Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
21 O ~
This invention relates to a nutritive composition
in the form of an oil-in-water emulsion preferably
intended for parenteral administration. The invention
also relates to a process for the production of this
nutritive CompOSitiQn.
Nutritive compositions in the form of oil-in-
water emulsions containing 20% lipids are known in
principle. Nutritive compositions containing 10% lipids
are also known. These nutritive compositions, which are
intended for parenteral administration, have to meet
strict requirements and, in particular, have to be
completely sterile. Now, it is known that the effect of
sterilization is in particular to destabilize the oil-
in-water emulsions which thus separate into two or more
phases. To solve this problem, an emulsifier is gener-
ally added to the emulsion during its preparation.
Lecithin in particular is added as the emulsifier in a
quantity of 1.2% to 2% by weight, enabling the nutritive
composition to be sterilized without destabilization.
This is illustrated, for example, in the Article by
Masson et al. published in Revue Française des Corps
Gras (0ct. 1984) 10, 391-394.
Now, in nutritive compositions of low lipid
content, the presence of a significant quantity of free
phospholipids, which are the majority constituents of
lecithin, gives rise to disadvantages. This is par-
ticularly noticeable in the case of 10% emulsions in
which the ratio of phospholipids to lipids can be of the
order of 10 to 15:100. It has been found that, when
there are too many free phosolipids in an emulsion, they
tend to form micelles of which the effect is to de-
stabilize the emulsion even further, particularly during
sterilization.
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On the other hand, it has been found that, when
a 10~ emulsion containing 1.2% lecithin is administered
to infants, the concentration of triglycerides in the
blood plasma increases considerably by comparlson with
the increase obtained where a 20% emulsion is used.
This problem is addressed in the Article by Haumont et
al. in "The Journal of Pediatrics" (1989), 115, 787-793.
An accumulation of cholesterol and low-density lipopro-
teins in the blood is also observed.
The problem addressed by the present invention
was to obviate these disadvantages and to provide a
nutritive composition which would be stable, even after
sterilizat~on, and which would contain a very small
quantity of an emulsifying compound.
Accordingly, the present invention relates to a
composition in the form of an oil-in-water emulsion
containing at least 10% by weight lipids and at least
0.4% by weight of an emulsifying compound comprising
phosphatidyl choline (PC) and phosphatidyl ethanolamine
(PE) in a ratio of PC to PE of 2 to 10:1.
The present invention also relates to a process
for the production of this composition, in which an
aqueous phase and a lipid phase are prepared, at least
0.4% of an emulsifying compound comprising phosphatidyl
choline (PC) and phosphatidyl ethanolamine (PE) in a
ratio of PC to PE of 2 to 10l is added to one and/or
the other of the phases, the two resulting phases are
mixed to form an emulsion containing at least 10% by
weight lipids and the emulsion obtained is sterilized.
It has been found that the use of an emulsifying
compound comprising phosphatidyl choline and phosphati-
dyl ethanolamine in a PC to PE ratio of 2 to 10:1
enables the quantity of emulsi~ier to be added to be
considerably reduced, particularly in compositions of
low lipid content, such as 10% emulsions. The use of
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the emulsifying compound in question al50 enables amino
acids to be added to the composition without causing
destabilization during sterilization. Yet another
advantage is that nutritive compositions can be prepared
without any undesirable odour and/or colour by virtue of
the small quantity of emulsifying compound added.
In the context of the invention, stability is
understood to be the property of an emulsion whereby it
has no tendency to separate into phases or into its
constituents.
The features and advantages of the present
invention will become apparent from the following
description in which parts and percentages are by weight
and the following abbreviations are used:
. PC : phosphatidyl choline
PE : phosphatidyl ethanolamine.
To carry out the process according to the inven-
tion, an oil-in-water emulsion is prepared in the form
of a mixture of an aqueous phase and a lipid phase. The
lipid phase may be formed by oils of vegetable origin,
such as palm oil, corn oil, canola oil, soybean oil,
; olive oil and sunflower oil, or by oils of animal
origin, such as butter oil or fish oil or even by
medium-chain triglycerides. A mixture of these various
oils may also be used. The aqueous phase consists
mainly of water, preferably distilled or demineralized
water, to which glucides may be added. The glucides may
be selected from the group consisting of monosaccharides
or polysaccharides, such as maltose, fructose or glu-
cose, maltodextrins having a dextrose equivalent (DE) of
10 to 50 and preferably of the order of 45 and poly-
alcohols, such as glycerol, sorbitol or xylitol.
