TURMERIC CURCUMIN COMPOSITIONS WITH LOW RESIDUAL SOLVENT

FIELD OF INVENTION

The present invention relates to turmeric curcuminoids/curcumin compositions with a very low amount of residual solvents, processes for making such low solvent turmeric compositions and use of these low solvent compositions for e.g. colouring a food/feed product.

TECHNICAL BACKGROUND AND PRIOR ART

Turmeric or "yellow root" is a general term for plants and plant materials having a high content of curcuminoids, compounds that have a strong colouring effect and which are used extensively in the colouring of e.g. food products. Turmeric plants belong to rhizomatous Curcuma species and have been known for centuries for their flavouring and colouring properties. The plants are grown commercially, particularly in India, but also in Bangladesh, China, Sri Lanka, Indonesia, Taiwan, Haiti, Jamaica and Peru.

Curcuma plant materials contain three different curcuminoid compounds including, as the predominant colouring compound, curcumin having a strong yellow colour, and minor yellow and brownish-red compounds, i.e. the term "curcuminoids" include curcumin (C), reddish orange and with two methoxy groups; demethoxy curcumin (DMC), orange-yellow with one methoxy group and bis-demethoxy curcumin (BDMC), yellow and without a methoxy group.

The Curcuma rhizomes, including the primary or mother rhizomes and several long cylindrical multi-branched secondary rhizomes growing downward from the primary rhizomes, that contain the curcuminoid compounds in an oily cell phase, are harvested at maturity, typically 8 to 9 months after planting.

After harvest, the rhizomes are cured in a process essentially comprising cooking the fresh rhizomes in water. This cooking step aids in producing a product of fairly uniform colour due to the diffusion of the yellow pigments from the individual oil containing cells into the surrounding tissues. After cooking, the material is spread and allowed to dry in the sun. When properly dried, the rhizomes become hard, almost horny and brittle, and of uniform yellow colour. This cured and dried turmeric product is marketed as bulbs and fingers, each type in polished and unpolished forms. This turmeric raw material is then made available to bulk purchase as a starting material for further processing resulting in commercial colouring agents. In figure 1 herein, this turmeric raw material is termed turmeric plant rhizomes.

To make commercial colouring agents the next step involves conventional extraction methods typically using organic solvents. The solvents are generally solvents of defined purity allowed by national and international food laws for the processing of food additives. For industrial production is normally used acetone in this extraction step, since curcuminoid are very soluble in acetone. After extraction, desolventation is obtained by e.g. performing a standard evaporation step.

The curcuminoid-containing phase that is obtained by the above extraction methods is in the form of an oleoresin comprising essential oils containing the curcuminoids. The curcuminoid content of the oleoresin is typically in the range of 30-50% by weight. In figure 1 herein, this extraction step is step (1 ) and the extracted material is termed turmeric oleoresin.

The essential oil fraction of the turmeric oleoresin has a very strong and bitter flavour, which for many purposes, such as colouring of food products, is undesirable.

In order to meet the increasing demand for a highly concentrated flavour-free curcuminoid product, the turmeric oleoresin may be processed further.

Thus, the oleoresin may subsequently be subjected to a so-called crystallisation step resulting in the obtainment of a curcuminoid crystal powder of a relatively high purity (typically >90% by weight) in respect of curcuminoids.

In figure 1 herein, this so-called crystallisation step is step (2) and the obtained crystal composition is termed curcuminoid crystal powder.

Solvents used in this so-called crystallisation step are also solvents allowed by national and international food laws. In the European Union is e.g. permitted use of ethyl acetate and isopropanol is allowed in e.g. USA and by the Joint FAO/WHO Expert Committee on Food Additives (JECFA).

Acetone - normally used in the extraction step - is normally not used commercially in the subsequent so-called crystallisation step. According to the prior art, one reason for this is that the curcuminoids are too soluble in acetone to efficiently obtain the curcuminoid crystals.

The solubility of curcumin in some organic solvents is: acetone > ethyl methyl ketone > ethyl acetate > methanol > ethanol > 1 ,2 dichloroethane > isopropanol > ether > benzene > hexane.

Due to the low solubility of curcumin in hexane it is often used to wash/remove the oils from the turmeric oleoresin, e.g. by washing the turmeric oleoresin with hexane.

In short, the prior art generally describes - see figure 1 for an illustration:

Step (1 ):

(i): Extraction of curcuminoids from Turmeric plant rhizomes by use of an organic solvent wherein the curcuminoids are highly soluble (normally acetone);

(ii): Evaporation of solvent (desolventation - to remove extraction solvent) to get the Turmeric oleoresin;

Step (2): (i): Crystallisation step in a different solvent wherein the curcuminoids are relatively less soluble (e.g. Ethyl acetate (EU) or Isopropanol (USA)) to get the curcuminoid crystal powder.

Some solvents are not commercially acceptable. For instance benzene is carcinogenic and ether is highly flammable. The solvent 1 ,2 dichloroethane (EDC) was earlier used, but later investigations have indicated that it is carcinogenic - accordingly it is not allowed anymore.

Further, even for approved solvents there is a maximum of allowable residual amounts of the solvents in the Turmeric colour product. For instance, JECFA issues guidelines for acceptable residual amounts of solvents plus standard analytical methods to measure the residual amounts of solvents.

The article of K.V. Balakrishnan (Indian Journal of Technology, 21 , 247 (1983)) describes that significant amount of the solvent ethylene dichloride (EDC) may be trapped within the crystal lattice of the curcuminoid crystal powder. In other to measure the trapped EDC they used a modified analytical method, using aqueous sodium hydroxide as solvent to increase the solubility of the curcuminoid crystal. The article explains that the earlier used analytical method did not dislodge the solvent trapped within the crystal lattice. Accordingly, since they also measured the trapped EDC they identified significantly more 5 EDC in the curcuminoid crystal powder than earlier measured.

The chromatograms of the article also indicate presence of acetone. With respect to this reads the article on page 248 "the acetone peak has resulted from the degradation of curcumin by alkali". This means that the authors believed that the acetone was present due to that the acetone is a degradation product derived from the alkali induced 10 degradation of curcumin. Said in other words, the author's prima facie believed that acetone was not present in the analysed curcuminoid crystal powder before the analysis was actually made by use of the alkali.

Verghese and Joy, (Flavour & Fragrance J. VoI 4, 31-32, 1989) describes a process 15 wherein the solvent ethyl acetate is used in both the extraction step [step (1 ) in figure 1 herein] and the subsequently so-called crystallization step [(step (2) in figure 1 herein]. As discussed above, industrially it is not normal to use ethyl acetate in the extraction step - acetone is more normal to use.

