U.S. patent application number 12/495930 was filed with the patent office on 2011-01-06 for method for pretreating grain before milling.
This patent application is currently assigned to BUHLER AG. Invention is credited to Walter Eugster, Uwe Schill, Jurgen Winter.
Application Number | 20110003065 12/495930 |
Document ID | / |
Family ID | 43412825 |
Filed Date | 2011-01-06 |
United States Patent
Application |
20110003065 |
Kind Code |
A1 |
Eugster; Walter ; et
al. |
January 6, 2011 |
Method for pretreating grain before milling
Abstract
The invention relates to a method for pretreating grain before
milling, comprising the following steps: a) providing cereal; b)
optionally: dampening and conditioning the cereal; c) selectively
removing a first fraction of husk components of the cereal obtained
from step b), wherein said first fraction substantially comprises
the outer husk components of the dampened cereal, and wherein 0.2
to 2% by weight of the cereal is removed; d) dampening and
conditioning the cereal obtained from step c); e) selectively
removing a second fraction of husk components of the cereal
obtained from step d), wherein said second fraction substantially
contains dietary fibers of the dampened cereal. The method makes it
possible to efficiently obtain contamination-free total dietary
fibers. An apparatus for carrying out the method, and advantageous
uses of the total dietary fibers are described.
Inventors: |
Eugster; Walter;
(Niederuzwil, CH) ; Winter; Jurgen; (Niederuzwil,
CH) ; Schill; Uwe; (Winterthur, CH) |
Correspondence
Address: |
SHOEMAKER AND MATTARE, LTD
10 POST OFFICE ROAD - SUITE 100
SILVER SPRING
MD
20910
US
|
Assignee: |
BUHLER AG
Uzwil
CH
|
Family ID: |
43412825 |
Appl. No.: |
12/495930 |
Filed: |
July 1, 2009 |
Current U.S.
Class: |
426/648 ;
426/482; 426/483; 99/600 |
Current CPC
Class: |
B02B 3/00 20130101; A23L
33/21 20160801; B02B 1/04 20130101; B02B 1/06 20130101; A23L 7/10
20160801; B02B 3/04 20130101; A23L 33/22 20160801; B02B 5/02
20130101 |
Class at
Publication: |
426/648 ;
426/482; 426/483; 99/600 |
International
Class: |
A23L 1/308 20060101
A23L001/308; A23L 1/10 20060101 A23L001/10; A23P 1/00 20060101
A23P001/00; B02B 3/00 20060101 B02B003/00 |
Claims
1-15. (canceled)
16. A method for pretreating grain before milling, comprising the
following steps: a) providing cereals; b) optionally: dampening and
conditioning the cereal; c) selectively removing a first fraction
of husk components of the cereal as per step a) or of the cereal
obtained from step b), wherein said first fraction substantially
comprises the outer husk components of the dampened cereal, and
wherein 0.2 to 2% by weight of the cereal is removed; d) dampening
and conditioning the cereal obtained from step c); e) selectively
removing a second fraction of husk components of the cereal
obtained from step d), wherein said second fraction substantially
contains dietary fibers of the dampened cereal.
17. The method as claimed in claim 16, wherein the cereal provided
in step a) has a moisture content of .gtoreq.14% by weight.
18. The method as claimed in claim 16, wherein the cereal provided
in step a) has a moisture content of <14% by weight.
19. The method as claimed in claim 16, wherein the second fraction
removed in step e) has a total dietary fiber content of .gtoreq.60%
by weight.
20. The method as claimed in claim 16, wherein the second fraction
removed in step e) has a starch content of .ltoreq.20% by
weight.
21. The method as claimed in claim 16, wherein step e) is carried
out in a plurality of partial steps e.sub.1) to e.sub.n).
22. The method as claimed in claim 21, wherein the fractions or
partial quantities thereof obtained in the partial steps e.sub.1)
to e.sub.n) are mixed with one another in such a manner that the
mixture has a total dietary fiber content of .gtoreq.60% by
weight.
23. The method as claimed in claim 21, wherein the fractions or
partial quantities thereof obtained in the partial steps e.sub.1)
to e.sub.n) are mixed with one another in such a manner that the
mixture has a starch content of 20% by weight.
