EP1968396A2

EP1968396A2 - Method for the production of saponified, carotenoid-containing oleoresin, and saponified, carotenoid-containing oleoresin

Info

Publication number: EP1968396A2
Application number: EP06829568A
Authority: EP
Inventors: Helge Nestler; Klaus-Uwe Schwarz
Original assignee: Lohmann Animal Health GmbH and Co KG
Current assignee: Lohmann Animal Health GmbH and Co KG
Priority date: 2006-01-05
Filing date: 2006-12-13
Publication date: 2008-09-17
Also published as: WO2007076920A2; WO2007076920A3; DE102006000870B3

Abstract

Disclosed is a method for producing saponified, carotenoid-containing oleoresin, in which unsaponified, carotenoid-containing oleoresin is intensely mixed with a solid, small-sized and/or powdery alkali metal hydroxide, and the oleoresin is saponified during said process.

Description

A method of producing saponified carotenoid-containing oleoresin and saponified carotenoid-containing oleoresin

The invention relates to a process for preparing saponified, carotenoid-containing oleoresin and saponified, carotenoid-containing oleoresin.

On the world market, the so-called carotenoid-containing oleoresins (extracts of marigold blossoms, peppers, etc.) are a "commodity." The subsequent treatment of these oleoresins is generally carried out with the aim of obtaining high-purity carotenoids, whereby the carotenoids become saponified subjected.

The reason for the saponification of the oleoresins lies in the chemical modification in which the carotenoids in the plants are usually stored. The plants synthesize e.g. the xanthophyll lutein together with two fatty acid residues to a luteindipalmitate or the like. What is desired, however, is the pure, unesterified carotenoid. This applies in particular to use in the animal feed sector. As a feed additive carotenoids (especially xanthophylls) are used in particular for the pigmentation of egg yolk and the skin of poultry. Poultry can poorly digest esterified carotenoids.

The saponification may be involved in a subsequent process of concentration to pure lutein or generally to pure xanthophylls. For example, in US 6,262,284 a simultaneous extraction, saponification and Concentration described. Characteristic of almost all methods of saponification is the use of aqueous KOH or NaOH or other alkali metal hydroxides. Basically, the saponification takes place via an alkaline ester hydrolysis.

For the feed sector, there is an application to saponify the oleoresins only to subsequently convert the saponified oleoresin into a solid formulation. The classic saponification process is characterized by the use of potassium hydroxide (about 15%), water (about 20%), oleoresin (about 50%), sometimes propanediol (about 20%) and / or ethanol. The saponification temperatures are usually 65 to 90 ⁰ C at a time of about 6 hours. The reaction usually takes place in a boiler with a slowly running anchor agitator. The slowly rotating stirring tools are used because the oleoresin has the property to become increasingly viscous with increasing degree of saponification.

The conventional method has the disadvantage that solid solvents, water and other additives are used to keep the product still flowable with increasing degree of saponification. These additives can not be removed or only with considerable effort from the product. This requires additional equipment or results in the loss of additives. Therefore, the choice is usually on the cheapest possible solvents. The high temperatures and long reaction times promote the oxidation of the sensitive carotenoids. This leads to degradation reactions such as radical chain reactions in the product.

On this basis, the object of the invention is to provide a gentle, easy-to-handle and economical method for producing saponified, carotenoid-containing oleoresin of improved quality.

The object is achieved by a method having the features of claim 1. Advantageous embodiments of the method are specified in the subclaims.

In the process according to the invention for producing saponified, carotenoid-containing oleoresin, unsaponified, carotenoid-containing oleoresin is intensively mixed with small-sized and / or pulverulent alkali metal hydroxide in the solid state, and the oleoresin is saponified.

The inventive method is based on an intensive mixing of the two educts unsaponified, carotenoid-containing oleoresin and small-sized and / or powdered alkali metal hydroxide. The large, reactive surfaces of the alkali metal hydroxide are covered or wetted by the oleoresin. In combination with very high shear forces this leads to an immediate hydrolysis of the oleoresin. The comminution of the alkali metal hydroxide can go as far as colloidal milling. This results in very large, reactive and of Oleoresin coverable or wettable surfaces which promote the direct hydrolysis of the oleoresin with the solid alkali metal hydroxide in particular. As a result, the temperature rise of the reaction mixture is reduced and achieved a gentle saponification. Due to the lower saponification temperatures, which may be in particular in the range of about 40 to 60 ⁰ C, there is little to no degradation of lutein instead. Basically, no further additives are required to make the reaction mixture flowable. As a result, the saponification process is less expensive. The saponification times are very short and the process is easily scalable. A system for carrying out the method can be built very compact and with a small footprint.

