Determination of 23 furocoumarins in 82 food samples and implications for risk assessment

Abstract

Background

Furocoumarins are a class of substances, which naturally occur in plants and may be present in certain foods. Roughly two dozen structurally different but related substances (congeners) have been described in plants to various degrees of depth. At sufficiently high concentrations furocoumarins pose a risk to consumers' health because of their phototoxic and photogenotoxic effects. Past studies on furocoumarin content in food usually focused on a limited number of congeners or specific food types. More information on occurrence in a broad range of foods was needed.

Results

In order to improve occurrence data, the content of 23 furocoumarin congeners in 82 food samples, known to contain furocoumarins, is presented in full. A method was developed using liquid chromatography coupled to a triple quadrupole mass spectrometer. Samples ranging from soft drinks to vegetables were extracted with a methanol/water mixture. Chromatography and transitions in the MS/MS detection were optimised and all parameters are given. The furocoumarin content quantified ranged from 29 μg/kg in ginger to 98 mg/kg in lime juice. A table showing all the results of each congener in each food sample is presented. As more congeners were covered in this study than in the past, previous risk assessments were revisited, in order to determine if the risk for consumers has changed.

Conclusion

The new occurrence data determined with the newly developed method makes a valuable contribution to the available data of furocoumarins in foods. The deducible exposure data enables a review of existing risk assessments on furocoumarins. Despite the higher number of analysed furocoumarins in this study compared to other studies, the total content for each food type was only slightly different to previously published data. Therefore, conclusions of previous risk assessments were found to be still valid: Normal dietary exposure should not lead to phototoxic effects in consumers. However, due to photogenotoxic properties of certain furocoumarins, their exposure should be reduced as much as possible and some foods should be consumed in moderation.