Note: Descriptions are shown in the official language in which they were submitted.
~0'7~'735
This invention relates to a process ~or the production
of an edible product based on vegetable proteins, especially
soya.
In the search ~or edible products based on vegetable
proteins which may be eaten in the guise of meat, ef~orts
have been concentrated on the composition, appearance9
taste and texture o~ the product. It is above all the last
of these various aspects which has been responsible for
the development o~ the main techniques used at present,
namely cooking-extrusion and spinning. However, in view o~
the relative imperfection of the results obtained by the
first technique and the e~treme complication of the second,
other avenues have been explored more or less successfully.
One recent known process for example comprise~ rolling an
aqueous protein paste and crimping the sheet obtained in
such a way that it has a quantity of small tight parallel
folds, which, in the mouth give the impression that a
fibrous product is being chewed. Agglomerates are ~ormed
from these sheets, which are extremely rich in proteins
but which hardly contain more than 1 /0 o~ fats, either by
folding them or by stacking them and then bonding them
together by means o~ an edible binding mixture rich in ~ats~
The number of operations involved in considerab]e. Some of
the operations involved, especially crimping, are fairly
dif~icult. In ether known processes, the product is given a
laminar ~tructure. In one such process, a layer o~ protein
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~0'73735
pregel is alternated with a l~yer o~ dough, the sandwich is
rolled out, folded around a layer of bind~r, rolled out
again and so on This elaborate technique i9 reminiscent of
the technique used for producing millefeuill~ in con~ectionary.
In another traditional process for producing an oriental
product known as yuba, soya milk is heated in a shallow
container, the skin formed on the sur~ace o~ the milk is
periodically removed, hung up to dry in air, the dried sheets
are soaked in a stock, stacked in a pile, the pile thus ~ormed
is made into a roll, the roll is secured and then steam-cooked.
This skilled process calls ~or considerable care and ef~ort
and cannot readily be carried out on a commercial scale.
Still on the subject of laminar products, re~erence may
also be made here to the technique which comprlses preparing
flakes o~ vegetable protein by drying a vegetable milk on
cylinders and grinding the sheet obtained in a mill. These
flakes may then be mixed with an aqueous emulsion o~ ~ats.
They are rehydrated during mixing and give the impression of
small pieces of meat in the imitation meat pate thus obtained
The present invention provides the possibility o~ producing
; by means of a very simple apparatus, ~rom starting materialsthat are easily prepared and with a minimum o~ ope~ions a
completely new product based on vegetable proteins which is
distinguished ~rom all known products by the quality of its
texture and its appearance and its taste.
According te the invention a layer o~ an aqueous colloidal
suspension o~ ~egetable proteins and ~ats is ~ormed on a heated
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1~'73'7;~5
surface, the layer o~ su~pen~ion on thiY ~urface is dried
to form a coherent film, the film thus ~ormed is removed
from the heated surface and moistened, layers of the
moistened film are ~tacked one on top of another, the layers
thus stacked one on top of another are compressed and the
compressed pile thus formed is cooked.
The process according to the invention is flexible, by
comparison with the crimping process for example, inso~ar as
the composition o~ the colloidal suspension may be ~aried
within wide limits. In particular, it may ha~e a high fat
content. In this way, it is possible directly to obtain a
complete product without any need ~or fats to be subsequently
incorporated either by way of a fatty binder or during an
additional treatment, such as frying for example~ The process
according to the invention is advantageous and reliable by
comparison with the process for producing yuba for example
because it may readily be carried out on a commercial scale
and comprises only a minimum o~ operations~ Finally, if the
gustative qualities which the above-mentioned paste based on
flakes of vegetable proteins dipped in ~at for example is
required to show are considered by way of comparison, the
process according to the invention gives surprising results.
The product which it enables to be obtained shows remarkable
qualities of texture, appearance and ta~te and equally
remarkable eating qualities. It has been found that, during
cooking of the pile, the films may become locally welded to one
another. They can form in one plane ~ones o~ homogeneous, ~irm
flesh which alternate with free zone~ and in space a network of
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links of meat containing small flattened air bubbles. The
expression "flaky texture" is used hereinafter to describe
this type of texture which is not unlike that o~ a good,
firm crumb of fresh bread for example. This network o~
flattened links of meat may be more or less dense or more
or less branched depending upon the quantity of water which
~; is incorporated in the pile as a result o~ moistening and
upon the degree of compression of the pile. The impression
which a slice or piece cut from this fine meat may create
when eaten may range from a crumb of bread to the meat
preparations known as Italian cheese ~ia roast veal in the
direction of increasing moisture content.