The residual amount of ethyl acetate in the curcuminoid crystal powder is said to be 300 20 ppm. It is not explained how the residual amount of the ethyl acetate has been measured.

The article says on page 32 that if needed "the residual solvent in the dye can be eliminated by desolventation involving co-distillation with ethanol".

In fact this sentence objectively does not refer to removal of solvent, but simply the substitution of ethyl acetate solvent with ethanol solvent. 25

The prior art illustrated in figure 1 and described above is further described in e.g. the review article of J. Verghese; Flavour s Fragrance Journal, Vol. 8, 315-319 (1993).

Reference is also made to EP1313808B1 (Chr. Hansen A/S), GB2132205A and K.V.

Balakrishnan et al: Evaluation of Curcumin, Perfumer & Flavorist, vol. 8, 1983, pages 46- 30 49 - all describing the prior art method illustrated in figure 1 herein.

Besides being used as a natural colouring agent, curcumin is known for its antitumor, antioxidant, antiarthritic, anti-amyloid and anti-inflammatory properties. Accordingly, there are numerous prior art documents that relates to special 35 pharmaceutical relevant compositions of curcumin. As known to the skilled person, an active pharmaceutical ingredient (API) shall generally be in a very pure form. Accordingly, the art also describes very detailed and sophisticated methods to make curcumin preparations to be used in curcumin pharmaceutical compositions. An example of such a detailed and sophisticated method is described in e.g. US5861415, which relates to use of a special curcuminoid composition for neutralizing free radicals in a patient. As evident to the skilled person, the economic value/profit for a pharmaceutical curcuminoid product is generally significantly higher than for a natural curcuminoid food colouring product.

Accordingly, the detailed and sophisticated curcuminoid production methods described for the pharmaceutical art would generally speaking be too expensive for the food colouring business.

SUMMARY OF INVENTION

The problem to be solved by the present invention may be seen in the provision of a turmeric curcuminoid composition that comprises less unwanted impurities as compared to prior art comparable turmeric compositions. The turmeric composition may in particular be used for food/feed colouring.

The solution of the present invention may essentially be seen in the removal of residual organic solvents in particular residual organic solvents that have been used as organic solvents in the extraction step (1 ) of figure 1 herein. The residual organic solvents are unwanted impurities.

This solution is based on that the present inventors surprisingly identified that such organic extraction solvents (e.g. acetone) are actually present in significant amounts in turmeric oleoresin and curcuminoid crystal powder colouring compositions-

Prior to our invention, the skilled person prima facie believed that such extraction step solvents (e.g. acetone) were NOT present in turmeric oleoresin and curcuminoid crystal powder compositions.

See e.g. the discussion of the article of K.V. Balakrishnan above. Here the author's actually identified acetone in a curcuminoid crystal powder sample but they identified this as a measurement "error" - i.e. they actually - as others in the art - believed that acetone was NOT present in the curcuminoid crystal powder sample as such. The reason for this is that the extraction solvents are routinely removed by evaporation [see step (1 ) (ii) of figure 1]. Since the extraction solvents (e.g. acetone) were believed to be removed the skilled person had no reason to believe that turmeric oleoresin and curcuminoid crystal powder compositions comprise significant amounts of such extraction solvents (e.g. acetone).

In summary, without being limited to theory one may say that the present inventors for the first time have identified a commercially relevant real life problem with the residual amounts of extraction solvents such as acetone in commercially relevant turmeric colouring products.

The present inventors analysed residual solvent content in a number of commercially available turmeric oleoresin and curcuminoid crystal powder compositions. The results are shown in table 1 of example 2 herein. To the surprise of the present inventors, all tested products comprised significant amounts of e.g. the extraction solvent acetone. As discussed above, it is known that acetone is used as extraction solvent and not in the subsequent so-called crystallization process. Further, it is known that the extraction solvent is removed by evaporation. Consequently, one would prima facie NOT have expected to identify significant amount of acetone in commercially available turmeric oleoresin and curcuminoid crystal powder compositions.

Without being limited to theory, it is presently believed that the present invention for the first time describe identification/measurement of significant amounts of acetone in commercially available turmeric oleoresin and curcuminoid crystal powder compositions.

As discussed above, official organizations such as JECFA provide standard analytical methods to measure residual solvents. However, in order to actually be able to identify that commercially available compositions comprise significant amount of solvents such as acetone, the present inventors actually had to develop a modified analytical method. It is described in details in example 1.

In essence, the analytical method of example 1 is based on JECFA well known standard described analytical methods - except that N,N-dimethyl-formanide (DMF) is used as a solvent in stead of water. The difference is that DMF can dissolve the curcuminoid crystals, which water can not do in a significant way.

To the surprise of the present inventors, the difference between using the "official" water and the DMF as solvent was drastically for the analytical results of the amount of residual solvents. By comparing table 1 (DMF) with table 2 (water) of example 2 one can see that by using the "official" water one identifies relatively very low amounts of acetone and virtually no ethyl acetate (EtAc).

As discussed above, DMF can dissolve the curcuminoid crystals, which water can not do. In line of this and without being limited to theory, it is believed that a substantial amount of the residual solvents identified by use of DMF as solvent are in fact solvents trapped within curcuminoid crystals lattice. Since water is not able to dissolve the curcuminoid crystals, use of water as solvent will not be able to measure such curcuminoid crystals trapped solvents, since in water the un-dissolved crystals will "keep" the trapped solvents within it and it will therefore not be identified/measured.

In line of above, the theory is that a significant amount of the curcuminoid crystals are actually already formed during the evaporation of the extraction solvent step (step (1 ) (ii) of figure 1 ).

Accordingly, the so-called crystallization step (step (2) of figure 1 ) is in fact not a "real" crystallization - but may be seen as simply the separation of already existing curcuminoid crystals from the complex matrix of the turmeric oleoresin. In other words, the theory is that the curcuminoid crystals are mainly already formed during the evaporation of the extraction solvent step (step (1 ) (ii) of figure 1 ) and NOT during the so-called crystallization step (step (2) of figure 1 ).

The theory, that the curcuminoid crystals are already formed during the extraction step could explain why the present inventors have measured so much acetone trapped within the crystals in the analysed commercial products (see table 1 of example 2).

This new herein described theory is contrary to what was believed in the art.

The art believed that the curcuminoid crystals were formed in the crystallization step.

However, this prior art belief can objectively not explain that significant amount of acetone are trapped within the curcuminoid crystals - as demonstrated herein - since acetone is not used commercially in the so-called crystallisation process.

As discussed above, without being limited to theory one may say that the present inventors for the first time have identified a commercially relevant real life problem with the residual amounts of extraction solvents such as acetone in commercially relevant turmeric colouring products.