24. The method as claimed in one of claims 21, wherein the cereal
is dampened and conditioned again between the partial steps
e.sub.1) to e.sub.n).
25. The method as claimed in claim 16, wherein the dampening and
conditioning in step b) are carried out in a dampener turbolizer;
and/or the dampening and conditioning in step d) and/or between the
partial steps e.sub.1) to e.sub.n) are carried out in a dampening
and retaining screw conveyor.
26. The method as claimed in claim 16, wherein the components of
the first and/or second fraction in the steps c) and d) are removed
from the cereal grain substantially by grain/grain friction.
27. A plant for carrying out a method as claimed in claim 16,
comprising, in the product flow direction: i) a device for
processing the surface of the cereal by peeling; ii) a dampening
unit for dampening and conditioning the cereal, preferably a
dampening and retaining screw conveyor; iii) a device for
processing the surface of the cereal by peeling.
28. The plant as claimed in claim 27, wherein the peeling in the
device(s) for processing the cereal by peeling can be obtained
substantially by grain/grain friction.
29. The plant as claimed in claim 27, wherein the device for
processing the surface by peeling has: a rotatably mounted rotor; a
stator which in particular is provided with processing tools; at
least one screen basket which is in particular formed from one or
more screen plates and is preferably arranged on the stator, the at
least one screen basket surrounding the rotor in such a manner that
a processing zone is formed; wherein the rotor comprises a hollow
shaft through which air can be fed into the processing zone, and
the rotor has, in the region of the processing zone, a roller.
30. A plant according to claim 27, further comprising, in the
product flow direction before the device i) for processing the
surface of the cereal by peeling a tempering bin for
preconditioning the cereal to a defined moisture content; and/or a
dampening unit for dampening and conditioning the cereal.
31. A method of supplementing foodstuffs chosen from the group
consisting of baked goods, preferably breads; cereals; snacks, in
particular bars; drinks; milk products, in particular yoghurt; food
supplements; diet foods; comprising the step of adding dietary
fibers obtained by a method as claimed in claim 16 to the
foodstuff.
Description
[0001] The invention relates to the field of milling, in particular
to the preparatory grinding treatment of cereals.
[0002] In a simplified depiction, the cereal grain has a triple
husk construction. The outer husk layer comprises the epidermis,
long and cross cells and also tube cells. Said outer husk layer can
make up up to 5.5% by weight of the total grain. The next layer to
the inside is a double layer comprising a "coloring layer" and a
colorless layer; a portion of approximately 2.5% by weight of the
total grain is assumed for this double layer. The next layer to the
inside is referred to as the aleuron layer and comprises
approximately 7% by weight of the total grain. The interior of the
grain contains the kernel (approx. 2.5% by weight of the entire
grain) and the actual endosperm which makes up the rest to a total
of 100% by weight.
[0003] It is known to pretreat the grain by peeling, abrading
and/or polishing in such a manner that as few husk components as
possible enter the actual grinding process.
[0004] DE 1 164 210 proposes a multi-stage method, in which the
husk components are stripped off in a quantity of 2.8 to 3.6% by
weight of the cereal grain in a first step. In a second step, a
further 0.4 to 2.1% by weight of the cereal grain is also stripped
off. Overall, in this method, a total of between 3.2 and 5.7% by
weight of the cereal grain is stripped off.
[0005] It is furthermore known that environmental poisons and/or
contaminations can be contained in an outer layer of the cereal.
The fact that these can be removed by removing part of the
outermost husk of the cereal is described, for example, in EP 801
984 B1.
[0006] The invention is based on the object of providing a method
which can be reliably used both to remove contaminated outermost
layers of the cereal and to supply as substantial a portion of the
cereal as possible for a value-adding use. In addition, the
invention is intended to be carried out as simply, efficiently and
cost-effectively as possible.
[0007] This object is achieved by the subject matter of the
independent patent claims.
