Evaluation of acetaldehyde and methanol in greek traditional alcoholic beverages from varietal fermented grape pomaces (Vitis vinifera L.)

Traditional alcoholic beverages produced from fermented grape pomaces (Vitis vinifera L.) are very popular in Greece and many other Mediterranean countries and some times consumed in large amounts daily. Acetaldehyde and methanol are two important toxic volatile compounds in wine and alcoholic beverages, that formed during grape pomace fermentation. The EU regulation 1576/89 fixed common analytical composition limits for those volatiles (1000 g/hL AA for methanol and 73–500 g/hl AA for acetaldehyde. In this study the two major toxic volatile compounds, methanol and acetaldehyde, were determined in varietal grape pomace distillates. Twelve of the most popular Greek grape varieties, six white and six red, were used for the production of grape pomace distillates that were collected in ten equal volume fractions. Grape pomace distillates were analysed by gas chromatography with f1ame ionization detector (FID) using pentanol-3 as an internal standard. The concentrations of these volatiles as well as their changes during distillation were measured. It should be also pointed out that the two toxic compound, acetaldehyde and methanol was detected far below the acceptable legal limits. The results may be useful for risk assessment of acetaldehyde and methanol.