CA1120779A

CA1120779A - Process for improving the properties of meals and flours of oily seeds

Info

Publication number: CA1120779A
Application number: CA000315711A
Authority: CA
Inventors: Merten Schlingmann; Gert-Wolfhard Von Rymon Lipinski
Original assignee: Hoechst AG
Current assignee: Hoechst AG
Priority date: 1977-11-02
Filing date: 1978-11-01
Publication date: 1982-03-30
Also published as: GB2030441A; FR2423988B1; FR2423988A1; GB2030441B; JPS5484052A; DE2748885A1; BE871745A; JPS6219820B2; NL7810892A

Abstract

PROCESS FOR IMPROVING THE PROPERTIES OF MEALS AND
FLOURS OF OILY SEEDS
Abstract of the disclosure:
A process for improving the properties of meals or flours of oily seeds by reducing their content of lipoid and water-soluble compounds, which comprises treating the crushed or ground seeds with an liquid extractant compris-ing ammonia or ammonium hydroxide and an organic solvent of the formula I
R1 - (CnH2n) - OR2 (I) in which either R1 and R2 each are hydrogen and n is 1, 2 or 3; or R1 is a hydroxy group, R2 is hydrogen, methyl or ethyl, and n is 2 or 3;
and after having removed the liquid extractant, washing the residue of the seeds with water.

Description

l~.Z~3779

- 2 - HOE 77/F 225 The invention provides a process for improving the properties of meals or flours of oily seeds by reducing their content of lipoid and water soluble compounds which have a negative influence on their smell, taste, nutrî-tive value and physiological acceptability. The smell is ~ adversely affected for example by secondary products of oxidation reactions of unsaturated fatty acids; peptidss containing certain components cause a bitter taste; some glycosldes such as mustard oil glycoside are toxic; and nucleic acids can provoke a pathological condition suchas gout or urinary calculi. Application of flours of oily seeds in fodder and especially food is thus limited to a large extent by the content of such compounds.
It is therefore the object of the present invention to remove lipoid compounds such as fat oxidation produots, nucleic acids, peptldes containing large amounts of hydro-phobic amino acids, and glycosides from ground oily seeds, and thus to increase the protein amount which is deci~sive for the nutritive value.
According to known processes, the lipides are removed , from cells by organic solvents, and the content of ama- -roids and toxic metabolites is reduced by extraction with water. However, the long extraction time is disadvantage- ~
ous, and the treatment of flours of oily seeds with orga- -nic solvents such as hexane is time-consuming as well and yields products which, because of their content of resi-dual fat (l to 4 ~) are neither free from disagreable smell nor stable in taste.
29 In accordance with this invention, there has been .. :..................................................... ~ ~

: . . . . .

- 3 - HOE 77/F 225 found a process for improving the properties of meals or ; flours of oily seeds by reducing their content of lipoid and water-soluble compounds, which comprises treating the crushed or ground seeds with a liquid extractant compris-ing ammonia or ammonium hydroxide and an organic solvent of the formula I
R1 - (CnH2n) ~ OR2 (I) in which either R1 and R2 each are hydrogen and n is 1, 2 or 3; or R1 is a hydroxy group, R2 is hydrogen, methyl or ethyl, and n is 2 or 3;
and after having removed the liquid extractant, washing the residue of the seeds with water.
As crushed or ground seeds there are used oily seeds the meals or flours of which, after degreasing, are con-sidered as protein carriers, for example soybean, rape, peanut, sunflower or cotton seeds.
Suitable solvents of formula I are advantageously al-cohols such as methanol, ethanol, n-propanol or isopropa-nol. Preferred are methanol and ethanol, especially metha-nol. Apart from the citad alcohols, glycols and their ;~ monoethers of formula I may be employed, especially glycol or monomethylglycol.
Ammonia can be added to the cited solvents either~in gaseous form (NH3) or as concentrated aqueous solution (NH40H), depending on the water content of the meal or - -flour, and on the amount of the solvent used and the water content thereof. NH40E~ is suitable ~or flour having a low 29 moisture content (O to 15 % ), NH3 is appropriate in the `; ,.

:

1~ 20779

- 4 - HOE 77/F 225 case of cell masses containing more water (10 to 30 %)~
Removal of the lipoid compounds depends on the total - water content (in weight % relative to the amount of sol-vent used) and on the NH3 concentration (in weight %, re-lative to the solvent used).
Especially good results are obtained at a meal or flour/solvent weight ratio of from 1:3 to 1:10 when r,letha-nol or ethanol is used, and f`rom 1:8 to 1:15 in the case of employing propanol, glycol or monoglycol ethers. The corresponding ammonia concentration, relative to the amount of solvent, is from 1 to 15, preferably 5 to 10, weight %.
The sum of the water amounts present in the cell mass, sol-vent and, optionally, aqueous ammonia, is from O to 30, preferably O to 20, especially O to 10, weight ~, relative to the solvent amount used.
'rhe fats are separated from the crushed or ground seeds by suspending the flour in the solvent, and NH3 is introduced or NH~OH is added subsequently. The suspension is advantageously agitated in order to ensure thorough in- ~ -: .
termixing. The temperatures of the treatment are general-ly in a range of from -2 to +60C, preferably 5 to 50C, and especially 10 to 30C. The time of treatment is from