[0008] The method for pretreating grain before milling according to
the invention comprises the following steps:
a) providing cereals; b) optionally: dampening and conditioning the
cereal, in particular for a period of time of .ltoreq.1 hour,
preferably for .ltoreq.10 minutes, furthermore preferably for
approximately 5 seconds to 5 minutes, furthermore preferably for
approximately 5 seconds to 30 seconds, and particularly preferably
for approximately 8 seconds to 15 seconds.
[0009] It has been demonstrated that this step can be dispensed
with, depending on the degree of contamination and type of
contamination. In general, with previous dampening and conditioning
of the cereal, more outer husk components can be removed in the
subsequent step c) if this is desirable or necessary (due to the
degree of contamination and/or type of contamination).
c) Selectively removing a first fraction of husk components of the
cereal as per step a) or of the cereal obtained from step b),
wherein said first fraction substantially comprises the outer husk
components of the dampened cereal, and wherein 0.2 to 2% by weight
of the cereal is removed, preferably 0.2 to 1% by weight, and
particularly preferably 0.2 to 0.5% by weight; d) dampening and
conditioning the cereal obtained from step c) in particular for a
period of time of 0.5 to 30 minutes, preferably for 0.5 to 15
minutes, and particularly preferably for approximately 1 to 5
minutes; e) selectively removing a second fraction of husk
components of the cereal obtained from step d), wherein said second
fraction substantially contains dietary fibers of the dampened
cereal.
[0010] In step c), only the surface layer is worn down to an extent
such that contaminations, such as environmental poisons and/or
other contaminations, are removed. It has been surprisingly
demonstrated that the removal of just 0.2 to 0.5% by weight is
entirely sufficient for this in order to obtain substantially
contamination-free cereal grains. In the step e), a further layer
is removed, said layer then being substantially free from
contamination and substantially containing dietary fibers of the
cereal. The contamination-free dietary fibers obtained in such a
way can be supplied for further use as valuable components.
[0011] Within the context of the present invention, dietary fibers
are understood as meaning the total dietary fibers determined as
per AOAC 985.29.
[0012] Cereal which has "storage moisture" or "grinding moisture"
can be provided in step a).
[0013] The provision of cereal which has "grinding moisture" takes
place with a moisture content of 14% by weight, preferably 14 to
20% by weight, furthermore preferably 15 to 20% by weight, and
particularly preferably 15 to 17% by weight, wherein said moisture
is distributed as substantially homogeneously as possible in the
cereal grain, in a manner optimum for the grinding process.
[0014] The provision of cereal which has "storage moisture"
preferably takes place with a moisture content of <14% by
weight, preferably 8 to 13.99% by weight, and particularly
preferably 10 to <13.99% by weight.
[0015] It has been demonstrated that the cereal in the steps b) and
d) can be dampened with very little water.
[0016] Typically, for example, from 0.1 to 3.5% by weight, and
preferably 0.2 to 2.5% by weight, of water is added (based on the
resulting overall weight) if cereal which has the abovementioned
"grinding moisture" is provided.
[0017] If cereal which has the abovementioned "storage moisture" is
provided, then typically from 0.1 to 4% by weight, and preferably
0.2 to 2.5% by weight, of water is added (based on the resulting
overall weight).
[0018] The conditioning in steps b) and d) can take place directly
during the dampening of the cereal, for example in a dampener
turbolizer. However, it is also possible for only part of the
conditioning to take place at the same time as the dampening (for
example in a screw conveyor into which water is fed), with the
dampened cereal then being subsequently conditioned separately (for
example in a screw conveyor into which no additional water is fed
any longer).
[0019] The dampening and conditioning of the cereal in steps b) and
d) lead surprisingly rapidly to sufficient moisture contents in the
outer layers of the grain, making the subsequent removal of husk
layers in steps c) and e) much easier.
[0020] Typically, dampening in step b) takes place during a period
of time of 1 hour, preferably for .ltoreq.10 minutes, furthermore
preferably for approximately 5 seconds to 5 minutes, and
particularly preferably for approximately 8 seconds to 30 seconds.
Said dampening preferably takes place in a dampener turbolizer.
[0021] Typically, in step d), dampening and conditioning take place
for approximately 0.5 to 30 minutes, preferably 0.5 to 15 minutes,
and particularly preferably for between 1 and 5 minutes. Said
dampening preferably takes place in a dampening and retaining screw
conveyor.
