Note: Descriptions are shown in the official language in which they were submitted.
~2~ 3~
The present invention relates to a process for producing
a crude oil containing an effective component in a large
amount by subjecting vegetable seeds to a special heat
treatment.
The present invention relates also to a process for
producing a crude oil which requires only remarkably
simplified refining steps.
For the production of vegetable oils from vegetable
seeds such as rapeseeds, there have been known (a) a press
process, (b) an extraction process with a solvent and ~c)
press~extraction process which comprises a combination of the
processes (a) and (b).
The press process (a) which has been employed since old
times comprises steps of removing foreign matters from
starting seeds, crushing the seeds, flaking them, subjecting
them to a heat treatment (indirect heat treatment) which
comprises heating, drying, sterilizing and breaking of the
cells by a thermal stress and treating them mechanically
with, for example, a screw press.
In the extraction process (b), the extraction is
conducted, taking advantage of the solubility of the oi:L
in a solvent such as n-hexane. In -this process, the
starting material which has been pre-treated substantially
in the same manner as in the press process (a) and then
shaped into flakes is fed into an extrac-tor and brough-t
into contact with a solvent to extrac-t the oil. The
so:Lvent containing the oil (micella) is distilled to
separate .it from the oil and then circulated into the
extractor again. Since a high oil extraction ra-te can
be provided by this process, this process is sui-table
for the extraction of an oil from material having a low
oil content such as soy beans, corns and rice bran.
This process is ~amous particularly as a process ~or the
production of soybean oil.
The press-extraction process (c) comprises a cornbi-
nation of the above-mentioned press process and extraction
process. In this process, a major part oE an oil is
pressed from a starting material and then a remaininy
oil is extracted from the starting material having a
reduced oil con-tent with a solvent. This process is
employed w:idely for the production of various vegetable
o.ils such as rapeseed o:il, saEflower oil, sun~lower oil,
cot~.on seed o:i.l and :l:Lnseed oil, s.i.nce it is the most
econom:i.cal.
'rhe crude oil thus obtained cannot be put on the
mar]ce-t as it is, since it contains vegetable gums such as
phospholipids. The crude oil is, therefore, stirred
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together with a several percent of water so that the
hydratable phospholipid in the crude oil is hydrated to
provide a difference in the specific gravity between the oil
and the phospholipids. The vegeta~le gum can be separated by
a centrifugation (degumming step).
The gum (oil foots) thus separated out is usable as a
starting material for phospholipids.
The phospholipids include PC (phosphatidyl choline), PE
(phosphatidyl ethanolamine), PI (phosphatidyl inositol), PA
(phostatidic acid), etc. Among them, PC is particularly
important, since it is a main constituent of animal and
vegetable cells and it has important physiological
activities. Therefore, it is quite advantageous to obtain a
phospholipid having a high PC content.
However, phospholipids recovered from crude oils
obtained by the above-mentioned conventional processes have a
PC content of around 25% which is not always satisfactory.
The present invention provides a proce~s for producing a
crude oil~containing phospholipids having a PC content higher
than that of a arude oil produced by the conventional
prQcess.
In a usual process for reEining a crude oil, an
inorganic acid such as phosphoric acid or an organic acid
such as citric acid is added in the degumming step
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so as to increase the degumming effect. Then, an alkali such
as an aqueous sodium hydroxide solution is added thereto to
conduct the deacidification and an adsorbent such as active
clay is added thereto to decolorize the product. Finally,
the product is deodorized by, for example, steam distillation
to obtain the refined oil.
Thus, in the conventional refining process, troublesome
operations and some chemicals are necessitated and, in
addition, repeated water washing and drying are indispensable
for removing a soap and alkali from the oil.
The present in~ention also provides a crude oil which
can be refined by a process which is simpler than the
conventional process, in which the number of the steps is
smaller than that of the conventional process and the amounts
of the chemicals used are smaller than those of the latter to
reduce the cost.
According to the present invention starting vegetable
seeds or a press cakes obtained after pressing the seeds are
subjected to a special heat treatment.
The present invention provides (1) a process for
producing a crude vegetable Gil characterized in that live
steam is directly introduced into crushed or
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3~7359
-- 5
non-crushed vegetable seeds to elevate the temperature
o the seeds -to 80C or higher within 30 min., the tem-
perature is ]cept at that point for at least 30 sec. and
the seeds are dried and then treated in an ordinary
manner to obtain the crude vegetable oil, and (2) a
process Eor producirlg a crude vegetable oil characterized
in lhat c:rushecl or non-crushed vegetable seeds a:re Eed
into a press at ambient temperature to 60C to extract
a major par-t of an oil thereErom, immediately -thereafter
live steam is directly introduced in the pressed cake to
elevate -the temperature oÆ the pressed cake to ~0C or
higher wi-thin 30 min., the temperature is kept at that
point for at least 3~ sec. and the cake is dried and -then
trea-ted in an ordinary manner to obtain the crude vege--
table oil.