The carotenoid-containing oleoresin can be supplied to the process in solid and / or liquid state. The use of carotenoid-containing oleoresin in the solid state simplifies the process. For liquefaction, the oleoresin is melted to the melting temperature, which may be about 53 ⁰ C. As a result, the wetting of the alkali metal hydroxide with oleoresin and thus the saponification reaction can be promoted.

It is possible to add small-sized and / or pulverulent alkali metal hydroxide to the process. According to one embodiment of the method, alkali metal hydroxide is comminuted into small-sized and / or pulverulent alkali metal hydroxide and mixed with the non-soaped, carotenoid-containing oleoresin. In this embodiment, the process is comminuted or only partially comminuted Supplied alkali metal hydroxide and this is comminuted in a suitable for the saponification or promotional this way. The crushing is eg breaking of alkali metal hydroxide into small pieces and / or grinding of alkali metal hydroxide into a powder.

The comminution of the alkali metal hydroxide is e.g. before mixing and reaction with the non-soaped carotenoid-containing oleoresin. According to one embodiment of the method, the comminution of the alkali metal hydroxide is carried out simultaneously or overlapping in time with the mixture and reaction of the alkali metal hydroxide with the non-soaped, carotenoid-containing oleoresin. In this way, a particularly efficient comminution of the alkali metal hydroxide and intensive mixing and reaction of the educts can be achieved. Furthermore, through the merging of the method steps, the throughput can be increased, the reaction times can be reduced and the expenditure on equipment can be reduced.

The process can in principle be carried out with all alkali metal hydroxides, if appropriate also with combinations of different alkali metal hydroxides. In one embodiment, the alkali metal hydroxide is KOH (potassium hydroxide) or NaOH (sodium hydroxide). These alkali metal hydroxides are available well or inexpensively.

For intensive contact of the oleoresin with the small-sized and / or pulverulent alkali metal hydroxide, it is beneficial if air inclusions in the mixture are avoided. For this is / will be in accordance with a Design the oleoresin and / or the alkali metal hydroxide degassed during comminution or mixing and / or reacting.

The process is carried out, for example, discontinuously. For this purpose e.g. the educts are mixed and / or comminuted and / or reacted in at least one discontinuous stirring and / or grinding plant. Optionally, the alkali metal hydroxide is previously comminuted and / or ground by means of a separate comminution device. For high production rates, the process according to one embodiment is carried out as a continuous process, in which the educts are fed continuously and the product is continuously withdrawn.

According to one embodiment, which is particularly suitable for the continuous performance of the process, the educts are fed to an extruder and mixed and reacted in this.

According to one embodiment, the alkali metal hydroxide is comminuted before entering the extruder and / or in the extruder. Crushing prior to entry into the extruder is feasible by means of at least one additional comminution device (e.g., crusher or mill). Due to the high shear forces in the extruder, the alkali metal hydroxide can additionally or instead be comminuted in the extruder.

According to a further embodiment, the extruder is a twin-screw extruder. In twin-screw extruder is by a controlled reflux of the extruded mass given a controlled mixing.

The invention includes embodiments in which the educts are fed to the screw flight of the extruder in the same axial position. According to one embodiment, the educts are fed to the screw flight of the extruder in different axial positions. This makes it possible to compress at least one reactant separately, to degas, to equalize and to comminute and to feed a further starting material into the educt thus prepared.

According to another embodiment, the educts are premixed before entering the extruder and fed to the same axial position in the extruder.

According to a further embodiment, the educts are premixed and degassed and then fed to the extruder.

According to another continuous embodiment of the process, which does not require an extruder, the educts are ground and premixed in an in-line colloid milling apparatus and intensively mixed and reacted in a downstream continuous mixer. An inline Kolloidmahlvoπϊchtung comprises a arranged in a funnel, conical grinding tool. Between the wide opening of the funnel and the large diameter of the grinding tool, a wide feed gap is present. Between the small diameter of the Mahlwerkzeuges and the small opening of the funnel is formed a narrow discharge gap. The grinding tool is rotated by a drive motor. It can have a helical profiling on the circumference. When the grinding tool is driven, the millbase is comminuted and conveyed from the feed gap to the discharge gap.

