GB2030441A

GB2030441A - Process for treating meals and flours of oily seeds

Info

Publication number: GB2030441A
Application number: GB7842963A
Authority: GB
Original assignee: Hoechst AG
Current assignee: Hoechst AG
Priority date: 1977-11-02
Filing date: 1978-11-02
Publication date: 1980-04-10
Also published as: BE871745A; JPS5484052A; DE2748885A1; FR2423988B1; CA1120779A; NL7810892A; JPS6219820B2; FR2423988A1; GB2030441B

Abstract

A process for treating meals or flours of oily seeds comprises treating a meal or flour with ammonia or ammonium hydroxide and one or more organic solvent(s> R1-(CnH2n)-OR2 (I> in which either R1 and R2 each represent hydrogen and n is 1, 2 or 3, or R1 represents hydroxy, R2 represents hydrogen, methyl or ethyl., and n is 2 or 3; wherein the organic solvent(s) is/are added to the meal or flour first or at the same time as the ammonia or ammonium hydroxide and an optional subsequent treatment with water which treatments give rise to meals and flour suitable for use in or as fodder and foodstuff additives.

Description

SPECIFICATION A process for treating meals and flours of oily seeds The invention relates to a process for improving the properties of meals or flours of oily seeds.

The meals and flours of oily seeds contain lipoid and water soluble compounds which are detrimental to.

smell, taste, nutritive value and physiological acceptability. For example, the smell is adversely affected by secondary products of oxidation reactions of unsaturated fatty acids; also peptides containing certain components cause a bitter taste, some glycosides, for example mustard oil glycoside, are toxic, and nuciceic acids can provoke certain pathological conditions, for example gout or urinary calculi. The application of flours of oily seeds for use in fodder and especially food is thus limited, to a large extent, by the content of such compounds.

To improve these meals and flours requires the removal of lipoid compounds for example fat oxidation products, of nucleic acids, of peptides containing large amounts of hydrophobic amino acids, and glycosides from ground oily seeds. The result of this will be to increase the amount of protein and so increase the nutritive value.

Lipids may be removed from cells by organic solvents, and the content of amaroids and toxic metabolites is reduced by extraction with water. However, the treatment of flours of oily seeds with organic solvents, for example hexane, is time-consuming and yields products which, because of their content of resisdual fat (1 to 4 %), are neither free from disagreeable smell nor stable in taste; also the extraction treatment takes a iong time.

The present invention provides a process for treating meals or flours of oily seeds, which comprises treating a meal or flour with ammonia or ammonium hydroxide and one or more organic solvent(s) of the general formula R1 - (CnH2n) - OR2 (1) in which either Ri and R2 each represents hydrogen and n is 1,2 or 3: or R1 represents a hydroxy group, R2 represents a hydrogen atom, or a methyl or ethyl group, and n is 2 or 3; wherein the organic solvent(s) is/are added to the meal or flour first or at the same time as the ammonia or ammonium hydroxide.

The meals or flours used may be those which, after degreasing, are considered as protein carriers, for example the flours or meals of soybean, rape, peanut, sunflower or cotton seeds.

Suitable solvents of the general formula (1 ) are advantageously alcohols, for example methanol, ethanol, n-propanol or isopropanol. Preferred solvents are methanol and ethanol, especially methanol. Apart from these solvents glycols and the monoethers thereof of the general formula (1 ) may be used, especially glycol or monomethyiglycol. A mixture of two solvents may also be used, for example methanol and ethanol.

Ammonia may be added to the solvent(s) either in gaseous form (NH3) or as a concentrated aqueous solution of ammonium hydroxide (NH40H), depending on the water content of the meal or flour and on the amount of the solvent used and the water content thereof. NH40H is suitable for flour having a low moisture content (0 to 15 %), whilst NH3 is more appropriate in the case of a higher moisture content (10 to 30 %).

The removal of the lipoid compounds depends on the total water content (in weight % relative to the amount of solvent used) and on the NH3 concentration (in weight %, relative to the solvent used).

Especially good results are obtained at a meal or flour to solvent weight ratio in the range of from 1 : 3 to 1: 10 when methanol or ethanol is used, and in the range of from 1 : 8 to 1:15 when using propanol, a glycol or a monogylcol ether. The corresponding ammonia concentration, relative to the amount of solvent, is in the range of from 1 to 15, preferably 5 to 10, weight %. The total amount of water present in the flour or meal, solvent and, optionally, aqueous ammonia, is in the range of from 0 to 30, preferably 0 to 20, especially 0 to 10, weight %, relative to the amount of solvent used.

