The Proanthocyanidin Profile in Beer and Its Raw Materials

The presence of proanthocyanidins, substances belonging to the general group of polyphenols in beer is generally rather undesirable due to their tendency to form complexes with proteins, and thereby degrade the colloidal stability of beer. On the other hand, these substances are useful because of their ability to bind free radicals and thereby improve sensory stability of beer. The knowledge of the profile of the proanthocyanidins in beer and raw materials and their individual behavior during the entire technological process could help to address the challenges associated with improving the sensory and colloidal stability of beer. Therefore, we have developed a novel method for determination of proanthocyanidins by liquid chromatography with high resolution mass detection. The method was used to monitor changes in the profile of selected proanthocyanidins during the brewing process and consequently to verify the specificity profile of proanthocyanidins for given variety of Czech hops.