AU670420B2 - Cereal extracts - Google Patents

Description

OPI DATE 15/06/93 AOJP DATE 19/08/93 APPLN. ID 29488/92 II 11111 ill1111II PCT NUMBER PCT/GB92/02122 11111111111111 IN AU9229488

(PCT)

(51) International Patent Classification 5 International Publication Number: WO 93/10157 CO8B 37/14, D21C 5/00 Al (43) International Publication Date: 27 May 1993 (27.05.93) (21) International Application Number: PCT/GB92/02122 (74) Agent: WILKINSON, Stephen, John: Stevens, Hewlett Perkins, I St. Augustine's Place, Bristol BSI 4UD (GB).

(22) International Filing Date: 16 November 1992 (16.11.92) (81) Designated States: AT, AU, BB, BG, BR, CA, CH, CS, Priority data: DE, DK, ES, Fl, GB, HU, JP, KP, KR. LK, LU, MG, 9124427.7 16 November 1991 (16.11.91) GB MN, MW, NL, NO, PL, RO, RU, SD, SE, UA, US. Eu- 9205406.3 12 March 1992 (12.03.92) GB ropean patent (AT, BE, CH, DE, DK. ES. FR, GB, GR, 9209094.3 27 April 1992 (27.04.92) GB IE, IT, LU, MC, NL, SE), OAPI patent (BF, BJ, CF, 9214392.4 7 July 1992 (07.07.92) GB CG, CI, CM, GA, GN, ML, MR, SN, TD, TG).

(71) Applicant (for all designated States except US): CPC IN- Published TERNATIONAL INC. [US/US]; P.O. Box 8000, Inter- With international search report.

national Plaza, Englewood Cliffs, NJ 07632 Before the expiration of the time limit for amending the claims and to be republished in the event of the receipt of (72) Inventors; and amendments.

Inventors/Applicants (for US only) GREENSHIELDS, Roderick, Norman [GB/GB]; 4 Beaconsfield Court, Sketty, Swansea SA2 9JU REES, Artis, Llywelyn [GB/GB]; I Brynawel, Pontardawe, Swansea SA8 4JP

(GB).

(54) Title: CEREAL EXTRACTS (57) Abstract Two cereal extracts are produced by means of a process comprising the steps of milling cereal material, suspending the milled material in an aqueous liquid, treating the suspension with an alkali, acidifying and separating the solid and liquid in the resulting mixture. The liquid and solid may be further purified and are useful as ingredients in comestible products.

24 JANUARY 1q94 CEREAL EXTRACTS This invention relates to a process for producing cereal extracts.

The use of corn bran extracts as bulking agents in food products is well-known. US 4927654 discloses a process for producing hemicellulose extracts from delignified plant fibres, such as corn bran, by extracting the plant fibres with sodium hydroxide solution and acidifying the resulting mixture to precipitate a first hemicellulose fraction. A second hemicellulose fraction is precipitated from the resulting filtrate by the addition of ethanol.

The present invention provides a process for producing two novel extracts from cereal-derived material.

A first cellulose-containing extract may be obtained by the following process. The extract may be produced as an insoluble bleached cellulose residue of alkaline extracted cereal material cell walls of maize bran) and may contain other insoluble biopolymers besides cellulose.

Accordingly, the present invention provides a process for producing a cellulose-containing cereal extract produced by the process comprising the steps of: milling cereal material; (ii) suspending the milled cereal material in an aqueous liquid; (iii) treating the resulting suspension with an alkali; (iv) lowering the pH of the treated suspension to from 5 to 7; separating the solids and the liquid in the nQr :i UJT SHEET T L I resulting mixture; (vi) treating the solids with hydrogen peroxide; (vii) washing the treated solids; and (viii) optionally drying the washed solids.

Step (vi) can comprise the following steps: resuspending the separated solids in an aqueous liquid; raising the pH of the resulting suspension; treating the mixture with hydrogen peroxide; lowering the pH of the mixture to below 7; and separating the solids from the mixture.

