SO2
is
used
at
many
____________________
in
wine
-
making
.
1
)
Sulphur
dioxide
(
SO2
)
helps
to
control
the
____________________
of
____________________
micro
-
organisms
.
As
the
antimicrobial
activity
____________________
when
the
pH
falls
,
it
seems
to
be
____________________
to
the
undissociated
sulphurous
acid
or
the
SO2
.
Total
sulphur
dioxide
levels
around
100
ppm
let
Saccharomices
cerevisiae
____________________
and
ferment
while
some
____________________
yeasts
such
as
Kloeckera
apiculata
and
lactic
acid
-
producing
____________________
are
suppressed
.
Furthermore
,
many
strains
of
wine
yeasts
themselves
____________________
SO2
reducing
the
sulphates
present
in
the
grape
juice
(
usually
about
10
mg
/
l
)
.
2
)
SO2
protects
must
and
wine
from
____________________
,
as
it
is
more
easily
oxidized
than
other
compounds
such
as
____________________
compounds
;
sulphites
become
____________________
.
3
)
SO2
____________________
the
activity
of
oxidative
enzymes
such
as
polyphenol
oxidase
(
PPO
=
tyrosinase
or
catecholase
)
and
laccase
that
cause
____________________
reactions
in
grape
juice
.
The
need
of
using
SO2
can
be
minimized
this
way
:
-
Careful
____________________
of
grapes
to
____________________
damaging
the
fruit
;
-
Rapid
transition
of
the
grapes
from
the
____________________
to
the
____________________
;
-
Good
sanitary
conditions
in
the
winery
,
especially
in
the
____________________
area
;
-
Use
of
____________________
when
possible
;
-
Regular
topping
up
of
barrels
to
exclude
____________________
;
-
Use
of
filtration
to
remove
microbes
,
especially
prior
____________________
bottling
.
