Technical Session 08: Sensory Session
Heinrich Rübsam, Institute of Brewing and Beverage Technology, TUM-Weihenstephan,Freising. Germany
Co-author(s): Martina Gastl, Institute of Brewing and Beverage
Technology, TUM-Weihenstephan, Freising, Germany; Martin Krottenthaler,
Hochschule Weihenstephan-Triesdorf, Freising, Germany; Thomas Becker,
Institute of Brewing and Beverage Technology, TUM-Weihenstephan, Germany
ABSTRACT: The content of high and low molecular weight
maltodextrins, as well as their structural properties in beer, may
influence the palate fullness of this beverage. Therefore, the possible
association between sensory impressions and structural analysis of
maltodextrins was investigated. To achieve this, a series of tasting
sessions using different beer and maltodextrin samples was performed in
parallel with various measurements of different structural parameters
using field-flow fractionation techniques. For these purposes a
selection of different maltodextrins products (2–100 kDa) was required.
These maltodextrins were classified, using different dextrose
equivalents (DE). First, the taste threshold of each maltodextrin in
beer was determined. To do this, the different maltodextrins were
independently added in increasing concentrations in a pilsner beer, and
all samples were tasted. Seven samples (control and 0.25, 0.5, 1, 2, 4,
and 8% maltodextrin in beer) were presented to the panelist, and these
were evaluated for the intensity of the palate fullness. Further, in the
same tasting, the threshold concentration of each maltodextrin at which
the flavor was not pleasant for the degustation panel was also
determined. To validate the previously determined threshold values and
to compare the characteristics of each type of maltodextrin in the beer
sample, a series of taste sessions was conducted. In these sessions, 4%
of maltodextrin was added to the corresponding beer sample. Furthermore,
the influence of maltodextrin to palate fullness was determined by the
application of defined matrices (maltodextrin-beer and
maltodextrin-water). Finally, a number of different commercial pilsner
beers (same wort extract and alcohol content) was selected and tested
for sensory palate fullness. All sensory tests were conducted 10 times
to obtain trustworthy results. Finally, the structural analysis of the
tasting matrices was carried out by means of a field-flow
fractionation-refractive index-light scattering measurement system. The
system was calibrated with different standards (pullulans, beta-glucan,
and proteins) at a molecular weight range of 6–800 kDa, and the
corresponding reproducibility was examined. All pilsner beers used for
the tasting sessions were analyzed. The correlation between the
analytical results and the sensory impressions was determined by the
comparison of the molecular weight distributions of the pilsner beers
with the degree of intensity of the palate fullness of each beer. From
the tested beers, it was found that the molecular weight distribution
ranged from 2 to 15 kDa. By correlation of the analytical data and the
results obtained from the tasting sessions, it is possible to conclude
that the beers with the higher palate fullness intensity corresponded to
the beers with molecular weight distributions from 6 to 15 kDa, while
the beers with molecular weight distributions from 2 to 15 kDa were
considered by the panelists to have lower palate fullness.
Heinrich
Rübsam completed his Dipl.-Eng. degree in chemical engineering at the
Metropolitan University, Caracas, Venezuela, in July 2004. He was then
employed by Polar Brewery Company at the research center. He
participated in different research projects: synthesis of
alpha-dicarbonyl compounds by application of HPLC, GCMS, and mass
spectrometry and quantification of alpha-dicarbonyl compounds and
Strecker aldehyde during the aging process of beer (2004–2006). The
results of this work were published in the Journal of Agricultural Food Chemistry
(56(11), pp 4134-4144, 2008). In 2007, he did an internship at the
Paulaner Brewery in Munich, Germany. He worked in the Production,
Bottling, and Quality Assurance departments. Additionally, he
participated in an independent project for the taste stability
determination of beer. Later, he studied brewing and beverage technology
at the Technische Universität München (TUM) in Germany and obtained his
M.S. degree in 2009. His work, in cooperation with the Paulaner Brewery
on optimizing brewhouse technology with reference to dimethyl sulfide,
was published in Brauwelt International in 2010. Currently he is
pursuing his Ph.D. at the Institute of Brewing and Beverage Technology,
TUM-Weihenstephan, Germany. His research focus is on the
characterization of the degradation of starch during the mashing
process, as well as the contribution of the content of high and low
molecular weight maltodextrins and their structural properties to palate
fullness of beer.
VIEW PRESENTATION 29
