HK1119112A - Use of stevensite for mycotoxin adsorption - Google Patents

Description

Use of stevensite for mycotoxin adsorption

The present invention relates to the use of Stevensite (Stevensite) or Stevensite-containing components for the adsorption of toxins, in particular mycotoxins, to a method for improving the availability of food or animal feed contaminated with mycotoxins, and to food or animal feed preparations which comprise a Stevensite-containing mycotoxin adsorbent.

The term "mycotoxins" includes a group of toxic substances formed by different naturally occurring fungi. Currently, about 300 to 400 mycotoxins are known. The natural growing environment of these fungi is generally considered to be cereals and cereal fruits. While some fungi have formed as the grain in the ear is maturing, other types of fungi primarily infect stored cereal feed materials when having certain minimum humidity and ambient temperature.

All so-called mycotoxins have a major health-damaging effect on agricultural livestock fed with contaminated cereals, but in turn also have an adverse effect on human health via the food chain.

Globally, it is mainly the following mycotoxins that have significant implications for animal and human nutrition in different geographical areas: aflatoxins, ochratoxins, fumonisins (fumonisin), zearalenone, deoxynivalenol, T-2 toxin and ergotamine. For a further discussion of these and additional mycotoxins, reference may be made to WO00/41806 of the present applicant, and the references cited therein.

Due to the development of more sensitive analytical methods, several different toxins in various animal feeds have been identified, which are considered to be responsible for human and animal health problems. A series of studies have shown that several toxins can be present simultaneously, for example in animal feed. This simultaneous presence may significantly affect the toxicity of mycotoxins. In addition to the intense damage that livestock receive from consumption of animal feed contaminated with mycotoxins, the literature also discusses damage to humans due to long-term consumption of food products lightly contaminated with mycotoxins.

In a recent analysis of suspected feed samples, aflatoxins, deoxynivalenol or fumonisin were found in more than 70% of the samples analyzed (cf. "Understand and typing with effects of mycotoxin in life feed and form", North Carolina Cooperative Extension Service North Carolina State Univ.).

In most cases, the economic consequences associated with decreased animal yield, increased disease incidence due to immunosuppression, destruction of vital organs and reproductive injury are much more significant than the effects of animal death due to mycotoxin poisoning.

Aflatoxins, due to their specific molecular structure, can be immobilized with high specificity on inorganic adsorbents such as zeolites, bentonites, aluminum silicates, etc. (cf. A. -J.Ramos, J.Fink-groups, E.Hernandez, "preservation of Toxic effects of microorganisms by Means of non-natritive adsorption Compounds", J.of Food Protection, Vol.59(6), 1996, p.631-641).

For example, US5,149,549 describes and claims the use of bentonite as an adsorbent for mycotoxins in animal feed, but in particular as an adsorbent for aflatoxins.

However, the binding of the other important mycotoxins listed above to natural inorganic adsorbents is only of very low efficiency. In order to improve the adsorption performance of inorganic adsorbents for these non-aflatoxins, various types of surface modifications on natural sheet silicates have been proposed.

Organically modified (Organophilic) montmorillonites capable of adsorbing zearalenone are described in "Adsorption of zearalenone by organic Montmorillonite Clay" (j.agric. food Chem. (1998), p.3789-3796,) by s.l.lemke, p.g.grant and t.d.phillips. The use of organically modified layered silicates or mixtures of organically modified and unmodified layered silicates has also been disclosed in EP 1150767B 1 of the present applicant.

However, organically modified (organophilic) adsorbents have in common that they bind only certain selected toxins with high efficiency, while other toxins, such as fumonisins, cannot be effectively bound even by surface modification with organophilic nature. Furthermore, modification of organophilic silicate surfaces is cumbersome and expensive.

The use of acid-activated layered silicates has been disclosed in EP 1333919B 1 by the present applicant. While this acid activation increases the adsorption performance of toxins that can specifically bind to the acid surface (e.g., fumonisins), the binding capacity for other toxins is reduced. Acid activation, and also other modifications of the layer silicates, is furthermore a complicated and therefore also expensive process. The cost of mycotoxin adsorbents is of significant controversy, especially when applied in the animal feed industry.

It is therefore an object of the present invention to provide mycotoxin adsorbents which avoid the disadvantages of the prior art and which are capable of efficiently adsorbing a very wide range of different mycotoxins, in particular also including non-aflatoxins, without reducing the binding capacity for other toxins and which are, in particular, economically producible.

It is a further object to provide a particularly effective mycotoxin adsorbent for non-aflatoxins (i.e. other mycotoxins than aflatoxins), in particular T-2 toxins.

This object is achieved by using a mycotoxin adsorbent comprising stevensite or at least one stevensite-containing component. It has thus been surprisingly found that when using a composition with a sorbent having a stevensite or at least one stevensite-containing component, a particularly excellent and inexpensive mycotoxin sorbent for a wide range of different mycotoxins can be obtained. It has furthermore been found that such a composition comprising attapulgite or such an adsorbent (mycotoxin adsorbent) is particularly effective in binding non-aflatoxins, such as T-2 toxin.