Today there is industrially produced a lot of bulk turmeric oleoresin in countries such as India. This turmeric oleoresin is distributed to many different production facilities to make e.g. relatively pure curcuminoid crystal powder compositions. From the present invention, it is evident that the majority of this - in e.g. India - bulk produced turmeric oleoresin will actually be contaminated with acetone without anyone actually knows it. As explained this acetone will then also be present - trapped in the crystals - in the final curcuminoid crystal powder products - also without anyone actually is aware of it today.

Further, as shown in table 1 of example 2, the present inventors have also identified problems (significant residual amounts) for other commonly used solvents such as EtAc, isopropanol etc.

Once the problem with the residual solvents - for the first time herein - has been identified one may start to resolve it.

Herein are described different novel methods to make turmeric oleoresin and curcuminoid crystal powder compositions with very low amounts of residual solvents.

It is evident that a standard solvent evaporation step involving heating/vacuum is not enough to remove solvents (e.g. acetone) trapped within the curcuminoid crystals. Otherwise the acetone would have been removed in the commercial oleoresin and powder samples analysed herein (see example 2), since it is known that commercial oleoresin and crystal powder production involves such standard solvent evaporation/drying steps. Further, without being limited to theory it is believed that the solvents (e.g. acetone) are trapped within the curcuminoid crystals if the solvents are present during the actual crystallization process, i.e. during the actual formation of the crystals.

The Verghese and Joy (1989) article discussed above suggest substitution of ethyl acetate solvent with ethanol solvent in curcuminoid crystal powder. It is evident that such a substitution will not give a low solvent powder - possible ethyl acetate trapped in the crystals will simply be substituted by ethanol trapped in the crystals.

In short, in order to make low solvent compositions as described herein, the present inventors developed novel methods that essentially are based on crystallisation of the curcuminoid in the oleoresin matrix without the presence of the extraction solvent. The inventors identified that one may remove the extraction solvent relatively rapidly - before crystallisation has started - and crystal formation can then under adequate conditions (e.g. stirring etc) be made in the oleoresin matrix as such.

Consequently, the curcuminoid crystals will be formed in the oleoresin matrix without the presence of the extraction solvent (e.g. acetone) and thereby one can get a low solvent oleoresin with essentially no residual solvent (e.g. acetone) trapped within the crystals.

Based on this principle is in working example 3 described how to prepare low solvent turmeric oleoresin compositions with very low amounts of residual solvents. See e.g. table 3 of example 3 together with the conclusions of example 3 - describing turmeric oleoresin with very low residual solvents. This should be compared to table 1 of example 2 - showing that the analysed commercial oleoresins all comprise significant more than 300 ppm residual solvents.

Based on the details disclosed herein and the common general knowledge of the skilled person it will now - for the first time - be routine work to make such novel low solvent compositions.

Accordingly, a first aspect of the invention relates to a low solvent turmeric oleoresin composition that comprises essential oils and from 25 to 50% curcuminoids, characterised by that the turmeric oleoresin comprises from 1 ppm to 100 ppm of residual organic solvent(s) trapped within the curcuminoid crystals present in the oleoresin and wherein the amount of trapped residual organic solvent(s) are measured by the analytical method as described in example 1 herein, wherein the amount of residual organic solvents are measured by making two separate measurements - one using water as solvent and in the second N,N-dimethyl-formanide (DMF) as solvent - and the amount of residual organic solvent(s) trapped within the curcuminoid crystals present in the oleoresin is then the difference between the amount measured by using DMF as solvent minus the amount measured by using water as solvent.

As discussed above, the analytical method of example 1 is based on JECFA well known standard described analytical methods - except that N,N-dimethyl-formanide (DMF) is used as a solvent in stead of the "official" water.

The difference is that DMF can dissolve the curcuminoid crystals, which water can not do in significant way. Accordingly, when DMF is used one measures total amount of residual solvents in the sample (solvent trapped in crystals plus "extra free" solvent) and when water is used one only measures the "extra free" solvent.

Consequently, by measuring the difference between the amount measured by using DMF as solvent minus the amount measured by using water as solvent - one identifies the amount of residual organic solvent(s) trapped within the curcuminoid crystals.

In summary, the analytical method of example 1 can easily be made and based on this can the skilled person routinely identify the total amount of residual organic solvent(s) trapped within the curcuminoid crystals.

As discussed herein, once one has low solvent turmeric oleoresin as described herein it is easy to make a similar low solvent turmeric curcuminoid crystal powder composition.

One may simply separate the - in the oleoresin - already formed crystals (without trapped solvent) from the other components (e.g. oils) of the oleoresin. By doing this one easily gets a low solvent turmeric curcuminoid crystal powder composition.

The separation may e.g. be done by addition of a suitable solvent (e.g. isopropanol) to the low solvent oleoresin - stirring until homogeneous solution is obtained - following by filtration to isolate the curcuminoid crystals. In the homogenous solution are the curcuminoid crystals not dissolved - but the other components (e.g. oils) of the oleoresin are dissolved in e.g. isopropanol. Accordingly, the curcuminoid crystals flouting around (suspended) in the homogeneous solution are easily isolated/separated by filtration - the crystals will be recovered on the filter and the oils etc will simply pass through the filter. See e.g. working example 4 herein for further details.

Accordingly, a second aspect of the invention relates to a low solvent turmeric curcuminoid crystal powder composition that comprises at least 80% curcuminoids by weight of the composition, characterised by that the turmeric curcuminoid crystal powder comprises from 1 ppm to 200 ppm of residual organic solvent(s) trapped within the curcuminoid crystals present in the powder and wherein the amount of trapped residual organic solvent(s) are measured by the analytical method as described in example 1 herein, wherein the amount of residual organic solvents are measured by making two separate measurements - one using water as solvent and in the second N,N-dimethyl-formanide (DMF) as solvent - and the amount of residual organic solvent(s) trapped within the curcuminoid crystals present in the powder is then the difference between the amount measured by using DMF as solvent minus the amount measured by using DMF as solvent.

A third aspect of the invention relates to a process for making a low solvent turmeric oleoresin composition of first aspect, wherein the process comprises following steps:

(a): starting with a turmeric oleoresin composition that comprises significant amounts of residual organic solvent(s) trapped within the curcuminoid crystals present in the oleoresin;

(b): dissolving curcuminoid crystals present in the oleoresin of (a) with a suitable solvent;

(c): removing the solvent used in (b) to get a sample essentially free from the solvent used in (b); (d): initiating crystallisation of curcuminoid within the sample, wherein the curcuminoid crystals are created without presence of significant amount of the solvent used in (b);

(e): continuing crystallisation until it is essentially completed and thereby getting the low solvent turmeric oleoresin composition of first aspect. A fourth aspect of the invention relates to a process for making a low solvent turmeric oleoresin composition of first aspect, wherein the process comprises following steps: (i): starting with a turmeric plant rhizome composition comprising curcuminoids; (ii): extracting the curcuminoids by use of a suitable organic extraction solvent; (iii): removing the solvent used in (b) to get a oleoresin sample essentially free from the solvent used in (b);

(iv): initiating crystallisation of curcuminoid within the sample, wherein the curcuminoid crystals are created without presence of significant amount of the solvent used in (b); and (v): continuing crystallisation until it is essentially completed and thereby getting the low solvent turmeric oleoresin composition of first aspect.

