AU596359B2 - Method and device for the extrusion of food products - Google Patents

Description

COMMON WEALT H OF AUST RALIA PATE14T ACT 1952 COMPLETE S3PECIFICATO 11 T 0N596359 FOR OtFFICE USE Class Int- Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published:, Priority: Relat'ed Art: qa-me of Applicant: Address of Applicant: Actual Inventor(s): Address for Service: HEINZ SCHAAF 4 UIlUcITD lIRZ~ TOI Quellwf.Ng 14 19a, 6277 Bad Camberg-Oberselters, FEDERAL REPUBLIC OF GERMANY Heinz SCHAAF DAVIES COLLISON, Patent Atto.rneys, 1 Little Collins Street, Melbouine, 3000.

Complete Specification for the in%. .ntion entitled: "METF OD AND APPARATUS FOR THE EXTRUSION OF FOSUS" The Ifoll,.wing statement is a full description of this invention, including tzhe best~ jethod of performing it. known to us 7.

AUAl 5 8 6 5 1 /86 CT WELTORGANISATION FOR GEISTIGES EIGENTUM INTRNTIOAL ANEL E ~E II N 9DDEM VERTRAG OJBER DIE INTERNTIONAL AN 3]M5 19DES PA rENTWESENS (PCT) INTERNATIONALE ZUSA MFNRE U B (51) Internationale Patentiklasslfikation 4: (11) Internationale Vero3ffentlichungsnummer: WO 86/ 06256 A23P 1/14 Al (43) Internationales Verliffentlichungsdatum: 6. November 1986 (06.1 1,86) (21) Internatlonales Aktenzeichen: PCT/EP86/00227 (81) Bestimmungsstaaten: AT (europ~iisches Patent), AU, BE (europliisches Patent), CH (europ~iisches Patent), (22) Interuationales Anmeldedatum: 17. April 1986 (17.04.86) DE (europAisches Patent), FR (europ~isches Patent), GB (europlaisches Patent), IT (europllisches Patent), JP, LU (europilisches Patent), NL (europ~isches Pa- (31) Priorilitsaktmizechen: P 35 15 617.1 tent), SE (europlisches Patent), US.

(32) "rirlitsdatum: 30. April 1985 (30.04.85) (33) Prlorltitsland: DEVeifntch 00 G, Mit intemationalem Recherchenbericht.

(71) Anmeleer (filr afle XBestimmungsstaaten ausser Mit gelinderten A nsprilchen.

HEINZ SCAF NHU SMTTEL= EXT SIe-E eit-H [DE/DE]; Quellenweg 14 19a, D-6277 Ba'd Camberg/Oberselters (DE).

(72) Erfinder; und Erfinder/Amelder (nur fur US) SCP.AAF, Heinz [DE/ .Q P. 8 DC19 c DEJ; Quellenweg 14 19a, D-6277 Bad Camberg- JP 8DCc Oberselters (DE).

(74) Anwalt: MOLLER-BORk, DEUFEL, SCHON, HER- AUSTRALIAN TEL, LEWALD, OTTO Postfach 260247, D-8000V 8 Mrnchen 26 1 8 NOV 1386 PATENT OFFICE (54) Title: METHOD AND DEVICE FOR THE EXTRUSION OF FOOD Pl'.ODUCTS (54) Bezeichnung: VERFAHREN UND VORRIGHTUNG ZUM EXTRUDIEREN VON NAHRUNGSMITTELN 26 E28 12 V 1 2 18 7) Ais~tract 22' 16 The extrusion of food products is carried out at a pressuro lower than ili'e atmospheric pressure, thereby enaling to reduce the temperature of the dough to be extruded, It becomes thus possible wo extrude materials and let them expand, which couid not otherwise be used, either because of their heat sensitivity or because of' their thermoplastic properties. Simultantously, vapors coming out of the extruder may be condensated, thlereby enabling to recover volatile aromas, and to thus 17tease the productivity of the process whilie preventing unpleasant smells from spreading throughout the production Ilocals, (57) Zusammenfassung Das Extrudieren der Nahrungsmittel erfolgt bei einem Drick, der geringer ist als der amrosphtirische Druck, Dadurch kann die Temperatur des zu extrudierenden Teiges niedriger gehalten werden, so dass Stoffe extrudiert und expandiert worden k~nnen, die entweder aufgrund ihrer Ternperaturenipfindlichkeit oder ihrer thermoplastischen Eigenschaften ansonsten nicht verwendbar sind. Gleichzeitig konnen die, aus df'im Extruder austretenden Dtlmpfe kondensiert Werden, so, dass flilchtige Aromastoffe rilckgewonnen werden kbnne.,. Dami t wird die Wintschaftlichkeit des Verfahreos erh~ht und eine Geruchsbeligstigung der Produktionssthtte verhindert.