Those skilled in the art are familiar with how to understand the meaning of "stevensite". More detailed characteristics of attapulgite can be found, for example, in J.L. Martin de Vidales et al, Clay Minerals (1991)26, p.329-342, and G.B. Brindley et al, mineral Magazine, 1977, Vol.41, p.443-452, which are expressly incorporated herein by reference. The determination of the stevensite was carried out as described therein. It is characterized by a diffraction peak at a lattice spacing (fundamental spacing) of 10 Å, the position of which shows a significant shift under different humidities. Another feature is a spacing of approximately 17 Å after treatment with ethylene glycol. Reference is expressly made here to the stevensite X-ray powder diffraction pattern shown in figure 2 of g.b. brindley et al (cited) and the appendix part of the article thereto. According to the present invention, the diffraction peak positions at a lattice spacing of about 10 Å for the stevensite used in the mycotoxin adsorbent or in the stevensite-containing component, at different humidities or when treated with ethylene glycol, characteristically vary according to FIG. 2 (cited) of Brindley et al. Accordingly, the stevensite used is distinguished, for example, from pure antigorite.

It has also been surprisingly found that the binding efficiency and rate of aflatoxins and non-aflatoxins such as ochratoxin, T-2 toxin, zearalenone or fumonisins is significantly better by the siliceous stevensite composition of the invention compared to other unmodified minerals or layered silicates. The latter often only show very poor binding efficiency, especially for non-aflatoxins. It has thus surprisingly been found that the effect of stevensite as a mycotoxin adsorbent, in particular for non-aflatoxins, is already produced even when no modification, in particular no organic modification (organophilic), for example with organic onium compounds, has been carried out. Therefore, it is preferred according to the invention to use the stevensite or at least one of the components comprising stevensite in the non-organically modified form in the adsorbent or in the composition of the invention. In a preferred embodiment, activation of the stevensite or of the stevensite-containing component, in particular no acid activation, is also not carried out, since this is surprisingly not necessary for obtaining advantageous mycotoxin adsorption properties. Furthermore, in one embodiment of the present invention, it is also preferred to use surface modifiers or contact agents (sequestering agents) as already disclosed in WO91/13555 for modifying the used stevensite or the stevensite-containing component. However, in another embodiment of the present invention, it may be substantially present in the composition.

For simplicity, the phrase "attapulgite" herein should also include compositions comprising attapulgite. The term "attapulgite-containing component" is used to indicate that components containing other ingredients in addition to attapulgite may also be used in the compositions of the invention. For example, many commercially available stevensite products contain different amounts of associated minerals in addition to the stevensite. In addition, mixtures of stevensite with other components, for example other mineral components, in particular sheet silicates, are also conceivable. The attapulgite-containing component preferably comprises at least 5% by weight of attapulgite or a attapulgite phase.

In a preferred embodiment, the composition or mycotoxin adsorbent of the present invention consists essentially or entirely of attapulgite or at least one attapulgite-containing component.

In a preferred embodiment, the composition contains at least 10% by weight, preferably at least 50% by weight, particularly preferably at least 75% by weight, more preferably at least 90% by weight, particularly preferably at least 95% by weight, of stevensite or at least one stevensite-containing component. It has thus been surprisingly found that good adsorption properties can be obtained for non-aflatoxins such as T-2 toxin, ochratoxin or zearalenone when stevensite constitutes the mineralogical predominant phase in the materials or components used in accordance with the invention.

In a further preferred embodiment of the invention, materials or mixtures can be used which contain on the one hand stevensite or at least one stevensite-containing component and on the other hand antigorite or at least one antigorite-containing component. It has been surprisingly found that such materials or mixtures comprising stevensite and antigorite, especially when used in small amounts or low concentrations, have been able to impart outstanding mycotoxin adsorption. In this case, in particularPreferred materials contain at least 5% by weight, particularly preferably at least 20% by weight, more preferably at least 40% by weight, of a antigorite or antigorite phase. How to understand the meaning of "antigorite" here is well known to the person skilled in the art and does not need to be explained further here. For example, reference may also be made herein to Brindley et al (cited). The measurement of the cobra stone can be performed as described therein. Chemical analysis of ophicalcitum yields a near R₃Si₄O₁₀(OH)₂H₂O, where R is predominantly Mg and n is about 0.8 to 1.2. Characterized by a diffraction peak at a lattice spacing (basic spacing) of 10 Å, the position of which does not show any expansion under different humidity and does not show any thermal shrinkage up to 500 ℃. Reference is expressly made herein to the X-ray powder diffraction pattern of the antigorite shown in FIG. 2 of G.B. Brindley et al and the appendix part of the article (citation) therein. In one possible embodiment of the invention, the stevensite or at least one stevensite-containing component may be partially or completely replaced by antigorite or at least one antigorite-containing component in the composition according to the invention. The following data for the stevensite or stevensite-containing compositions may also apply to the antigorite and antigorite-containing compositions in this embodiment, respectively.

