Program Book - Master Brewers Association of the Americas

P-177
Enhancements to the flavor stability of beer through reaction
rate improvements in oxygen scavenging crown liner
compounds
GREGORY POLLOCK (1), Thomas Kunz (2), Frank-Jurgen
Methner (2)
(1) Grace Davison, Cambridge, MA; (2) VLB Berlin, Berlin,
Germany
Recent studies have illustrated the use of electronic spin resonance
(ESR) spectroscopy as an indicator of natural antioxidant
concentration and flavor stability in beer. It is also possible to extend
this technique to the evaluation of active packaging materials and
the their impact on beer stability over the course of the shelf life. In
this study, an evaluation of three different crown liner materials was
conducted, correlating oxygen control with sensory analysis and
ESR measurement of the beer’s endogenous antioxidant potential
(EAP). As expected, beer packed under oxygen scavenging crown
liners exhibited higher flavor stability through both measurement
techniques, than that under non-scavenger controls. Furthermore,
improvements to the oxygen reaction rates within the liners
correlated with sensory and EAP improvements toward the latter
half of the six-month shelf life. The oxidation of beer has been
well attributed in the literature to the formation of unsaturated
aldehydes, through several reaction mechanisms. Although the
mechanisms differ in their reactive components, they all involve
species formed from molecular oxygen, highlighting the importance
of oxygen control both in the brewing process and the beer package.
As the reaction rate of the oxygen scavenging crown liner is
improved, it consumes oxygen at a rate that is more competitive with
the natural uptake of oxygen in beer, and flavor stability over time is
enhanced.
Greg Pollock has been with W.R. Grace since July 2005, working in
the Closure Sealants R&D group for Grace Davison Materials and
Packaging Technologies (formerly Darex). During that time, he has
supported the growing oxygen-scavenging technology business,
by developing the new Celox faster oxygen-scavenging sealants,
providing customer technical support on oxygen-scavenging
technology and helping to identify and validate new opportunities
for active packaging beyond sealants for beer bottles. Prior to
joining Grace, Greg received a B.S. degree from the University of
Texas at Austin and a Ph.D. degree from the Massachusetts Institute
of Technology, both in chemical engineering. While at MIT, Greg
worked as a research assistant in the U.S. Army-funded Institute for
Soldier Technologies, where he did his thesis work on the synthesis
and characterization of silk-inspired thermoplastic polyurethane
elastomers.
P-178
Development of a new sensor to control bottle conveyors
ANDRE SORGATZ (1), Horst-Christian Langowski (1), Tobias Voigt
(1), Axel Kather (1)
(1) Technische Universität München, Freising, Germany
In modern bottling plants a variety of machines are working
together. Each machine in the plant executes a specific function.
To make the single machines work, bottles have to be transported
from one machine to the next. For this conveyors are installed.
The conveyors are commonly used as buffers as well. They have the
functionality to compensate for the downtime of a single machine.
There are two types of buffers: the so called anti-starve buffer
supplies bottles to the next machine while the machine before it
has a breakdown. The anti-block buffer absorbs bottles during
the breakdown of the following machine. Integrating these buffer
types in a bottling plant can reduce plant downtime caused by
short downtimes of single machines. Following this strategy, it is
important to control buffers correctly. Nowadays the filling level
of buffers is detected by inductive or capacitive switches which are
activated by the accumulating bottles. The disadvantage of this
method is that the fill factor is determined only in steps. So the
speed of the conveyor can be changed only stepwise. Simulation
studies at the Chair of Food Packing Technology showed that it
would be better to change the speed continuously. Following this
the efficiency of the plant could increase up to 5%. For this concept
of a continuous control a new sensor is needed, which is able to
count grouped bottles. Two kinds of sensors have been developed
at the Chair of Food Packing Technology. One is a combination of
standard sensors with a PLC (programmable logic control), the
other is based on a CMOS-camera (complementary metal oxide
semiconductor), which takes pictures of the passing bottles. The
analysis of the pictures is performed by a special processor unit
based on a FPGA (field programmable gate array). This intelligent
camera transmits the number of counted bottles to the PLC, which
calculates the correct speed of the conveyors. First experiments with
different sensor systems also showed other advantages of this kind of
control: reduction of noise by the slower impact speed of the bottles;
reduction of abrasion of the bottles (scuffing); higher utilization of
the buffer area.
André Sorgatz (born 1980) trained as a brewer and maltster from
September 2001 until June 2003 at the Paulaner brewery in Munich.
In June 2003 he graduated and became a Munich Master of Young
Brewers and Master of the South Bavarian Brewers Champion. After
that he studied from 2003 until 2007 at the Technische Universität
München/Weihenstephan. In November 2007 he graduated as an
engineer with a Dipl.-Ing. degree in brewing science and beverage
technology. In December 2007 he started working as doctoral
candidate and research associate at the Chair of Food Packaging
Technology, Technische Universität München. His fields of activity at
the university include development of a new sensor to control bottle
conveyors, control of conveyors at bottling plants, and reduction of
noise at bottling plants.
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