1. OIL ENCAPSULATION USING W/O AND O/W EMULSIONS BY INVERSE GELATION
Adiwijaya
Zenia1,
Mar0ns
Evandro1*,
Renard
Denis2
and
Poncelet
Denis1
1
ONIRIS,
Nantes,
France;
2
INRA,
UR1268
BIA,
Nantes,
France
*evandrombi@yahoo.com.br
INTRODUCTION
Capsules by inverse gelation can be produced using O/W or W/O emulsions. However, previous works showed that the usage of W/O
emulsion required a bigger amount of calcium chloride (Anderson et al. 2005). Therefore, the objective of this work is to optimize the
production of capsules using W/O emulsion by reducing calcium chloride concentration necessary to form stable capsules. Capsules
produced with W/O and O/W emulsions are then compared on the process and properties basis.
• Abang et al. (2012) Effects of
process on the encapsulation of
oil in ca-alginate capsules using
an inverse gelation technique.
Journal of Microencapsulation
1-12.
• A n d e r s o n e t a l . ( 2 0 0 5 )
Polysaccharide capsules and
methods of preparation. U.S.
Patent 2005/0106233 A1.
• Martins et al. (2014). Oil core
microcapsules by alginate inverse
gelation technique. Submitted to
Journal of Microencapsulation.
1)
W/O
AND
O/W
EMULSION
PRODUCTION
Fig.1
Produc0on
of
W/O
and
O/W
emulsions.
For
the
W/O
emulsion
0.01
g
of
PGPPR
90
was
added
and
for
O/W
emulsions
0.5
mL
of
Tween
85
and
0.5
mL
of
Span
85
were
added.
2)
CAPSULES
PRODUCTION
3)
MECHANICAL
RESISTANCE
Fig.3
Determina0on
of
the
rupture
force
of
the
capsules.
Capsules
were
compressed
unTl
rupture
using
a
compressive
strength
machine
(Instron,
MassachuseWs,
USA)
• Capsules were produced by inverse gelation using W/O emulsions containing only 13. 8 g/L (% plutôt que C en g/L) of CaCl2
• Spherical capsules can be easily produced using O/W emulsion and the use of emulsion destabilizers is not necessary (???)
• Capsules produced with W/O and O/W emulsions show similar diameter and membrane thickness; however, capsules produced with W/O emulsions tend to be more resistant to
the rupture
• The quantity of membrane in the capsules can be controlled by tuning CaCl2 concentration in emulsions and core volume
• Capsules produced with W/O emulsions can’t be used in food areas due to the use of acetone (enlèves cette phrase; de plus, tu dis au-dessus que les emulsion destabilizers ne
servent à rien)
A)
B)
Fig.
4
Capsules
produced
with
W/O
(A)
and
O/W
emulsions
(B).
Scale
bar:
1
mm.
RESULTS
METHODOLOGY
REFERENCES
CONCLUSION
1)
EFFECT
OF
CaCl2
CONCENTRATION
ON
THE
CAPSULES
DIAMETER
AND
MEMBRANE
THICKNESS
2)
EFFECT
OF
THE
VOLUME
CORE
ON
THE
MEMBRANE
VOLUME
For
the
capsules
produced
with
alginate
solu0on
at
10
g/L,
the
capsule
diameter
and
the
membrane
thickness
increased
with
increasing
CaCl2
concentra0on
in
the
W/O
and
O/W
emulsions.
For
the
capsules
produced
with
W/O
emulsions,
the
percentage
of
membrane
tended
to
increase
with
the
increase
of
CaCl2
concentra0on,
an
opposite
behavior
being
observed
for
the
capsules
produced
with
O/W
emulsions.
In
addi0on,
the
size
of
capsules
and
quan0ty
of
membrane
in
the
capsules
can
be
controlled
by
CaCl2
concentra0on
in
the
emulsions.
The
percentage
of
membrane
and
the
membrane
volume
in
the
capsules
decreased
with
the
increase
of
core
volume.
Voluminous
oil
cores
retain
higher
amount
of
Ca2+
available
to
form
the
membrane.
Therefore,
a]er
analyses
of
the
curves,
it
is
observed
that
a
frac0on
of
Ca2+
does
not
par0cipate
to
the
membrane
forma0on
since
lower
values
of
percentage
of
membrane
and
membrane
volume
are
achieved
in
higher
core
volumes.
In
other
words,
a
subtan0al
quan0ty
of
CaCl2
is
retained
in
the
W/O
and
O/W
emulsions
and
does
not
par0cipate
to
the
membrane
forma0on.
(remplaces
volume
membrane
dans
le
graphe
par
membrane
volume)
3)
RUPTURE
FORCE
OF
DRIED
CAPSULES
Dried
capsules
produced
with
W/O
and
O/W
emulsions
are
compressed
un0l
the
rupture.
The
rupture
force
of
the
capsules
increases
with
the
increase
of
wet
membrane
thickness.
It
is
supposed
that
thicker
wet
membranes
contain
a
higher
quan0ty
of
dry
material
and,
consequently,
bigger
resistance
to
the
rupture.
More
important,
capsules
produced
with
W/O
emulsions
are
more
resistant
to
rupture.
(pourquoi
parles
tu
de
membrane
humide
alors
que
tu
travailles
avec
des
capsules
sèches
?
changes
les
valeurs
sur
l’axe
des
abcisses:
0.1,
0.2,…)
Fig.2
Capsules
produc0on.
For
the
W/O
emulsions,
2
mL
of
Tween
20
and
20
mL
of
acetone
was
added
to
200
mL
of
alginate
soluTon
in
order
to
destabilize
the
W/O
emulsion.
For
the
O/W
emulsions,
1
mL
of
Tween
85
was
added
to
200
mL
of
alginate
soluTon.
Tween
85
decreases
the
surface
tension
of
the
alginate
bath
decreasing
therefore
the
deformaTon
of
the
capsules.