In the context of the present invention, it has also been found that particularly suitable adsorbents or mycotoxin adsorbents (generally: materials) or stevensite or components containing stevensite are those in which the magnesium oxide content is at least 15% by weight, in particular at least 17% by weight, more preferably at least 20% by weight. Corresponding materials, in particular stevensite or components containing stevensite, are commercially available. It is also preferred that the magnesia, in particular the stevensite or the constituent containing the stevensite, of the material used has a content of up to 40% by weight, in particular up to 35% by weight, in most cases more preferably up to 30% by weight.

The content of magnesium oxide is also critical for the precise structuring of the layered structure of the material. The invention is not limited to the correctness of the assumption that the layered structure of the materials used according to the invention, in particular of the attapulgite, provides particularly good porosity and a particularly effective surface for adsorbing a large number of different mycotoxins.

It is furthermore preferred that the material used, in particular the stevensite or the composition containing stevensite, has a thickness of at least 80m²A/g, in particular of at least 100m²A/g, in particular of at least 110m²BET surface area in g (determined to DIN66131, see methods). These high BET surface areas clearly enable more efficient adsorption of some mycotoxins. It has furthermore been found that particularly good results are provided in particular by those materials having a Cation Exchange Capacity (CEC) of less than 40meq/100g, in particular less than 35meq/100g, more preferably less than 30meq/100 g. CEC can be determined as described in the methods section below.

In another preferred embodiment, the material or the stevensite or the components of the stevensite used are those whose CEC is at least 5meq/100g, preferably at least 10meq/100g, in particular at least 15meq/100 g.

As mentioned above, the layered structure and composition of the material used according to the invention provide particularly good mycotoxin adsorption prerequisites. It has also been found that phyllosilicate materials having a fibrous structure, such as pure sepiolite, in scanning electron micrographs can significantly degrade mycotoxin adsorption. In a preferred embodiment of the invention, the inventive composition or the inventive mycotoxin adsorbent therefore contains less than 20% by weight of fibrous phyllosilicates, in particular sepiolite, preferably less than 10% by weight, particularly preferably less than 5% by weight and more preferably less than 1% by weight. In one embodiment of the invention, the composition according to the invention or the mycotoxin adsorbent according to the invention is free of fibrous phyllosilicates, in particular free of sepiolite.

In another embodiment of the invention, the materials used in accordance with the invention, in particular stevensite or at least one stevensite-containing component, may also be used as an effective and inexpensive alternative to other, more expensive, mycotoxin adsorbing components in mycotoxin adsorbent compositions, or to provide or improve the adsorption of certain toxins. For example, a comparison of the binding capacity of stevensite or stevensite-containing components with other adsorbents or commercially available mycotoxin adsorbents shows particularly good binding capacity, especially for the T-2 toxin, which is otherwise difficult to bind. Such inventive compositions may then also have a low content of the material used according to the invention, in particular of the stevensite or of at least one component containing the stevensite, for example in the range from 1 to 50% by weight, preferably from 5 to 30% by weight, in particular from 5 to 20% by weight. The exact proportions of the materials used in accordance with the invention (stevensite or at least one of the components comprising stevensite) in the compositions of the invention will depend in each case on the intended use and the other components of the composition.

The materials used according to the invention, in particular the stevensite or the components containing stevensite, can be used in any form. Depending on the form in which the compositions are designed, they are preferably used in particulate form. Powders, granules and shaped bodies are also conceivable. Suspensions or slurries are also included. In most cases, the most practical and inexpensive option is to use a clay (attapulgite) type of commercially available particle size. However, the particle size or particle size used may also have an effect on the adsorption performance.

In a preferred embodiment, however, the materials used, in particular the stevensite used or the components containing the stevensite, are used as powders or granules, wherein they can also be applied in immobilized form on a carrier. In a possible embodiment of the invention, the average particle size (D) of the material used according to the invention, in particular of the stevensite or of the stevensite-containing component used₅₀) Less than or equal to about 100. mu.m, in particular less than or equal to about 80 μm. The wet sieve residue above 45 μm is preferably less than about 50% and the dry sieve residue above 45 μm is less than about 60%. However, other particle sizes are possible.

In a preferred embodiment of the invention, as described above, the composition according to the invention may also contain at least one further component in addition to the material used according to the invention, in particular the stevensite or the at least one stevensite-containing component. The additional components are preferably those which, according to the intended use, are capable of providing positive properties without impairing the adsorption properties of the materials used according to the invention, in particular of the stevensite or of at least one of the components comprising stevensite in the composition. In particular, outstanding adsorption properties can be found for non-aflatoxins such as T-2 toxin, ochratoxin or zearalenone.