A

The invention relates to a method for extrusion of foodstuffs wherein in an extruder a mixture is prepared from carbohydrates, protein, fats, aromatic substances and water and said mixture is processed by an extruder screw to a dough which emerges with expansion from a nozzle, and an apparatus for carrying out said method.

In the extrusion of foodstuffs which is carried out at a temperature of 100 0 C and more vapours are formed on emergence from the nozzle head. These vapours are either sucked off or blown off to avoid condensate formation in the expansion space or chamber and to prevent the production area being inpaired by moisture and odours.

On emergence of the extrudate from the nozzle head an expansion occurs when the extrudate, which normally contains a vapourizable liquid, moves from a zone of high pressure at a temperature which is higher than the vapourization temperature of the respective liquid to a zone of low pressure.

A foodstuff dough containing water is extruded at a temperature of over 100°C and because of the pressure drop on passage through the extruder nozzle this dough expands due to the water vapour forming.

Present-day conventional methods for extrusion of foodstuffs have the disadvantage that due to the necessary high temperature for example fats of low melting point are not suitable.

In addition, due to the evaporation of the liquid contained in the dough a major part of the nati.cal or added flavouring substances contained in the raw material is lost because these substances also evaporate on emergence from the nozzle.

In the production of snacks, flat bread and the like a loss occurs of the flavouring substances used (for example onions, caraway, celery, peppermint, herbs of all kinds, etc.) of the order of magnitude of 40 to 80%. Losses of aromatic 3 substances also occur when using concentrated aroma compositions of natural or natural-identical type as have been offered by the essence industry for a long time, in spite of optimization as regards their volatility. To compensate these losses aromatic substances must be added to an increased amount so as to obtain the desired flavouring in the final product. Such an admixture of aromatic and flavouring substances in large amounts can easily come up against limits from the process technology point of view or the manufacture can be forced to obtain the ?romatization of the extruded foodstuffs with specially prepared aromas by subsequent coating. This necessarily restricts the range of products which can be made or makes economic production impossible.

The invention is based on the problem of providing a method and an apparatus with which foodstuffs can be extruded without significant detrimental effects thereon and the amount of aromatic or flavouring substances added can be significantly reduced.

According to a first aspect of th present invention, there is provided a method for extrusion of foodstuffs comprising the steps of i) preparing a mixture from carbohydrates, protein, fats, aromatic substances, water and the like, ii) processing said mixture by the use of an extruder screw to a dough which emerges with expansion from a nozzle, the emergence of the s -i 4 extrudate from the extruder nozzle taking place into a space of sub-atmospheric pressure, iii) condensing vapours liberated on expansion, comprising aromatic substances, and iv) either returning the aromatic substances to the extruder or collecting the aromatic substances for use in further processing of said mixture, According to a second aspect of the present invention, there is provided apparatus for extrusion of foodstuffs comprising an extruder and a cutting means disposed in front of a nozzle head of the extruder, in particular for carrying out the method according to either of claims 1 or 2, characterized in that the nozzle head and the cutting means are disposed in a vacuum chamber provided with a reduced SI pressure means, that at the vacuum chamber a lock or sluice is provided for the discharge of extruded and cut-off foodstuff from the chamber and that the vacuum chamber is connected to a condensor arranged for condensing said vapours in step iii).

Since the boiling point of liquid depends of course on the ambient pressure it is possible when an appropriately large vacuum is employed to keep the temperature of the extruded mixture lower so that for the extrudate components can be used which would undergo undesirable changes at the otherwise usual temperature of more than 100°C. If the pit-sure in the space in front of the nozzle head is about 0.1 4 a bar the material to be extrueled has a temperature of at the most 90 0

C.

If in preferred manner the vapours liberated in the expansion are condensed the volatile aromatic substances can be returned to the extruder so that no loss of expensive aromatic and flavouring substances occurs. Furthermore, there is no annoying production of odours in the place of manufacture because the evaporated aromatic substances are not discharged into the surroundings.

The lock or sluice may for example be constructed cis *a cellular wheel sluice.

