Note: Descriptions are shown in the official language in which they were submitted.
t7~
Thls invention relates to soybean products for human
consumption.
The need to utilise vegetable protein directly for
human food is widely acknowledged and it is also qenerally
known that soybeans contain a high proportion of protein
and a valuable oil content.
Soybean crops are grown in very large tonnages in many
regions of the world. However, the major proportion of the
world soybean crop is used for the extraction of oil with
the consequent production of huge tonnages of defatted soy
meal or cake. Most of this meal or cake is used as
stockfood.
Defatted soy meal, while high in protein, has an
unacceptable flavour for use in human food, having a strong
beany or bitter flavour and only as the result of expensive
and capital-intensive further processing can this meal be
converted into forms which are more acceptable to human
taste. Even so~ a residual beany flavour usually persists
which substantially reduces its consumer acceptance.
In some cases where the meal is intended for human
consumption special steps are taken in the oil extraction
and associated steps to improve the flavour, however the
resultant meal still suffers to some degree from the above
mentioned disadvantages.
If whole soybeans are simply ground to a meal or
flour, the flavour is objectionable being described as
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7~:3~ 3
"green", "painty" and "raw" such 1avours being a
consequence of the enzymatic activity in the full-fat soy
flour so prepared. What is more, raw soybeans or flour
prepared therefrom contain certain anti-nutritional factors
which affect digestion and absorption of food. It has been
proved that it is very important to reduce substantially
such factors in such soybean products for human consumption.
Since the mentioned anti-nutritional factors are
rendered inactive by heat, it has become common practice to
subject soybeans to heating, for example, toasting, and a
similar toasting process is used to improve the nutritional
quality of defatted soy bean meal or flakes after
extraction of soybean oilsO However we observed that all
commercially available full fat soy flours or defatted soy
flours which we have examined still have a noticeable
"beany" or "bitter" flavour and therefore are generally
unsuitable for human food unless used as a very low
proportion ingredient in food and/or used in conjunction
with flavouring substances which will hide the
"objectionable" flavours.
Mustakas et~al (U.S. Patent 3,290,155) have described
a process for producing a superior full-fat soy flour usin~
dehulled full-fat soy bean flakes or grits as a raw
material in conjunction with a screw-type extruder in which
the soy material is heated to 115-145~C under a
dynamic pressure of 375-400 p.s.i. so as to expel from the
soybean flakes as much soy bean oil as can be resorbed by
the flakes on release from the pressure zone. Even with
the use of such specialised equipment, we observe that the
full-fat soy flour still has the mentioned beany flavour,
which carries over into food products prepared therefrom
Further methods are described in the prior art whereby
use of elevated temperatures on pre-hydrated soyabeans
results in slightly improved edible properties. (Tussaud in
UX Patent 364,309 used the action of sulphur dioxide at a
temperature of 110C-140C for 25-40 minutes on
soybeans which had been soaked in about 2 1/2 times their
weight of water resulting in a final moisture content of 4
1/2%). Other methods use live steam in contact with whole
or dehulled and split soybeans for periods of time, such as
25-40 minutes at 100C or about 5-10 minutes at an
elevated steam pressure and a temperature well in excess of
100C but typically 120C-130C. We have observed
that the resultant products display a noticeably beany
flavour whicb limits their use to very low percentages of
use in a food product.
In the preparation of many foods it is desirable to
add extra protein of high quality. Many of such foods
contain fats or oils. Full fat soy flour normally contains
about 40~ of protein and about 18-20~ soy bean oil. Soy
bean oil is of hiqh quality and includes a high proportion
of unsaturated fatty acids a characteristic which is
--4--
considerecl pre:Eerable for health reasons over more
saturated fats.
In consequence it would be highly desirable if
soy flours could be added to foods in any desired
proportion without encountering the problem of off-
flavors referred to and without the necessity of
adding supplementary flavoring substances for the
purpose of masking objectional flavors.
The invention resides in a method of processing
soybeans, which comprises the steps of:
(a) treating dehulled soybeans (1) with live
steam or water under atmospheric pressure, the soybeans
being held at temperatures from 85 to 100CC for
2 1~2 to 20 minutes; or (2) with live steam under
pressure in excess of atmospheric pressure or hot
water under steam pressure in excess of atmospheric
pressure, for a time period sufficient to avoid
green, painty or raw flavors developing in the
soybean product on storage but short enough such
that beany or bitter flavors do not develop in the
product; and
(b) compressing the beans as they exit from
step (,a) to flatten them and form a p~urality of
cracks or fissures throughout the beans while allowing
the beans to cool.