[0022] Whereas, in step c), only precisely so much surface layer of
the cereal is abraded for a substantially contamination-free
residual grain to be obtained, the intention, in step e), is for a
fraction having the highest possible dietary fiber portion to be
obtained, the intention being that the endosperm is as far as
possible not damaged. The portion of the second fraction obtained
in step e) in percent by weight of the pure grain can vary as a
function of the type of cereal and the contaminated layer removed
in step c). However, suitable control or regulation of the method
can easily be determined by routine tests; for this purpose, the
content of total dietary fibers of the second fraction and the
content of starch (as an indication of damage to the endosperm) can
be used (individually or in combination).
[0023] Therefore, in preferred embodiments, the second fraction
removed in step e) has a total dietary fiber content of .gtoreq.60%
by weight, preferably .gtoreq.70% by weight, and particularly
preferably .gtoreq.80% by weight.
[0024] In further preferred embodiments, the second fraction
removed in step e) has a starch content of .ltoreq.20% by weight,
preferably .ltoreq.15% by weight, and particularly preferably
.ltoreq.10% by weight.
[0025] In the context of the invention, the starch content is
determined in accordance with Schweizerische Lebensmittelbuch
[Swiss Food Manual] SLMB (2002), chapter 3.6.1.
[0026] In particularly preferred embodiments of the invention, step
e) is carried out in a plurality of partial steps e.sub.1) to
e.sub.n). The fractions obtained in such partial steps can in
particular contain differing quantities of the cereal (in percent
by weight of the total weight of the cereal used). This enables
particularly fine access to a maximally exposed endosperm to be
achieved; in particular, a smaller isolated fraction can be
selected the greater the amount of dietary fibers already
abraded.
[0027] Particularly advantageously, the fractions or partial
quantities thereof obtained in the partial steps e.sub.1) to
e.sub.n) can be mixed with one another in such a manner that the
mixture has a total dietary fiber content of .gtoreq.60% by weight,
preferably .gtoreq.70% by weight, and particularly preferably
.gtoreq.80% by weight. The first partial fractions typically have a
total dietary fiber content of >80% by weight, in particular
>85% by weight. Later partial fractions--despite a smaller total
dietary fiber content--can also still be isolated and added to the
earlier partial fractions as long as this does not cause the total
dietary fiber content to fall below a desired amount (for a maximum
tolerated starch content, see below, to be exceeded).
[0028] Furthermore advantageously, the fractions or partial
quantities thereof obtained in the partial steps e.sub.1) to
e.sub.n) can be mixed with one another in such a manner that the
mixture has a starch content of .ltoreq.20% by weight, preferably
.ltoreq.15% by weight, and particularly preferably .ltoreq.10% by
weight. The first partial fractions typically have a starch content
of <6% by weight, in particular of <5% by weight. Later
partial fractions--despite a higher starch content--can also still
be isolated and added to the earlier partial fractions as long as
this does not cause a maximum tolerated starch content to be
exceeded (or the total dietary fiber content to fall below a
desired amount).
[0029] The cereal can advantageously be dampened and conditioned
again between the individual partial steps e.sub.1) to
e.sub.n).
[0030] In further preferred embodiments, the dampening and
conditioning in the steps b) and d) and, if appropriate, between
the partial steps e.sub.1) to e.sub.n) take place with a dampener
turbolizer or with a dampening and retaining screw conveyor. A
dampener turbolizer has surprisingly turned out to be particularly
suitable for use in step b) whereas the dampening and retaining
screw conveyor has proven particularly successful in step d) and,
if appropriate, between the partial steps e.sub.1) to e.sub.n); in
particular, the sequential use of a dampening screw conveyor (with
addition of water) and a subsequent retaining screw conveyor
(without addition of water) has proven particularly
advantageous.
[0031] In a particularly advantageous manner, the components of the
first and/or second fraction in the steps c) and e) are removed
from the cereal grain substantially by grain/grain friction. Such
friction is particularly gentle, being expressed by low breakage of
the grain. Alternative methods substantially based on grain/metal
or grain/stone friction are less gentle and are therefore
unsuitable in many cases for obtaining the selectivity, which is
desired in the steps c) and e), in the removal of husk
components.
