Prof. Dr.-Ing. Vladimir Ilberg

Researchers from several disciplines are interested in understanding the spontaneous and eruptive overfoaming (gushing) of carbonated beverages, as it is an essential problem of both brewing and beverage industries. In order to understand the mechanism(s) taking place in gushing-beer, several beer ingredients have been investigated as model substances in much simpler matrix of carbonated water. For this purpose, sinapic acid, vanillic acid, ferulic acid, cinnamic acid and palmitic acid have been chosen as model beer ingredients. Gushing formation of the investigated beer ingredients depends on degree of stabilized solvated molecular carbon dioxide in water. For this purpose, functional groups which are capable of forming hydrogen bonds with electronegative oxygen atoms of carbon dioxide are needed. However, solubility of substances plays an important role in abundance of these functional groups in undissociated form to interact further with solvated molecular carbon dioxide. The reported data provide valuable insights into the gushing problem and help to understand its formation pathways. Each gushing-positive substance has an individual mechanism related to its structural conformation and solubility level. Therefore, possible gushing mechanisms have been proposed with respect to structural changes in model substances to clarify the differences in observed overfoaming and gushing stability levels.