DET~ILED DESCRIPTION OF THE INVENTION:
Though the process oE the present invention can be
empLoyed in the production of any of crude oils from seeds
of vegetables usually used as starting materiaLs for oils
and ;Eats, the process is suitable particular:Ly when the
sLart:ing materi.al is rapeseeds, saE~Lower seeds, sunElowe~
seeds, cotton seeds or llnseeds.
The crushed or non-crushed vegetable seeds are heat-
treated in the first invention. On the other hand, in
the second inven-tion, the crushed or non-crused vegetable
seeds are ~ed in a press such as a screw press at ambient
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735~
t~ perat~rc to 60C -to extrac-t a major part oE the oil,
-tllen the press cake is sealed in a vessel such as a
hea~:ing coLumn and stearn is dirèctly introduced therein
-through the bot-tom of the vessel to conduct the sparging
directly or, alternatively, the press cake is -thrown in
a screw extruder in which steam can be introduced to
heat the ca]ce directly. Though the tempera-ture and the
time :in this step are as described above, it is more
preEerred tha-t the temperature of the seeds or press cake
is elevated to 95~C or higher within 5 min. and then kept
at that point for at least 5 min.
The object of the present invention cannot be
a-ttained unless live steam is thus directly introduced
therein to elevate the temperature in a short time and
then the temperature is kept at that point for a given
period of time. The effect of the present invention
cannot be obtained by the conventional processes wherein
the ternperature is elevated slowly by an indirect heating
and no regard is paid to the reten-tion time.
In the second invention, it is necessary to feed
the vegetable seeds in the press at ambient temperature
to 60C. When an ind:Lrect heating to a high temperature
is conduc~ed once as :in the conventional process, the
object of l:he present invention cannot be attained.
I-t is also necessary -that steam is introduced in the
press cake immediately (preferably within 60 min.).
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When the press calse is heat-treated after leaving the
same Eor a long period of time, the object of the present
:Lnvention cannot be attained.
The eEfect of the present inven-tion can be obtained
also when the vegetable seeds are heat-treated according
-to the present invention and a press cake from this
startlng material is subjected again ~o the heat treat-
ment o~ -the present invention.
The PC conten-t oE the phospholipids in the crude oil
produced by -the present invention is as high as 40 % or
above, while that in the crude oil produced by -the con-
ventional process is only around 25 %. Thus, the phos-
pholipids recovered from the crude oil produced by the
present invention are more valuable than the phospholipids
obtained by the conventlonal processes.
On the other hand, PA content of the phospholipids
in the crude oil produced by the present inven-tion is as
low as only 10 % or below~ while that in the crude oil
produced by the conven-tional process is as high as around
30 ~. In addition, since PA is non-hydra-table and PC is
hydratable, the phospholipids (gums) can be removed
eEEect:ively frorn the crude oil obtalned by the present
inverlt:Lon merely by addi.ng water thereto to obta.in a raw
o:i.l having only a very ~ow phospholipid con-tent.
~ lor example, a raw oil ob~ained by adding wate:r to
the crude oil to conduct the degumming accordlng to -the
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~ ~7359
present in~en-tion has a phospholipid content oE V.05 ~,
while the phospholipid content oE that obtained by the
conventional process is around 1.5 ~. When the oil is
soybean oil, the phospholipid content is 0.05 ~ or below
according to ~he present invention, while it is around
0.5 ~ according to the conventional process. Therefore,
the present inven-tion has an advantage that -the s-tep of
degumllling of the start:ing o:il and the deacidification
step which are i.ndispensable in the conventional process
are not always necessary in the present inven-tion.
~ccordingly, costs of chemicals are substantially unneces-
sary and the mechanical devices such as a centrifugal
separator and the process are simplified. Na~ely, the
crude oil can directly be subjec-ted;to a steam reEining
process (SR process) to obtain a refined oil having
a h:igh quality by effectively eliminating a dye, Eree
fatty acids and offensive components simultaneously.