5 to 180? preferably 35 to 60, minutes. Generally, the treatment is carried out under normal pressure.
After the solvent/ammonia treatment is completej the ;
degreased residue is separated from the solvent according to any usual method such as centrifugation, filtration or sedimentation; filtration ~eing preferred.
29 In order to remove the lipids as completely as pos-:, , :

::

t~79 sible, the solid residue obtained can be treated again with an organic solvent. For removing solvent remainders and ammonia, the residue can be dried, advantageously under reduced pressure, preferably of from 80 to 150 ~m Hg, and at slightly elevated temperatures, preferably of-from 40 to 50C. The products so degreased and dried are odorless and nearly white.
The liquid phase separated frorn the solid phase ac-cording to the above method contains ammonia and lipoid compounds. The solvent used can be separated from the fats by vacuum distillation, and reused. The remaining fats can be subsequently subjected to the usual fat refining - operations.
Subsequently, the degreased and optionally dried flours are absorbed in water. Preferred are such amounts of water which are in a weight ratio of from 1:t to 1:30, especially l:5 to 1:i5, to the meal or flour; at least, the quantity of water must allow agitation of the suspen-sion.
During the treatment with water, the pH should be in the range of from 4 to ~.5, preferably 5 to 7.5. Optional-ly, it has to be adjusted correspondingly, which is re~uir-ed above all in the case where flours from the first extrac-tion steps are used which are not at all or incompletely dried and thus contain residual amounts of ammonia possib-ly causing a high pH. This extraction is to reduce the content of undesirable metabolites such as nucleic acids, bitter peptides or toxic glycosides, and it is generally 29 carried out at a temperature of from 30 to 95C, preferably . , ` :
.

l~ Z~7g

- 6 - HOE 77/F 225 . _ 40 to 70C, especially 50 to 60C, under normal pressure.
Depending on the extraction temperature and the amount of water, the extraction time is in a range of from 5 to 120 ~-minutes; good results are obtained within a period of from 25 to 45 minutes. For separating solid and liquid components, the suspension is filtered, preferably at temperatures of from 10 to 30C. Further suitable separa-tion processes are sedimentation or centrifugation.
The solid phase is liberated from liquid remainders according to usual methods such as vaccum freeze drying, vacuum drying or spray drying.
The products have agreable taste and odor, a very pro-nounced water-binding power, and a white color. These pro- ;
pertiés are not deteriorated even after a several month's storage.
The products treated according to this invention have an especially low content of lipoid compounds (0.3 to 0.8 weight %) and nucleic acid (0.4 to O.g weight %), which makes them particularly appropriate as fodder and additive for foodstuffs.
The process of the invention avoids the disadvantages of known solvent extractions such as large solvent amounts and long treatment times.
The ammonia used in accordance with the invention does not only act as solvent, but changes also the mecha-; nical structure of the flours, so that the extraction time is reduced and the efficiency of the extraction is in-creased.
29 The following Examples illustrate the invention.

077~

- 7 - HOE 77/ 225 E X A M P L E 1:
1iO g of ground soybean seeds having a residual moi-sture of 11 %, 23 % of crude fat (after acidic hydrolysis), 44.6 p of crude protein (N2 x 6.25), 4.3 % of nucleic acids and 4.8 % of ashes were suspended in 500 g of methanol.
While agitating the suspension, 15 g of NH3 gas were introduced and dissolved. The temperature was maintained by cooling at 25 - 35C during this introduction. The mix-ture of methanol, ammonia and flour was agitat~d for 30 mi-nutes at 20C.
In order to separate the solid and the liquid phase,the batch was filtered, and the solid residue was extract-ed once with 100 ml of methanol and once with 300 ml of acetone. After another filtration, the ~iltrates were united. This brown solution contained the lipoid com-pounds of the starting substance. Methanol, acetone and ammonia were removed by vacuum distillation (100 mm Hg, 40C~. The residue, that is 22.5 weight % of the dry matter used, was in the form of a brown oil.
The solid residue of the extracted flour obtained in the filtration was dried for 5 hours in vacuo (100 mm Hg) at 40C. 80 g of degreased flour having a residual moisture of 3 % were obtained, which flour was odorless and had a lighter color than the startlng substance.
In order to reduce the content of undesirable water-~
soluble compounds, this cell mass was suspended in 80o ml of water. The pH of the suspension homogenized by agita-tion was 6;9.
29 After raising the temperature to 55C, agitation was ,