Preferably the fats are separated from the crushed or ground seeds by suspending the flour, or meal, in the solvent, and adding either the NH3 or the NH40H subsequently. Advantageously the suspension is agitated in order to ensure thorough intermixing. The temperatures of the treatment are generally in a range of from -2 to 260"C, preferably 5 to 50 C, and especially 10 to 30"C. The time of treatment is in the range of from 5 to 180, preferably 35 to 60, minutes. Generally, the treatment is carried out under normal pressure.

After the solvent/ammonia treatment is complete, the degreased residue may be separated from the solvent by any suitable method, for example centrifugation, filtration or sedimentation; filtration being preferred.

In order to remove the lipoids as completely as possible, the solid residue obtained can be treated again with an organic solvent. To remove any reamining solvent and ammonia, the residue may be dried, advantageously under reduced pressure, which is preferably in the range of from 80 to 150 mm Hg, and at a slightly elevated temperature, preferably in the range of from 40 to 50"C. The products so degreased and dried are odourless and nearly white.

The liquid phase when separated from the solid phase, as above, contains organic solvent(s), ammonia and lipoid compounds. The solvents may be separated from the fats by vacuum distillation, and reused. The remaining fats may be subsequently subjected to the usual fat refining operations.

Subsequently, the degreased and optionally dried flours may be absorbed in water and so further treated to remove water-soluble, undesirable metabolites, for example nucleic acids, bitter peptides or toxic glycosides. Preferred are such amounts of water which are in a weight ration in the range of from 1 1 to 1: 30, especially 1 :5to 1:15, to the meal or flour; at least the quantity of water must allow agitation of the suspension.

During this treatment with water, the pH should be in the range of from 4 to 8.5, preferably 5 to 7.5.

However, the pH may have to be adjusted to these values paritcularly where flours from the first extraction stage are used which have not been dried or have been only partially dried and thus contain residual amounts of ammonia possibly causing a high pH. It is generally carried out at a temperature in the range of from 30 to 95"C, preferably 40 to 700C, especially 50 to 60"C, 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 can be obtained within a period of from 25 to 45 minutes. For separating solid and liquid components, the suspension may be filtered, preferably at temperatures of from 10 to 300C. Further suitable separation processes are sedimentation or centrifugation.

The solid phase may be separated from the liquid phase by such methods as vacuum freeze drying, vacuum drying or spray drying.

The resulting products have an agreeable taste and odour, a very pronounced water-binding power, and are white in colour. These properties do not deteriorate even after several months' storage.

The products treated according to this invention have an especially low content of lipoid compounds (0.3 to 0.8 weight %) and nucelic (0.4 to 0.9 weight %), which makes them particularly appropriate as fodder and additives for foodstuffs.

The process of the invention avoids the disadvantages of prior solvent extraction processes of requiring large amounts of solvent and long treatment times.

There is an additional advantage in this process in that the ammonia used not only acts as solvent, but also changes the mechanical structure of the flours, so that the extraction time is reduced and the efficiency of of extraction is increased.

The following Examples illustrate the invention. Unless otherwise stated all percentages are on a weight basis.

Example 1: 110 g of ground soubean seeds having a residual moisture of 11 23% of crude fat (after acidic hydrolysis), 44.6% 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 at 25 - 35"C during this introduction by cooling. The mixture of methanol, ammonia and flour was agitated for 30 minutes at 200C.

In order to separate the solid and the liquid phase, the batch was filtered, and the solid residue was extracted once with 100 ml of methanol and once with 300 ml of acetone. After another filtration, the filtrates were mixed together. This brown solution contained the lipoid compounds of the starting substance. The methanol, acetone and ammonia were then removed by vacuum distillation (100 mm Hg, 40"C). The residue, that is 22.5% 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 40"C. 80 g of degreased flour having a residual moisture of 3% were obtained, which flour was odourless and had a lightercolourthan the starting substance.

In order to reduce the content of undesirable water-soluble compounds, this cell mass was suspended in 800 ml of water. The pH of this suspension homogenised by agitation was 6.9.