To carry out the process according to the invention, the
colloidal aqueous suspension may be prepared from whole
vegetable seeds or from a standard commercial grade vegetable
flour, such as defatted soya ilour for example. In the
second case, the fat is added to the suspension. An animal
fat, a vegetable oil or a hydrogenated vegetable ~at may be
used for this purpose. The colloidal suspension prepared
preferably has a dry matter content of from 10 to 30 % by
weight and, in /0 by weight of dry matter, contains from 3
to 65 % of fats and from 35 to 90 /0 of proteins.
In cases where the colloidal aqueous suspension is prepared
-~rom whole grains, they may optionally be hulled, crushed and
ground in the presence of water in a colloidal mill. The
suspension obtained may even be refined in a hammer mill for
example before removing a solid residue by centrifuging.
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~073735
There~fter the antitryptic ~actor may be destroyed by brief
heating at a very high temperature, ~or example by injecting
steam. The suspension may be homogenised a~ter concentration
or after purification by isoelectric precipitation for example
which enables the flatulent sugar content to be reduced. It is
also possible to keep the solid residue left after grinding in
the presence of water rather than removing it by centrifuging
which enables most of the constituents o~ the grain to be
utilised whilst at the same time maintalning the possibility
of reducing the flatulent sugar content. Homogenisation of
the suspension is highly recommended because it facilitates
formation of the coherent film during drying.
In cases where the colloidal aqueous suspension is
prepared from a vegetable ~lour rich in proteins, such as a
defatted soya flour for e~ample, the ~lour may be suspended
in water by means of a mixer, the antitryptic ~actor may be
eliminated by brie~ly heating the suspension to elevated
temperature and, optionally a~ter puri~ication by isoelectric
precipitation, the intended ~ats may be added to the protein
suspension, followed by homogenisation of the lipido-protein
suspension thus obtained.
It is also possible to add to the lipido-protein suspension
colorants, aromas, aroma precursors, aroma strengtheners and
other standard edible additives ~or providing the product with
particular nutritive, gustative or keeping properties.
A heated surface which has proved to be particularly
practical for carrying out the process according to the
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~t7;~35
in~ention is that of a drying cylinder. The number o~
cylinders, their dimensions, the width of the gap between
two adjacent cylinders, the speed o~ rotation o~ the
cylinders and the temperature o~ their surfaces may all
be varied within wide limits. For example, it is possible
to use a dryer comprising two cylinders o~ whiGh the
directions of rotation converge downwards at the nip
separating them. In cases where a dryer o~ this type
is used, the cylinders may be heated to a temperature of
from about 120 to 160C, the depth of the pool of liquld and
the width of the gap between the-cylinders may be ~ixed
within the usual limits for this type of apparatus and
the cylinders may be rotated at such a speed that the
drying time is between about 2 seconds and 12 seconds.
- The coherent film ~ormed by the colloidal suspension
I dried on the heated sur~ace may be detached by means of a
¦ doctor which is particularly well adapted to the surface in
! question. The film may be detached from a drying cylinder
for example by applying a straight-edge doctor at a certain
angle against its surface parallel to its axis. In cases
where a two-cylinder dryer o~ the kind described above is
used for e~ample, one doctor may be applied against each
of the two cylinders on the side opposite the gap separating
them The detached film may have a residual moisture content
of the order of 2 to 15 %~by weight.
The detached ~ilm may be moistened by spraying water onto
it or by passing it through a stream o~ steam for example.
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10'73~;~S
The film may be moistened in such a way that it has a moisture
content of from 10 to 90 o/O by weight. The ~ilm may also be
drawn in order to thin it out or to perfect its structure.
It is possible either to stack separate sheets o~ the ~ilm or
to wind onto a support several layers of a continuous ribbon
of the ~ilm for example. In cases where a cylinder dryer is
used, the detached film may be collected and wound onto a
rotary cylinder arranged parallel to the drying cylinder. In
this case, the film may be moistened during its travel between
the drying cylinder and the winding cylinder or during its
windingO In cases where it is desired to spray water onto the
film being wound, it is of advantage to use $or this purpose
at least one flat-jet nozzle so that the ~ilm i9 mOiSterled
homogeneously over its entire width. Water with a temperature
of from 5 to 90C is preferably used for moistening. Colorants,
aromas, aroma precursors, aroma strengtheners and other standard
edible additives may be added to the water Por providing the
product with particular nutritive, gustative or keeping
properties.
