Aromatic alcohols are compounds which exhibit a strong sensory influence on beer. This is especially true of some top-fermented beers with the pronounced aroma of guaiacol. Phenolcarboxylic acids are precursors of these substances and, in fact, possess antioxidative properties.
4-Vinylguaiacol and 4-vinylphenol are derivatives of ferulic acid and coumaric acid, respectively. Both substances appear in higher concentrations in Southern German wheat beers (Weissbier). 4-Vinyl guaiacol is considered an indicator substance.
4-Vinylguaiacol and 4-vinylphenol are compounds that play an important role in beer, especially in wheat beer and pale lager. These compounds are produced exclusively by POF-positive yeasts (phenol-off-flavor). While 4-vinylguaiacol is desirable in wheat beer and provides the characteristic spicy and clove aromas, both compounds are undesirable in pale lager beer and are considered off-flavors. These off-flavors can be caused by contamination with foreign yeasts and various lactobacilli, which has a negative impact on the quality and taste of the beer.
Determination of 4-vinylguaiacol and 4-vinylphenol in beer. The method can also be used for wort.
The method is suitable for beers of all original gravity ranges and alcohol contents. The method can also be used for wort.
4-Vinylguaiacol and 4-vinylphenol are separated by isocratic HPLC on a Spherisorb separation column and the concentration is determined by UV detection at 260 nm.