The invention further resides in a method of
processing soybeans, which comprises the steps of
treating dehulled soybeans with live steam or hot
- 5 -
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water under atmospheric pressure, the soybeans being
held at temperatures ranging from 85 -to 100C for
2 1~2 to 20 minutes; thereafter compressing the
soybeans to flatten them and form a plurality of
cracks or fissures throughout the soybeans while
allowing the beans to cool; subjecting the flattened
soybeans to extraction by water to remove a substantial
proportion of oligosaccharides therefrom; and
thereafter reducing the flattened soybeans to a flour,
meal or grits.
The invention still further resides in a method
of processing soybeans, which comprises treating
dehulled soybeans with live steam under pressure in
excess of atmospheric pressure or hot water under
steam pressure in excess of atmospheric pressure,
the -treatment being continued for such a time period
as to avoid green, painty or raw flavors developing
in the soybean product on storage, the treatment
being short enough that beany or bitter flavors do not
develop in the soybean product; thereafter compressing
the soybeans to flatten them and form a plurality
of cracks or fissures throughout the soybeans while
allowing the beans to cool; subjecting flattened
soybeans to extraction by water to remove a substantial
proportion of oligosaccharides therefrom; and
thereafter reducing the flattened soybeans to a
flour, meal or grits.
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The invention also resides in PSM (processed
soy material) produced in accordance with the men-tioned
process.
The beans are reduced in size for example by
rolling as they exit from the steam treatment. The
reasons for this are that the cooling of the beans
is facilitated and the beans are softer when they are
steaming hot so that less energy is needed for size
reduction. Additionally, it is more economical
and quicker to carry out a subsequent drying step
(where this is required) after the beans have been
so reduced in size.
If the beans are dehydrated after steaming
it may be necessary to further pulverise the material
after dehydration depending on the physical form and
the ultimate use of the material. This further
pulverising operation is very simple to carry out
and because the beans have already been partly
pulverised immediately after steaming only low energy
consumption is involved in further pulverising
operations.
A further advantage is that less heat is
generated during grinding because the beans have
already been partly pulverised.
For certain applications or for certain market
areas it may be desirable to remove a substantial
proportion of the oligosaccharides from soy beans,
especially stachyose and rafEinose. This operation
7 -
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may be easily incorporated into the process after
the compression step in which the beans are compressed
by passing them between smooth rollers in a roller
mill set at a gap of 0.6 - 1.0 mm. The beans will
exit from the mill in a well flattened out but in
otherwise intact form.
The flattened beans while still hot may be
subjec-ted to the percolating and extracting action of
water, preferably hot, either on a batch basis, or
preferably in a continuous operation for example by
counter current ex-traction. The use of a basket
~ centrifuge or a con-tinuous centrifuge is a convenient
final step before drying. Because the beans have
been reduced in thickness and have a sintered
structure induced in them as a consequence of the
hot rolling operation, the soluble oligosaccharides
are readily eluted~ The flattened beans remain
intact. The extracted soybeans may then be further
pulverised and/or dehydrated as described, or may
be used directly in the preparation of other food
products.
When processin~ c~ PSM is carriecl out at 100C,
a treatment time of 7-12 minutes is preferred for
many applications. However, where considerable
further heating may be involved in the manufacture of
the ultimate food product in which PSM is a significant
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.. . . . , .. , . , , . . .... . .. , . . . ,, . .. . . ,_
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component, a period of treatment at 100C in steam of
2 1/2 - 5 minutes is preferred. This is because
there exists the po-tential for contained PSM to
develop to a degree some beany or bitter flavors
if the food product in which the PSM is a component
is held at an elevated temperature for an excessive
period of time.
With regard to use of steam under pressure,
examples show that to achieve an equal degree of
blandness in the PSM as is achieved at 2 1/2 -
20 minutes at 100C, the period of treatment is
considerably shortened. Thus, treatment of dehulled
split soybeans for 2-2 1/2 minutes at 135C
(103 X 10 N/m tl5 psi) gauge) is about equivalent to
20 minutes at 100C.