The cereal material is preferably milled (either in wet or dry form) to a particle size of from 50 to 250 Lm 80 to 180 tm. The aqueous liquid in which the milled cereal material is suspended is preferably water but may also be a solution or a suspension of other substances in water provided that this does not adversely interfere with the subsequent steps in S15 the process. The suspension preferably contains from 5 to 10% dry :1 S weight/volume of milled corn bran and may be formed at ambient temperature.

The cereal material is preferably cereal husk or bran and may be obtained from cereals such as maize, corn, barley, wheat, rice or oats, or malt or malt culms. Preferably the cereal S material is corn bran. The milled material may be air classified or sieved to remove starch 20 and the starch removal process may comprise starch removal by suitable enzyme treatment, for example, with diatase (alpha- or beta-amylase).

Many alkalis may be used to effect the alkaline treatment step (step (iii)) of the process metal hydroxides such as sodium and potassium hydroxides or metal carbonates such as sodium or calcium carbonate. Preferably, potassium hydroxide in the form of a solid) is added to the suspension to provide a concentration of not less than 48 w/v of KOH. The mixture may be stirred to dissolve the potassium hydroxide. This is accompanied by a colour S change to bright yellow or orange. The mixture is preferably .o.o.o [N:\LIBAA]00470;KE 3 heated to from 700 to 80 0 C for from 11 to 21 hours in order to effect maximum extraction or until a rapid increase in viscosity is noticed. The reaction mixture is then adjusted to a pH of from 5 to 7 neutral pH) with an acid dilute or concentrated hydrochloric acid). This may be accompanied by a visible paling in colour and "clouding" of the material. The extract is preferably separated from the insoluble material by filtration through a coarse filter grade 0 sintered glass at lab scale/5-50 um plastic mesh on larger scale) with the application of partial vacuum or by centrifugation.

The insoluble material may be washed in situ on the filter with warm water to give the desired degree of extraction. Extraction by this process typically yields 45-55% of the dry weight of the material.

The insoluble material obtained from alkali extraction of the hemicellulosic material after step may be resuspended in water 'to give a from 2 to preferably from 2.5 to 3.0% w/v, suspension in water.

The pH is adjusted to from 12 to 13 (preferably 12.2- 12.5) preferably by adding 40% w/v potassium hydroxide solution.

After raising the temperature to from 70 to 0 C) in an indirectly heated vessel, hydrogen peroxide 30 volume or 10 volume) is added preferably in an amount such that the peroxide is present at an amount of from 15 to 20% dry wt/dry wt insoluble material. The temperature is maintained, with gentle stirring, at an elevated temperature preferably from 70 to 80 0 C (such as from 70 to 75 0

C)

,C for from 2 to 5 hours 3-4 hours). Allowance 24 JANUARY 1994 4 should be made in the capacity of the vessel for up to foaming on addition of peroxide. The suspension may be stored for some days at this stage without loss or damage.

Following the reaction with peroxide, the pH of the suspension is "lowered to below 7 from 5.5 to with an acid such as hydrochloric acid.

Solubilised material is preferably removed by filtration under partial vacuum. (Grade 0 sintered glass filter on laboratory scale, 5-50 pm plastic mesh on larger scale).

The insoluble material may then be washed on the filter with water, preferably with at least 3 volumes of water. The washed material may be stored aseptically, or suspended and spray dried.

This extract can be used as a bulking agent in foodstuffs but also possesses lipomimetic properties.

The hemicellulose-based extract obtained in the extraction process may be purified in the following manner: 1 Extracts and washings are combined and diluted such that the total dissolved solids are in the region of 2.5% w/v.

2 The diluted extract is applied to a tangential flow ultrafiltration apparatus. (Under the following conditions during a pilot scale trial).

Starting volume 100 litres Membrane area 6 m 2 Membrane configuration parallel tubes Pjr/' 2/0 21227 :-np 5 Membrane type Average flux rate Run time polysulphone 15,000 mwco 9 to 10 litres m-2.h- 1 85 min The concentrated retentate was diluted with 30 1 of water and the operation repeated three times before the solids content of the filtrate approaches zero.