~s described above, two steps, i.e. a step of extracting
an oil by press and then a step of ex-traction wi-th a
solvent, are indispensable in the extraction of the oil
:Erom seeds having a h.igh oil content such as rapeseeds or
safElower according to the conven-tional process and thus
-the operat:Lon o~ the direct extraction with solven-t i5
diEE:icult. Elowever, when the starting material treated
acco:rd.ing to the process of the present inven-tion is
used, the oil can be extracted directly with a solvent
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3'73~9
advantageously.
Fur-ther in the degumming step and deacidification
step in the conventional process, a large amount of oil
Eoo-ts mainly comprising a gum or fatty acid soaps are
formed and, therefore, they must be decomposed wi-th an
acid. Ilowever, the acid decomposition has defects that
the trea-tment of a waste water becomes clifficult Ere-
quen-t:l.y, since the phospholipids in a high concen-tration
are ermulsified and that the pollution load is extremely
high. The present invention has advantages that the
phospholipid content of the oil is low, that the forma-
tion of the oil foots is only slight and that the waste
water can be treated easily.
Examples:
Example 1
Rapeseeds were roughly crushed to such an extent
that no whole seeds remained. The product was heated
to 98C in a stack cooker. In this step, the steam
introduction rate was controlled so that the temperature
of the starting material would be elevated to 95C or
higher within S min. and the heating was conducted for
10 mln. in -total. Then -the starting rnaterial was dried
by introduc-tion oE hot air and pressed with a screw press
to obtain a pressed o:il and a press cake. The press calce
was placed :in an ex-tractor and ex-tracted with hexane at
60UC. Three batches of the extraction were conducted
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-- 10 --
for 75 min., -the time required for ~ach batch being
25 min. The obtained extraction micella was dis-tilled
to ob-tain a distillate having a phospholipid content of
1.8 ~ (PC content of the phospholipids: 41.4 ~). 3 ~ oE
water was added to the crude rapeseed oil in an ordinary
manner to conduct hydration and degumming and to obtain
a raw rapeseed oil and oil foots in which PC content of
the phospholipids was 43.4 ~. The amounts of other com-
ponents were as shown in Table 1.
Example 2
The same rapeseeds as in Example 1 were roughly
crushed to such an extent that no whole seeds remained.
The p~oduct was fed in a screw press at ambielt tempera-
ture to obtain a pressed oil and a press cake. The press
cake was immediately placed in the same stack cooher as
ln Example 1 and heated to 98C. In this step, the steam
introduction rate was controlled so that the temperature
of the cake would be elevated to 95C or higher within
5 min. and the heating was conducted for 10 min. in totaI.
Then the cake was dried by heating with hot air, placed
,in an extractor and extxacted with hexane at 60C. Th:ree
batches o:E the extraction were conducted Eor 75 rnin.,
the l::l.me requ.ired ;~or each batch being 25 min., as in
Examp:le 1. The obta:ined extraction micel1a was distilled
to obtain a distillate having a phospholipid content of
1.8 ~ (PC content of the phospholipids: 42.4 %). 3 ~ of
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water was added to the crude rapeseed oil in an ordinary
manner -to conduct hydration and degumming and to obtain
a raw rapeseed oil and oil foots in which PC content of
the phospholipids was 38.2 ~ The amoun-ts of other
components were as shown in Table 1.
Example 3
The press cake obtained in Example 2 was placed in
EXP~NI)ER (a trade -~a~e~of TECNAL Co., Brazil) immediately
aEter the press. The steam introduction rate was con-
-trolled so that -the temperature oE the cake would be
elevated to 95C within 5 min. This device was a screw
extruder having a function of heating by the direct
introduction of steam. The cake shaped in-to pelle-ts
was dried and then extracted in an extractor wi-th hexane
a-t 60C. Three batches of the extraction were conducted
for 75 min., the time required for each batch being 25 min.,
AS in Example 1. The obtained extraction micella was
distilled to ob-tain a distillate having a phospholipid
content of 1.8 ~ (PC conten-t of the phospholipids: 41.8 %).
3 ~ of water was added to the crude rapeseed oil irl an
ordinary manner to conduct the hydration and degumming
and to obta:in a raw rapesee,d oil and oil ~oots in whlch
PC content of -the phospholipids was 39.4 ~. ,The amounts
oE other components were as shown ii~ Table 1.