The continuous mixer is e.g. a stirrer with a suitable stirring tool. According to one embodiment, the continuous mixer is a static mixer. The static mixer is a tube with fixed internals. The internals cause a mixing of a flowing medium. When mixing in the static mixer, the reaction of the starting materials takes place at the same time.

According to one embodiment, the reaction of the oleoresin with the alkali metal hydroxide is temperature-controlled. For example, the temperature is controlled by cooling so that adverse degradation reactions are suppressed.

According to a further embodiment, the reaction is carried out at a temperature between 20 ⁰ C and 100 ⁰ C. The temperature is preferably at most 65 ^° C. For temperature control, for example, the extruder and / or the inline colloid milling apparatus and / or the continuous mixer are cooled.

According to a further embodiment, which counteracts an undesired oxidation of the carotenoids, antioxidants are added to the reaction mixture fed. According to a further embodiment, the antioxidants comprise BHT and / or BHA and / or ethoxiquin and / or vitamin C and / or chemical modifications of vitamin C and / or tocopherols.

Basically, the mixture of solid and / or liquid oleoresin and solid alkali metal hydroxide has sufficient flowability for batch or continuous processing. According to one embodiment, a flow aid is additionally added to the reaction mixture. In one embodiment, the flow aid is propanediol. To aid flowability, significantly smaller amounts of flow aids are required than conventional additives must add to conventional saponification processes to maintain flowability of the reaction mixture.

Furthermore, the invention relates to saponified, carotenoid-containing oleoresin, prepared by the method described above.

The oleoresin according to one embodiment has a water content of 0 to 5 wt .-%. The water content is thus significantly below the water content of the oleoresin, which results in conventional saponification.

According to a further embodiment, the oleoresin contains no decomposed carotenoids or only a small proportion of decomposed carotenoids at the detection limit. Due to the gentle treatment by the method according to the invention, the carotenoids are decomposed at best to a very limited extent. Finally, the invention relates to a feed containing a saponified, carotenoid-containing oleoresin of the above type.

The invention will be explained in more detail by means of exemplary embodiments, which are illustrated by the accompanying drawings. In the drawings show:

1 shows an apparatus for producing saponified, carotenoid-containing oleoresin with an extruder and comminution of the alkali metal hydroxide in the extruder in a longitudinal section;

Fig. 2 apparatus for producing saponified, carotenoid-containing oleoresin with an extruder and a mill for crushing the alkali metal hydroxide in a longitudinal section;

Fig. 3 Apparatus for producing saponified, carotenoid-containing oleoresin with an in-line colloid mill and a static mixer in a longitudinal section.

The following preliminary investigations were carried out on a laboratory scale:

The materials used were unsaponified oleoresin containing 121 g / kg of total xanthophylls. In addition, KOH cookies and - in a part of the experiments - 1, 2-propanediol and water. Of devices and machines, a mortar, a mixer of the type Ultra Turrax (with a rated speed of 18000 ^{min -1),} and a heating plate beakers were used (with a capacity of 500 ml).

In an experiment VI, KOH cookies were ground in a mortar.

The oleoresin was melted in the beaker on the hot plate (melting temperature about 53 ⁰ C).

The pre-shredded KOH was added to the molten oleoresin and the product mixed with the Ultra Turrax until the material was no longer agile. The mixing time was about 2 to 3 minutes.

In an experiment V2, the procedure was as in VI, but the KOH was not pre-shredded, but instead a direct attempt was made to comminute the cookies with the Ultra Turrax.

In an experiment V3 was also proceeded as in Vl, but with the addition of 1, 2-propanediol, the stirring time was extended.

In experiment V4, the procedure was as in experiment VI, but the KOH was dissolved in water and then mixed with the molten oleoresin.

The test results are summarized in the table below.

* GX = total xanthophyll = valuable substance

It can be seen from the measurement results for experiment V4 that a water-containing mixture brings almost no saponification effect (degree of saponification: 4.88%).