As discussed above, the process of the third and fourth aspect are both based on crystallisation of the curcuminoid in the oleoresin matrix essentially without the presence of the extraction solvents. Without being limited to theory, it is believed that the present invention for the first time describes this principle.

A fifth aspect of the invention relates to a process for making a low solvent turmeric curcuminoid crystal powder composition of second aspect, wherein the process comprises following steps:

(A): preparing a low solvent turmeric oleoresin composition by a process of of the third or fourth aspect; and

(B): isolating, by use of a suitable organic solvent, turmeric curcuminoid crystals from the turmeric oleoresin of step (A); and (C): drying the in step (B) isolated turmeric curcuminoid crystals to get the turmeric curcuminoid crystal powder colour composition of the second aspect.

As discussed above, the process of the fifth aspect is based on that one may simply separate the - in the oleoresin - already formed crystals (without trapped solvent) from the other components (e.g. oils) of the oleoresin. As discussed above, without being limited to theory it is presently believed that the present invention for the first time describes that the crystal are already present/formed in the oleoresin.

A sixth aspect of the invention relates to a use of a (I) a low solvent turmeric oleoresin composition of first aspect; or (II) a low solvent turmeric curcuminoid crystal powder composition of second aspect; for colouring a product of interest.

A seventh aspect of the invention relates to a low solvent turmeric oleoresin composition of the first aspect obtainable by the process of the third aspect or the process of the fourth aspect.

An eight aspect of the invention relates to a low solvent turmeric curcuminoid crystal powder composition of the second aspect obtainable by the process of the fifth aspect.

DRAWINGS

Fig. 1 : It illustrates the general prior art plus some of the novel technical discoveries as described herein.

DETAILED DISCLOSURE OF INVENTION

When there herein is referred to an object of an aspect of the invention - e.g. a "turmeric oleoresin composition of first aspect" it should herein be understood as it refers to the object (e.g. turmeric oleoresin) of the aspect (e.g. first aspect) plus all the herein described related embodiments to this aspect. Such relevant related embodiments are described below.

Turmeric oleoresin

In the present context the term "turmeric oleoresin" is well known to the skilled person. As known to the skilled person, a turmeric oleoresin composition comprises essential oils and typically from 25 to 50% curcuminoids.

The ratio of the three curcuminoids in the turmeric oleoresin is typically: curcumin about 50-70%, demethoxy curcumin about 10-30% and bis-demethoxy curcumin about 10-30% the sum of the three compounds being 100%.

A turmeric oleoresin is made by solvent extraction of the curcuminoids from curcuminoids containing plants. In one embodiment of the present invention the plant specie include a plant of the genus Curcuma. Useful curcuminoid producing species of this genus include Curcuma longa L, C. aromatica Salisb., C. amada Roxb., C. zedoaria Rose, and C. xanthorrhiza Roxb.

In industrial production of colouring turmeric oleoresin compositions are normally produced in large scale - e.g. the production fabric makes a large scale bulk composition. Accordingly, the weight of the low solvent turmeric oleoresin composition of the first aspect may be from 10 kg to 500 kg, such as from 20 kg to 200 kg. The weight relates to the weight of the composition as such within a suitable package.

Turmeric curcuminoid crystal powder

In the present context the term "turmeric curcuminoid crystal powder" is well known to the skilled person. As know to the skilled person the turmeric curcuminoid crystal powder is derived from the turmeric oleoresin, i.e. it is made by use of turmeric oleoresin as starting material (see e.g. figure 1 herein).

Preferably the low solvent turmeric curcuminoid crystal powder composition of second aspect is a composition that comprises at least 90% curcuminoids by weight of the composition. Commercial curcuminoid crystal powder compositions typically comprise at least 90% curcuminoids by weight of the composition.

The ratio of the three curcuminoids in the turmeric curcuminoid crystal powder is typically: curcumin about 50-70%, demethoxy curcumin about 10-30% and bis-demethoxy curcumin about 10-30% the sum of the three compounds being 100%.

In industrial production of colouring products turmeric curcuminoid crystal powder compositions are normally produced in large scale - e.g. the production fabric makes a large scale bulk composition.

Accordingly, the weight of the low solvent turmeric powder composition of the second aspect may be from 10 kg to 500 kg, such as from 20 kg to 200 kg. The weight relates to the weight of the composition as such within a suitable package. Residual organic solvent(s) - amounts (ppm):

As said above, the first aspect relates to a low solvent turmeric oleoresin characterised by that the turmeric oleoresin comprises from 1 ppm to 100 ppm of residual organic solvent(s) trapped within the curcuminoid crystals present in the oleoresin.

In a preferred embodiment the low solvent turmeric oleoresin comprises from 1 ppm to 75 ppm, more preferably from 1 ppm to 50 ppm, even more preferably from 1 ppm to 30 ppm and most preferably 1 ppm to 20 ppm of residual organic solvent(s) trapped within the curcuminoid crystals present in the oleoresin.

The lower limit of "1 ppm" may be seen as relating to that one in practice can not remove all residual solvents. If e.g. acetone is used for the extraction one will at the end of the day have at least very small amounts of such residual acetone in a final curcuminoid composition as described herein.

For practical/economic reasons it may that there will be at least 5 ppm or 10 ppm residual solvent in a low solvent turmeric oleoresin composition as described herein.

In the second aspect - relating to a low solvent turmeric curcuminoid crystal powder composition - the range is from 1 ppm to 200 ppm.

The upper range is a bit higher than for the turmeric oleoresin - this is logical due to in the powder the essential oils etc are removed and thereby concentrated - giving a higher ppm number for the similar absolute amount of solvent(s).

In a preferred embodiment the low solvent turmeric curcuminoid crystal powder comprises from 1 ppm to 150 ppm, more preferably from 1 ppm to 100 ppm, even more preferably from 1 ppm to 60 ppm and most preferably 1 ppm to 40 ppm of residual organic solvent(s) trapped within the curcuminoid crystals present in the oleoresin.

For practical/economic reasons it may that there will be at least 2 ppm residual solvent in a low solvent turmeric curcuminoid crystal powder as described herein.

