David Riveros (1), Guy Derdelinckx (1), Almeida Fran (1); (1) KULeuven, Leuven, Belgium
Analytical
Poster
Although primary gushing in beer is not a widespread phenomenon
within the global beer industry. The presence of one gushing event in
front of a client is bad enough to affect greatly the brand image of a
company. Primary gushing is created from the marriage between
surface-active molecules, in this case class II hydrophobins, and CO2
present naturally in beer. Due to the amphipatic nature of
hydrophobins, these will form elastic monolayers at the gas-liquid
interface present at the bottleneck of the beer bottle. The hydrophobic
part of this monolayer will adsorb strongly CO2 molecules
that, by the movement of the bottle during the process, will be trapped
and stabilized in the shape of a nanobubble. These nanobubbles of about
100 nm at atmospheric pressure will shrink to about 60-70 nm at 4 bar,
remaining stable until the opening of the bottle, when sudden expansion
of the bubble will break them, releasing enough energy to induce
nucleation and strong overfoaming. The detection of 100 nm nanobubbles
has been done already by dynamic light scattering (DLS); however, the
detection of stabilized CO2 nanobubbles inside the bottle at 4
bar had remained elusive until now. In an effort to solve this problem
we used a pressured DLS, as well as known experimental conditions of the
sample, such as CO2 concentration, opening temperature and
hydrophobin concentration. After this, the detection of 60-70 nm
nanobubbles has been solved with reproducible results. These exciting
finding are not just the experimental proof of nanobomb theory, but an
additional step to include the DLS method of detection for primary
gushing in beer.
David Riveros received a B.S. degree in microbiology from
Pontificia Universidad Javeriana in Colombia. Later on, in 2008, he
obtained his master’s degree in Valdivia (Chile). He is now pursuing his
doctoral studies at Katholieke Universiteit Leuven in Leuven, Belgium,
under the supervision of Prof. Guy Derdelinckx. He is working in a team
fully devoted to understanding and controlling primary gushing
phenomenon.