If it is desired to use steam under pressure,
it will be necessary to carry out test runs to
determine the
- 8a -
124'7~2~
duration oE heat treatment in live steam under a particular
pressure (i.e. at a particular temperature in excess of
100C) which will result in the desired bland tasting
product. The treatment will need to be long enough to
avoid green, painty or raw flavours de~eloping in the PSM
on storage, but short enough so that beany or bitter
flavours do not develop in the PSM.
It will be apparent to persons skilled in the use of
pressure steam treatments that a wide range of temperatures
may be achieved according to the pressure of steam used.
person of reasonable skill will be able to establish by
preliminary tests based on the experience recorded herein,
a temperature (pressure)/time combination which is
appropriate for the available processing facilities and
which will produce a suitably bland-flavoured PSM.
When particulate split soybeans are treated a~
increasingly elevated temperatures, the temperature
differential between the surface and the center of a bean
becomes greater. This leads to an increasing degree of
overheating of the surface by the time the center is
processed adequately to avoid "green" or "painty"
flavours. Thus, use of temperatures for processing in
excess of about 120C results in products which tend to
be less bland, even though the duration of the heat
treatment is reduced, because the surface of the beans has
been processed to the "beany" or "bitter" stage.
,..,~
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7~ 3
The PSM produced according to the invention
generally has a protein content of about 40-42% and
a fat content of about 20-21% when prepared from
dehulled beans depending on the composition of the
original soybeans. The PSM thus produced represents
an important source of high quality fat, as well as
protein. The low cost of processing soybeans into
PSM coupled with its extreme blandness of flavor,
makes it a very sui-table ingredient for use in
many fat-containing foods in which other commercially
available full fat soy flour or other types of soy
flours are unsuitable because of the residual beany
flavor of the latter.
In the preferred embodiments of the invention,
soybeans are processed to produce full fat soy flour,
meal or grits in such a way that the end product,
hereafter referred to processed soy material (PSM) is
free or substantially free of the mentioned "beany",
"bitter", "painty", "raw" or "green" flavors, and of
such bland character that it may be used as or in
food products suitable for human consumption in
substantial proportion so that significant improvement
in protein content thereof i~ achieved.
With the preferred embodiments of the invention,
the nutritional quality of the PSM is maximised for
human food use so that there be no problems from
residual anti-trypsin factors or other anti-nutritional
factors.
C - 1 0
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In accordance with the preferred embodiments o~
the invention, the process is economical to carry
out and does not require the use of expensive or
specialised equipment.
In the preferred embodiments of the invention,
the process has a low energy requirement and is
capable of being operated by persons of reasonable
skill but not requiring persons having a high degree
of technical training and specialised skills.
The preferred embodiments of the invention can
provide PSM which when dried is stable under
atmospheric conditions and is able to be stored for
long periods of time in a dry state without significant
deterioration.
The preferred embodiments of the invention can pro-
videPSM which should be capable of being used in the
manufacture or preparation of more-or-less conventional
foods which have a ready acceptance in all or most
parts of the world. This is an important consideration
since it is often found very difficult or impossible
to introduce foods of special nutritional quality to
peoples in need of such nutrition unless the foods
are similar to or identical with the styles of foods
with which such peoples are familiar.
We have found that the development of "green",
"raw" or "painty" flavors is caused by the action of
the enzymes of soybeans on the oil in the soybeans
when the natural integral structure of the soybean is
r~ ~s
.~
partially or wholly destroyed by mechanical processing.
Whereas prior art methods describe the use of
heat, applied in a variety of ways, as a means of
producing full fat soy flours, surprinsingly we have
found it is the very use of heat as previously
described which can be in fact responsible for the
development of "beany" and "bitter" flavors.
Thus we have found that he development of
"beany" and "bitter" flavors can be caused as a
consequence of subjecting the soybean material to
time/temperature conditions beyond certain limits.
Experiments have shown that development of these
undesirable flavors is not an "all or nothing"
phenomenon but that there can be a progressively
increasing objectionable flavor developed in the
soybean material as the time/temperature exposure
ncreases.
Furthermore, we have also found that the same
holds true for products which include a substantial
proportion of PSM. If the product is subject to
excessive time/temperature exposure the undesirable
beany flavor can be induced in the prepared product
even though the PSM used as a major ingredient at the
commencement of the manufacturing process was bland
in flavor. We have discovered, that as long as these
principles are understood, it is possible to produce
a wide variety of highly acceptable high protein
foods, consisting of or containing PSM all having
excellent storage life.