[0032] A further aspect of the invention relates to a plant for
carrying out the above-described method. Such a plant according to
the invention comprises, in the product flow direction:
a) optionally: at least one tempering bin for preconditioning the
cereal to a defined moisture content; b) optionally: at least one
dampening unit for dampening and conditioning the cereal,
preferably a dampener turbolizer; c) at least one device for
processing the surface of the cereal by peeling; d) at least one
dampening unit for dampening and conditioning the cereal again,
preferably a dampening and retaining screw conveyor; e) at least
one device for processing the surface of the cereal by peeling.
[0033] It goes without saying that, given suitable process
management (for example with temporary storage of intermediate
products), if appropriate the same dampening unit can be used in
the steps b) and d); similarly, in the steps c) and d), the same
device for processing the surface by peeling can be used. However,
continuous operation of the plant with separate devices for
treatment of the surface by peeling in the steps c) and e) is
preferred.
[0034] Particularly advantageously, the peeling in the device(s)
for processing the cereal by peeling can be obtained substantially
by grain/grain friction, as already explained above in conjunction
with the method according to the invention.
[0035] The device for processing the surface by peeling in the
above-described plants particularly advantageously has the
following components:
[0036] a rotatably mounted rotor;
[0037] a stator which in particular is provided with processing
tools;
[0038] at least one screen basket which is in particular formed
from one or more screen plates and is preferably arranged on the
stator, the at least one screen basket surrounding the rotor in
such a manner that a processing zone is formed;
the rotor comprising a hollow shaft through which air can be fed
into the processing zone, and the rotor having, in the region of
the processing zone, a roller which in particular is provided with
processing tools.
[0039] As processing tools, flat segments can be provided on the
stator; however, said segments may also be provided with baffle
bars, cams or the like.
[0040] Protruding strips, studs or the like can be provided as
processing tools on the rotor.
[0041] The screen baskets can be matched in particular in the size
of their holes to the specific use (in particular to the particular
type of cereal) by routine tests carried out by an expert.
[0042] A further aspect of the invention relates to the use of
dietary fibers, obtained by an above-described method, in
particular by an above-described plant, as an additive in
foodstuffs, in particular baked goods, preferably breads; cereals;
snacks, in particular bars; drinks; milk products, in particular
yoghurt; food supplements and diet foods. According to the
invention, substantially contamination-free dietary fibers can be
obtained in a particularly simple manner and in high yield and can
be supplied for further use. The grain product which is obtained
and treated (freed from an outer layer of the husk components) can
likewise be further processed.
[0043] The invention is explained below with reference to exemplary
embodiments and figures without restricting the subject matter of
the invention to said embodiments. In the figures:
[0044] FIG. 1: shows a flow diagram of a variant for carrying out
the method;
[0045] FIG. 2: shows a longitudinal section of a light peeler;
[0046] FIG. 3: shows a cross section of a light peeler;
[0047] FIG. 4: shows a longitudinal section of a peeler;
[0048] FIG. 5: shows a cross section of a peeler;
[0049] FIG. 6: shows a longitudinal section (on the left) and cross
section (on the right) of a dampener turbolizer;
[0050] FIG. 7: shows a cross section of a dampening and retaining
screw conveyor.
[0051] In the flow diagram in FIG. 1 of a variant for carrying out
the method, cereal having a defined grinding moisture is supplied
from a tempering bin (not shown) to the process. The cereal first
of all passes through a magnet 1 for sorting out metallic parts.
The cereal is subsequently supplied to a dampener turbolizer 2
which has a water supply 3 for dampening the cereal. The dampener
turbolizer 2 is explained in more detail in the description of FIG.
