Development of methods for the quantitative detection of hydrophobins in barley and malt

'Gushing' is defined as the spontaneous and uncontrolled overfoaming of carbonated drinks when opening unshaken bottles. Especially in the beer industry, gushing is a major problem, and can lead to major economic and image damage for breweries. The phenomenon is caused by certain temperature-stable proteins, mainly Class II hydrophobins, which may be present in barley due to fungal infections. However, the presence of these proteins in barley, malt and wort is difficult to detect with existing methods. In this project I will try to develop accurate, selective and inexpensive detection systems that can be directly implemented in the industry. In the first instance, a compact, user-friendly system based on a dipstick sensor will be developed that allows for a quantitative detection of such infections before barley and malt are used in the brewing process. The measuring principle is based on impedance-spectroscopy in combination with synthetic receptors as a selective recognition element. In addition, an Enzyme-Linked Immuno Sorbent Assay (ELISA) will be developed as an alternative strategy. Finally, this project will also examine whether certain brewing parameters (e.g. the addition of certain hop oils) can inhibit the action of hydrophobins, and thus have a curative effect on gushing.