NZ500824A - Production process, used in particular for obtaining lecithin from dehydrated egg - Google Patents

Abstract

A process for obtaining products from animal raw materials containing protein and fat, and in particular for obtaining lecithin from dehydrated egg, characterized in that: A feedstock comprising lipid, phospholipid (lecithin) and protein constituents is subjected to a supercritical extraction process using a solvent for extracting lipids and flavours to yield a decreased feedstock, the lipids and flavours being extracted from the supercritical solvent by pressure reduction; The degreased feedstock with its proteins and phospholipids is subjected to a further extraction stage using a supercritical solvent and an organic solvent, which is liquid under normal conditions, as the entrainer (cosolvent) to separate the phospholipids from the proteins; The extract comprising the phospholipids and the cosolvent is concentrated and removed from the system with the help of a solvent, the phospholipids produced being obtained as solid matter and being dried by the supercritical medium; and Subsequent to the supercritical extraction process, the lipids and flavours are yielded from the solvents using pressure reduction.

Description

N.Z. No.

NEW ZEALAND Patents Act 1953 COMPLETE SPECIFICATION PRODUCTION PROCESS, USED IN PARTICULAR FOR OBTAINING LECITHIN FROM DEHYDRATED EGG We, KRUPP UHDE GMBH, a German Company of, Friedrich-Uhde-Strape 15, 44141 Dortmund, Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - (Followed by 1A) HoiitlLtUTUAL PROPERTY"0FFIC~ 1 OF NZ ~ 4 NOV 1999 _RECE1VFD 1A If o Production process, used in particular for obtaining lecithin from dehydrated egg The invention involves a process for obtaining useful products from raw materials containing protein and fat, and in particular for obtaining lecithin from dehydrated egg.

It is known that lecithin can be extracted, e.g. from raw egg yolk, using a solvent, e g. using liquid dimethyl ether as described in DE-28 33 371-C3 or in the corresponding US-4 157 404. A similar process using solvents which are gaseous under NTP conditions, is described in DE 32 29 041-A1. A procedure, which is essentially characterised by heat treatment, is described in US-4 844 926 and US-5 028 449.

The objective of the invention is to create a solution with which useful products can be extracted in several stages, special emphasis being placed on the production of lecithin According to the present invention, there is provided, a process for obtaining products from animal raw materials containing protein and fat, and in particular for obtaining lecithin from dehydrated egg, characterised in that: a) a feedstock, comprising lipid, phospholipid (lecithin) and protein constituents, is subjected to a supercritical extraction process using a solvent for extracting lipids and flavours, to yield a degreased feedstock, the lipids and flavours being extracted from the supercritical solvent by pressure reduction; b) the degreased feedstock, with its proteins and phospholipids, is subjected to a further extraction stage using a supercritical solvent and an organic solvent, which is liquid under normal conditions, as the entrainer (cosolvent) to separate the phospholipids from the proteins; INTELLECTUAL PROPERTY OFFICE OF N.Z. 1 5 AUG 2001 RECEIVED 1 B 50 f)p>p a ^ ^ \J O (L V c) the extract, comprising phospholipids and the cosolvent, is concentrated and removed from the system with the help of the solvent, the phospholipids produced being obtained as solid matter and being dried by the supercritical medium, and subsequent to the supercritical extraction process, the lipids and flavours are yielded from the solvents using pressure reduction.

This last stage of the procedure causes extensive degreasing of the feedstock e.g. the dehydrated egg, with the aid of the supercritical agent acting at a pressure between its critical pressure and e.g. 500 bar and at a temperature between its critical temperature and e.g. 100°C. The solvent can be recycled during the supercritical extraction process.

The intermediate product, i.e. the raffinate, obtained by this extraction process is the degreased raw material with the proteins and the phospholipids which remain in the extraction vessel. The degree of degreasing can be varied in accordance with the extraction parameters and cycles.