One possible set of additional components also includes other mycotoxin adsorbents. Essentially any mycotoxin adsorbent known in the art can be used. As non-limiting examples which can be used particularly advantageously according to the invention, mention should be made of acid-activated layer silicates and organically modified layer silicates. It has thus also been found within the scope of the present invention that mixtures of the materials used according to the invention, in particular stevensite or at least one stevensite-containing component, with organically modified sheet silicates as described, for example, in EP1150767 of the applicant or acid-activated sheet silicates as described, for example, in EP1333919 of the applicant, can lead to particularly advantageous compositions which are capable of effectively absorbing a wide range of aflatoxins and mycotoxins other than aflatoxins. The relevant disclosures of EP1333919a1 and EP1150767a1 with regard to the mycotoxin adsorbents described therein, which comprise acid-activated layered silicates or organically modified layered silicates, are hereby expressly incorporated into the present description by reference. The terms "adsorption" and "absorption" are used synonymously herein. Mixtures of attapulgite or at least one of the components comprising attapulgite with unmodified or organically modified bentonite are also particularly advantageous due to good adsorption properties and inexpensive preparation. The bentonite is added to further improve the binding capacity to the aflatoxin.

When the composition according to the invention contains at least one other phyllosilicate, it may, in a possible preferred embodiment, be chosen from the smectite group, the serpentine-kaolin group, the pyrophyllite group, and from the group of phyllosilicates of the attapulgite/palygorskite, vermiculite, illite, sepiolite and/or mica group. Layered silicates from the smectite group include trioctahedral smectites such as saponite and hectorite, and dioctahedral smectites such as montmorillonite, beidellite and nontronite. The serpentine-kaolinite group includes, for example, chrysotile, antigorite, kaolinite, and halloysite. Pyrophyllite includes pyrophyllite. Particularly preferred phyllosilicates are montmorillonites such as montmorillonite, particularly bentonite, and also attapulgite and halloysite and natural mixtures thereof. In a preferred embodiment of the invention, the further phyllosilicate comprises montmorillonite, in particular bentonite, or a natural mixture of attapulgite and halloysite and/or talc or chlorite. The other phyllosilicates may be unmodified, acid-or base-activated and/or organically modified phyllosilicates.

When the composition of the present invention comprises at least one acid-activated layered silicate, in a preferred embodiment, the layered silicate may be activated with only about 0.5 to 8% by weight, particularly 1 to 6% by weight, more preferably about 1.5 to 4% by weight of the acid. Although the acid action time depends on the amount of acid used and the activation temperature, an activation time of less than 2 hours, in particular less than 1 hour, is generally sufficient. For example, the activation temperature may be maintained below 80 ℃. Various types of acid activation (e.g., dry mixing with solid acid, spraying with acid solution or boiling) are possible. The phyllosilicate used according to the invention may be any phyllosilicate which can be activated with an acid (see above).

Other possible constituents of the compositions according to the invention relate, for example, to organic or inorganic constituents which, according to the prior art, enable improved utilization of contaminated animal feed, enable the health of the animals, in particular their immune system, to be stabilized, or enable metabolic processes to be influenced in a positive manner. It may comprise, among others: vitamins, enzymes, plant components or extracts, and other substances known under the name of probiotics.

In a particularly preferred embodiment of the invention, in addition to or in the composition according to the invention, further mycotoxin adsorbents are used, in particular non-acid-activated sheet silicates such as calcium-or sodium-bentonite and/or organophilic sheet silicates, in particular organophilic bentonite, and/or acid-activated sheet silicates, in particular acid-activated bentonite, attapulgite or hectorite. The phrase "in addition to the compositions of the present invention" is intended to mean that the compositions of the present invention can also be used with other mycotoxin adsorbents or other compositions, either simultaneously or sequentially. An example here is the treatment of animal feed or animal feed. In many cases, it is advisable or possible to combine the individual mycotoxin adsorbents or components in the compositions of the present invention, especially by adding together or mixing together.

In one possible embodiment of the invention, the other mycotoxin adsorbents or components used, as described therein, may be present as a mixture with or in the composition. Thus, when more than one component is present, the compositions of the present invention are made, for example, by conventional mixing.

In a particularly preferred embodiment of the invention, the compositions of the invention are particularly suitable for the adsorption of mycotoxins from the group consisting of aflatoxins and non-aflatoxins such as ochratoxins, fumonisins, zearalenone, deoxynivalenol, T-2 toxin and ergotoxin. One aspect of the present invention thus relates to the use of a composition according to the invention as defined herein for adsorbing at least one mycotoxin as defined above, in particular T-2 toxin, ochratoxin, fumonisin, zearalenone and/or deoxynivalenol. It is particularly advantageous to adsorb aflatoxins and non-aflatoxins, particularly fumonisins and toxins from trichothecenes (deoxynivalenol, T-2 toxin and HT-2 toxin), both efficiently and inexpensively. The compositions of the invention are preferably used in the case of those substances to be treated (for example food or animal feed) which comprise at least one or more of the above-mentioned mycotoxins, in particular selected from the group consisting of: aflatoxins, T-2 toxins, citrinin, cyclopiazonic acid, ochratoxins, patulin, representatives of trichothecenes such as fusarenol, deoxynivalenol, HF-2 toxin, fumonisin, zearalenone and ergot alkaloids.