In accordance with the art - the term "ppm" means parts-per-million. The ppm numbers here relates to the total amount of solvent(s) trapped within the curcuminoid crystals - i.e. there may be one or more different types of solvents (e.g. acetone, EtAc etc).

Residual organic solvent(s) - preferred types:

For commercial production of turmeric colour compositions are commercially used solvents such as acetone, ethyl methyl ketone, ethyl acetate (EtAc), methanol, ethanol, dichloromethane, isopropanol , hexane, n-butanol and/or ethylene dichloride (EDC).

Accordingly, such solvents are in practice many times examples of residual solvents as discussed herein - see e.g. table 2 of example 1.

Accordingly, in a preferred embodiment the 1 ppm to 100 ppm of residual organic solvent(s) trapped within the curcuminoid crystals present in the oleoresin of the first aspect, includes at least one solvent selected from the group consisting of acetone, ethyl methyl ketone, ethyl acetate (EtAc), methanol, ethanol, dichloromethane, isopropanol , hexane, n-butanol and ethylene dichloride (EDC).

This embodiment should be understood as a limitation of the first aspect in the sense that measurable amounts of at least one of above listed solvents shall be present as a residual organic solvent(s) trapped within the curcuminoid crystals present in the oleoresin.

As discussed above, the solubility of curcumin in some organic solvents is: acetone > ethyl methyl ketone > ethyl acetate > methanol > ethanol > 1 ,2 dichloroethane (EDC) > isopropanol > ether > benzene > hexane.

As discussed above, acetone is normally used as an extraction solvent [step 1 (i) of figure 1 herein] due to the solubility of curcumin is high in acetone.

Accordingly, in a preferred embodiment the 1 ppm to 100 ppm of residual organic solvent(s) trapped within the curcuminoid crystals present in the oleoresin of the first aspect, includes at least one solvent which has a higher solubility of curcumin as compared to the solubility of ethyl acetate.

It is routine work for the skilled person to determine the solubility of curcumin in a specific solvent of interest under herein relevant conditions which is defined as room temperature and atmospheric pressure. Accordingly, it is routine work to identify if a specific solvent of interest has a higher solubility of curcumin as compared to ethyl acetate.

From table 3 and table 4 of example 3 can be seen that in this example were made low solvent turmeric curcuminoid crystal powder compositions with around 1 ppm to 38 ppm residual acetone present in the samples. Accordingly in this example 3 were also made low solvent turmeric oleoresin compositions with this low amount of residual acetone.

In line of this it may be the at least one solvent which has a higher solubility of curcumin as compared to ethyl acetate is one or more solvent(s) that in total is/are present in an amount of 1 ppm to 50 ppm or in an amount of 1 ppm to 25 ppm.

This should be understood as if e.g. such "high solubility" solvents are present in e.g. an amount of 20 ppm then there may at maximum be up to 80 ppm (to reach the maximum of

100 ppm) of other "low solubility" solvents such as e.g. isopropanol.

In a preferred embodiment the 1 ppm to 100 ppm of residual organic solvent(s) trapped within the curcuminoid crystals present in the oleoresin of the first aspect includes at least the solvent acetone.

If acetone is present it is typically present in an amount of 1 ppm to 50 ppm, more preferably in an amount of 1 ppm to 25 ppm and even more preferably in an amount of 1 ppm to 10 ppm.

As discussed above, the residual solvents trapped in a oleoresin will at least to some degree also still be present in a low solvent turmeric curcuminoid crystal powder as described herein - since such a crystal powder preferably are made by a "simply" separating already crystal from the oleoresin.

Accordingly and in line with above - in a preferred embodiment the 1 ppm to 200 ppm of residual organic solvent(s) trapped within the curcuminoid crystals present in the powder of the turmeric curcuminoid crystal powder of second aspect, includes at least one solvent selected from the group consisting of acetone, ethyl methyl ketone, ethyl acetate (EtAc), methanol, ethanol, dichloromethane, isopropanol, hexane, n-butanol and ethylene dichloride (EDC). Further, in a preferred embodiment the 1 ppm to 200 ppm of residual organic solvent(s) trapped within the curcuminoid crystals present in the powder of the second aspect, includes at least one solvent which has a higher solubility of curcumin as compared to ethyl acetate. In line of this it may be the at least one solvent which has a higher solubility of curcumin as compared to ethyl acetate is one or more solvent(s) that in total is/are present in an amount of 1 ppm to 100 ppm, more preferably in an amount of 1 ppm to 50 ppm. This should be understood as if e.g. such "high solubility" solvents are present in e.g. an amount of 40 ppm then there may at maximum be up to 160 ppm in the powder (to reach the maximum of 200 ppm) of other "low solubility" solvents such as e.g. isopropanol.

In a preferred embodiment the 1 ppm to 200 ppm of residual organic solvent(s) trapped within the curcuminoid crystals present in the powder of the second aspect includes at least the solvent acetone. If acetone is present it is typically present in the powder in an amount of 1 ppm to 100 ppm, more preferably in an amount of 1 ppm to 50 ppm and even more preferably in an amount of 1 ppm to 20 ppm.

Process for making a low solvent turmeric oleoresin composition

As discussed above, the process of the third and fourth aspect are both based on crystallisation of the curcuminoid in the oleoresin matrix essentially without the presence of extraction solvents. Without being limited to theory, it is believed that the present invention for the first time describes this principle. Based on this principle is in working example 3 described how to prepare low solvent turmeric oleoresin compositions with very low amounts of residual solvents.

In third aspect is in step (a) started with a turmeric oleoresin composition that comprises significant amounts of residual organic solvent(s) trapped within the curcuminoid crystals present in the oleoresin.

This may herein be considered a prior art turmeric oleoresin composition. As discussed above, according to the prior art the skilled person were - before the present disclosure - not aware of the problem with the significant presence of e.g. extraction solvents like acetone in commercially relevant turmeric oleoresin compositions. In steps (b) to (e) is the trapped residual solvent removed to get a low solvent turmeric oleoresin composition of the first aspect.

In step (b) is curcuminoid crystals dissolved in a suitable solvent.

As discussed above, the present inventors have identified that it is important to dissolve the crystals in order to remove the therein trapped solvents. One can not do this by a simple solvent evaporation step involving e.g. standard heating/vacuum.

Since the objective of this step (b) is to dissolve the crystals it is preferred to use a solvent wherein the solubility of curcumin is relatively high such as e.g. acetone. Acetone is used in example 3 herein. However, one may use another suitable solvent as known to the skilled person - plus one may use a combination of two or more different solvents.

In step (b) one should dissolve the oleoresin and thereby the crystals within it under suitable conditions. Suitable conditions may include stirring, adequate temperature (e.g. room temperature) under atmospheric pressure.