The emulsion according to the invention is
distinguished in particular by the fact that it contains
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at least 10% lipids and a~ least 0.4% o~ an emulsifying
compound comprising phosphatidyl choline and phosphati-
dyl ethanolamine in a ratio of PC ~o PE of 2 to lO:l~
Depending on its solubility, this emulsifying compound
may be added to the aqueous phase or to the lipid phase
before they are mixed.
To prepare the oil-in-water emulsion, the aqueous
and lipid phases may be separately heated with con-
tinuous stirring to a temperature in the range from 40
to 60C, preferably in an inert gas atmospher2, for
example in a nitrogen atmosphere, in order to avoid
possible contamination or oxidation of the fats. The
two phases may then be mixed, for example by addition of
lO to 40 parts lipid phase to lO0 parts aqueous phase
with continuous stirring at a temperature in the range
from 40 to 60C.
To improve the stability of the emulsion ob-
tained, the average size of the droplets of the lipid
phase may be reduced, for example by homogenization. It
is also possible in this way to establish the narrowest
possible particle size distribution. To this end, the
emulsion may be prehomogenized under a pressure of 15 to
25 bar to obtain an average droplet size of the order of
l.5 to 2.5 ~m and then homogenized under high pressure
(2 to 1200 bar), for example in a homogenizer. This
last step may be repeated several times to obtain an
emulsion of which the average droplet size of the lipid
phase is of the order of 0.15 to 0.35 ~m. The homogeni-
zation step is preferably carried out at 40 to 60C.
Th~ homogenized emulsion is then continuously stirred in
an inert gas atmosphere, for example of nitrogen. After
homogenization, the emulsion is left to cool to ambient
temperature and then neutralized, for example by addi-
tion of sodium hydroxide, t4 obtain a pH value of 7 to
7.5. The emulsion may then be sterilized, for example
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by heat treatment for 8 to 30 minutes at 120 to 130C,
and then packed under aseptic conditions in cans,
cartons or bottles.
An oil-in-water emulsion havin~ a lipid content
of at least 10% is obtained in this way. The emulsion,
which contains at least 0.~% of an emulsifying compound
comprising PC and PE in a ratio of PC to PE of 2 to
10:1, is capable of retaining its stability for long
periods.
The emulsion may be used in the field of paren-
teral feeding either as such or after dilution.
Thus, in one particular application, a nutritive
composition containing 1 part emuIsion to 0-15 parts
wateroptionally containing an amino acid source may be
prepared from the emulsion.
The amino acid source may be added, preferably in
the form of an aqueous solution, to the prepared emul-
sion eithar before or after homogeni~ation and/or
sterilization. The amino acid source may also be addad
to the aqueous phase before preparation of the emulsion.
The amino acid source may be formed, for example, b~
amino acids and/or peptides. It has been found that, by
virtue of the present invention, up to 6% of an amino
acid source may be added to a 10 or 20% emulsion of
lipids without causing destabilization of the composi-
tion after sterilization. A stable nutritive composi-
tion containing amino acids which is suitable for use in
the ~ield of parenteral feeding is thus obtained after
sterilization.
The invention is illustrated by khe ~ollowing
Examples in which the various measurements are carried
out as follows:
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1) Measurement of osmolality
Osmolalitv is understood to be the number of
osmotically active moles per kilogram of product taken
as reference, in the present case per kilogram,of water
(unit Osm/kg water). Osmolality is measured with a
Roe~ling osmometer by measurement of the cryoscopic
depression of the solution using pure water as refer-
ence.
2) Measurement,of,t e fats content
The fats content of the composition is determined
by measurement of the quantity of lipids as follows:
~ .,
- an exact quantity - between 10 and 50 g - of the
liquid to be analyzed is removed,
- this liquid is diluted with 20 ml of a 10%
aqueous NaCl solution,
- a pH value of 3 is adjusted by addition of a 0.1
N aqueous HCl solution,
- the lipids are extracted four times with 50 ml of
a solution containing parts n-hexane and 2 parts
isopropanol, ;
- the organic phase obtained is washed with 30 ml
10% NaCl while the aqueous phase obtained is
washed with 30 ml n-hexane,
- the organic phases aræ. combined and dried over
anhydrous sodium sulfate and then filtered.