12
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The following examples illustrate the invention.
Example 1
Soybeans used were of sound quality, well
cleaned and free from extraneous weed seeds and other
materials. In carrying out the dehulling operation,
the following steps were followed:
A) the beans were ~irst heated in a stream of
hot dry air at a temperature of 90C for 5-8 minutes,
or until the hulls become a little loosened from the
cotyledons. It is only necessary that the hulls have
become loosened to the extent that the entire hull
can be easily removed by rubbing in the palm of the
hand.
B) the warm surface-dried beans are passed
through a hulling machine in which the beans are
abraided against
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themselves and also against an abrasive element which is
included in such machines. Xt has been found that an
abrasive rice whitener is very suitable for this purpose.
Machines manufactured by Satake Engineering Co. Ltd. of
Tokyo, Japan, in particular model HS-2B have been found
suitable for the dehulling step. It is important that the
hulls are separated with a minimum of mechanical damage
being done to the cotyledons, such as scratching, cracking
or breaking. Avoidance of mechanical damage is especially
important if the hulled soybeans are to be stored from some
period of time prior to further processing. The reason for
this is that when the cells of the soybean cotyledons are
physically damaged at this stage, the enzymes present begin
to react with the contained soybean oil, resulting in
development of off flavours, especially "painty" or "green"
flavours or aromas.
C) the dehulled soybeans are then separated from the
hulls as completely as possible, using aspiration
equipment. At the same time the dehulled soybeans may be
cooled down, which is especially important if the dehulled
material is to be stored for some period of time before
further processing.
D~ the dehulled soybeans were then subjected to a
controlled heat treatment. The degree of heating of the
beans is determined to some extent by the use to which the
ultimate PSM will be put. In the example being described
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~L2~L7~2~3
the dehulled soybeans are placed in a well insulated
batch-type steamer so arranged that the steamer is filled
from the top, and emptied from the bottom at the end of the
steaming period. Live steam is fed into the soybeans
through a vertical perforated tube running almost the full
vertical length of the steamer. A supply of dry potable
steam at atmospheric pressure is passed through the
soybeans until the beans reach a temperature of 100C, as
indicated by a thermometer as well as by the observation
that live steam is escaping from the top of the mass of
beans. The steam flow is maintained so that the beans are
held at 100C for ten minutes. Then the steam is turned
off and the hot steaming beans are dropped from the steamer
into an insulated container.
While still very hot the soybeans were passed between
smooth rollers in a roller mill with the gap between rolls
set at 0.4mm. The soybeans exit from the mill in a flaked
condition, the flakes having a plurality of cracks and
fissures throughoutO The soybeans cool down to some degree
during rolling due to loss of steam from the beans,
especially as th~y are flattened by the rolls.
The soybean flakes were further dried in a forced
draft dehydrator using hot air at an inlet temperature of
90C. The temperature of the flakes is kept below
80C. Because the flakes are very thin, and have a
fractured structure they dry very rapidly in the
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dehydrator. The soybeans are dehydrated to about 3-4%
moisture content and cooled to 30C or less: theY may
then be pulverised in a grinder to a deqree of fineness
suitable for ~urther use applications.
In an alternate method the dehulled and split soy
beans are fed at a uniform rate through a trap into a
continuous steamer. This consists of a well insulated
horizontal trough in which is turning a helix and paddles,
the speed of which can be varied b~ an appropriate speed
controller. Potable steam is injected into the base of the
trough through a plurality of orifices. Thus as the split
soybeans enter the trough through the trap they are
subjected to rapid heating by live steam and are
simultaneously mixed by the paddles to ensure uniform
heaing and are transported through the steam zone. The
speed of rotation of the helix is adjusted so that the
residence time of the dehulled and split soybeans at
100C is 10 minutes. The treated beans exist from this
continuous steamer directly into the nip of the smooth
rolls of a roller mill described above, then are ~urther
processed by dryinq and pulverisinq as described.
The pulverised PSM produced from the flaked dried
soybeans had almost no flavour, being quite bland. The
minimal flavour which could be detected is a pleasant
slightly sweetr bu~tery, egg-like flavour. The PSM was
completely lacking in any beany or bitter flavour, and was
also lacking in painty or green flavour.
