1. Average
difference
Coefficient
βi
Significance
(%)
Conclusions
(Best
condi;ons
among
the
levels)
Emulsificant
concentra;on
1
=
1%;
2
=
10%
2
-­‐
1
-­‐11,67
32,2
*
10%
of
emulsifier
Type
of
membrane
1
=
Glass;
2
=
Nylon;
3
=
Cellulose
ester
1
-­‐
3
2,44
85,6
*
Glass
and
Nylon
membranes
are
beDer
than
Cellulose
ester
2
-­‐
3
-­‐13,34
41,3
*
Type
of
emulsifier
1
=
Whey
Protein
Isolate;
2
=
Sodium
Caseinate;
3
=
Arabic
gum
1
-­‐
3
-­‐13,44
34,8
*
Sodium
Caseinate
2
-­‐
3
3,53
82,1
*
Ra;o
oil
:
wall
material
1
=
1:1;
2
=
1:2;
3
=
1:3;
4
=
1:4
1
-­‐
4
-­‐4,30
78,4
*
RaOo
1:1
2
-­‐
4
-­‐14,15
38,8
*
3
-­‐
4
-­‐35,00
7,5
*
Wall
material
1
=
Maltodextrin;
2
=
Starch;
3=
Sodium
Caseinate;
4
=
Arabic
gum
1
-­‐
4
-­‐17,91
28,8
*
Arabic
gum
2
-­‐
4
-­‐13,81
39,8
*
3
-­‐
4
-­‐0,97
95,0
*
[1]
V.
Paramita,
T.
Furuta,
and
H.
Yoshii.
High-­‐Oil-­‐Load
Encapsula;on
of
Medium-­‐Chain
Triglycerides
and
d-­‐Limonene
Mixture
in
Modified
Starch
by
Spray
Drying.
J.
Food
Sci.,
77,
(2012)
E38-­‐44.
[2]
A.
Nazir,
K.
Schroën,
R.
Boom,
Premix
emulsifica;on:
A
review,
J.
Membrane
Sci.,
362
(2010)
1.
[3]
A.
Tren;n,
S.
De
Lamo,
C.
Güell,
F.
López,
M.
Ferrando,
Protein-­‐stabilized
emulsions
containing
beta-­‐carotene
produced
by
premix
membrane
emulsifica;on,
J.
Food
Eng.
106
(2011)
267–274
[4]
S.
Ramakrishnan,
M.
Ferrando,
L.
Aceña-­‐Muñoz,
S.
De
Lamo-­‐Castellví,
C.
Güell,
Fish
Oil
Microcapsules
from
O/W
Emulsions
Produced
by
Premix
Membrane
Emulsifica;on,
Food
and
Bioprocess
Technology
(2012)
in
press.
Lemon
essen;al
oil
Water
+
Emulsifier
Spray
drying
Microcapsule
Wall
material
addi;on
Membrane
Fine
emulsion
Coarse
emulsion
Low
pressure
Ultraturrax
(15000
rpm,
3
min)
0
1
2
3
4
5
6
1
2
3
Flux
(Kg/m2·∙s)
Premix
Cycle
Cellulose
ester
membrane
20%
oil
+
1%
Whey
Protein
Isolate
+
Metricel
20%
oil
+
10%
Sodium
Caseinate
+
Metricel
20%
oil
+
10%
Whey
Protein
Isolate
+
Metricel
!
Produc;on
of
microcapsules
entrapping
lemon
essen;al
oil
by
Premix
Membrane
Emulsifica;on
and
Spray
Drying
J.
Carmona,
S.
De
Lamo,
M.
Ferrando,
J.
Ferré*
and
C.
Güell
Departament
d’Enginyeria
Química
*
Departament
de
Química
AnalíOca
i
Química
Orgànica,
Universitat
Rovira
i
Virgili,
Spain
Avda.
Països
Catalans,
26,
43007
Tarragona
Tel:
+34977558504;
email:
carme.guell@urv.cat
Produc;on
of
lemon
essen;al
oil
emulsion
Materials
&
Methods
Introduc;on
&
Aim
Flavours
are
widely
used
in
the
food
industry
as
an
addiOve
to
many
types
of
food
and
drinks
for
its
aromaOc
properOes.
Because
of
their
labile
nature
it
is
necessary
to
entrap
them
inside
microparOcles
providing
protecOon
against
degradaOon
reacOons
and
loss
of
core
material.
Although
several
methods
are
used
to
produce
microcapsules,
the
most
widely
used
involve
(oil-­‐in-­‐water,
O/W)
emulsificaOon
followed
by
spray-­‐drying
[1].