After raising the temperature to 55"C, agitation was continued for a further 20 minutes, the batch was cooled to 300C and separated by filtration to give a solid and a liquid phase. The sediment obtained was again mixed with 300 ml of water and agitated for 10 minutes at 20"C, subsequently filtered again, and finally, the sediment was dried under reduced pressure. Thus, 50 g of a white, odourless flour were obtained, which had an agreeable smell in its moist state.

The result of this and the further Examples are listed in Table I.

Example2: The starting material was the same soybean flour as described in Example land it was subjected to the same process steps and conditions with the exception that instead of gaseous NH3 40 ml of concentrated NH40H (33 % strength) were used as reagent.

Example 3: The procedure was as in Example 2; however, 30 g of NH3 were used.

Example 4: The procedure was as in Example 2; however, instead of methanol, ethanol was used as solvent.

Example 5: The procedure was as in Example 2. Instead of methanol, isopropanol was used as solvent.

Example 6: The soybean flour as described in Example 1 was used as starting material. 110 g of this four were extracted as described in Example 3; however, the residue was not completely dried. The filter cake, which contained 65% of solids, remaining after a thorough suction-filtration was suspended in 900 ml of water. The pH adjusted itself to 8.9 because of the ammonia remaining in the moist matter.

The temperature of the suspension was raised to 65"C with agitation, and after 5 minutes, the pH was adjusted to 6.8 by adding HCI. Subsequently, agitation was continued for a further 15 minutes at 65"C, the batch was cooled to 40"C and filtered. The sediment obtained was dried.

Example 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 methanol, and 50 g of NH3 were introduced with agitation and at a temperature of 20"C. Subsequently, agitation was continued for 1.5 hours at the latter temperature, and the batch was filtered.

The residue was washed twice with each 100 ml of methanol and then once with 300 ml of acetone.

At 200 mm Hg and 40"C, 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 adjusted itself. After having raised the temperature to 50"C, the pH was readjusted to 6.5 by means of hydrochloric acid, and the mixture was agitated for 45 minutes at 500C.

After cooling to 300C, the batch was filtered, whereafter the residue was washed once with 300 ml of water at 20"C. Subsequent lyophilisation gave 40 g of a light, odourless powder.

Example 8 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 was used Table 1 Some analytical data of the products before and after the process.

Weight % relative to dry matter.

Starting Material. Final products 110 g seeds used (ground) (4 % residual moisture) Ex. Species Water Crude Nucleic Protein Amount Crude Nucleic Protein content fat acid fat acid wt.-% wt.-% wt.-% wt.-% (g) wt.-% wt.-% wt.-% 1 soybean 11 23 4.3 40 51.0 0.7 0.6 60.2 2 " 11 23 4.3 40 52.3 0.8 0.8 59.4 3 " 11 23 4.3 40 49.4 0.4 0.5 63.2 4 " 11 23 4.3 40 52.8 0.7 0.7 59.1 5 " 11 23 4.3 40 53.4 0.8 0.9 58.7 6 " 11 23 4.3 40 49.8 0.5 0.4 62.8 7 rape 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 0.4 49.5

Claims

1. A process for treating meals or flours of oily seeds, which comprises treating a meal or flour with ammonia or ammonium hydroxide and one or more organic solvent(s) of the general formula R1 - (CnH2n) - OR2 (I) in which either R1 and R2 each represent a hydrogen atom and n is 1,2 or 3; or R1 represents a hydroxy group, R2 represents a hydrogen atom, or a methyl or ethyl group, and n is 2 or 3; wherein the organic solvent(s) is/are added to the meal or flour first or at the same time as the ammonia or ammonium hydroxide.

2. A process as claimed in claim 1, wherein the ammonia or ammonium hydroxide and organic solvent is added in the form of a liquid.

3. A process as claimed in claim 1 or claim 2, wherein the organic solvent is added to the meal or flour first and the ammonia or amonnium hydroxide added subsequently.

4. A process as claimed in any one of claims 1 to 3, wherein the oily seeds are soybean, rape, peanut, sunflower or cotton seeds.

5. A process as claimed in any one of claims 1 to 4, wherein the organic solvent is an alcohol having from 1 to 3 carbon atoms.

6. A process as claimed in any one of claims 1 to 5, wherein the organic solvent is methanol, ethanol, glycol or monomethyl glycol.