In other aspects, the mycotoxin contaminants include two or more mycotoxins, particularly in addition to aflatoxins, and also include other toxins such as ochratoxins, fumonisins, zearalenone, deoxynivalenol, and/or T-2 toxoids.

In a preferred embodiment, at least 0.01% by weight, preferably at least 0.05% by weight, in particular at least 0.1% by weight, of the composition according to the invention or of the material used according to the invention, based on the amount of mycotoxin-contaminated material, is used.

In another aspect, the invention relates to an animal feed formulation comprising an animal feed contaminated with mycotoxins and a composition of the invention as described herein.

Finally, in another aspect, the invention relates to a method for better utilizing or improving the suitability of humans and animals for food or animal feed contaminated with mycotoxins. In this case, the composition of the invention as described above is added to the animal feed before or at the same time as it is consumed by the animal. According to the method of the invention, an improved weight gain can be obtained in case the adsorbent of the invention is mixed with a mycotoxin contaminated feed or food product.

Unless otherwise stated, the parameters given herein are determined by the aspects specified below.

1. Determination of the specific surface area (BET)

The measurements were carried out with a microphotology "Gemini 2360" unit according to DIN 66131.

2. Determination of the particle size distribution (according to Malvern)

The particle size distribution was determined according to Malvern. This is a common approach. Mastersizer from Malvern Instruments ltd, UK was used according to the manufacturer's instructions. Measurement in airThe sample chamber described above ("dry powder feeder") is used for the determination, and the values based on the volume of the sample (including the average particle size D) are determined₅₀)。

3. Determination of cation exchange Capacity (CEC analysis) and cation fraction

The principle is as follows: with a large excess of aqueous NH₄The clay was treated with a Cl solution, washed with water, and the NH retained on the clay was determined by elemental analysis₄ ⁺The number of the cells.

Me⁺(Clay)^-+NH₄ ⁺——NH₄ ⁺(Clay)^-+Me⁺

(Me⁺＝H⁺，K⁺，Na⁺，1/2 Ca²⁺，1/2Mg²⁺... .)

The instrument comprises the following steps: sieve, 63 μm; 300ml of ground conical flask; an analytical balance; 400ml of membrane suction filter; cellulose nitrate filter, 0.15 μm (from Sartorius); a drying oven; a reflux condenser; heating plates; distillation apparatus, VAPODEST-5 (from Gerhardt, No. 6550); standard flask, 250 ml; flame Atomic Absorption Spectrometer (AAS).

Chemical products: 2N NH₄Neusler reagent Cl solution (available from Merck, Art. No. 9028); 2% boric acid solution; 32% sodium hydroxide solution; 0.1N hydrochloric acid; 0.1% NaCl solution; 0.1% KCl solution.

The method comprises the following steps: 5g of clay are sieved through a 63 μm sieve and dried at 110 ℃. Thereafter, exactly 2g were weighed into a ground-neck conical flask by differential weighing on an analytical balance and reacted with 100ml of 2N NH₄The Cl solutions were mixed. The suspension was boiled under reflux for 1 hour. High CaCO in bentonite₃When the amount is large, ammonia is precipitated. In this case, NH must be added₄Cl solution until there is no more ammonia odor. Additional checks can be made with wet test paper. NH after a standing time of about 16 hours₄+ Bentonite filtered off via a membrane suction filter and washed with deionized water (ca.800 ml) until its baseEssentially no ions are contained. Verification that rinse water contains no ions is NH by Neusler reagent sensitive thereto₄+ ionic. The amount of washing may vary between 30 minutes and 3 days, depending on the type of clay. Washed NH₄+ the clay was removed from the filter, dried at 110 ℃ for 2 hours, ground, sieved (63 μm sieve) and dried again at 110 ℃ for 2 hours. Thereafter, NH of clay₄ ⁺The content was determined by elemental analysis.

Calculating CEC: CEC of Clay by NH in the usual manner₄ ⁺NH of clay₄ ⁺Content, which must be determined by elemental analysis of nitrogen content. For this purpose, the Vario EL3 instrument from Elementar-Heraeus, Hanau, Germany was used according to the manufacturer's instructions. The data are reported in meq/100g of clay (meq/100 g).

Example (c): the nitrogen content is 0.93%;

molecular weight: 14.0067g/mol of nitrogen

CEC 66.4meq/100g NH4+ Bentonite

The presence of the attapulgite in the materials or compositions used in the present invention is determined in a conventional manner (by X-ray), as described in Brindley et al (cited) and Martinde Vidales et al (cited).

The invention will be elucidated by way of the following examples in a non-limiting manner.

Description of the drawings:

FIG. 1 shows a graphical illustration of the efficient adsorption of T-2 toxin by the inventive material (composition) (Sorb1 to Sorb3) and the comparative material (C1).

Figure 2 shows a graphical illustration of the effective adsorption of aflatoxin B1 by the inventive material (composition) (Sorb1 to Sorb4) and two comparative materials (C1 and C2).

