Characterization of phenolic compounds in virgin olive oil and their effect on the formation of carcinogenic/mutagenic heterocyclic amines in a modelsystem

Mutagenic heterocyclic amines (HAs) are formed at low levels during cooking of meat and fish, and some of them are considered to be possible human car cinogens. The formation of HAs may be affected by the presence of synthetic or naturally occurring antioxidants. In the present study the effect of vi rgin olive oil (VOO) phenolic compounds, identified and quantified by LC-MS , on the formation of HAs in a model system was evaluated. An aqueous solut ion of creatinine, glucose, and glycine was heated in the presence of two s amples of VOO differing only in the composition of phenolic compounds. The addition of VOO to the model system inhibited the formation of 2-amino-3-me thylimidazo[4,5-f]quinoxaline (IQx), 2-amino-3,8-dimethylimidazo[4,5-f]quin oxaline (MeIQx), and 2-amino-3,7,8-trimethylimidazo[4,5-f]quinoxaline (DiMe IQx) by between 30 and 50% compared with the control. Fresh-made olive oil, which contained a high amount of dihydroxyphenylethanol derivatives, inhib ited HA formation more than a 1-year-old oil did. The inhibition of HA form ation was also verified using phenolic compounds extracted from VOO.