Further decolourisation and deodorisation may be achieved by passing the diluted desalted filtrate over a carbon column containing Anthrosorb for odour removal and Norit C for colour removal.

The extract which at this stage is quite viscous may be dried by freeze drying, vacuum drying or spray drying. The extract is essentially an alkali-soluble comolex hemicellulose mixture.

The extract may be used as a bulking agent or a thickening agent in food products) and has adhesive properties.

The present invention thus allows the production of both an insoluble polysaccharide and an alkali soluble polysaccharide which may be used as food ingredients.

PCT inti~nli'll a-001121 rirc

Claims (12)

1. A cellulose-containing cereal extract produced by the process comprising the steps of: milling cereal material; (ii) suspending the milled cereal material in an aqueous liquid; (iii) treating the resulting suspension with an alkali; (iv) lowering the pH of the treated suspension to from 5 to 7; separating the solids and the liquid in the resulting mixture; (vi) treating the solids with hydrogen peroxide; (vii) washing the treated solids; and (viii) optionally drying the washed solids.

2. A cereal extract as claimed in claim 1, wherein step (vi) comprises the steps: resuspending the separated solids in an aqueous liquid; raising the pH of the resulting suspension; treating the mixture with hydrogen peroxide; lowering the pH of the mixture to below 7; and separating the solids from the mixture.

3. A cereal extract as claimed in claim 2, wherein in step the suspension contains from 2 to 5 w/v separated solids. 20 4. A cereal extract as claimed in claim 2 or claim 3, wherein in step the pH of the suspension is raised to from 12 to 13 by the addition of potassium hydroxide solution.

5. A cereal extract as claimed in any one of claims 2 to 4, wherein in step (c) hydrogen peroxide is added in an amount to give from 15 to 20% weight hydrogen peroxide/weight insoluble material and the mixture is maintained at from 70 to 80 0 C for from 2 to 5 hours. o6. A cereal extract as claimed in any one of claims 2 to 5, wherein in step the pH of the mixture is lowered to from 5.5 to 6.0 with hydrochloric acid.

7. A cereal extract as claimed in any one of claims 2 to 6, wherein in step the solids are separated from the mixture by filtration.

8. A cereal extract as claimed in any one of claims 1 to 7, wherein the cereal material is husk or bran.

9. A cereal extract as claimed in any one of claims 1 to 8, wherein the cereal is corn. A cereal extract as claimed in any one of claims 1 to 9, wherein the suspension formed in step (ii) contains from 5 to 10% dry weight/volume of milled cereal material.

11. A cereal extract as claimed in any one of claims 1 to 10, wherein in step the cereal material is milled to a size of from 50 to 250pmm.

12. A cereal extract as claimed in claim 11, wherein the cereal material is milled to Ssize of from 80 to 180[mn. [N:\LIBAA0047O:KEFI

13. A cereal extract as claimed in any one of claims 1 to 12, wherein step (iii) comprises the addition of potassium hydroxide in an amount such that the mixture contains potassium hydroxide at a concentration of at least 4% weight/volume and maintaining the mixture for a time and at a temperature until a rapid increase in the viscosity of the mixture occurs.

14. A cereal extract as claimed in claim 13, wherein the mixture is maintained at from 70 to 80°C for from 11/2 to 21/2 hours. A cereal extract as claimed in any one of claims 1 to 14, wherein the separation in step is effected by filtration. Dated 7 May, 1996 CPC International Inc. Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON S eo e *S o [N:\LIBAAJ00470:KEII INTERNATIONAL SEARCH REPORT International Application No PCT/GB 92/02122 I. CLASSIFICATION OF SUBJECT MATTER (If several classification symbols apply, indicate all)' According to International Patent classification (IPC) or to both National Classification and IPC Int.Cl. 5 C08B37/14; D21C5/00 11. FIELDS SEARCHED Minimum Documentation Searched7 Classification System Classification Symbols Int.Cl. 5 C08B ;D21C Documentation Searched other than Minimum Documentation to the Extent that such Documents are included in the Fields Searcheds