The superposed layers of film may be compressed by applying
a pressure to the pile or, in the case of winding, by causing
the winding cylinder to rotate at a higher peripheral speed
than the drying cylinder. In the latter case, the film may
simultaneously be drawn by applying sufficient traction to it.
Stacking or winding is preferably continued in such a way that
a total thickness of the superposed, compressed layers of from
about 0.5 to 10 cm is obtained. In the case of winding, the
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mass obtained may be separatea by cutting it along a
generatrix o~ the cylinder and then spread ~lat.
The compressed pile of moist flaky mass may be cooked in
different ways including, for example, cooking with steam in a
chamber at atmospheric pressure, cooking in a water bath at
temperatures of from 65 to 100C, cooking in an autoclave at
temperatures o~ ~rom 100 to 140C, or cooking in a microwave
oven. Cooking times of less than 1 hour and cooking temperatures
above 60C are preferred. For cooking methods such as the
first three mentioned above for example, it is advisable to
cook the mass in a protective wrapping or container, an
optionally sealed polyethylene or polycarbonate bag for example,
which throughout cooking con~erves or maintains the moisture
content of the product at a le~el similar to that which prevailed
before cooking. It is also possible to combine moistening and
cooking, for example in cases where moistening is carried out -
with steam and in particular when a continuous film is moistened
with steam before bein~ wound onto a cylinder.
Accordingly, it is possible by the process according to the
invention to obtain a product which, after the cooking stage, is
in the form of a wet mass with a flaky, cellular structure.
In cases where a soya-based material is used as the starting
material, it is possible to obtain a product which has a fine
natural clear colour, reminiscent of that of a crumb of brown
bread, coupled with a neutral and appetising taste and odour
completely free of any trace of the bitter bean taste ~hich
often indelibly marks soya-based products.
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The product obtained by the process according to the
invention may be consumed in many di~erent ways ei-ther fresh
or after preserving treatments, such as dehydration, deep-
freezing or sterilisation in cans with or without sauces or
vegetables for example with which it combines excellently.
I~ cases where the product obtained by the process according
to the invention is to be eaten fresh9 it is possible ~or
example to cut 0.5 to 1 cm thick slices with the grain of the
mass and to saute them in a frying pan. Be~orehand the slices
may if desired be salted, soakea in salt water or coated with
; egg or breadcrumbs for example. The slices thus prepared can
easily be cut with a table knife into juicy, succulent pieces
reminiscent of omelette, Italian cheese or roast veal for
example, depending upon the moisture content o~ the mass and
the method of preparation used ~or the slices.
; The invention is illustrated by the following Examples,
in which the percentages quoted are percent by weight.
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3'735
EXAMPLE 1
, ~
20 kg of hulled, rough-ground soya beans with a dry
matter (d.m.) content o* 9? /0 are ground ~or 20 minutes
~ in the presence of 140 kg of water in a Polytxon colloidal
mill turning at 2000 revolutions per minute, The suspension
obtained is re~ined by two suceessive treatments in a
Fitzmill hammer mill which rotates at 6000 rpm and which is
provided with a o.6 mm wire for the -first treatment and with
a 0.3 mm wire ~or the second treatment. A~ter the operation~
the suspension has a pH-value o~ 6.5.
A solid residue o~ the suspension ~cellulosic ~ibres7
polysaccharides and substantially insoluble proteins3 is
separated by centrifuging in a WESTFALIA sludge remover.
30 kg of wet residue are thus obtained and dlscarded. The
soya milk is then heated at 140C ~or 60 seconds by the
; injection o~ steam, followed by cooling to ambient temperature.
134.4 kg of milk with a dry matter content of 7.2 % are obtained
in thi 9 way.
The milk is acidified to pH 4.6 by the addition o~ 10 %
hydrochloric acid. The preci~itate obtained is eeparated by
centrifuging in an ALFA LAVAL plate centrifuge. The serum,
which primarily contains the soluble carbohydrates (succrose,
stachyose and raffinose), is discarded. The pH o~ the
precipitate (38.5 kg3 is adjusted to pH 6.6 by the addition
o~ 10 % sodium hydrogide. The suspension is homogenised by
being passed twice, first at 250 and then at 50 kg/cm2, through
a MANTON GAULIN homogeniser. On completion of the operation,
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10'~3735
40 kg o~ suspension are obtained with a d.m. of 20.5 ~ o~ which,
expressed in perc~n-t by weight o~ dry material, 55 /0 are proteins
and 30 /0 are fats.
