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P 006
Predicting the flavor stability of
beer using redox potential
P 007
Classification of malting barley according
to harvest year and quality
by using mid infrared spectroscopy
and multivariate analysis
P 008
Microwave superheated water
extraction of brewers´ spent grain
arabinoxylans
Dario Cotterchio 1
1Technische Universität München (TUM), Forschungszentrum
Weihenstephan für Brau- und Lebensmittelqualität (BLQ),
Freising, Germany
Budour Ajib 1 , Frantz Fournier 1 , Patrick
Poivin 2 , Marc Schmitt 2 , Michel Fick 1
1Lorraine University, Vandoeuvre les Nancy, France, 2 IFBM,
Vandoeuvre les Nancy, France
Tiago Brandão 2 , Elisabete Coelho 1 ,
Mariana Pinto 1 , Tiago Brandão 2 ,
Manuel A. Coimbra 1
1Universidade de Aveiro, Department of Chemistry, Aveiro,
Portugal,
2Unicer Bebidas, SA, Porto, Portugal
DESCRIPTION OF TOPIC:
Changes in the freshness of a beer‘s flavor
are contingent on the free reaction enthalpy
of all active redox pairs. In order to determine
the enthalpy, an inert electrode is placed in a
redox solution where it then accumulates a
charge over a set period of time after which
the corresponding voltage is measured. This
reveals the scope of all the chemical processes
occurring in the beer that involve the
exchange of electrons and serves as an indicator
for the extent of the interplay between
compounds, responsible for the development
of perceptible sensory characteristics associated
with aging. Experiments have shown
that it is not the level of the redox potential
but rather the change in the value while the
sample ages that correlates with the formation
of a perceptible level of aging compounds
in beer. Various beer styles were tested and
a distinctive electrochemical signature was
established for each one, which allows for a
reliable prediction of the flavor stability to be
made.
DESCRIPTION OF TOPIC:
To realize successful malting process yielding
satisfactory malt, it is necessary to adapt the
malting conditions to the changes in the quality
of raw material. This adaptation is very
time and money consuming and must be repeated
every year as climate conditions and
site influence barley quality.
In this project, the quality of malt has been assessed
using Mid-InfraRed spectroscopy. The
quality of a wide variety of barley has been
studied 394 samples, including 3 harvest
years, winter and spring barley, 77 barley
varieties, collected on 16 cultivation places.
Conventional barley quality index (Moisture
content, Protein, Betaglucan) was determined.
The database thus depicts a large and
unique range of barley quality.
The results indicate that MIR spectrometry
could be a very usefull and rapid analytical
tool to assess malting barley quality. It allows
barley classification according to harvest
year and quality.
DESCRIPTION OF TOPIC:
Brewers‘ spent yeast (BSY) is the second
major by-product of brewery industry. These
residues comprise polysaccharides, namelyglucans
and mannoproteins, which should be
recovered due to their bioactive properties.
In order to solubilize all these polysaccharides,
a sequential extraction with hot water
and alkali solutions from 0.1M to 8M of KOH,
followed by a partial acid hydrolysis was performed.
The 4M KOH solubilized 6% of the carbohydrates,
corresponding to 26% of the total mannoproteins
and 1% of glucans. The 8M KOH
solubilized 18% of the carbohydrates, corresponding
to 1% of total mannoproteins and
22% of glucans. The glucans present in the
residue left were solubilized by partial acid
hydrolysis. Using this procedure, BSY can be
a source of cold water soluble polysaccharides
able to be used as food ingredients to be
incorporated in aqueous matrices as dietary
fiber.
We thank FCT for financial support of Research
Unit 62/94-QOPNA and post doctoral
grant SFRH/BPD/70589/2010.
Dario Cotterchio
Budour Ajib
Tiago Brandão
Dario Cotterchio was born in 1982 in Eschsur-Alzette,
Luxembourg. He studied brewing
and beverage technology at the Technische
Universität München and graduated with the
degree Dipl.-Ing. in 2008. After graduation he
worked in the engineering and biogas industry.
Since April 2009 he is scientific assistant
and a consulting engineer at the Research
Center Weihenstephan for Brewing and Food
Technology. He is working on the field of development
of the measure redox potential (ORP)
in breweries.
AJIB Budour
Mail: Budour.ajib@univ.lorraine.fr.
Phone : 0033383595769
Université de Lorraine (UDL)/ École nationale
supérieure d‘agronomie et des industries alimentaires
(ENSAIA) / Laboratoire Réactions
Génie des Procédés (LRGP-UMR 7274) / CNRS
Equipe Bioprocédés - Biomolécules 2, avenue
de la forêt de Haye - TSA 40602, 54518 - VAN-
DOEUVRE CEDEX. PhD student in Biotechnologies
Process. Thesis subject :( studying and
modeling barley during malting process)
Tiago Brandao: Education: MSc Biotechnology
– Leicester University, Biochemistry – Porto
University, Brewmaster – Scandinavian
School of Brewing. Current Positions: Innovation,
Research & NPD Manager at Unicer Bebidas,
SA since 2007, Executive Board member
at Maltibérica, SA since 2007
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