Membrane
emulsificaOon
(ME),
and
parOcularly
Premix
ME,
is
an
alternaOve
to
convenOonal
homogenizaOon
technologies
because
it
produces
mono-­‐disperse
emulsions
with
a
low
energy
input,
and
enables
to
use
proteins
and
other
biopolymers
sensiOve
to
mechanical
stress
as
emulsifiers
[2,
3,
4].
The
aim
of
this
study
was
to
determine
how
different
microfiltraOon
membranes,
organic
and
inorganic,
affected
the
Premix
ME
process
and,
therefore,
the
final
properOes
of
the
microcapsules.
Membrane
Emulsifica;on
(Three
cycles)
Experimental
design
Conclusions
The
authors
acknowledge
funding
from
the
Spanish
Ministry
of
Economy
and
Compe;;veness
for
suppor;ng
this
research
work
(Project
funding
CTQ2011-­‐22793)
and
Dallant
S.A
for
providing
the
essen;al
oil
and
technical
support.
Jaume
Carmona
thanks
Universitat
Rovira
i
Virgili
for
his
scholarship.
Factor 1 Factor 2 Factor 3 Factor 4 Factor 5
Emulsifier
concentration
Type
of membrane
Wall material
Ratio
Lemon oil : Wall material
Type
of emulsifier
1% Glass Maltrodextrin
1:4
Whey
Protein
Isolate
1% Nylon Starch
1:3
Sodium
Caseinate
1% Cellulose
ester
Sodium
Caseinate
1:2
Arabic
gum
1% Glass Arabic
gum
1:1
Whey
Protein
Isolate
10%
Glass Sodium
Caseinate
1:1
Sodium
Caseinate
10%
Nylon Arabic
gum
1:2
Whey
Protein
Isolate
10%
Cellulose
ester
Maltrodextrin
1:3
Whey
Protein
Isolate
10%
Glass Starch
1:4
Arabic
gum
1% Glass Arabic
gum
1:3
Arabic
gum
1% Nylon Sodium
Caseinate
1:4
Whey
Protein
Isolate
1% Cellulose
ester
Starch
1:1
Whey
Protein
Isolate
1% Glass Maltrodextrin
1:2
Sodium
Caseinate
10%
Glass Starch
1:2
Whey
Protein
Isolate
10%
Nylon Maltrodextrin
1:1
Arabic
gum
10%
Cellulose
ester
Arabic
gum
1:4
Sodium
Caseinate
10%
Glass Sodium
Caseinate
1:3
Whey
Protein
Isolate
Fluxes
during
Premix
membrane
emulsifica;on
References
The
combina;on
of
a
low
energy
technique
(Premix
ME)
and
spray-­‐drying
was
successfully
used
to
encapsulate
essen;al
lemon
oil.
The
experimental
design
allowed
us
to
screen
the
opera;ng
condi;ons
with
a
reduced
number
of
experiments.
As
a
result
of
the
factorial
screening
model,
the
best
opera;onal
condi;ons
to
obtain
a
small
droplet
size
distribu;on
of
the
essen;al
oil
emulsions
are:
10%
of
arabic
gum
as
emulsifier.
Nylon
and
Glass
membranes
are
bexer
than
Cellulose
ester
but
we
could
not
dis;nguish
between
them.
Regarding
the
essen;al
lemon
oil
encapsula;on
efficiency,
the
factorial
screening
model
concludes
that
the
best
opera;onal
condi;ons
are:
10%
of
sodium
caseinate
as
emulsifier,
ra;o
1:1
of
oil:
wall
material
and
Arabic
gum
as
wall
material.
Nylon
and
Glass
membranes
are
also
bexer
than
Cellulose
ester
but
we
could
not
dis;nguish
between
them.
Results
Droplet
size
(D3,2)
during
Premix
membrane
emulsifica;on
0
1
2
3
4
5
6
7
1
2
3
Flux
(Kg/m2·∙s)
Premix
Cycle
Nylon
membrane
20%
oil
+
1%
Whey
Protein
Isolate
+
Nylon
20%
oil
+
1%
Sodium
Caseinate
+
Nylon
20%
oil
+
10%
Whey
Protein
Isolate
+
Nylon
0
2
4
6
8
10
12
14
0
1
2
3
D
3,2
(μm)
Premix
Cycle
Cellulose
ester
membrane
20%
oil
+
1%
Whey
Protein
Isolate
20%
oil
+
1%
Arabic
gum
20%
oil
+
10%
Sodium
Caseinate
20%
oil
+
10%
Whey
Protein
Isolate
0
2
4
6
8
10
12
14
0
1
2
3
D
3,2
(μm)
Premix
Cycle
Glass
membrane
20%
oil
+
1%
Whey
Protein
Isolate
20%
oil
+
10%
Sodium
Caseinate
20%
oil
+
1%
Sodium
Caseinate
20%
oil
+
10%
Whey
Protein
Isolate
20%
oil
+
1%
Arabic
gum
20%
oil
+
10%
Arabic
gum
0
2
4
6
8
10
12
0
1
2
3
D
3,2
(μm)
Premix
Cycle
Nylon
membrane
20%
oil
+
1%
Whey
Protein
Isolate
20%
oil
+
1%
Sodium
Caseinate
20%
oil
+
10%
Arabic
gum
20%
oil
+
10%
Whey
Protein
Isolate
Cellulose
ester
Figure
3.
