Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~ g~ 07 (R)
A PROCESS AND AN APPARATUS FOR PRODUCING EDIBLE
EMNLSIO~S
The pre~ent invention relatee to an apparatus and a
process for producing edible emul~ion3, particularly
oil- and water-containing emul ions such as spread3 of
the margarine-type or o~ the low-calorie-type~
Such products are conventionally produced from an
aqueous pha~e and a fat pha~e which are combined to
form a pre-emulsion which i~ ~ubjected to cooling and
te~turising treatments in order to obtain a plastic
10 product ~uch as a s~ick mar~arine or a ~ub margarin~.
The pla~tic fat product i~ automatically packed by a
packaging machine. Quite often ~he packaging machine-
breaks down or ha~ ~o be stopped for one reason or
another. In that cas~ the product is normally remelt-
ed and recircula~ed or it ha~ to be dumped. These pro-
cedures clearly have disadvantages, since as a result
of this sOmetL~eS large quantitiee of the product can
be lost or, in the ca~e where emulsions of the duplex
type, i.e. emulsions of the o/w/o-type are produced,
starting from a cream containing fat proteins and
thickeners, the character of ~he emulsion i~ strongly
af~ected owing to changes occurr~ng in the sen~itive
structures (e.g. particle ~ize of the dispersed phase)
and pha~e inversion may occur, resulting in emulsions
of a different type than originally int~nded (o/w in-
stead of w/o emulsion~). Loss of oil from the dispersed
cream may al~o occur. Also a problem may arise due to
the variou~ amounts o recircula~ed product (10-100~)
encountered in standard margarine processing.
Applicants have found a process and an apparatus which
alleviate the above-mentioned problems to a great ex-
tent.
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According to the invention there is provided a process for
producing an edible oil- and water-containiny emulsion, which
comprises (i) processing by heat-exchanye, cooling, cr~stallizing,
homogenizing or pasteurizing individual phases of the emulsion,
(ii) separately recirculating back into its respective container
at least part of each of the individual phases of the emulsion;
(iii) mixing the processed phases of the emulsion to obtain the
final emulsion.
The individual streams of components of the emulsion may comprise
an aqueous phase or a fat phase or an oil- and water-containing
emulsion, preferably an oi1-in-water emulsion (cream).
Preferably, at least one of the individual streams of components
consisting of e.g. an aqueous phase is processed through one or
more heat exchangers,wherein pasteurisation takes place or
cooling is effected to achieve a temperature somewhat higher,
equal to or lower than the temperature at which the fat used for
producing the emulsion starts crystallizing. Cooling is
preferably carried out to achieve a temperature within the range
of -10 to 15C.
One or more aqueous phases may contain a viscosity increasing
agent, such as a gelling agent, a thickening agent or a protein,
whereas another aqueous phase may be non-gellable.
Preferably, at least one of the individual streams of components
consisting of a fat phase is processed through a heat exchanger
and/or a fat conditioning system in which fat crystal nucleation
and fat crystal growth occur. One of the individual streams of
components may consist of a water- and oil-containing emulsion
which is processed through a heat exchanger (in which inversion
may take place).
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Accordirlg to a pre0rred embodiment of ~he pre~ent in-
vention
(i) an individual component tream consisting of an
oil-in~water 0mulsion and an individual component
stream consisting of a fat phase are separately
p~ocessed;
(ii) at least part of the oil-in-water emulsion and at
least part of the fat phase are recirculated;
(iii) said processed oil-in-water emulsion and fat
phase are mixed to obtain an oil-in-water-in-oil
emul3ion.
For instance, in case of breakdown of the packaging ma-
chine, the individual stream~ of emulsion components
consisting of the atty phase(s) and the aqueous phase(s)
of the emulsion are separately recirculated, preerably
via heat-exchangers, to their respective containers,
from which they can be reintroduced into the system,
preferably via a common proportioning pumpO
The individl~al recirculating streams are usually con-
stantly in operation at a low rate of recirculation to
keep the mechani$m at the readyO
The present invention also relates to an apparatus which
is useful for producing edible multiple-phase emulsions,
particularly oil- and water-containing emulsions of the
margarine or low-fat-spread type.
The apparatus in it~ ~implest form comprises:
means (A) for processing individual streams of compo-
nents of the emulsion;
means ~B) for separately recirculating each of the com-
ponent~ of t~e emul~ion;
means (C) for mixing the proce~sed individual streams of
components of the emulsion.