However, if the KOH in the undissolved state, finely divided with the oleoresin comes into contact, sets in a very short time a very high degree of saponification. This is the case in experiments V1 and V2 (saponification degrees: 51.4% and 25.7%, respectively). The limits of these reactions are in the mixing tool, because this no longer absorbs the oleoresin from a certain viscosity and further mixing is no longer possible with the high intensity.

Experiment V3 proves that the addition of propanediol as flow aid, the mixture could be kept low viscosity so long that a virtually complete saponification took place (degree of saponification: 97.8%). By means of an extruder, much higher shear forces can be achieved than in an Ultra Turrax. Therefore, the use of an extruder allows virtually complete saponification, even without the use of a flow aid.

According to FIG. 1, an extruder 1 in a housing 2 comprises at least one cylinder 3 or screw flight, in which at least one screw 4 is arranged. The worm 4 can be driven by means of a drive motor 5. The extruder 1 is e.g. a twin-screw or twin-screw extruder or a ring extruder.

In the region of an inlet 6, the cylinder 3 is connected to the small diameter of a funnel-shaped template and feed 7. The template and feed 7 is open at the large diameter. In the template and feed 7, a stirrer 8 is arranged.

In the region of the inlet 6, the screw 4 has a gradually decreasing slope. Adjacent to the inlet 6, the cylinder 3 has a degassing region 9 with at least one degassing duct 10 for air.

Adjacent thereto, the cylinder 3 has a feed region 11 for solids with at least one inlet channel 12 for alkali metal hydroxide. This is followed by another degassing region 13 with at least one further degassing duct 14 for air. This is followed by a grinding zone 15, in which the alkali metal hydroxide is finely ground. From the inlet 6 to the grinding area 15, the pitch of the screw decreases and its outer diameter increases. In the grinding area 15, the minimum slope and the maximum outer diameter is reached. There, the extruder or the screw can have a special milling insert. In Mahlreich 15, the housing 2 has a cooling chamber 16 with a cooling water inlet 17 and a cooling water outlet 18th

Adjacent thereto, the extruder 1 has a reaction region 19 in which the screw 4 has the same pitch and the same outside diameter as in the grinding region 15. Also, the reaction region 19 is surrounded by a cooling chamber 20 having a further cooling water inlet 21 and a further cooling water outlet 22.

The reaction part 19 opens into an outlet channel 23. The cross-section of the outlet channel 23 is smaller than that of the cylinder 3. The outlet channel 23 is e.g. designed as a nozzle head.

The extruder 1 is fed unsaponified, carotenoid-containing oleoresin via the template and feed 7. There, the oleoresin is uniformly mixed by means of the stirrer 8 and enters the inlet 6, to be promoted by the screw 4 to the outlet channel 23. In the inlet 6, the educt is gradually compressed and transported by the screw 4 to the degassing 9. There, extruded air and other gases exit through the degassing passage 10. In the feed region 11, alkali metal hydroxide is metered in the form of a lump through the inlet channel 12.

In the following further degassing 13, the mixture of oleoresin and alkali metal hydroxide is compressed by the screw 4, wherein air and other gases escape through the further degassing 14.

In the grinding zone 15, the alkali metal hydroxide is finely ground and mixed intensively with the oleoresin. This takes place under constant cooling. The densification, degassing and grinding processes in the areas 13 and 15 are already accompanied by a reaction of the educts with each other. In the reaction region 19, finally, the essential part of the reaction takes place. The reaction is also cooled. Finally, saponified oleoresin is squeezed out of the outlet channel 23.

The extruder 1 'of Fig. 2 differs from the extruder 1 of Fig. 1 in that the alkali metal hydroxide first a mill (eg roller mill, roller mill, agitator mill (eg agitator ball mill, Spaltrührwerksmühle), inline homogenizer (rotor-stator systems) - For example Silverson) 24 is supplied. The ground alkali metal hydroxide passes from the mill 24 through the inlet channel 12 into the feed region 11. There and in the subsequent degassing 13 and reinforced in the subsequent reaction region 19, the saponification reaction takes place. The saponified, carotenoid-containing product leaves the extruder 1 'through the outlet channel 23. The extruder 1' has no additional grinding area 15th and can therefore be made somewhat shorter than the extruder of FIG. 1.

The apparatus of Fig. 3 comprises a continuous kneader 25 with a kneading tool 26, which is connected on the input side with a funnel-shaped template and feed 27 having a stirrer 28.

