Variation in Malting Quality and Heat Resistance in the Malting Barley Variety "Alexis"
Birthe
Møller1,
Jose
Luis
Molina-Cano2
and
Lars
Munck1,3
1The
Royal
Veterinary
and
Agricultural
University,
Dairy
and
Food
Science,
Food
Technology,
Rolighedsvej
30,
Dk-1958
Frederiksberg
C
2Centre
UdL-IRTA,
Lleida,
Spain.
E-mail:
JoseLuis.Molina@irta.es
3Corresponding
author:
E-mail:
lmu@kvl.dk
J. Inst. Brew. 108(3), 294-302, 2002 | VIEW ARTICLE
ABSTRACT
In
earlier
studies
concerning
vigour,
where
subsamples
are
heat-treated
before
germination
there
was
found
heat-sensitive
as
well
as
heat-resistant
barley
samples.
The
vigour
model
developed
by
Ellis
and
Roberts
and
further
developed
at
Carlsberg,
could
only
describe
the
heat-sensitive
barleys.
Seventeen
samples
of
the
"Alexis"
variety
grown
widely
in
Europe
were
collected
from
the
EBC
trials
in
1994
in
order
to
see
if
heat
resistance
in
barley
was
influenced
by
different
growing
conditions.
We
found
both
heat-sensitive
samples
following
the
vigour
model
as
well
as
pronounced
heat-resistant
samples,
but
these
were
not
divided
according
to
growing
conditions.
The
germination
curves
dependent
on
heat
treatment
and
germination
time
were
evaluated
by
Principal
Component
Analysis
(PCA).
Heat-resistant
barley
samples
could
be
differentiated
from
heat-sensitive
samples
already
after
½
h
of
heat
treatment
at
68°C
(12%
moisture)
and
after
3
days
of
germination.
The
barley
samples
were
analysed
with
regard
to
malting
quality.
The
PCA
evaluation
of
the
data
divided
the
samples
according
to
growing
location,
mainly
due
to
differences
in
protein
and
β-glucan.
However,
the
malting
analyses
could
not
describe
the
differences
in
heat
resistance
and
sensitivity
of
the
barleys.
The
biochemical
background
of
the
heat
resistance
found
is
discussed
on
the
basis
of
literature.
Our
findings
should
give
an
experimental
basis
for
exploiting
a
biochemical
principle
for
heat
resistance,
which
is
formed
during
grain
filling
and
consumed
during
storage
and
germination.
Key words:
Heat resistance, malting barley quality, principal component analysis, vigour.
Publication no. G-2002-0826-045 ©2002 The Institute & Guild of Brewing