The organic solvents are then evaporated under
30 reduced pressure and the quantity of lipids is obtained
by weighing. The fats content T, expressed in ~, is
obtained by establishing a ratio between the weighed
quantity of lipids and the quantity of liquid initially
removed.
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3) Determination of the stability index
In order quantitatively to characterize the
physical stability of the nutritive compositions pre-
pared, the stability index (SI) is determined as fol-
lows:
- a first sample of the prepared composition is
removed and its fats content T1 is determined,
- a second sample is removed and centrifuged for 15
minutes at 1000 r.p.m~/25C; this yenerally
results in separation into two more or less
distinct phases; ,~ ''
- the fats content T2 of the 'lower phase of the
centrifuged sample is determined and
- the stability index SI (in %) is obtained by ~,
establishing the ratio: T 2 x 100
T 1
4) Preparation of the PC/PE compounds
Some of the emulsifying compounds used in the
following Examples were prepared as follows:
- a quantity Ql of lecithin with a PC:PE ratio of
4 :1 is weighed and dissolved in 100 ml of a 2:1
mixture of dichloromethane and methanol,
- a quantity Q2 of lecithin with a PC:PE ratio of
10:8 (or a quantity Q3 of pure PE3 is added and
the whole is thoroughly mixed,
- the solvent is evaporated to dryness, ~'
- 100 ml water are added and the product obtained
is redispersed with stirring and then freeze-
dried.
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Quantities to be added for the various PC:PE mixtures:
PC:PE 2.5.1 6:1 8:1
Q1 1 ~2 g 1 g
~2 1.832 g 3.223 g
Q3 0.125 g
Example
An aqueous phase is prepared by mixing 14.6 ml
~0 water, 0.4 ml glycerol and egg lecithin with a PC:P~
ratio of 4.1:1 in the quantity defined in the following
Table with stirring at 45C. 3.8 g of a soybean oil are
then slowly added to this aqueous phase with continuous
stirring, the temperature being kept at approximately
45~.
An emulsion containing 20~ lipids is obtained in
this way and is subsequently homogenized after five pas- ~-
sages through a suitable apparatus of the "Microfluid-
izer" type under a pressure of 1100 bar and at a temper-
ature of 20C to 50C in order to obtain an average
droplet size in the lipid phase of 250 to 950 nm. The
pH of the emulsion thus prepared is ad~usted to 7.4 with
0.5 N sodium hydroxide, after which the emulsion is
packed in 100 ml bottles which are sterilized for 9
minutes at 126C.
The osmolality and the pH of the emulsion are
determined before and after sterilization. The stabil-
ity of the emulsion is also Yisually observed.
The following results are obtained:
Al A2 A3 A4 A5 A6
% 1.28 1.05 0.83 0.62 0.41 0.21
Osmo 1 342 346 351 327 353 327
pH 1 3.87 3.99 4017 4.67 5.06 5.82
Osmo 2 343 349 353 325 353 328
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Al A2 A3 A4 A5 A6
pH 2 ~.76 5. ns 5.08 5.3~ 5.29 5.23
T0 -~ t + ~ +
T1 + ~ +
T2 +
~ : percentage of lecithin in the emulsion
Osmo 1 : osmolality before sterilization (in mOsm/kg)
pH 1 : pH before sterilization
Osmo 2 : osmolality after sterilization (in mOsm/kg)
pH 2 : pH after sterilization
T0 : observation just after prepara~ion of th emulsion
Tl : observation after storage for 1 month at ambient
temperature
T2 : observation after storage for 2 months at ambient
temperature
+ : stable emulsion
0 : slight trace of separation, emulsion homogeneous
again after stirring
1 : incipient separation, flocculation and/or sedimen-
tation
- : distinct separation, emulsion irreversibly broken
Accordingly, it can be selen that the addition of
a quantity of 0.21% lecithin with a PC:PE ratio of 4.1~il
is not sufficient to obtain an emulsion which remains
stable after storage for one or two monthsO The addi- .-
tion of a quantity of 0.4% of a lecithin having a PC:PE
ratio of 4.1:1 is sufficient to keep the emulsion stable
for at least two months.