-15-
~Z~'7~3'~3
E~amole II
Dehulled soybeans were treated as in example l except
that the final dehydration step was omitted. The cooled
flaked soybeans were frozen and packaged for further use
then used as required in the preparation of various food
products, for example for inclusions in high protein bread
doughs. Alternately, the cooled flaked soybeans were used
directly as an ingredient in high protein biscuits
(cookies) without having to be held frozen. In this case
the flakes were used in the manufacture o~ biscuits on the
day of their manufacture, or held overnight in a cool-room.
Example III
Dehulled soybeans were processed as in example I
except that the time of steaming at 100C was varied to
cover a range of periods of time, as shown. In each case
the dried soya flakes were reduced to a fine meal usinq a
laboratory grinder. The resultant soy flours were compared
for flavour and appearance.
Time of steaming Colour of Flavour/aroma
- at 100Csoy flour of soy flour
-
2 l/2 minutes light straw colour bland
5 minuteslight straw colour bland
7 minuteslight straw colour bland
10 minuteslight straw colour bland
15 minuteslight straw colour bland
20 minutesstraw colour almost bland and
accepta~le as a
bland product
- 30 minutes darker straw colour slightly beany
40 minutes dark straw colour beany
-16-
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It ls apparent from the above results that with
increasing time of steaming at 100C for longer than
a~out 20 minutes there is deterioration in flavour of and
appearance of the soy ~lour when tasted in the powdered
form.
EXAMPLE IV
Dehulled and split soy beans were prepared as in
example I (A,B,C) and were then subjected to a controlled
heat treatment in heated water instead of in live steam.
The dehulled soybeans were added to an excess of water
held at the temperatures and for the times shown in the
results hereunder. The times of exposure were measured
from the -time at which the temperature of the water
returned to the stated temperature after addition of the
dry dehulled beans.
After completion of each nominated heat treatment, the
beans were removed from the water, quickly drained and
weighed, then, while still hot, rolled into flakes, dried
and pulverised as described in example I. The following
observations were made to compare the various treatments:
Temp. of Duration Colour of soy Flavour/aroma of
treatment of flour soy flour
in water treatment
95C 20 mins Liqht straw Bland
95C 15 mins Light straw Bland
95C 10 mins Light straw Very slightly
raw flavour
90 C 20 mins Light straw Bland
90C 15 mins Light straw Very slightly raw
85C 20 mins Light straw Almost bland
80C 20 mins Light straw Raw, green and painty
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It is apparent from the above results that whereas it
is possible to produce a bland tasting soy flour or meal by
subjec.ing t,he soybeans to heating for up to 20 minutes in
water at 85C, the flavour quality of the resultant
product is unacceptable if the temperature in water is at
80C for 20 minutes.
In an alternate method, the dehulled and split
soybeans were fed continuously and at a controlled rate,
into a continuous rotary wa-ter blancher in which the water
was maintained at 95C. The speed of rotation of the
screw section of the water blancher was controlled so that
the beans were at 95C for a ~otal of 15 minutes ~efore
being lifted from the hot water by the emptYing device on
the blancher. The beans so treated passed across a
dewatering screen, then fed while still very hot to a
roller mill and were further processed as in example I to
produce a dried and pulverised meal. The resultant product
had a light straw colour and a completely bland flavour and
aroma.
Comparat~ve ~xample I
Dehulled soybeans were processed as in exa~ple 1
except that instead of being steamed at atmospheric
pressure at 100C, the beans ~ere steamed under pressure
at 120C Eor periods of 2 1/2, 5, lO and 20 minutes. The
following observations were made:
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7~
Time of Pressure Colour of ~oy Flavour/aroma
Steaming at 120C Flour of soy flour
2 1/2 minutes straw colour slightly beany
5 minutes dark straw colour beany
10 minutes light brown more beany
20 minutes medium brown very beany
It is apparent when soybeans are treated at a
temperature of 120C, as compared to example 3 (100C)
2 1/2 minutes exposure at 120C is approximately
equivalent to 20-30 minutes at 100C as far as
development of the beany flavour is concerned. Along with
increase in beany flavour, there is also a pronounced
darkening of the soy flour.