ESEM
images
of
external
and
internal
morphology
of
lemon
oil
microcapsules:
a)
1%
of
whey
protein
Isolate,
raOo
1:4,
maltodextrin
and
glass
membrane;
b)
1%
of
sodium
caseinate,
raOo
1:3,
starch
and
nylon
membrane;
c)
1%
of
arabic
gum,
raOo
1:2,
sodium
caseinate
and
cellulose
ester
membrane.
Figure
1.
Emulsion
flux
for
each
emulsificaOon
cycle
using
Nylon
(a)
and
the
Cellulose
ester
membrane
(b)
and
different
emulsifiers
Membrane
Porous
size
(μm)
Membrane
configuration
Diameter/ length
(mm)
Type
of membrane
Wettability
Working
pressure
(MPa)
Nylon 0.8
Flat
47
Organic
Hydrophillic
0.7
Cellulose
ester
0.8
Flat
47
Organic
Hydrophillic
0.7
Glass 1.0
Tubular
100
Inorganic
Hydrophillic
0.2
Table
1.
Factors
and
levels
defined
to
each
experiment.
Experimental
condi;ons
during
Premix
ME
Model:
PlackeD-­‐Burman
screening
factorial
model
Responses
of
interest:
droplet
size
(D3,2)
of
the
end
of
Premix
ME
and
oil
encapsulaOon
efficiency
(EE)
Number
of
experiments:
16
plus
4
replicates
Number
of
factors:
5
Factor
levels:
Factor
1:
2
levels;
Factor
2:
3
levels;
Factor
3:
4
levels;
Factor
4:
4
levels;
Factor
5:
3
levels
This
model
enables
to
opOmize
among
the
several
levels
of
each
factor
by
comparing
the
averages
of
the
responses,
using
equaOons
1
and
2.
xvx
Eq.
1
xi
=
(X
–
X)/ΔX
Where
xi
is
the
dimensionless
coded
value
of
the
variable
xi;
x0
is
the
value
at
the
central
point;
ΔX
is
the
change
in
the
magnitude
of
the
variable
Eq.
2
Y
=
β0
+
Σβi
+
Σβij·∙xi
2
+
Σβij
·∙
xi
·∙
xj
Where
Y
is
the
predicted
response;
the
subscripts
i
and
j
range
from
1
to
the
number
of
variables;
β0
is
the
intercept
term;
βi
is
the
linear
coefficients;
βij
is
the
quadraOc
coefficients.
Experiments
Figure
2.
Progress
of
mean
droplet
size
during
Premix
membrane
emulsificaOon
using
(a)
Nylon,
(b)
Cellulose
ester
and
(c)
Glass
membranes
and
different
emulsifiers.
Droplet
size
of
the
coarse
emulsion
corresponds
to
Cycle
0.
(a)
(b)
Results
of
the
screening
factorial
model
External
and
internal
morphology
of
lemon
oil
microcapsules
b
c
a
Acknowledgment
(c)
(b)
(a)
Factor
Levels
Average
difference
Coefficient
βi
Significance
(%)
Conclusions
(Best
condi;ons
among
the
levels)
Emulsificant
concentra;on
1
=
1%
2
=
10%
2
-­‐
1
1,43
7,8
*
10%
of
emulsifier
Type
of
membrane
1
=
Glass;
2
=
Nylon;
3
=
Cellulose
ester
1
-­‐
3
2,35
3,5
Glass
and
Nylon
membranes
are
beDer
than
Cellulose
ester
2
-­‐
3
0,04
96,6
*
Type
of
emulsifier
1
=
Whey
Protein
Isolate;
2
=
Sodium
Caseinate;
3
=
Arabic
gum
1
-­‐
3
-­‐0,11
89,0
*
Arabic
gum
2
-­‐
3
-­‐1,30
20,5
*
Encapsula;on
Efficiency
Droplet
size
(D3,2)
of
the
end
of
Premix
ME
*
Significance
values
above
than
5%
are
not
significant.