OFFICE OF N.z. 2 7 JUL 2001 Received The lipids and flavours can be removed from the solvent as the extract by pressure reduction This is also provided for by the invention It should be observed at this point that the "Journal of Food Science", vol. 61, no 6, 1996, p 1230 ff mentions that soya flakes can be treated with supercritical CO2 and a cosolvent The treatment of animal products containing considerable amounts of proteins is not referred to in this particular article Practical embodiments of the invention referred to in the subclaims are as follows- In the second stage of the process, the invention provides for the degreased feedstock, with its proteins and phospholipids, to be subjected to a further extraction stage using a supercritical solvent and an organic solvent, which is liquid under NTP conditions, acting as the entrainer (cosolvent) to separate the phospholipids from the proteins. Alternatively, the separation process can be effected at a pressure close to atmospheric pressure using the cosolvent as the solvent, as is provided for by one of the embodiments of the invention.

In this stage the proteins can be obtained as raffinate from the raw material in the moist entrainer The phospholipids remain in the entrainer as the extract in solution.

During this stage, the raffinate is dried by the supercritical solvent and is obtained as the product The cosolvent can then be separated from the gaseous solvent by pressure reduction The solvent can be recycled in this case as well, whilst the cosolvent can be collected and fed back to the process.

A third stage provided for enables the extract, comprising phospholipids and the cosolvent, to be concentrated with the aid of the solvent and removed from the system, the phospholipids precipitating as solid matter and dried by the supercritical medium This stage can be implemented under pressure with the solvent in a supercritical or liquid state.

During this stage, the cosolvent is mixed with the solvent and can be separated from the gaseous solvent using pressure reduction, as provided for by the invention. In this case as well, the solvent and the cosolvent can, as stated above, be returned to the process separately.

Further features, details and advantages of the invention are portrayed in the following description and in the diagram which shows the process layout in the form of a block diagram The raw material (1) is fed to the first treatment stage (2) in which degreasing takes place using high-pressure extraction This is achieved, for example, by adding a supercritical gas as the solvent (3). Once the raw material has been degreased, separation (4) can take place by reducing the pressure so that the lipids and flavours can be recovered as useful products in the form of an extract or separately in several individual extract fractions (5).

The residue (6) remaining in the system is subjected to a second treatment stage (7) again using, for example, the supercritical solvent (from 3) and/or a cosolvent (8), e g. ethanol.

The residue (9) from the treatment stage (7), which comprises protein and cosolvent, is fed to a drying stage (10) The drying stage can be effected using a supercritical solvent The proteins (11) contained therein are obtained as useful products. The solvent and the cosolvent are fed in one stream (12) to a separation stage (13) using pressure and recycled within the system (represented by lines 14 and 15) An extract (16) is obtained directly or indirectly from the treatment stage (7) The extract comprises phospholipids and the cosolvent and is subjected to a further treatment stage (17) in which the phospholipids are concentrated with the solvent at high pressure. Cosolvent residues can be removed in an extractive drying stage (18) so that the useful product lecithin stream (19) can be withdrawn from the system.

Just like the solvents and cosolvents originating from stage (18), the cosolvents and/or solvents originating from the concentration stage (17) are also fed to the separation stage (13) before being fed back to the system via lines (14 and 15) A solvent separation stage (20) can be arranged downstream of the second stage (7) to obtain the extract. This is also shown in the diagram.

Of course, the embodiment described can be altered in a variety of ways without deviating from the basic principle. This means that the invention is not just limited to the treatment of eggs or dehydrated eggs, but can also, for example, be used to treat milk or animal tissue if these are prepared accordingly.

Claims (7)

WHAT WE CLAIM IS: 4' '1

1. A process for obtaining products from animal raw materials containing protein and fat, and in particular for obtaining lecithin from dehydrated egg, characterised in that: a) a feedstock, comprising lipid, phospholipid (lecithin) and protein constituents, is subjected to a supercritical extraction process using a solvent for extracting lipids and flavours, to yield a degreased feedstock, the lipids and flavours being extracted from the supercritical solvent by pressure reduction; b) the degreased feedstock, with its proteins and phospholipids, is subjected to a further extraction stage using a supercritical solvent and an organic solvent, which is liquid under normal conditions, as the entrainer (cosolvent) to separate the phospholipids from the proteins; c) the extract, comprising phospholipids and the cosolvent, is concentrated and removed from the system with the help of the solvent, the phospholipids produced being obtained as solid matter and being dried by the supercritical medium, and subsequent to the supercritical extraction process, the lipids and flavours are yielded from the solvents using pressure reduction.