- 8 - HOE 77~F 225 continued fc,r a further 20 minutes, the batch was cooled to 30C and separated by filtration to give a solid and a li~
quid phase. The sediment obtained was again mixed with 300 ml of water and agitated for 10 minutes at 20C, sub-sequently filtered again, and finally, the sedimènt wasdried under reduced pressure. Thus, 50 g of a white, odor-less flour were obtained, which has an agreable srnell in moist state.
The result of this and the further Examples are list-ed in Table I.E X A M P L E 2:
': :
Starting material was the same soybean flour as des-cribed in Example 1, and it was subjected to the same pro-cess steps and conditions with the exception that instead of gaseous NH3 40 ml of concentrated NH40H (33 ~ strength) were used as reagent.
E X A M P L E 3: ;;
Operations were as in Example 2; however, 30 g of NH3 were used.
E X A M P L E 4:
: '' - :
Operations were as in Example 2; however, instead of methanol, ethanol was used as solvent.
E X A M P L E 5:
Operations were as in Example 2. Instead of metha nol, i-propanol was used as solvent.
E X A M P L E 6:
The soybean flour as described in Example 1 was used as starting material. 110 g of this flour were extracted 29 as described in Example 3; however, the residue was not 1~ 779

- 9 - HOE 7 /F 225 completely dried. The filter cake remainin~ after a tho-rough suction-filtration which contained 65 ~ of solid~s was suspended in 900 ml of water. The pH adjusted itself to 8.5~ because of the ammonla remaining in the moist matter.
The temperature of the suspension was raised to 65C
with agitation, and after 5 minutes, the pH was adjusted to 6.8 by adding HCl. Subsequently, agitation was cor-` tinued for a further 15 minutes at 65C, the batch was cooled to 40C and filtered. The sediment obtained was dried.
- E X A M P L E 7:
.. ... _ 110 g of rape seeds containing 13 % of water, 42.9 %
of crude fat, 24.7 % of crude protein, 3.7 % of nucleic acid and 4.6 % of ashes were suspended in 500 ml of metha-t5 nol, and 50 g of-NH3 were introduced with agitation and at a temperature of 20C. Subsequently, agitation was con-tinued for 1.5 hours at the latter temperature, and the batch was filtered.
The residue was washed twice with each 100 ml of metha-~ ~ 20 nol and then once with 300 ml of acetone.
;;; At 200 mm Hg and 40C, the residue was dried for 2 hours, and subsequently suspended in 600 ml of water, while~
,"
because of remaining amounts of ammonia a pH of 8.2 adjust~
ed itself. After having raised the temperature to 50C, 25 the pH was readjusted to 6.5 by means of hydrochloric acid, and the mixture was agitated for 45 minutes at 50C.
After cooling to 30C, the batch was filterecl, where- ~ -.
after the residue was washed once with 300 ml of` water at 29 20C. Subsequent lyophilization gava 40 g of a light, : :~
~.

, . .

- 10 - HOE 77/F 225 odorless powder.
E X A M P L E &:
. _ The same rape seed flour as described in Example 7 was used as starting material, which was subjected to the same process steps and conditions as indicated in Example 7; however, instead of methanol n-propanol ~ras used.
T A B L E
. Some analytic data of the products before and after the process.
Weight % relative to dry matter.
- Final products 110 g seeds used (ground) (4 % residual mois~ure) .
Ex. Species Water Crude Nucleic Protein Amount Crude Nucleic Protein content fat acid fat acid wt.-% wt.-% wt.-% wt.-% (g) wt.-% wt.-% ~..-%

?soybean 11 23 1~.3 4051.0 0.7 0.6 60.2 2 " 11 23 4.3 I~o 52.3 0.8 0.8 5~.4 3 tl 11 23 4.3 40 49.4 0.4 0.5 63.2 1~ " 11 23 4.3 40 52.8 0.7 0.7 59.1 " 11 23 4.3 40 53.4 0.8 0.~ 58.7 6' . 11 23 4.3 40 49.8 0.5 o.4 62.8 . .
7rape 13 42.9 3.7 20 40.2 ~0.7 0.5 51.2 8 " 13 42~9 3.7 20 42.6 0.8 o.4 49~.5 :. - :
--.
.. : .

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A process for improving the properties of meals or flours of oily seeds, in which crushed or ground seeds are treated with a liquid extractant comprising ammonia or ammonium hydroxide and an organic solvent of the formula I
R1 - (CnH2n) - OR2 (I) wherein either R1 and R2 each are hydrogen and n is 1, 2 or 3; or R1 is a hydroxy group, R2 is hydrogen, methyl or ethyl, and n is 2 or 3;
the liquid extractant is removed and the residue of the seeds is washed with water.

2. A process as claimed in claim 1, in which the solvent of the formula I is an alcohol having from 1 to 3 carbon atoms.

3. A process as claimed in claim 1, in which the total water content during the extraction is from 0 to 30 weight %, relative to the solvent amount used.

4. A process as claimed in claim 1, claim 2 or claim 3 in which the water content is from 0 to 20 weight %, relative to the solvent amount used.

5. A process as claimed in claim 1, claim 2 or claim 3 in which the water content is from 0 to 10 weight %, relative to the solvent amount used.

6. A process as claimed in claim 1, claim 2 or claim 3 in which the NH3 content during the extraction is from 1 to 15 weight %, relative to the solvent amount used.

7. A process as claimed in claim 1, claim 2 or claim 3 in which the NH3 content during the extraction is 5 to 12 weight %, relative to the solvent amount used.

8. A process as claimed in claim 1, claim 2 or claim 3 in which the NH3 content during the extraction is from 6 to

9 weight %, relative to the solvent amount used.