S For recovery of the aromatic substances, according to a preferred embod~iment the condensor is preferably disposed between the vacuum chamber and reducod pressure means. The return of the condensed aromatic substances for recycling can take place via a conduit which is conn~ected either to a container for the aromatic substances or to chargLing means of the extruder.

An example of an embodiment of the invention will be o~xplained hereinafter in detail, by way of excample only, with the P-I of the drawing.

*.*The drawing -hows in schematic illustration an extude 10an extruder Screw is disposed via which a mixureandfeed of the material to be extruded is effected. At the discharge end of the extruder a 7 1 nozzle head 14 is disposed.

2 3 In front of the nozzle head 14 a vacuum chamber 16 is 4 disposed. The reduced pressure in the vacuum chamber 16 is brought.

6 7 8 9 11 12 13 14 *0 16 17 *S*a 18 19 21 22 23 e 24 26 27 28 29 31 32 33 34 36 37 900220,aldspe001,58651,spe,1 about by a vacuum pump 18 which is cbnnected via a conduit to the vacuum chamber 16. In the vacuum chamber 16, which adjoins the sealing head 14 in sealed manner a cutting means (not shown) suitable for the foodstuff to be extruded is disposed. The emergence of the extrudate from the vacuum chamber 16 is via a product discharge lock 22 which in the example of embodiment illustrated is in the form of a cellular wheel sluice.

If in the vacuum chamber 16 ar absolute pressure of 0.1 bar obtains the vapourization temperature of the water emerging with the extrudate from the nozzle head is reduced to about 0 C. The dough emerging from the nozzle head 14 has for ex .e a temperature of 90 0 C. With these values in the ext mare the same expansion occurs as can be achieved in conventional methods with a starting temperature of 140 0

C.

Thus, substances can be extruded and expanded which because of their temperature sensit,ity or their thermoplastic properties hitherto cuuld ii-t be used.

Between the vacuum chamber 16 and the pump 18 in the conduit a condenser 24 is disposed in which the sucked-off vapours are condensed. After appropriate preparation of the vapours precipitated aromatic or flavouring substances can be returned to the raw material or said aromatic substances can be used to make a coating solution. The objective of the preparation of the vapours is preferably to obtain the resulting aromatic substances as concentrated as possible. Apparatuses for condensing and separating the desired substances, either in the vapour phase or in the liquid phase, are adequately known.

For returning the precipitated aromatic substances-e thp condenser a conduit 26 is provided which leads to a container 28 in which the aromatic substances to be added to the material to be extruded are contained.

Tire bi fell.... 8 e oty limfit the seepie 9o& the rozspootivo eltms.

Claims (8)

1. Method for extrusion of foodstuffs comprising the steps of i) preparing a mixture from carbohydrates, protein, fats, aromatic substances, water and the like, ii) processing said mixture by the use of an extruder screw to a dough which emerges with expansion from a nozzle, the emergence of the extrudate from the extruder nozzle taking place into a space of sub-atmospheric pressure, iii) condensing vapours liberated on expansion, comprising aromatic substances, and iv) either returning the aromatic substances to the extruder or collecting the aromatic substances for use in further processing of said mixture.

2. Method according to claim 1, characterized in that the dough has a temperature of about 90°C and the pressure in front of the nozzle, in the space of sub-atmospheric pressure, is about 0.1 bar. S

3. Apparatus for extrusion of foodstuffs comprising an extruder and a cutting means disposed in front of a nozzle head of the extruder, in particular for carrying out the method according to either of claims 1 or 2, characterized in that the nozzle head and the cutting means are disposed in a vacuum chamber provided with a reduced pressure means, that at the vacuum chamber a lock is provided for the discharge of extruded and cut-off foodstuff from the chamber and that the vacuum chamber is 7 connected to a condensor arranged for condensing said vapours in step iii).

4. Apparatus according to claim 3, characterized in that the condenser is disposed between the vacuum chamber and reduced pressure means.

Apparatus according to claim 3 or 4, characterized in that the condensor is connected via a conduit to a container for aromatic substances.

6. Apparatus according to any one of claims 3 to 5, characterized in that the lock is constructed S as a cellular wheel sluice.

7. A method substantially as described Ss. hereinbefore with reference to the accompanying drawing.

8. Apparatus substantially as described hereinbefore with reference to the accompanying drawing. 0 o a *s boo S DATED this 31st day of May, 1989. HEINZ SCHAAF OHG By their Patent Attorneys Davies Collison 4 4