A nutritive composition is then prepared. An
aqueous solution containing amino acids, namely L
leucine, glycine, L-alanine and L-proline, in a total
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quantity of 6.0 g in 75 ml water is initially prepared.
81 g of this aqueous solution are added to l9 g of the
emulsion prepared as described above. The nutritive
composition obtained is sterilized for 1 minute at
126C.
The osmolality and pH of the nutritive composi-
tion before and after sterilization are determined. The
stability of the composition is also visually observed.
The following results are obtained:
Bl B2 B3 B4 B5 B6
% 0.2~ 0.20 0.16 0.12 0.08 0.04
Osmo 1 753 784 611 752 755 746
pH 1 8.01 8.09 8.08 8.16 8.25 8.35
Osmo 2 756 789 614 752 758 744
pH 2 8.07 8.09 7.99 8.02 8.21 8.33
T0 ~ + + + + o
T1 0 0 0
T2 o 0 0
% : percentage of lecithin in the final nutritive
composition
Osmo 1 : osmolality before stlerilization (in mOsm/kg)
Osmo 2 : osmolality after sterilization (in mOsm/kg)
25 pH l/pH 2 : pH before/after sterilization
T0 : observation just after preparation of the
composition
Tl/T2 : observation after storage for 1 month and 2
months at ambient temperature
+ : stable nutritive composition
0 : slight trace of separation, emulsion homogen~ous
again after stirring
l : incipient separation, flocculation and/or sedimen-
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tation
- : distinct separation, emulsion irreversibly broken
Accordingly, it can be seen that the addition of
a quantity of 0.04% lecithin with a PC:PE ratio of 4.1:1
is not sufficient to obtain a stable nutritive composi
tion. The addition of a quantity of 0.08% lecithin with
a PC:PE ratio of 4.1:1 is sufficient to obtain a stable
nutritive composition containing 20% lipids and also
amino acids, but not to keep it stable during storage
for several months.
Ex~mple 2
An aqueous phase is prepared by mixing 14.6 ml
water, 0.4 ml glycerol and egg lecithin with a PC:PE
ratio of 4.8:1 in the quantity defined in the following
Table with stirring at 4~C. 3.8 g of a soybean oil are
slowly added to the aqueous phase thus prepared with
continuous stirring, the temperature being kept at
approximately 45C. An emulsion containing 20~ lipids
is obtained in this way and is homogenized in the same
way as before to obtain an average droplet size in the
lipid phase of 250 to ~50 nm. The pH of the emulsion
thus prepared is adjusted to 7.4 with 0.5 N sodium
hydroxide solution, after which the emulsion is packed
in 100 ml bottles which are sterilized for 9 minutes at
126C.
The osmolality and pH of the emulsion are deter-
mined before and after sterilization. The stability of
the emulsion is also visually observed: ~
The following results are obtainedo
Cl C2 C3 C4 C5 C6
% 1.28 1.05 0.83 0.62 0.41 0.21
Osmo 1 333 321 331 341 341 376
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C1 C2 C3 C~ C5 C6
p~ 1 ~.26 ~.58 ~.59 5.18 5.05 6.20
Osmo 2 331 325 333 342 339 377
pH 2 5.33 5.68 6.02 5.41 5.52 5.30
T0 + + + ~ + o
Tl + + -~ + -~ -
T2 + + + 1 - -
% : percentage of lecithin in the emulsion
Osmo 1 : osmolality before sterilization (in mOsm/kg)
Osmo 2 : osmolality after sterilization (in mOsm/kg)
pH l/p~ 2 : pH before/after sterilization
TO : observation just after preparation of the
emulsion
Tl/T2 : observation after storage for 1 month and 2
months at ambient temperature
+ : stable emulsion0 0 : slight trace of separation, emulsion homogeneous
again after stirring
1 : incipient separation, flocculation and/or sedimen-
tation
- : distinct separation, emulsion irreversibly broken
Accordingly, it can be seen that the addition of
a quantity of 0.21% lecithin with a PC:PE ratio of 4.8:1
is nvt sufficient to obtain an emulsion which remains
stable after storage for one or two months. The addi-
tion of a quantity of 0.4% of a lecithin having a PC:PEratio of 4.8:1 is sufficient to keep the emulsion stable
fo~ at least one month.