It is evident that the conditions should be so that essentially all crystals are dissolved.

Based on the details provided herein (e.g. example 3) and the common general knowledge of the skilled person it is routine work for the skilled person to adjust the conditions so essentially all crystals - within the oleoresin - are dissolved.

In step (c) is removed the solvent used in (b) to get a sample essentially free from the solvent used in (b). This step (c) shall be seen in conjunction with step (d) - saying that the crystallization shall take place without the presence of significant amount of the solvent used in step (b).

Accordingly, the idea is that in step (c) is the solvent relatively rapid removed - to get it removed before significant start of crystallisation in step (d). In line with the common general knowledge of the skilled person - in step (c) the solvent may be relatively rapid removed by using an adequate temperature (e.g. from 8O ⁰ C to 110 ⁰ C) under suitable vacuum conditions for a suitable time (e.g. from 20 to 80 minutes). Based on the information herein (see e.g. example 3) and common general knowledge the skilled person can optimize the conditions of step (c) to get solvent removed. In step (d) is initiated the crystallisation so the curcuminoid crystals are created without presence of significant amount of the solvent used in (b) - i.e. the crystals will comprise low amounts of trapped solvents.

As known to the skilled person a number of factors may influence start of crystallisation. For instance one may add seeds crystals to catalyze the start of crystallisation.

As illustrated in example 3 - appropriate stirring of the sample is suitable way to properly initiate the crystallisation in step (d). In example 3 it can be seen that a sample after step (c) (i.e. a desolventised oleoresin) may initially be dark brown and homogeneous. By appropriate stirring of such a sample it took 10-15' to see visible turbidity and crystallisation. However, if simply left at ambient temperature without stirring it took several days to see the first crystals.

As shown in example 3, one may facilitate the stirring of the relatively viscous oleoresin by adding viscosity lowering substance such as propylene glycol (PG) or by increasing the temperature.

In example 3 this was done by adding propylene glycol or by increasing stirring temperature to 70-80°C. Based on the information herein (see e.g. example 3) and common general knowledge the skilled person can optimize the conditions of step (d) to properly initiate the crystallisation process - e.g. by using viscosity lowering substance such as propylene glycol (PG) or by using an alternative different viscosity lowering substance. As known to the skilled person suitable examples of such other alternative different viscosity substances may for example be mineral oil, ethylene glycol, glycerol etc.

In step (e) is continued crystallisation until it is essentially completed and thereby getting the low solvent turmeric oleoresin composition of first aspect.

Based on the information herein (see e.g. example 3) and common general knowledge the skilled person can routinely control/follow such a crystallisation until it is essentially completed.

As illustrated in example 3, under proper stirring it seems as it seems that 24 hours is enough time for the crystallisation to complete. In the fourth aspect is in step (i) started with a turmeric plant rhizome composition comprising and in step (ii) made extracting the curcuminoids by use of a suitable organic extraction solvent.

These steps (i) and (ii) may herein be seen as standard steps made according to the art - i.e. correspond to step (1 ) (i) as illustrated in figure herein. As discussed herein - acetone may be a good extraction solvent.

Steps (iii) and (iv) may be seen as the novel important steps and technically essentially corresponds to steps (c) and (d) of the third aspect as discussed above. Accordingly, the preferred embodiments/details for steps (c) and (d) are also preferred embodiments/details for these steps (iii) and (iv).

Similar step (v) technically essentially corresponds to steps (e) of the third aspect. Accordingly, the preferred embodiments/details for step (e) are also preferred embodiments/details for this step (v).

Process for making a low solvent turmeric curcuminoid crystal (TCC) powder composition

As discussed above, the process of the fifth aspect is based on that one may simply separate the - in the oleoresin - already formed crystals (without trapped solvent) from the other components (e.g. oils) of the oleoresin. As discussed above, without being limited to theory it is presently believed that the present invention for the first time describes that the crystal are already present/formed in the oleoresin.

By doing this one easily gets a low solvent turmeric curcuminoid crystal powder composition.

The separation may e.g. be done by addition of a suitable solvent (e.g. isopropanol) to the low solvent oleoresin - stirring until homogeneous solution is obtained - following by filtration to isolate the curcuminoid crystals. This is illustrated in example 4 herein - by use of different solvents.

In step (A) is started with a low solvent turmeric oleoresin of the first aspect.

In step (B) is isolated, by use of a suitable organic solvent, turmeric curcuminoid crystals from the turmeric oleoresin of step (A). The term "isolating" could alternatively have been termed "separating", i.e. separating the crystals from other parts (e.g. oils) of the oleoresin.

In example 4 herein this was done by use of different solvents. Acetone would in this step properly be a less good solvent since the solubility for curcumin is relatively high in acetone and at this step (B) the objective is not to get the crystals dissolved but simply to separate/isolate them from the rest of the oleoresin components.

However, the skilled person knows a number of other suitable solvents. As illustrated in example 4 suitable examples are ethyl acetate, methanol, ethanol, isopropanol or n- butanol. A mixture of methonal/hexane also worked well.

As illustrated in example 4, step (B) by be performed by adding suitable solvent to the low solvent turmeric oleoresin of step (A); mixing at adequate temperature to get a homogenous mixture with the crystals suspended in the mixture and isolating the crystals by e.g. filtration.

Based on the information herein (see e.g. example 4) and common general knowledge the skilled person can routinely perform this Step (B).

In step (C) is simply dried the in step (B) isolated turmeric curcuminoid crystals to get the turmeric curcuminoid crystal powder colour composition of the second aspect. This is a routine step.

Use of a low solvent turmeric composition as described herein:

As said above, the sixth aspect of the invention relates to a use of a (I) a low solvent turmeric oleoresin composition of first aspect; or (II) a low solvent turmeric curcuminoid crystal (TCC) powder composition of second aspect; for colouring a product of interest.

The use as such may be seen as a use according to the art. The product to be coloured may e.g. be a food or feed product. It may be a solid or liquid food/feed product. The products may be in any conventional form including products in tablet or capsule dosage forms that may comprise separate compartments which can be coloured separately.

In a further useful embodiment, the product may be textile. In the present context the term "textile" refers to any filament, fibre or yarn that can be made into fabric or cloth and used in e.g. wearing apparel, household linens and beddings, upholstery, draperies and curtains, wall coverings, rugs and carpets.

The product may also be a medical/pharmaceutical product, wherein the low solvent turmeric composition as described herein beside the colouring effect could also have a medical/pharmaceutical effect. An example could be an antitumor, antioxidant, antiarthritic, anti-amyloid or anti-inflammatory effect as known in the art. In line of this, a separate aspect of the invention relates to use of a

(I) a low solvent turmeric oleoresin composition of first aspect; or

(II) a low solvent turmeric curcuminoid crystal (TCC) powder composition of second aspect; for making a pharmaceutical composition.