This suspension is dried on an ESCHER WYSS dryer with
two cylinders 60 cm long and 35 cm in diameter. The speed
of rotation o~ the cylinders is adjusted to 11 rpm, the steam
pressure inside the cylinders to 2.4 atms gauge and the gap
between the cylinders to 0.75 mm. The depth of the pool of
suspension is kept at 20 cm~ A dry film substantially 60 cm
wide is obtained.
The dry film i9 wound successively around a cylinder 1 cm
long and 20 cm in diameter driven by a variable speed motor.
The speed of rotation of the cylinder is adjusted in such a
way that the ~ilm is constantly under tension.
Water is sprayed on$o the ~ilm as it is being w~und onto
the cylinder by means of two flat jet nozzles of the spraying
system type fed under a pressure of 1.5 atms gauge. The
process is continued until the total thickness o~ the superposed
layers on the cylinder reaches 3 cm. The mass obtained has a
moisture content of 61 /0. The mass is separated ~rom the
cylinder by cutting it along a generatrix of the cylinder.
The wet flaky mass is then in the -~orm of a slab measuring
approximat01y 60 x 60 x 3 cm. It i9 placed in a bag o~ sealed
plastics material. The whole is cooked in steam in a chamber
at atmospheric pressure. The temperature at the centre o~ the
slab reaches 98C a~ter about 20 minutes. The slab is
withdrawn from the chamber after about 30 minutes. The
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~073~S
cooked mass has a flaky, aerated texture with a neutral
flavour.
EXAMPLES 2 to 11
A colloidal suspension is prepared in the same way as
described in Example 1. The colloidal suspension thus prepared
has a d~m. of 20.5 % of which, in percent by weight of dry matter,
55 % are proteins and 30 /0 are ~ats. This suspension is
dried on a two-cylinder dryer in the same way as described
in Example 1. 10 di~ferent cooked slabs measuring approximately
60 x 60 x 3 cm are then prepared in the same way as described
in Example 1 except for one or two differences which concern
the moistening process or the cooking process. With one
exception, all the products obtained have a ~ine clear flesh
anda neutral flavour although they do dif~er ~rom one another
according to the circumstances, above all in their more or
less dense texture. The moistening and cooking conditions
and the characteristics o~ the texture of the masses obtained
are shown inthe following Table:
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~0'~3~735
! ~ . . __
Ex. Moistening Cooking
No _
. medium moisture medium Itemp time Texture
. . /~ . . . _ C mins _ __ __ __ ___
2 water 20 chamber lO0 3o flaky and aerated
3 water 40 chamber lO0 3o
l water 60 chamber 100 3o ~'
4 water 80 chamber 100 3o dense, compact
slightly aerated
water 60 autoclave 14~ 15 dense, compact
hard dark brown
colour
6 water 60 water-bath 65 3o ~laky, relatively
7 water 60 water-bath 95 3o ,.
8 water 60 oven 5 ............. ..
9 steam 20 chamber100 3o ~laky and aerated
steam 60 3o ~laky, relativelY
ll water 60 ohamber100 30 _Lab dense
This Table prompts the following commentsl reminders
or additional information:
- in the column headed "moistening medium'l 9 the term
"water" implies the spraying of water through two ~lat
jet nozzles onto the film in the process of being wound,
whereas the term "steam" implies that the ~ilm passes
over a stream o~ saturated steam at atmospheric pressure
during its travel between the drying cylinder and the
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107;~35
winding cylinder.
- in the column headed "moisture", the figure quoted
represents the total moisture content of the slab be~ore
it is cooked.
- in the column headed "cooking medium1', the term "chamber"
means that cooking takes place in the steam in a chamber,
whilst the term l'microwave oven" means that cooking
takes place in a microwave oven with an outpu$ o~ 4 KW.
- in the column headed "texture" the arrow implies that
the texture of the product changes progressively from a
flaky aerated te~ture to a dense, compact and slightly
aerated texture in the course of an increase in the
moisture content from 20 /0 to 80 /0 in stages of 20 /
- In Example 10~ the treatment with steam is such that
the temperature of the mass reaches 80C on the winding
cylinder. Examination of its te~ture proves that it
ha~ undergone the transformation due to cooking,
Accordingly, the cooking stage is completed on the
cylinder itself.
- In Example 11, the mass is cooked in a metal mould9
whereas in Examples 1 to 9 the mass is cooked in a
sealed bag o~ plastics material.