Example 4
Rapeseeds were roughly crushed -to such an extent that
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r:37359
- 12 -
no whole seeds remained. The product was placed in the
same ~XPANDER as in Example 3. The steam introduc-tion
rate was con-trolled so tha-t the temperature would be
elevated -to 95C within 5 min. After heating Eor 4 min.,
the thus treated material was dried. A pressed oil and
ex-traction micella were obtained in the same manner as
:in Example l. The extraction micella was distilled to
obta:in a distillate having a phospholipid conterlt of
1.7 ~ (PC content oE the phospholipids: 42.5 ~). 3 % of
water was added to the crude rapeseed oil in an ordinary
manner to conduct the hydration and degumming and to
obtain a raw rapeseed oil and oil foots in which PC
content of the phospholipids was 40.5 ~. 2 ~ of an acid
clay was added to the raw oil and the mixture was heated
at 105C + 5C in ~acuum Eor 20~ min. to decolorize the
oil. The acid clay was removed by filtration. The
decolorized oil was heated at 260C in vacuum (1 to
3 mmHg) for 90 min. while 3 to 5 %, based on the oil,
of steam was introduced therein. The thus reflned oil
had a quali-ty comparable to that of an oil refined by
an ordinary process, though the former was not subjected
to the degumming step or deacidi.~ication step wi-th an
allcali. The amounts oE other components were as shown
:Ln Table l.
Exalnple 5
Rapeseeds were -.^oughly crushed to such an ex-tent
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1~373~
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that no whole seeds remained. The product was placed
in the same EXPANDER as in Example 3. The steam in-tro-
duc-tlon rate was controlled so that the temperature would
be elevated to 98C within 10 min. After heating for
3 min., the thus treated material was dried and the
whole amount of the material was subiected to the
extraction with hexane at 60C. The extraction proce-
dure could be conducted smoo-thly. The extraction micella
was d:istilled to obtain a distillate having a phospho-
lipid con-tent of 1.7 % (PC content of the phospholipids:
40.8 ~). The amounts of other components were as shown
in Table 1.
Example 6
The skins of soy bèans were removed and the beans
were flaked. They were placed in the same EXPANDER as
in Example 3. The steam introduction rate was controlled
so that the temperature would be elevated to 95C within
5 min. After heating for 3 min., the thus treated material
was dried and the whole amount of the material was sub-
jected to the extraction with industrial hexane at 60C.
The ex-trac-tion micella was distilled to obtain a dlstil-
:Late having a phospholipid con-tent of 1.8 ~ (PC content
oE the phospholipids: 30.8 ~). The amounts of other
components were as shown in Table 1.
Comparative Example 1
The same rapeseeds as in Example 1 were roughly
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-- 14
crushed to such an exten-t that no whole seeds remained,
the obtained product was further pulverize~, flaked,
heat--trea-ted by indirect heating (90 to 110C) to break
the cells and pressed in a screw press in an ordinary
manner to obtain a pressed oil and a press cake. The
press cake was extracted with industrial hexane at 60C
by the above-mentioned extraction process. The obtained
extraction micella was distilled to obtain a distilla-te
having a phospholipid content oE 1.7 % (PC content of
-the phospholipids: 26.4 %). 3 % of water was added to
the crude rapeseed oil in an ordinary manner to conduct
the hydration and degumming and to obtain a raw rapeseed
oil and oil foots in which PC content of the phospholipids
was 27.3 %.
Comparative Example 2
The press cake obtained in Example 2 was lef-t to
stand for 24 h. and then it was heated, dried and sub-
jected to the e~traction.
Comparative Example 3
1'he press cake obtained in Example 2 was subjected
to the ex-trac-tion with the solvent without heating.
Con~parak:ive Example 4
The ex-trac-ted oil ob-tained in Example 1 was reEined
by an ordinary refin:Lng process. In particular, 0~05
oE phosphoric acid was addea thereto, the mixture was
st.irred, 16Be sodium hydroxide was added thereto in
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-- 15 --
an amount of 120 % based on the acid value of the oll and
the mix-ture was stirred at 85 to 90C. Then, the mixture
was contrifuged to separa~e a soap stock. 12Be sodium
hydroxide was added thereto in an amount of 1 % based on
the oil. The mixture was stirred at 85 to 90C and cen-
-trifuged to separate a soap stock. The oil was washed
w:ith water and dried. 1 % of clay was added thereto and
l.he m:ixture was heated at 105C in vacuum or 20 m:in. to
bleach the ~il. rrhe clay was removed by filtra-tion.
The bleached oil was deodorized by heating at 260C for
90 min. while 3 to 5 % , based on the oil, of steam was
introduced therein in vacuum (1 to 3 mmllg). The quali.ty
of the thus obtainea refined oil was substantially the
same as that in Example 4, although the oil was treated
according to the above-mentioned steps.
The composition of the phospholipids in the crude
rapeseed oils obtained in the above examples and compara-
tive examples were as shown in Table 1.
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