6. The dampened cereal is subsequently supplied to a first device
for treatment of the surface of the cereal by peeling, namely a
"light peeler" 4; the latter is explained in more detail in
conjunction with FIG. 2 and FIG. 3. However, instead of a light
peeler, a peeler 12 may also be used; the latter is explained in
more detail in conjunction with FIGS. 4 and 5. The fiber fraction
leaving the light peeler 4 (or peeler 12) can be supplied for a
further use (not illustrated). The cereal fraction is conducted
through an aspiration passage 5. The loose parts which were not
removed by the screen jacket of the light peeler are sucked off
here. The cereal is then supplied to a depot 6 in which it can be
temporarily stored in order to compensate for different capacities
of the individual process steps. It can be ensured by means of a
pair of scales 7 that defined quantities of cereal are supplied to
the subsequent process stages, which is essential in particular for
the later dampening. The cereal is dampened and at the same time
conveyed in a dampening screw conveyor 8; the dampening screw
conveyor 8 is fed with water via a water supply 9. The dampened
cereal is subsequently conditioned again in a retaining screw
conveyor 10. The construction of the dampening screw conveyor 8 and
retaining screw conveyor 10 is identical except for the water
supply and is explained in more detail in conjunction with FIG. 7.
The dampened cereal is again guided past a magnet 11 in order to
sort out any metallic contamination. The cereal is subsequently
supplied to a second device for treatment of the surface of the
cereal by peeling, in this case to a peeler 12; the latter is
explained in more detail in conjunction with FIG. 4 and FIG. 5.
However, in this method step, a light peeler 4 can alternatively
also be used if a more gentle treatment with less abrasion of husk
material is desired. The fiber fraction leaving the peeler 12 can
be supplied for a further use (not illustrated). The cereal passes
through a further aspiration passage 13 and a further magnet 14 and
is subsequently supplied to the grinding process.
[0052] FIG. 2 and FIG. 3 illustrate the light peeler 4 in more
detail. The cereal is supplied to the light peeler 4 via a product
inlet 15 and passes to a feed screw 20. The light peeler 4 has a
stator 19 and a rotor 25. A treatment space 18 for the cereal is
formed between the rotor 25 and stator 19 and also screen plates 27
(FIG. 3). The distance between the rotor 25 and stator 19 can be
reduced at the top and bottom by putting the segments 41 thereunder
in order to obtain a more intensive treatment of the process
product. The distance between the screen plates 27 and rotor 25 can
likewise be adjusted; a greater distance is associated with a more
gentle treatment of the process product. The rotor 25 has a hollow
shaft 26 which is driven via a motor 23. The hollow shaft has air
openings 24 via which air can be supplied to the treatment space
18. By regulation of the backing-up devices 21 and 22, the
intensity of the treatment in the treatment space 18 can be
regulated by the backing-up pressure of the cereal in the light
peeler 4 being adjusted. The fiber fraction leaves the light peeler
4 via the outlet 16; the treated cereal leaves the light peeler 4
via the outlet 17.
[0053] The peeler 12 is illustrated in more detail in FIG. 4 and
FIG. 5. Parts having substantially the same function are referred
to with the same reference numbers as in the light peeler 4. The
cereal is supplied to the peeler 12 via a product inlet 15 and
passes to a feed worm 20. The peeler 12 has a stator 19 and a rotor
25. A treatment space 18 for the cereal is formed between the rotor
25 and stator 19 and also screen plates 27 (FIG. 5). The distance
between the rotor 25 and stator 19 can be reduced at the top and
bottom by putting the segments 41 thereunder in order therefore to
obtain a more intensive treatment of the process product. The
distance between the screen plates 27 and the rotor 25 can likewise
be adjusted; a larger distance is associated with a more gentle
treatment of the process product. The rotor 25 has a hollow shaft
26 which is driven via a motor 23. The hollow shaft has air
openings 24 via which air can be supplied to the treatment space 18
by means of a ventilator 28, as a result of which the severing of
the husk fraction can be made easier and completed. The treatment
space 18, which is narrower in the peeler 12 in comparison to the
light peeler 4, also intensifies the treatment of the cereal (cf.
FIG. 3). By regulating the backing-up devices 21 and 22, the
intensity of the treatment in the treatment space 18 can be
regulated by the backing-up pressure of the cereal in the peeler 12
being adjusted. The fiber fraction leaves the peeler 12 via the
outlet 16; the treated cereal leaves the peeler 12 via the outlet
17.
