (for reviews see 3,19).…”

“…According to the hypothesis illustrated in Scheme 1, amino acids act as precursors of HAs partly by serving as a nitrogen source in pyridine or pyrazine formation (18). However, mutagenic activity and HA yield previously reported in model systems vary depending on the particular amino acid used (for reviews see 3,17).…”

Cooking of meat and fish in Europe—results from the European Prospective Investigation into Cancer and Nutrition (EPIC)

“…HCA are formed during high temperature cooking of meat and fish from creatinine, amino acids, and sugar (Skog et al, 1998). These compounds can react together during cooking at high temperatures in Maillard reactions (Jägerstad et al, 1983). The carcinogenicity of different members of the HCA family has been proven in animal models (Adamson et al, 1990;Shirai et al, 1995).…”