Example v
Dehulled split soybeans were steamed in batches as
described in Example I, except that the beans were held at
100C for quite short periodsr ranging from 30 seconds to
2 1/2 minutes, with an unheated control treatment. The
heat-treated beans were flaked, dried and further
pulverised as described. The unheated control was simply
puLverised in the raw state. There was a marked range of
flavour characters in the treatments as follows:
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Heat treatment - number E'lavour of soy flour
of minutes at 100C (tasted 30 days after
(steam heated) processin~)
.0 mins Very raw,green,painty flavour
0.5 mins Raw, green, painty flavour
1.0 mins Raw, green, painty flavour
1.5 mins Less raw,green,painty flavour
2.0 mins Slight "raw'l flavour
2.5 mins Bland flavour
It is apparent from this test that, under the above
conditions of steaming of dehulled split soybeans, 2-2 1/2
minutes at 100C is the threshold minimum range for
preventing the development of green, painty or raw flavours
in soy flour~
EXA~IPLE VI
Dehulled soybeans were processed as in example V
except that instead of being processed in steam under
pressure in excess of atmospheric pressure at a temperature
of 120C, the beans were processed at higher
temperatures. To achieve this on a batch basis, it was
ne~essary to use a small pressure vessel with a quick
release lid.
-20-
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~L2fl~7~
Temp. in Duration Colour of soy Flavour/aroma of
steam of flour soy ~lour
under treatment
pressure
.
130C 0.5 min. straw slightly raw flavour
1.0 min. straw bland
1.5 min. dark straw reasonably bland
2.0 min. dark straw slightly beany
2~5 min. fawn beany
135C 0.5 min. straw bland
1.0 min. straw bland
1.5 min. dark straw slightly beany
2.0 min. fawn beany
2.5 min. light brown beany
It is apparent from these results that with treatment
in steam at increasing temperatures, time required to
eliminate the green, raw or painty flavour is reduced.
Likewise the time required to induce a beany flavour is
reduced.
It will be realised that a degree of delay is involved
in reducing the pressure after each steam treatment so the
beans can be removed from the vessel, and a similar delay
is involved in each treatment.
It was observed that the flavour quality o~ a soy
flour produced in steam at 100C and described as bland
is of superior flavour as compared to the bland treatments
produced at higher temperatures. It is believed that this
may be because the surface of an individual soybean reaches
a higher temperature when treated at, say 130C before
the centre of the bean reaches a temperature adequate to
prevent development of a raw flavour in the centre tissue.
At that stage, the surface tissue may have then
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already developed a degree of beany flavour. The final
flour may thus be a mixture of different flavour ~ualities
to a greater extent than for treatments carried out at a
lower temperature.
The foregoing examples are illustrative of the
invention only and it will be appreciated that various
times, temperatures and pressures may be selected within
the ranges disclosed which will result in the production of
a satisfactory productO
In order to evaluate the importance of the invention,
the various samples of processed beans prepared as referred
to herein were incorporated into a liquid formulation, in
which form an~ flavour chanqes became ver~ perceptible to
the palate. The liquid formulation used was in the nature
of a milk-like beverage. The hulled soybeans variously
treated and at ~% moisture content (103.g) were added to 1
litre of water to which had been added O.9g sodium
bicarbonate. This was brought to the boil, then simmered
10 minutes. The weight of this was restored to the initial
weight, then the mixture was ~lended in a liquidizer at
full speed for l minute. To this was added 9g of bland
vegetable oil, lg salt (NaCl) and 12.5g of sugar, and the
mixture was blended for a further 1 minute at full speed.
The mixture was then homogenised in a laboratory
homogeniser. The "milks" were chilled overnight, then
tasted.
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Steaming treat- Flavour of Colour of Comments
ment to which "milk" "milk"
hulled soybeans prepared
had been exposed from product
2 1/2 mins Bland flavour Milky white Very
100C acceptable
5 mins Bland flavour Milky white Very
100C acceptable
10 mins Bland flavour Milky white Very
100C acceptable
20 mins Very slightly Slightly Reasonably
100C beany note darker acceptable
40 mins Slight beany Light brown Unacceptable
100C note colour
2.5 mins Very slight Light brown Reasonably
120C beany note colour acceptable
5 mins Slight beany Light brown Reasonably
120C note colour acceptable
10 mins Obvious beany Browner Ob~ectionable
120C flavour
20 mins Strong beany Quite browned Objectionable
120C flavour
These results show that the flavour and colour
differences between the various heat treatments follow
through into a food product in which they are used.
Quite clearly, by use of other flavourants or
seasonings it is possible to disguise a mild degree of
beany flavour in a prepared food. However, the need to do
this represents a serious limitation to the general
utilisation of normal full fat soy flours.
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