[0054] FIG. 6 shows the dampener turbolizer 2 in detail. The cereal
is supplied to the dampener turbolizer 2 via the product inlet 34
and is conducted through the dampener turbolizer in a helical
direction (indicated by the arrow line in the interior of the
dampener turbolizer 2). Water is supplied to the interior of the
dampener turbolizer 2 in a metered manner via a water feed (not
shown in detail). An upper shaft 30 and a lower shaft 31 are
arranged in the interior of the dampener turbolizer 2; paddles 32
and are provided on said rotating shafts in such a geometry and
arrangement that the above-described, helical conveying movement is
achieved. The shafts 30 and 31 are driven via a common motor 29.
The dampened cereal leaves the dampener turbolizer via the product
outlet 35.
[0055] FIG. 7 shows a retaining screw conveyor 10 in detail. The
cereal is supplied to the retaining screw conveyor via a product
inlet 36. A shaft 38 on which paddles 40 are provided in such a
geometry and arrangement that a conveyor movement is achieved is
arranged in the interior of the retaining screw conveyor 10. The
cereal leaves the retaining screw conveyor via the product outlet
37. The shaft 38 is driven by the motor 39. A dampening screw
conveyor (not shown in detail) can be formed in an analogous
manner, but with a water supply preferably being provided in the
front part of the interior in the product flow direction.
[0056] The following results were obtained (by way of example) with
the method according to the invention:
[0057] Swiss quality wheat with a storage moisture of 12.6% by
weight and an ash content of 1.83% with reference to the dry
substance was used as the cereal. Prior to the experiment, the
wheat was dampened to a moisture content of approximately 16% by
weight. The subsequent tempering time prior to the experiment
lasted 18 h.
[0058] A dampener turbolizer 2 was used for the dampening. The
treatments of the surface were carried out using a peeler 12
(MHXM-W; Buhler AG).
[0059] The peeler 12 was always operated at the following
settings:
Product input rate: 3 t/h Rotational speed of the rotor: 335 rpm
Screen perforation: 1.1 mm.times.12 mm Distance of rotor from
segment 41: 13 mm Distance of rotor from screen: 8 mm.
[0060] Prior to each surface treatment in the peeler 12, dampening
took place in the dampener turbolizer (below: experiments 1 to 4),
with a flow time through the dampener turbolizer of approximately
0.3 minute, and with the following quantities of water supplied for
the dampening:
Experiment 1: 0.2% by weight Experiment 2: 0.4% by weight
Experiment 3: 0.6% by weight Experiment 4: 1.4% by weight
[0061] Subsequently, a further husk fraction was separated off
after dampening in a dampening screw conveyor followed by a
retaining screw conveyor (below: experiment 5). This dampening
required 2% by weight of water to be supplied, with a retaining and
conditioning time in the dampening screw conveyor and the retaining
screw conveyor of a total of 3 minutes prior to entry into the
peeler 12.
[0062] The fractions obtained in experiments 1-5 were characterized
as follows:
TABLE-US-00001 Experiment # 1 2 3 4 5 Isolated fraction in % 0.36
0.43 0.50 1.76 1.4 by weight of the total grain used Ash 1.90 1.81
1.86 2.11 3.37 Total dietary fibers in 88.0 86.5 85.1 86.4 61.2 %
by weight Starch in % by weight 2.99 4.09 4.09 2.08 12.8
[0063] It is apparent from the above results that, with the method
according to invention and with the use of a plant according to the
invention, husk components of the cereal can be selectively
isolated and successively severed without the endosperm being
significantly damaged. Damage to the endosperm can at most be
assumed only in fraction 5, since the starch content here has after
all risen to 12.8% by weight. Nevertheless, this fraction can still
also be used, since it still also contains 61.2% by weight of total
dietary fibers--i.e. primarily contains the latter.
[0064] With the fraction according to experiment 1, essentially all
of the contaminations have already been removed. Therefore,
combining the fractions according to experiments 2 to 4 (if
appropriate also including the fraction according to experiment 5,
see above) results in a highly pure total dietary fiber fraction
which can be supplied for further use in foodstuffs.
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