Figure 3 shows a graphical representation of the effective adsorption of ochratoxin by the materials (compositions) of the invention (Sorb1 to Sorb 4).

Figure 4 shows a graphical representation of the effective adsorption of zearalenone by three materials (compositions) of the invention (Sorb1, Sorb2 and Sorb 4).

Examples

The different mycotoxins were obtained as crystalline pure substances (SIGMA AG) and contained in methanol (50. mu.g/ml). For the adsorption experiments, dilutions were prepared with buffer solution (citrate buffer) containing 2000. mu.g of different mycotoxins per liter.

The adsorption and desorption efficiencies were determined as follows:

1. testing the adsorption efficiency:

A) adsorption

For the adsorption tests, aqueous solutions with in each case 2000ppb of toxin were prepared. Depending on the toxin, the solution is adjusted to a pH between 3 and 5.5 by means of a citrate buffer. For ochratoxins, zearalenone, fumonisins, adsorption at pH3 was analyzed, since these toxins are stable under this condition. For aflatoxins, the procedure was carried out at pH5.5, since rearrangement would occur at lower pH values which would disrupt fluorescence spectroscopy detection. For the T-2 toxin, the adsorption was analyzed at pH4.5, since below this pH conversion to H-T-2 toxin would occur. This compound is likewise toxic, but can no longer be effectively quantified.

0.1g of the compositions according to the invention and not according to the invention (see below) are suspended in 25ml of these solutions in each case and stirred at 37 ℃ for more than 2 hours. The suspension was centrifuged at 2800rpm for 5 minutes and the clear supernatant was analyzed by high performance liquid chromatography for the remaining amount of non-adsorbed mycotoxin. The difference between the amount of toxin initially added and the amount of toxin still remaining in solution after the absorption phase corresponds to the amount adsorbed and is reported later as a percentage of the amount of toxin initially added. In each case, the average of the two determinations is reported.

B) Desorption of

In subsequent experiments, the adsorbed toxins in the first step were analyzed for possible desorption. For this purpose, the solid obtained after centrifugation of the suspension described in A was resuspended in 25ml of distilled water or citrate buffer and adjusted to pH 7. The now pH-neutral suspension is again stirred at 37 ℃ for 2 hours and then centrifuged. The amount of toxin adsorbed was determined by HPLC analysis in the clear supernatant. The amount of endotoxin in solution is compared to the amount of toxin originally used in the adsorption assay and is reported later as the percentage of toxin desorbed. In each case, the average of the two determinations is reported.

The values reported in the table for effective absorption in each case correspond to the difference in% adsorbed amount minus% desorbed amount. In each case, the average of two determinations is reported.

The HPLC measurements were carried out under the following conditions:

a chromatographic column: spherisorb ODS-2125X 4 mm

Aflatoxins:

derivatization: f₃CCOOH/CH₃COOH/H₂O 2∶1∶7

Eluent: 75/15/10 Water/acetonitrile/methanol

Flow rate: 1.2ml/min

A detector: fluorescence

Wavelength: EX 364nm/EM 440nm

Ochratoxin and zearalenone:

eluent: 570ml acetonitrile/410 ml water/20 ml acetic acid

Flow rate: 1.0ml/min

A detector: fluorescence

Wavelength: EX274nm/EM 445nm

Quantitative determination of T-2 toxin concentration by HPLC:

the supernatants from the adsorption and desorption experiments were injected directly into the HPLC. An RP18 column (manufacturer: Perkin Elmer) with Spheri-5ODS 2 silica gel was used. The particle size is 5 μm; the column size was 4.6X 250 mm. The mobile phase used was a water-methanol-acetonitrile mixture in a ratio of 250: 100. A2 ml/min flow was established. T-2 toxin was detected by UV spectrometry at 200 nm.

Quantitative determination of fumonisins by HPLC:

the same HPLC column was used here as already described for the T-2 toxin. The aqueous solution containing fumonisins is first concentrated by evaporation, dried and derivatized with naphthalene dicarboxaldehyde (which enables fumonisins to be detected by fluorescence of the derivative), as described in Bennet, Journal of the AOACInternational, Vol77, No.2, 1994, pg 501-506. The mobile phase used was an acetonitrile-water-methanol-acetic acid mixture in a ratio of 45: 49.3: 4.8: 0.9. A flow rate of 2.0 mm/min was established. Fumonisins are detected via fluorescence at 500nm, which is excited at 420 nm.

The adsorption rate% was calculated from the results.

For this test, the following four kinds of attapulgite-containing materials were used as the ground coarse clay, respectively, wherein the average particle sizes (D50) of Sorb1, Sorb2, Sorb3 and Sorb4 were 31 μm, 32 μm, 38 μm and 66 μm, respectively. The wet sieve residue up to 45 μm is in each case less than 50%, and the dry sieve residue up to 45 μm is less than 60%. Stevensite as the (main) phase has proven effective according to Brindley et al (cited) and Martin de Vidales et al (cited). The content of antigorite was also detectable in all the materials used (Sorb1 to Sorb 4). As described in the above two references, stevensite can be distinguished from antigorite and other smectite-type phyllosilicates, in particular on the basis of the powder diffraction pattern of X-rays and the shift in the diffraction pattern following treatment with ethylene glycol, followed by heating and/or under different humidity. To characterize the materials of the present invention, a magnesium oxide composition and CEC may be used.