On the output side, the kneader 25 is connected to a pump 29. The pump 29 is e.g. an eccentric screw pump, cellular wheel pump, gear pump. This is followed by a degassing region 30, which is connected to at least one degassing channel 21.

The degassing channel 31 is followed by an in-line colloid mill 32. The InLine colloid mill is e.g. a tooth colloid mill or a corundum disc mill. On the output side, it is connected to a reaction region in the form of a static mixer 33.

Bulk alkali metal hydroxide and unsaponified carotenoid-containing oleoresin are fed to the receiver and feed 27. In it they are premixed.

Thereafter, the mixture enters the kneader 25. From there, it is withdrawn by means of the pump 29 and compressed in a degassing 30. There, the squeezed gas leaves the mass through the degassing 31st The compressed mixture enters the in-line colloid mill 32 where the alkali metal hydroxide is finely ground. Thereafter, the reaction mixture passes into the static mixer 33, in which the saponification of the carotenoid takes place. The saponified carotenoid-containing product exits the device through an exit channel 34.

Claims

Claims:

1. A process for the preparation of saponified, carotenoid-containing oleoresin, in which unsaponified, carotenoid-containing oleoresin with befindlichem in the solid state, small-sized and / or powdered alkali metal hydroxide mixed thoroughly and in this case the oleoresin is saponified.

2. The method of claim 1, wherein the carotenoid-containing oleoresin is supplied in a solid and / or liquid state.

3. The method of claim 1 or 2, wherein the alkali metal hydroxide is comminuted and mixed with the non-soaped, carotenoid-containing oleoresin.

4. The method according to any one of claims 1 to 3, wherein the comminution of the alkali metal hydroxide is carried out simultaneously or overlapping with time with the mixture and reaction of the alkali metal hydroxide with the non-soaped, carotenoid-containing oleoresin.

5. The method according to any one of claims 1 to 4, wherein the alkali metal hydroxide is KOH and / or NaH.

6. The method according to any one of claims 1 to 5, wherein the oleoresin and / or the alkali metal hydroxide is degassed during comminution and / or mixing and / or reacting / are.

7. The method according to any one of claims 1 to 6, which is carried out as a continuous process in which the reactants are continuously fed and the product is continuously withdrawn.

8. The method according to any one of claims 1 to 7, wherein the reactants are fed to an extruder and mixed and reacted in this.

9. The method of claim 8, wherein the alkali metal hydroxide is crushed before entering the extruder and / or in the extruder.

10. The method of claim 9, wherein the extruder is a twin-screw extruder.

11. The method according to any one of claims 8 to 10, wherein the reactants are premixed before entering the extruder.

12. The method of claim 11, wherein the reactants are premixed and degassed and fed to the extruder.

13. The method according to any one of claims 8 to 12, wherein the educts are fed to the screw flight of the extruder in different axial positions.

14. The method according to any one of claims 1 to 7, wherein the reactants are ground in an inline Koloidmahlvorrichtung and premixed and mixed intensively in a downstream continuous mixer and reacted.

15. The method of claim 14, wherein the continuous mixer is a static mixer.

16. The method according to any one of claims 1 to 15, wherein the reaction of the oleoresin is temperature-controlled with the alkali metal hydroxide.

17. The method of claim 16, wherein the reaction is carried out at a temperature between 20 ° C and 100 ° C.

18. The method of claim 17, wherein the reaction is carried out at a temperature of at most 65 ⁰ C.

19. The method according to any one of claims 1 to 18, wherein the reaction mixture, antioxidants are supplied.

20. Method according to claim 19, wherein the antioxidants comprise BHT and / or BHA and / or ethoxiquin and / or vitamin C and / or chemical modifications of vitamin C and / or tocopherols.

21. The method according to any one of claims 1 to 20, wherein the reaction mixture, a flow aid is added.

22. Saponified, carotenoid-containing oleoresin, prepared by the process according to any one of claims 1 to 21.

23. Oleoresin according to claim 22, having a water content of 0 to 5 weight percent.

24. Oleoresin according to claim 22 or 23, containing no or only a small proportion of decomposed carotenoids at the detection limit.

25. Feed comprising a saponified, carotenoid-containing oleoresin according to one of claims 22 to 24.