EXAMPLES

EXAMPLE 1 - Analytical method to measure residual organic solvent(s) trapped within the curcuminoid crystals

The analytical method of this example 1 is based on JECFA well known standard described analytical methods - except that N,N-dimethyl-formanide (DMF) is used as a solvent in stead of the "official" water. The difference is that DMF can dissolve the curcuminoid crystals, which water can not do in significant way. Accordingly, when DMF is used one measures total amount of residual solvents in the sample (solvent trapped in crystals plus "extra free" solvent) and when water is used one only measures the "extra free" solvent. Consequently, by measuring the difference between the amount measured by using DMF as solvent minus the amount measured by using water as solvent - one identifies the amount of residual organic solvent(s) trapped within the curcuminoid crystals.

Standards

2 ml of the following solvents, hexane, acetone, ethylacetate, methanol, isopropanol, ethanol and 1.2 dichloroethane were weighed out in a 50 ml volumetric flask and diluted with DMF containing 1 % citric acid (=standard stock solution approx. 40.000 ppm) 5 μl_ of this dilution was added to 4.00 ml of DMF and the vial was immediately closed with teflon lined septum.

Samples

Approx 0.1 g sample (4 decimals precision) was added to the headspace vial.

4.00 ml of DMF was added and the vial closed.

Head space sampling conditions

Head Space sampler: Perkin Elmer HS101

Equilibration temperature: 80 ⁰ C

Equilibration time: 30 min. Pressurization time: 2 min at 50 ml He/min at 30 psi (207 kPa)

Injection time: 0.02 min (splitless)

GC conditions

Perkin Elmer GC8500 Column: FFAP 25m ^* 0.20mm ^* 0.33μm (Agilent)

Head pressure: 30 psi

Temperature program:

60 ^o C(2min)-30°C/min-220°C(1 min)

Cycle time: 20 min Detector FID: 220 ⁰ C

The "water" reference assay

The "water" reference assay is made identical to the above, wherein water is used instead of DMF - apart from standard stock solutions that are made with DMF as described above. Conclusion - Measurement of residual solvent

By using the samples and conditions above one get a chromatogram were one routinely can identify the total amount of residual solvents in the sample. In order to quantity amount of a specific solvent of interest (e.g. acetone) one simply uses a relevant standard as indicated above -it is routine to make a standard for a specific solvent of interest.

EXAMPLE 2 - Analysis of residual solvents in commercial turmeric colour compositions

Using the analytical method of example 1 was measured amounts of residual organic solvents trapped within the curcuminoid crystals present in commercially available turmeric colour compositions.

The results are shown in tables below. The term "powder" in the tables refers to turmeric curcuminoid crystal powder composition and the term "oleoresin" refers to turmeric oleoresin composition.

In table 1 was used DMF as solvent and in table 2 was used water as solvent.

10 Powder 249 23 12 142 4316 22

1 1 Powder 1 1 1017 1 1 308 509 15

12 Oleoresin 181 99 12 13

13 Oleoresin 182 108 12 16

14 Oleoresin 287 131

15 Oleoresin 254 14

16 Oleoresin 1 178 14 24

Table 1 : DMF as solvent.

Table 2: Water as solvent.

Conclusions:

As discussed herein - the results of the "water" reference measurement may be seen as results the skilled person probably prima facie could have expected - i.e. results that show some relatively limited residual solvents in the commercial samples. However, the results of table 1 were very surprising for the present inventors. The results of table 1 show that there are significant residual organic solvent(s) trapped within the curcuminoid crystals of the analysed commercially available turmeric colour compositions.

EXAMPLE 3 - Making low solvent turmeric oleoresin composition followed by separation of crystals to get a turmeric curcuminoid crystal powder composition

Materials and methods

Curcumin content: Visible spectrophotometry, E1 %=1601 in acetone at 420 nm. Residual solvents: Measured as described in example 1 using DMF as solvent. .

Separation of crystals: Mixing the oleoresin with methanol 80 % (20 % water) and hexane at ambient temperature, filtration and drying at 105°C at least 2 hours.

Starting materials - turmeric oleoresin composition that comprises significant amounts of residual organic solvents

T40-01-02 ORT Turmeric 40%. 38.6% curcumin

Viscous liquid not pourable at ambient temperature. Yellow-brown colour.

Residual solvents: Acetone 187 mg/Kg

Ethyl acetate 269 mg/Kg Hexane 3 mg/Kg

1 ,2-Dichloroethane 28 mg/Kg

Methanol, Ethanol, IPA, <10 mg/Kg each Propylene glycol: not detected

T30-01-01 ORT Turmeric 30%. 28.6% Curcumin Liquid, low viscosity, pourable at ambient temperature Residual solvents: Acetone 1 18 mg/Kg

Ethyl acetate 39 mg/Kg Hexane 2 mg/Kg 1 ,2-Dichloroethane, Methanol, Ethanol, IPA, <10 mg/Kg each.

Propylene glycol 20%

Description of process and results

The technique developed consists in dissolving the oleoresin turmeric (ORT) in acetone (the best solvent for curcumin, and with the lower boiling point of the solvents allowed in EU, except dichloromethane which is out of question being an halogenated), and removing it as fast as possible, to avoid the start of crystallisation until the solvent is removed.

The oleoresin was stirred after desolventation to speed up crystallisation. ORT is too 5 viscous to be stirred at ambient temperature, so it may be preferred to reduce viscosity. Two techniques have proved successful in this step:

1.- Adding propylene glycol (PG) to the solution of oleoresin in acetone. This helps also the desolventation: lower viscosity of the mixture allows faster evaporation of the last traces of acetone, and lower concentration reduces the risk of premature precipitation of 10 curcumin.

This technique is applicable when the purpose is to obtain crystals, but when we just want to obtain desolventised ORT, we have a limitation: the concentration is lowered by the presence of the carrier so we obtain ORT with max. 30% curcumin. 2.- Stirring at above-ambient temperature, without a carrier. For 40% oleoresin, the 15 minimum temperature that allows magnetic stirring is 70-80°C. ORT is heat stable enough, so it can be stirred for several days at these temperatures without colour loss. The weak point is that it requires longer time and higher desolventation temperature than oleoresin diluted with PG, and sometimes a small amount of acetone is trapped. It can be more difficult to control in industrial scale. 20

ORT (ca. 20 g) was dissolved in 200 ml. acetone, different amounts of propylene glycol were added, and the solution was desolventised for 30-60' minutes at 90 or 100°C under vacuum (500 mm Hg) and air current (1 L/min). The residual solvent of oleoresins treated this way ranged from 2 to 7 mg/Kg acetone when PG was present, and 10-30 mg/Kg in 25 40% ORT without PG.