The analytical data for the materials used in the present invention are set forth in tables 1 to 3 below.

Table 1: analyzing data

	BET specific surface area, m2/g	Cation Exchange Capacity (CEC), meq/100g
			Sorb1	224.2	20
Sorb2	184.3	26
			Sorb3	180.1	33
Sorb4	125.3	20

Table 2: associated minerals

	Associated minerals (from X-ray diffraction)
		Sorb1	1-2% of quartz, 1-2% of feldspar and 3-4% of calcite
Sorb2	1-2% of quartz, 2% of feldspar and 1% of calcite
		Sorb3	1-2% of quartz, 2% of feldspar, 6-7% of calcite and 2% of dolomite
Sorb4	2-3% of quartz, 2-3% of feldspar and 0.5-1% of calcite

Table 3: silicate analysis

	Sorb1	Sorb2	Sorb3	Sorb4
					Al2O3，％Fe2O3，％CaO，％MgO，％Na2O，％K2O，％TiO2，％SiO2，％SiO2Loss on ignition of the/MgO ratio%	3.61.14.825.60.130.80.1250.51.9712.7	7.12.61.722.30.351.30.2452.52.3511.2	12.54.36.410.60.262.10.4348.54.5714.1	6.61.91.126.00.321.40.2552.02.009.5

Example 1:

in mycotoxin binding for T-2 toxin (here the solution is 2000ppb), the adsorption efficiency proceeds as described above. Adsorption was performed at pH3 and desorption was performed at pH 6. For comparison a mixture of 85% calcium bentonite and 15% SBDMA organoclay (bentonite organically modified with SBDMA) (C1) was used. The values obtained (% effective adsorption) are summarized graphically in FIG. 1. The dosages (concentrations) of the materials used are given in the legend.

Figure 1 shows that even at low doses the materials Sorb1 to Sorb3 according to the invention still have outstanding adsorption properties compared to the commercially available comparative materials according to the prior art. The materials Sorb1 and Sorb2 (see table 1) having an MgO content of more than 20% by weight have a significantly higher efficiency compared to Sorb3 having an MgO content of only 10.6% by weight.

Example 2:

in mycotoxin binding for aflatoxin B1, the adsorption efficiency was performed as described in example 1 above. For example, in this example, the calculation of effective adsorption performance from the adsorption value at pH5.5 and the desorption value at pH7 is described in detail. A mixture of 85% calcium bentonite and 15% SBDMA organoclay (bentonite organically modified with SBDMA) (C1) was again used for comparison with commercially available talc (average particle size 2.5 μm) (C2). The values obtained (% effective adsorption) are summarized graphically in fig. 2. The dosages (concentrations) of the materials used are given in the legend.

Fig. 2 shows that the materials Sorb1 to Sorb4 of the present invention have excellent adsorption properties. Particularly at low doses (e.g. 0.25kg/t), the materials Sorb1, Sorb2 and Sorb4 of the present invention having an MgO content of more than 20% by weight (see table 1) clearly have superior adsorption properties compared to the comparative materials C1 and C2. Sorb1 is notable for a relatively high wax serpentine content of over 40% by weight.

Examples 3 and 4:

in mycotoxin conjugation for ochratoxin and zearalenone, the adsorption efficiency proceeds as described in example 1 above. For example, in this example, the calculation of effective adsorption performance from the adsorption value at pH3 and the desorption value at pH7 is described in detail. The values obtained (% effective adsorption) are summarized graphically in fig. 3 (ochratoxin) and fig. 4 (zearalenone). The dosages (concentrations) of the materials used are given in the legend.

Figures 3 and 4 show the good adsorption performance of the material (composition) of the invention on ochratoxin and zearalenone. In particular, the adsorption performance of the materials Sorb1, Sorb2 and Sorb4 (see table 1) of the present invention having an MgO content of more than 20% by weight is surprisingly good.

In supplementary tests, it has also been shown that the materials of the invention (Sorb1 to Sorb4) have very good adsorption properties in the mycotoxin binding for fumonisins.

Claims (27)

1. Use of a composition comprising stevensite for adsorbing mycotoxins.

2. Use according to claim 1, characterized in that: for using at least one attapulgite-containing component in place of or in addition to attapulgite.

3. Use according to one of the preceding claims, characterized in that: the composition consists of at least 10% by weight, preferably at least 50% by weight, in particular at least 60% by weight, more preferably at least 80% by weight, of attapulgite or a attapulgite-containing component.