EXAMPLE 12
20 kg of rough-ground soya beans are treated in the
same way as described in Example 1, except that the solid
residue is not separated from the suspension after grinding
in the presence of water. 83 kg of suspension with a d.m.
:
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~10'73~S
of 17.5 % are obtained The ~uspengion is dried and the ~ilm
is wound in the same way as described in Ex~ ple 1. The
~ilm is moistened during its winding by spraying water
through two flat jet nozzles in such a way that the mass
of wound iilm has a total moisture content o~ 60 /0. The
mass is separated from the winding cylinder by cutting it
along a generatrix of the cylinder. A mass in the ~orm of
a slab measuring approximately 60 x 60 x 3 cm is obtained
and is placed in a bag o~ plastics material. The slab is
cooked in its bag ior 30 minutes with steam at atmospherie
pressure in a chamber. A cooked mass with a fine clear
colour and a neutral flavour is obtained with a relatively
dense flaky texture. This mass proves to be slightly ~ibrous
and gritty when chewed.
EXAMPLE ~
20 kg of rough-ground soya beans are treated in the
same way as described in Example 1. After the suspension
has been heat-treated, it is not subjected to isoelectric
precipitation, but instead is directly concentrated in vacuo ~-
by means of a heat exchanger with a scraped sur~ace until it
has a dry matter content o~ 20 /0. The suspension is homogenised,
dried and the ~ilm obtained is wound onto a cylinder in the
same way as described in Example 1. The film is moistened
and the slab obtained is cooked in the same way as described
in Example 12. A clear mass with a neutral flavour is obtained
with a relatively dense, ~laky texture.
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~()7373S
EXAMPLE 14
20 kg o~ de~atted soya ~lour with a d.m. ol 88 ~0
(Soya~luf~ W 200, a product o~ CENTRAL SOYA) are suspended in
152 kg of water using a blade mixer. The suspension is
heated at 140C ~or 50 seconds by the injection o~ steam and
then cooled to ambient temperatureO It is then acidified to
pH 4.6 by the addition o~ 2.4 litres o~ 10 ~0 hydrochloric acid.
The precipitate obtained is separated by centrifuging in a
A
WESTFALIA sludge remover. The serum is clarified by
centri~uging in an ALFA LAVAL plate centrifuge. The two
precipitates thus obtained are com~ined and neutralised
to pH 6.6 by the addition of 1.8 litres of 10 /0 sodium
hydroxide. On completion o~ the operation, 65.7 kg of precipitate
with a d.m. oY 14.2 /0 are obtained.
32.8 kg of the neutralised precipitate are mixed with
2.2 kg of soya oil and homogenised in a MANTON-GAULIN
homogeniser. 35 kg o~ a lipido-protein emulsion with a d.m.
of 19.5 % are thus obtained, the lipids representing 31.4 %
o~ the total dry matter.
The suspension is dried and the film obtained is wound
in the same way as described in Example 1. The ~ilm is moistened
and the slab obtained cooked in the same way as described
in E~ample 12. A clear mass with a neutral ~lavour is obtained
with a relatively dense, flaky texture. This mass proves
~5 to be slightly ~ibrous and gritty when chewed~ By slightly
increasing the proportion of fats in the suspension,
a mass of smoother appearance and texture is obtained.
~ fr~de /Y)~rl~
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1~73~35
EXAMPLE 15
The procedure is as described in Example 14, except that
2.2 kg of hydrogenated peanut $at ~re used instead of the 2.2 kg
of soya oil. The pro~uct obtained has the same properties
and characteristics as the product obtained in Example 14.
EXAMPLE 16
The procedure is as described in Example 14, egcept that
2.2 kg of lard are used instead of the 2.2 kg of soya oil.
The product obtained has the same properties and characteristics
as the product described in E~ample 14.
EXAMPLE 17
20 kg of horse beans (vicia faba) with a d.m. of 88 /0, .,
of which 1.5 /0 are fats, are rough ground and then fine ground
in the presence of water in the same way as described in
Example 1. Before homogenisation, 1 kg of soya oil is added
and 17.2 kg of an emulsion with a d.m. of 19.7 /0 are obtained.
The suspension is dried and the film obtaine~ is wound onto
a cylinder in the same way as described in Example 1. The
film is moistened and the slab obtained is cooked in the manner
described in Example 12. A greyish brown mass with a soft,
fruity flavour and a flakyS aerated texture is obtained.
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