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Means (A) may con~ist of one or more heat-e~changers
and/or one or more fat cond.itioning sy~tems in which fat
cry~tal nucleation and growth occur. Means (A) prefer-
ably con~ist~ of one or more scraped-surface heat-
^j 5 exchanger~ and/o~ one or more crystallizer units, e.g.Votator A~ and C-unit~ as described in "Margarine" by
Ander3en and Williams, Pergamon Pres~, 1965.
Means (B) may comprise valves directing the individual
~tream~ through either a recirculation loop (which may
compri~e a he~t-e~changer) to eparate containers or to
means (C), which may comprise a static mixer, a scraped-
surface heat-~xchanger, a crystallizer unit, a homogen-
izing valve, optionally driven by a high-pre~sure hy-
draulic pump, or combinations thereof. Means 5B) prefer-
ably consist in ganged valves.
Mean~ (C) are preferably connected to a sensory unit,
for instance an electric conductivity meter, enabling
checking of the quality of the emulsion produced, and ~o
a valve dir~cting ~aid emul~ion to either the packaging
machine or to dump.
The mi~ing unit ~C) i8 most conveniently a low-capacity
mixer (0.5 to 20 litres), ~o that in the ca~e of mate-
rial having to be dumped the los of material i~ mini-
mized.
The advantages of the proces~ and apparatus according to
the invention can be ~ummarized as follows: .
(1) By having provision to recirculate the oil phase(s)
and the aqueous phase( 8) a~ individual separate stream(s),
followed by a volume~rically relatively small mixing de-
vice, 108~ of material due to overworking in a standard
Votator on hold-up i~ eliminated or at lea~t greatly re-
stricted.
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(~) Possible problem~ cau~ed by varying amounts o re-
circulatecl (reworked) product (L0-100~), encountered in
standard processing, are eliminated since in the present
inven~ion, instead of the product itself, individual
streams of product-components are recirculated.
(3) Products with delicate structures (e.g. thi~otropic
aqueous phases) can be handled.
(4) Products produced from mul~iple, differently formu-
lated aqueous phases which should not be intermixed can
be processed.
The invention will now be illustrated in the following
examples and drawing.
E~ample 1
In this e~ample an apparatus according to the invention
is illustrated. The numeral3 refer to the figures appear-
ing in the appended drawing.
The apparatus comprises in its simple form:
~A) a container (1), from which e.g. an aqueous phase (w)
can be dispensed, a valve (2) directing the flow of
aqueous pha~e to a 5 1 mixing unit (7) or through a re-
circulation loop (4) leading to the con~ainer (1);
(B) a container (2), from which e.g. a fat phase can be
dispensed, a valve (6) directing the flow of fat phase
to a mixing unit (7) or to a recirculation loop (8)
leading to fat phase container (53.
In a more sophisticated apparatus, which is appropriate
for producing spreads, container (1) and container (5)
are preferably connected to a common proportioning pump
(10).
The aqueou~ phase is processed through heat-exchanger(s)
(9), whereas the at phase i 8 processed through a series
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of Votator A- and C-units (12), wherein the fat i8 pre-
crystallized.
Valves (2) and (6) ar~ ganged valves. Recirculating loops
(4) and (8) comprise heat-exchangers (3) and (13) re-
spectively.
Mixing device (7) i5 connected to an electric conducti-
vity meter (11). Through valve (14) the emulsion is
directed to either a packaging machine or to dump.
Example 2
In this example the production of an o/w/o-emulsion
using the proce3s according to the inventisn i8 illus-
trated.
Using the apparatus illustrated in E~ample 1, an o/w/o-
emulsion was produced fxom a cream (i) containing:
11.0% of fat, 0.08~ of K-sorbate, 20 43% of whey pro-
tein, 1,0~ of carboxymethylcellulose and 56.49~ of water,
pH 502.: and a fat phase (ii), containing 28.37% of fat,
0.6% of monoglyceride and 0.03% of colouring agent.
The fat phase (ii) was cooled to 0C and the cream phase
(i) to 5C before final mixing in a Votator C-unit ro-
tating at 1000 rpm.
Individual stream~ of 'che components of the emulsion were
constantly recirculated at a low rate.
The emulsion obtained was of the o/w/o-type, having
cream drops of an average diameter of about 8 microns,
disper3ed in a continuous fat phase. Very little or no
1038 of oil from the dispersed p~ase had occurred.
The electric conductivity was about 0.2 micro S cm~l.