4. Use according to one of the preceding claims, characterized in that: contains at least one material, in particular stevensite or at least one stevensite-containing component, having a magnesium oxide content of 15% by weight, preferably at least 17% by weight, in particular at least 20% by weight.

5. Use according to one of the preceding claims, characterized in that: the composition comprises a antigorite or at least one antigorite-containing component in addition to the antigorite or at least one antigorite-containing component.

6. Use according to one of the preceding claims, characterized in that: the attapulgite or at least one of the components comprising attapulgite is used in a form which is not acid-activated.

7. Use according to one of the preceding claims, characterized in that: containing at least one material, in particular stevensite or at least one component containing stevensite, having a particle size of at least 80m²BET surface area/g, preferably of at least 100m²Per g, particularly preferably at least 110m²/g。

8. Use according to one of the preceding claims, characterized in that: containing at least one material, in particular stevensite or at least one stevensite-containing component, having a Cation Exchange Capacity (CEC) of < 40meq/100g, preferably < 35meq/100g, particularly preferably < 30meq/100 g.

9. Use according to one of the preceding claims, characterized in that: the Cation Exchange Capacity (CEC) of the material is > 5meq/100g, preferably > 10meq/100g, particularly preferably > 15meq/100 g.

10. Use according to one of the preceding claims, characterized in that: the composition consists essentially of, or consists entirely of, attapulgite or at least one constituent comprising attapulgite.

11. Use according to one of the preceding claims, characterized in that: the material and/or composition does not contain any fibrous phyllosilicates.

12. Use according to one of the preceding claims, characterized in that: contains at least one material, in particular brucite, or at least one component containing brucite, having a magnesium oxide content of < 40% by weight, preferably < 35% by weight, in particular < 30% by weight.

13. Use according to one of the preceding claims, characterized in that: at least one other phyllosilicate is also present in the composition as a further component.

14. Use according to one of the preceding claims, characterized in that: the at least one other layered silicate comprises an unmodified, acid-or base-activated and/or organically modified layered silicate.

15. Use according to one of the preceding claims, characterized in that: the at least one other phyllosilicate is selected from the group consisting of montmorillonite, attapulgite/palygorskite, vermiculite, illite, serpentine/kaolin, pyrophyllite or mica-type phyllosilicates.

16. Use according to one of the preceding claims, characterized in that: the at least one other phyllosilicate includes smectite clays, particularly bentonite, and natural mixtures of attapulgite and halloysite.

17. Use according to one of the preceding claims, characterized in that: the material or at least one of the components comprising attapulgite comprises attapulgite as the mineralogical main phase.

18. Use according to one of the preceding claims, characterized in that: in addition to the composition, other mycotoxin adsorbents are used, in particular non-acid-activated sheet silicates such as calcium-or sodium-bentonite and/or organophilic sheet silicates, in particular organophilic bentonite, and/or acid-activated sheet silicates, in particular acid-activated bentonite, attapulgite or hectorite.

19. Use according to one of the preceding claims, characterized in that: other mycotoxin adsorbents are present in admixture with the composition.

20. Use according to one of the preceding claims, characterized in that: the mycotoxins to be adsorbed include one or more toxins selected from the group consisting of aflatoxins, citrinin, cyclopiazonoic acids, ochratoxins, patulin, representatives of trichothecenes such as fusarenol, deoxynivalenol, T-2 toxin, HT-2 toxin, fumonisins, zearalenone and ergot alkaloids.

21. Use according to one of the preceding claims, characterized in that: mycotoxins to be adsorbed include, in addition to aflatoxins, other toxins such as ochratoxins, fumonisins, zearalenone, deoxynivalenol and/or T-2 toxoids.

22. Use according to one of the preceding claims, characterized in that: at least 0.01% by weight, preferably at least 0.05% by weight, particularly preferably at least 0.1% by weight, of the composition is used, based on the amount of mycotoxin contaminated material to be treated.

23. A mycotoxin adsorbent comprising stevensite or at least one stevensite-containing component and at least one other mycotoxin adsorbent selected from the group consisting of antigorite or antigorite-containing component, an acid-or base-activated layered silicate, a non-acid-activated layered silicate and/or an organophilic layered silicate.

24. A mycotoxin adsorbent as defined in claim 23 or a composition as defined in one of claims 1 to 22, further comprising an organic compound suitable for adsorbing mycotoxins, such as an ion exchanger or activated carbon, and optionally comprising organic compounds capable of improving mycotoxin-containing animal feed utilization or stabilizing metabolic processes in the animal's body, such as vitamins, micronutrients and probiotics.

25. An animal feed formulation comprising a mycotoxin contaminated animal feed and a composition comprising stevensite or at least one stevensite-containing component.

26. A method for improving the availability of mycotoxin contaminated animal feed, characterized by: administering a composition as defined in one of the preceding claims or a mycotoxin adsorbent as defined in claim 23 or 24 to an animal prior to, simultaneously with, or together with or after the animal feed.

27. The method of the preceding claim, characterized in that: the composition or mycotoxin adsorbent is added to or mixed with the animal feed prior to consumption by the animal.