Influence of the acetification process on phenolic compounds.

Little is known about the change of phenolic compounds and total phenolic content by the acetification process. The aim of this study was to assess the contents of selected phenolic compounds of cider and red and white wines in comparison to phenolic profiles in corresponding vinegars by using a new HPLC method for the simultaneous separation and quantification of polar phenolic acids and less polar flavonoids. Identifications were made by retention times and by means of mass spectra. Additionally, total phenolic contents of wines and vinegars were determined photometrically. The decrease in total phenol content by the acetification process was highest for cider vinegars (40%) and lower for red and white wine vinegars (13 and 8%, respectively). A decrease in the contents of individual phenolic compounds of vinegars from white white and ciders was not observed. In contrast, the contents of individual phenolic compounds in red wine vinegar decreased approximately 50%.