These desolventised oleoresins are initially dark brown and homogeneous, and were left at ambient temperature alternatively with and without stirring, When stirring was applied, it took 10-15' to see visible turbidity and crystallisation, while in the samples stored without stirring it takes several days to see the first crystals.

30 The addition of propylene glycol helps the crystallisation, but without stirring the crystallisation is uncontrolled:

- experiments with the same treatment give different yields,

- in some cases the crystallisation is very advanced when we add solvent to obtain the crystals, so very little solvent is trapped, while in other cases part of the crystallisation takes place when the solvent reduces the viscosity and then the crystals contain a lot of solvent.

To let crystallisation happen by itself without control ends in non-consistent results and has to be avoided.

The tables 3 and 4 below show the results of e.g. yield of colour and residual solvent in the curcuminoid crystal powder compositions. The crystals were separated from the low solvent oleoresin - made as described above in this example - by the separation method as described in the material and methods section of this example 3 - i.e. a separation method using methanol/hexane.

The term "ORT+PG stirring. Ambient temperature." of table 3 and the term "ORT + stirring. HOT temperature" of table 4 refers to how the low solvent oleoresin was made as described above.

- ORT+PG stirring. Ambient temperature.

Table 3. Me = methanol, Ac = acetone and Hx = hexane. PG = propylene glycol.

By mixing with propylene glycol and stirring the desolventised ORT (the propylene glycol is just added to reduce the viscosity and thus be able to stir at ambient temperature), it is possible to get the same yield as from the original oleoresins.

The crystal formation is visible after very short time and it seems that 24 hours is enough time for the crystallisation to complete. None of the experiments is contaminated with solvents and the yield is close to the original ORT. - ORT + stirring. HOT temperature.

Table 4. Me = methanol, Ac = acetone and Hx = hexane.

To close the circle, it was necessary to try to recover the desolventised ORT without carrier, and this can be done by stirring the heated oleoresin to allow crystals grow, again we recover the same yield of crystals as from the untreated oleoresin. The danger here is that the 40% oleoresin is more viscous than diluted ones so there is some acetone trapped in some experiments. This is not a problem in ORT itself, because the level is still below the 50 ppm limit, but there is some risk to get crystals with too much solvent (CX-82-02 Y: 62 mg/Kg).

The target yield of curcumin crystals from the experiments was that obtained from the original oleoresins: T30-01-01 : 63-68% T40-01 -02: 59-60%

Conclusions In this example was started with a turmeric oleoresin composition that comprises significant amounts of residual organic solvent(s) trapped within the curcuminoid crystals present in the oleoresin.

Essentially was then performed the steps (b) to (e) of the process of the third aspect as described herein and there was then obtained a low solvent turmeric oleoresin composition.

The crystals were then separated from the low solvent turmeric oleoresin and there was obtained low solvent curcuminoid crystal powder compositions.

As can be seen in table 3 and 4, there were obtained low solvent curcuminoid crystal powder compositions of second aspect as described herein - i.e. a powder with very low amounts of residual organic solvent(s) trapped within the curcuminoid crystals present in the powder.

As evident to the skilled person in view of the description herein - the in this example made low solvent turmeric oleoresins also had very low amounts of residual organic solvent(s) trapped within the crystals - otherwise one could not have simply separated the low solvent crystal powder of table 3 and 4.

EXAMPLE 4 - Making a low solvent turmeric curcuminoid crystal powder composition

Description of process

The starting material was turmeric oleoresin compositions with curcuminoid crystals present in the oleoresin.

The experiments included an addition of solvent to the oleoresin and stirring at ambient temperature until a homogeneous suspension was achieved and then filtrated. Filtration of the homogeneous suspension was performed and the crystals were recovered from the filter. After recovery the crystals were dried at 1 10 ⁰ C for one hour.

Five different solvents tested/used were: ethyl acetate, methanol, ethanol, isopropanol and n-butanol. Further a mixture of methanol/hexane was also tested.

Results The maximum colour yield was around 60% for all solvents if properly used in adequate ratio to oleoresin. 60% yield means that 60% of the colour of the oleoresin is isolated as crystals.

This more than indicates that the crystals were already present in the oleoresin. The solvent simply removes essential oils/resins from the precipitated crystals, and the crystals can be separated from the mother liquid.

Since the crystals were already precipitated in the oleoresin the only time needed to get maximum yield was sufficient time to free the crystals from the other components in the oleoresin.

Discussion of the results

The crystals are already formed in the oleoresin. One can only expect to isolate these crystals as turmeric powder. It is not possible to isolate more colour as powder. The time needed to free the crystals is the time it takes to "dissolve" the oleoresin in the solvent. Nothing is gained by prolonged contact with the solvent.

lsopropanol is a good solvent for production of curcumin powder. By increasing the amount of solvent from ratio 0.5 part of solvent and 1 part of oleoresin to ratio 3-4 parts of solvent and 1 part of oleoresin, practically all the already formed crystals could be isolated in acceptable purity and maximum yield without washing. The ratio used today gives a wet filter cake that needs washing with fresh solvent, which means loss of product. The product is legal in the US.

n-butanol would work just as well as isopropanol but the solvent seems not to be used commercially.

Methanol can be used to produce legal powders for both the EU and the US. The yield would be lower than when using isopropanol.

Ethanol could be used instead of methanol with a higher yield than for methanol (but still lower than for isopropanol) giving legal powders for both the EU and the US. Ethyl acetate can be used to produce legal powders for the EU. The yield would be lower than when using isopropanol. Actually, the yield will be the lowest of all the solvents.

Methanol/hexane can be used to produce powders of high purity and maximum yield legal for both the EU and the US. The system, including the washing, should be adapted to each individual oleoresin.

Conclusions

The results of this example demonstrate that the isolation/separation of the curcuminoid crystals already present in the oleoresin gave a good crystal powder yield.

Accordingly, by starting from a low solvent turmeric oleoresin as described herein [step (A) of the fifth aspect] and then performing step (B) and (C) of the fifth aspect - as done in this example 4 - then one gets a low solvent turmeric curcuminoid crystal powder composition as described herein.

REFERENCES

1 : K.V. Balakrishnan (Indian Journal of Technology, 21 , 247 (1983))

2: Verghese and Joy, (Flavour s Fragance J. VoI 4, 31-32, 1989)

3: J. Verghese; Flavour and Fragnance Journal, Vol. 8, 315-319 (1993).

4: EP1313808B1 (Chr. Hansen NS).

5: US5861415

6: GB2132205A

7: K.V. Balakrishnan et al: Evaluation of Curcumin, Perfumer & Flavorist, vol. 8, 1983, pages 46-49