A nutritive composition is then prepared. An
aqueous solution containing amino acids, namely L-
leucine, glycine, L-alanine and L-proline, in a total
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13
quantity of 6.0 g in 75 ml water is initially prepared.
81 g of this aqueous solution are added to 19 g of the
emulsion prepared as described above. The nutritive
composition obtained i5 sterilized for 1 minute at
1~6C.
The osmolality and pH of the nutritive composi-
tion before and after sterilization are determined. The
stability of the composition is also visually observed.
The following xesults are obtained:
Dl D2 D3 D4 D5 D6
% 0.24 0.20 0.16 0.12 0.08 0.04
osmo 1 797 780 627 747 746 761
pH 1 8.06 8.08 8.05 8.22 8030 8.29
Osmo 2 751 779 625 750 758 758
pH 2 8.01 8.07 8.00 8.31 8.30 8.26
T0 ~ + + + + o
Tl 0 0 0
T2 0 1 1 1 - -
% : percentage of lecithin in the final nutritive
composition
Osmo 1 : osmolality before sterilization (in mOsm/kg)
Osmo 2 : osmolality after sterilization ~in mOsm/kg)
25 pH l/pH 2 : pH before/after sterilization
T0 : observation just after preparation of the
composition
Tl/T2 : observation after storage for 1 month and 2
months at ambient temperature
+ : stable nutritive composition
0 : slight trace of separation, emulsion homogeneous
again after stirring
1 : incipient separation, flocculation and/or ~edimen-
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14
tation
- : distinct separation, emulsion irreversibly broken
The addition of a quantity of 0~04% lecithin with a
5 PC:PE ratio of 4.8:1 is not sufficient to obtain a
stable nutritive composition. The addition of a ~uan-
tity of 0.12~ lecithin with a PC:PE ratio of 4.8:1 is
sufficient to obtain a stable nutritive composition
containing 20% lipids and also amino acids.
Example 3
An aqueous phase is prepared by mixing 14.6 ml
water, 0.4 ml glycerol and an emulsifying compound with
a PC:PE ratio in the concentrations defined in the
15 following Table with stirring at 45C. 3.8 g of a
soybean oil are then slowly added to this aqueous phase
with continuous stirring, the temperature being kept at
approximately 45C. An emulsion containing 20% lipids
is thus obtained and is homogenized in the same way as
20 before. The pH of the emulsion thus prepared is ad-
justed to 7.4 with 0.5N sodium hydroxide.
A nutritive composition is then prepared. An
aqueous solution containing amino acids, namely L-
leucine, glycine, L-alanine and L-proline, in a total
25 quantity of 6.0 g in 75 ml water is initially prepared.
81 g of this aqueous solution are added to 19 g of the
emulsion prepared as described above. The nutriti~e
composition obtained is sterilized for 1 minute at
126C.
The osmolality and pH of the nutritive composi-
tion before and after sterilization are determined. The
stability of the composition is also visually observed.
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The following results are ~btained:
Remarks
~ PC/PE Osmo 1 osmo 2 pH 1 p~ 2 T0 T1 T~ SI
0.16 2.5/1 709 711 7.92 7.88 + 1 87
0.04 4.1/1 746 745 8.35 8.33 0 - -
.08 " 755 758 8.25 8.21 + 1 - 72
0.12 " 752 751 8.16 8.02 + 1 1 92
0.16 " 611 614 8.08 7.99 + 0 0 95
0.20 " 784 789 8.09 8.09 + 0 0 96 :
0.24 " 754 757 8.01 8.07 ~ 0 0
0.04 4.8/l 761 758 8.29 8.26 0 - -
0.08 " 746 749 8.30 8.30 + - - ;
0.12 " 747 750 8.22 8.31 + 1 1 89
0.16 " 627 625 8.05 8.00 + 0 l 90
0.20 " 780 779 8.03 8.07 ~ 0 1 93
0.24 " 797 751 8.06 8.01 + 0 0
0.16 6.0/1 709 709 8.02 7.82 + 1 87
0.16 8.0/1 697 698 7.91 7.80 + 1 87
0.04 10.8/1 705 701 8.00 7.89
0.08 " 694 697 8.06 8.03 0
0.12 " 702 699 8.03 7.99 0 - 34
0.16 " 679 680 8.08 8.03 + - 34
0.20 " 684 676 7.80 7.92 + - 24
0.24 " 737 736 8.1~ 7.92 ~ -
% : percentage of lecithin in the ~inal nutri-
tive composition
PC/PE : PC:PE ratio of the emulsifying compound .