2. A process in accordance with claim 1, further characterised in that separation is carried out by single-stage pressure reduction (ps<pkrit) to extract all solvent-soluble constituents from the overall solvent stream. INTELLECTUAL PROPERTY OFFICE OF N.Z. 15 AUG 2001 RECEIVED

3. A process in accordance with claim 1, characterised in that pressure reduction is carried out in several stages to separate different products at different pressures (Ps1 > ps2 » psn).

4. A process according to any one of claims 1 to 3, wherein the phospholipids are separated from the proteins at a pressure close to atmospheric pressure using the cosolvent as the solvent.

5. A process according to any one of claims 1 to 3, wherein the phospholipids are separated from the proteins at high pressure in a supercritical entrainer extraction process using the supercritical solvent and the cosolvent.

6. A process in accordance with claim 5, characterised in that the entrainer is fed in a range of 0 and 20% of the volume used in the supercritical extraction process 7. A process in accordance with claim 5 or 6, characterised in that the phospholipids with the entrainer are separated from the solvent by pressure reduction (ps < pkrit) such that they are then obtained as a solution in the cosolvent. 8. A process according to any one of claims 1 to 7, wherein the entrainer (cosolvent) mixed with the solvent is separated from the solvent using pressure reduction and both are recycled in the system. 9. A process in accordance with any one of the preceding claims, particularly for obtaining lecithin from egg yolk, characterised in that C02 is used as the solvent and ethanol or hexane, for example, as the entrainer (cosolvent). 'NTEALFHfUA,!; PROPERTY OFFICE OF N.Z. 2 7 JUL 2001 RECEIVED 7 10. 11. 12. 13. 14. A process in accordance with claim 9, characterised in that degreased egg yolk is obtained as an intermediate and egg-yolk oil as the extract in the first supercritical extraction stage. A process in accordance with claim 10, characterised in that the egg-yolk oil obtained as the extract in this stage is separated into a fraction which is rich in lipids and in flavours. A process in accordance with claim 10 or 11, characterised in that the proteins obtained as the raffinate during the second extraction stage are made available as egg-yolk proteins. A process in accordance with any one of claims 9 to 12, characterised in that the phospholipids, which are obtained subsequent to the concentration and drying steps of step c), are removed from the process as the main product, lecithin. A process in accordance with claim 13, characterised in that the composition, i.e. the content of phospholipids, is varied by the control parameters of the supercritical extraction process performed during the first stage. A process according to claim 1 substantially as herein described or exemplified. INTELLECTUAL PROPERTY OFFICE OF N.Z. 2 7 JUL 2001 RECEIVED KRUPP UHDE GMBH Rv Their Attorneys 3 raw material Process for obtaining lecithin from raw materials containing protein and fat '1 solvent supercritical gas eg COj cosolvent e g ethanol M l,vr 1 degreasing using high-pressure extraction P > Pk.it T>TU residue degreased raw material proteins + phospholipids solid matter X/ 3. removal of phospholipids using only a cosolvent at atmospheric pressure or a solvent + cosolvent at high pressure residue 'J proteins + cosolvent |

7. drying extractive drying with solvent to remove cosolvent residues | proteins ' / 2 separation gaseous solvent single or multistage by pressure reduction . 4 separation gaseous solvent by reducing pressure l0P< Pk* yt;IV;40;41;At;solvent + cosolvent r;lipids/flavours as a total extract or separately as several extract fractions;4Q;I extract.;phospholipids + cosolvent ft;5 concentration of phospholipids /| with solvent at high pressure;_ 1;6 drying extractive drying with solvent to remove cosolvent residues f I cosolventT" I "[solvent;"J2-;-} cosolvent i 3;phospholipids (lecithin);solvent;>;separation by pressure reduction w;J*