113. DOCUMENTS CONSIDERED TO BE RELEVANT 9 Category 0 Citation of Document, it with indication, where appropriate, of the relevat passages L2 Relevant to Claim No.1 3 X EP,A,O 371 493 (NISSHIN FLOUR MILLING CO. 1,2,9-12 LTD) 6 June 1990 see page 3, line 34 line 46; example 1 y 3-5,8, 13,14, 16,18 Y US,A,4 239 906 (ANTRIM ET AL.) 3-5,8, 16 December 1980 13,14, 16,18 see column 6, line 16 column 7, line 28 oSpecial categories of cited documents 10 T71 later document published after the international filing date ~A dcumnt efiingthegenral tat ofthean hic isnotor priority date and not in conflict with the application but ''dcnside nn toe gatenealueo thearwichisno cite to understand the principle or theory tunderlying the consdere tobe o paticuar elevnceinvention 'E earlier document but published on or after the international 'X document of particular relevance; the claimed Invention filing date cannot be consideed novel or cannot be considered to document which may throw doubts oprority claim(s) or involve ant inventive step which Is cited to establish the pub[].a on date of aother Y' document of particular relevance; the claimed invention citation or other special reason (as specified) cannot be considered to Involve an Inventive step when the *0 document referring to an oral disclosure, use, exhibition or document is combined with one or more other such docti- other means ments, such combination being obvious to a person skilled 'P document published prior to the international filing date but in the art. later than the priority date claimed 'A document member of the same patent family 2 IV. CERTIFICATION Date of the Actual Completion of the International Search Date of Mailing of this International Search Report 01 MARCH 1993 2 3. 01 93 Inteaaioaal Searcing Autholt Signatiure of Auitlioiiz Officer EUROPEAN PATENT OFFCE MAZET J F. Fm. ?Cl7ISAfllO (Mmd maol (jn 7 Ifti) PCT/GB 92/02122 International Application No 111. DOCUMENTS CONSIDERED TO BIE RELEVANT (CONTINUED FROM THE SECOND SHEET) Category 0 Citation of Document, with indication, where appropriate, of the relev'ant passage Relevant to Claim No. Y US,A,4 649 113 (Jl. M. GOULD) 3-5,8, March 1987 13,14, 16,18 see column 2, line 60 column 3, line 3 see column 3, line 39 line 42 see column 3, line 51 line 54 see column 3, line 58 line 62 see column 4, line 66 column 5, line 22 A US,A,2 801 955 RUTENBERG) 1-3,6,8, 6 August 1957 9,11,12 see column 1, line 43 line see column 2, line 65 column 3,-line 21 A US,A,2 709 699 J. WOLF) 1-4,8,9 31 May 1955 see the whole document A DATABASE WPIL 1,2,6,9, Week 9007, Derwent Publications Ltd., London, GB; AN 90-048354 JP,A,2 001 701 (NISSHIN FLOUR MILL KK) 8 January 1990 see abstract Fee PCMISA21 (an" Lb") IJNNUV ANNEX TO THE INTERNATIONAL SEARCH REPORT ON INTERNATIONAL PATENT APPLICATION NO. GB 9202122 SA 67501 This annex lists the patent family members relating to the patent documents cited in the above-mentioned international scarch report. The members are as contained in the European Patent Office EDP file on The European Patent Office is in no way liable for these particulars which are merely given for the purpose of information. 01/03/93 Ptat document Publication Patent family Publication cited in search report dat memberfs) dat EP-A-0371493 06-06-90 JP-A- 2149532 08-06-90 AU-B- 626610 06-08-92 AU-A- 4577689 07-06-90 DE-U- 6890298 29-10-92 'US-A- 5174998 29-12-92 US-A-4239906 16-12-80 None US-A-4649113 10-03-87 CA-A- 1242191 20-09-88 US-A- 4806475 21-02-89 US-A-2801955 None US-A-2709699 None bi For more details about this annex e Official Journal of the European Patent Office, No. 12/82