7. A process as claimed in claim 5 or claim 6, wherein the organic solvent is methanol.

8. A process as claimed in any one of claims 1 to 7, wherein when the flour or meal has a moisture content in the range of from 0 to 15% by weight ammonium hydroxide is used.

9. A process as claimed in any one of claims 1 to 7, wherein when the flour or meal has a moisture content in the range of from 10 to 30% by weight gaseous ammonia is used.

10. A process as claimed in any one of claims 1 to 9, wherein the meal or flour to solvent ratio is in the range of from 1:3 to 1:10 by weight, when methanol or ethanol is used.

11. A process as claimed in any one of claims 1 to 9, wherein the meal or flour to solvent ratio is in the range of from 1:8 to 1:15, by weight, when propanol, a glycol or a monoglycol ether is used.

12. A process as claimed in any one of claims 1 to 11, wherein the ammonia concentration is in the range of from 1 to 15% by weight based on the amount of solvent used.

13. A process as claimed in claim 12, wherein the ammonia concentration is in the range of from 5 to 10% by weight based on the amount of solvent used.

14. A process as claimed in any one of claims 1 to 11, wherein the NH3 content is in the range of from 1 to 15% by weight based on the amount of solvent used.

15. A process as claimed in claim 14, wherein the NH3 content is in the range of from 5 to 12% by weight based on the amount of solvent used.

16. A process as claimed in claim 15, wherein the NH3 content is in the range of from 6 to 9% by weight based on the amount of solvent used.

17. A process as claimed in any one of claims 1 to 16, wherein the total amount of water present is in the range of from 0 to 35% by weight based on the amount of solvent used.

18. A process as claimed in claim 17, wherein the total amount of water is in the range of from 0 to 20% by weight based on the amount of solvent used.

19. A process as claimed in claim 18, wherein the total amount of water is in the range of from 0 to 10% by weight based on the amount of solvent used.

20. A process as claimed in any one of claims 1 to 19, wherein the treatment is carried out at a temperature in the range of from-2 to 60"C.

21. A process as claimed in claim 20, wherein the temperature is in the range of from 5 to 50"C.

22. A process as claimed in claim 21, wherein the temperature is in the range of from 10 to 30"C.

23. A process as claimed in any one of claims 1 to 22, wherein the time of treatment is in the range of from Sto 190 minutes.

24. A process as claimed in claim 23, wherein the time of treatment is in the range of from 35 to 60 minutes.

25. A process as claimed in any one of claims 1 to 24, wherein after treatment with ammonia or amonnium hydroxide and the organic solvent the resulting meal or flour is treated with water.

26. A process as claimed in claim 25, wherein the ratio of water to meal or flour is in the range of from 1:1 to 1:30.

27. A process as claimed in claim 26, wherein the ratio of water to meal or flour is in the range of from 1:5 to 1:15.

28. A process as claimed in any one of claims 25 to 27, wherein the pH during treatment with water is in the range of from 4 to 8.5.

29. A process as claimed in claim 22, wherein the pH is in the range of from 5 to 7.5

30. A process as claimed in any one of claims 25 to 29, wherein the temperature during the treatment with water is in the range of from 30 to 95"C.

31. A process as claimed in claim 30, wherein the temperature is in the range of from 40 to 70"C.

32. A process as claimed in claim 31, wherein the temperature is in the range of from 50 to 60"C.

33. A process as claimed in any one of claims 25 to 32, wherein the time of treatment is in the range of from 5 to 120 minutes.

34. A process as claimed in claim 33, wherein the time of treatment is in the range of from 25 to 45 minutes.

35. A process as claimed in any one of claims 1 to 34, wherein the resulting solid phase is separated from the liquid phase by vacuum freeze drying, vacuum drying or spray drying.

36. A process as claimed in claim 1, carried out substantially as described in any one of Examples 1 to 8 herein.

37. A meal or a flour which has been treated by a process as claimed in any one of claims 1 to 36.

38. The use of a meal or flour as claimed in claim 37 in or as fodder.

39. The use of a meal or flour as claimed in claim 37 as an additive for foodstuffs.

40. Fodder which comprises a meal or flour as claimed in claim 37.

41. Afoodstuffwhich contains a meal or flour as claimed in claim 37.