Osmo 1 : osmolality before sterilization (in mOsm/kg)
Osmo 2 : osmolality after sterilization (in mOsm/kg)
. . . .:
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pH 1/pH 2 : pH before/after sterilization
T0 : observation just after preparation o~ the final
nutritive composition
T1/T2 : observation after storage for 1 month and 2
months at ambient temperature
+ : stable nutritive composition
0 : slight trace of separation, composition homogeneous
again after stirring
1 : incipient separation, 1Occulation and/or sedimen-
tation
- : distinct separation, emulsion irreversibly broken
SI O stability index
Accordingly, it can be seen that a quantity of
0.08% emulsifying compound is sufficient to keep a
nutritive composition containinq 20% lipids and having
a dry matter content of approximately 10% stable provid-
ing the emulis~ying compound has a PC:PE ratio o 2 to
10~
,, ~ .
Example 4
An aqueous phase is prepared by mixing 14.6 ml
water, 0.4 ml glycerol and an emulsifying compound with
a PC:PE ratio in the concentrations defined in the
following Table with stirring at 45C. 3.8 g of a
soybean oil are then slowly added to this aqueous phase
with continuous stirring, the temperature being kept at
approximately 45C. An emulsion containing 20% lipids
is thus obtained and is homogenized in the same way as
before. The pH of the emulsion thus prepared is ad-
justed to 7.~ with 0.5N sodium hydroxide.
A nutritive composition is then prepared. An
aqueous solution containing amino acids, namely L-
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' 17
leucine, glycine, L-alanine and L-proline, in a total
quantity of 6.0 g in 75 ml water is initially prepared~
~1 g of this aqueous solution are added to 19 g of the
emulsion prepared as described above, The nutritive
composition obtained is sterilized for 1 minute at
12~C.
The stability index of the various nutritive
compositions is determined as a function of the storage
time.
The ~ollowing results are obtained:
Stability index SI (%)
% PC/PE T0 ~1 T2 T3
0.08 4.1 76 73 77 76
0.12 4.8 94 87 86 84
0.20 4.8 85 85 85 83
0O20 10.8 55 54 54 56
% : percentage of emulsifying compound in the final
nutritive composition
It can be seen that these nutritive compositions
have a relatively constant and. high stability index
which means that they remain stable for at least 3
months.
Example 5
~n aqueous phase is prepared by mixing 14.6 ml
water, 0.4 ml glycerol and an emulsifying compound,with
a PC:PE ratio as defined in the following Table in a
concentration of 0.16% in the final composition ~0.83%
in the emulsion) with stirring at 45C. 3.8 g of a
soybean oil are then slowly added to this aqueous phase
with continuous stirring, the temperature being kept at
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18
approximately ~5C. An emulsion containing 20% lipids
is thus obtained and is homogenized in the same way as
before. The pH of the emulsion thus prepared is ad-
justed to 7.4 with 0.5N sodium hydroxide.
A nutritive composition is then prepared. An
aqueous solution containing amino acids, namely L- -
leucine, glycine, L-alanine and L-proline, in a total
quantity of 6.0 g in 75 ml water is initially prepared.
81 g of this aqueous solution are added to 19 g of the
~0 emulsion prepared as described above. The nutritive
composition obtained is sterilized for 1 minute at
126C.
The stability index of the various nutritive
compositions obtained is determined.
The following results are obtained:
Total lipids SI
PC/PE % %
0.5 4.2 25
2.5 4.5 87
4.1 4.
4.8 4.2 90
6.0 3.9 87
8.0 3.9 87 ;
10.8 401 34
~he stability index SI is determined after ;~
centrifugation for 15 minutes at 2000 r.p.m.
The stability index is relatively high except for
the compositions containing an emulsifying compound with
a PC:PE ratio that is not between 2 and 10:1. ;~
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