Identification and quantification of α-dicarbonyl compounds in balsamic and traditional balsamic vinegars and their cytotoxicity against human cells

Eight balsamic and five traditional balsamic vinegars from Italy were analyzed to verify the presence of α-dicarbonyl compounds. The occurrence of glyoxal (GO), methylglyoxal (MGO), 2,3-butanedione (2,3-BD), 3-deoxyglucosone, 3,4-dideoxyglucosone-3-ene, and hydroxypyruvaldehyde or dihydroxyacetone, is shown by RP-HPLC-DAD-ESI-MS/MS analysis. Quantification of GO, MGO and 2,3-BD was performed by a validated RP-HPLC-DAD method. GO, MGO and 2,3-BD were also found in red wine vinegars and in E150a food additive (caramel), which are used in balsamic vinegar production. Moreover, the cytotoxic activity of GO, MGO, 2,3-BD subjected to simulated in vitro gastro-duodenal digestion, either as a mixture or individual compounds, was evaluated against an intestinal (HCT116) human cell line. The toxicity of these compounds, as far as we could see, seemed to be minimal even after 72 h of continuing exposure with a 50% decrease of cell vitality toward human cells at concentrations definitely superior to those that can be taken up with diet. In conclusion, it does not appear that dietary intake of the tested α-dicarbonyl compounds might be a significant source of toxicity.