MX2007008369A - Method for the manufacture of partially modified surface zeolites useful for sequestering wide spectrum mycotoxins. - Google Patents

Abstract

The present invention concerns a method for manufacturing a partially modified surface zeolite resulting from the reaction between a zeolitic material and an ammonium quaternary salt acting as a wide spectrum mycotoxin sequestering agent useful in domestic and farm animals feed. The process for manufacturing the present invention does not require filtrating steps or sophisticated equipment such as high speed mixers, thus turning the process into a cost effective process.

Description

MODIFIED TO BE USED AS SEQUESTERS OF WIDER SPECTRUM MICOTOXINS.

BACKGROUND OF THE INVENTION CORRESPONDING FIELD OF THE TECHNIQUE Manufacture of modified surface minerals as mycotoxin sequestrants for use in feed for farm and domestic animals. Classification A23K1 / 175H according to the international classification of patents STATE OF THE ART Mycotoxins are fungal metabolites present in an appreciable quantity of grains destined for animal consumption throughout the world. These mycotoxins, when present in small quantities, are responsible for a number of symptoms such as nonspecific diarrhea, metabolic problems of fats and proteins, increase in the number of infectious diseases, vaccine failure, reproductive problems and abortions, among others. . When they are found in large quantities they can cause death.

Mycotoxins of major importance in the world, due to their ability to have considerable effects on human health and animal productivity, are: aflatoxins, zearalenone, ochratoxin A, fumonisin B l, and T-2 toxin.

At the beginning of the nineties, the use of bentonites, clays and other non-metallic minerals as mycotoxin sequestrants began, with varying successes according to the type, origin and purity of said materials.

A mycotoxin sequestrant is a non-digestible substance, capable of physically or chemically binding to mycotoxins by decreasing or preventing them from being absorbed in the digestive tract.

The use of zeolites as mycotoxin adsorbents, in substitution of bentonites and other clays, has demonstrated its great aflatoxin sequestrants superiority, which can be captured at levels higher than 99%, however, it has also demonstrated its low effectiveness in the uptake of other mycotoxins such as zearalenone and ochratoxin A, in which the levels of uptake are about 30%.

This is due to both the surface electrical charge of the zeolite and the surface energy of the zeolite, which makes it highly hydrophilic. The hydrophilic nature allows an aqueous layer to form around each particle of zeolite, which may contain polar molecules such as aflatoxins, while the surface charge attracts them, and some say with them capturing them permanently. However, other mycotoxins such as zearalenone and ochratoxin A have very low dipole moments, which means that the electrical charge does not attract them and that the aqueous layer tends to repel them.

In order to reduce both the surface charge and the surface energy of the zeolites, these can be treated with inorganic acids or can be subjected to heat treatments with and in e m e ming some omos e a n n e s its cr ua r r ura. The most effective method is to treat the surface with organic compounds, such as amines and long-chain quaternary ammonium salts, the latter being extremely effective especially when they also contain an aryl group. Among them deserves special mention the octadecyl dimethyl benzyl ammonium chloride.

The quaternary salts perform an ion exchange reaction with the interchangeable cations of the zeolite, usually calcium and potassium. The molecule of a quaternary salt is too large to be exchanged with the acid sites that are inside the zeolite so that they can only react with the surface sites, orienting themselves so that their polar end is towards the zeolite particle and its The non-polar end is directed to the opposite side, thus modifying the surface characteristics of the zeolite.

The exchange reaction is highly irreversible, which makes the zeolites modified with quaternary ammonium salts, excellent mycotoxin sequestrants despite the pH changes in the digestive tract.

The usual method of carrying out this reaction consists in reacting a dispersion diluted between 25% and 50% of zeolite sprayed with a dispersion of the quaternary ammonium salt, stirring for several minutes, filtering, drying the cake. filtration and remodel again to a size less than 150 microns.

In order to eliminate the filtration stage and make the manufacturing process more economical, Tomasevic et al. developed and patented a tribochemical, dry method, in which the pulverized zeolite is introduced, together with the anhydrous quaternary salt, into a turbo mixer adapted with blades rotating at 9000 RPM without the addition of water. According to the creators of the method, the water molecules around the zeolite exchange cations are activated by the high intensity mechanical energy provided by the turbo mixer, promoting the right conditions for the reaction between the salt and the zeolite, obtaining a dry product ready to be packed.

RELATED PATENTS WO 02/052950 A l Tomasevic et al. "Organomineral adsorbent of mycotoxins as an animal feed additive, procedure for production and application." WO 02/064502 Tomasevic et al. "Processes of trybochemical obtaining organozeolite adsorbent of mycotoxins, Procedure for production and Application." US 6,827,959 Schall, et al. "Mycotoxin adsorbents." MX PA00007077A Lara arellano. "Process to prepare organoaluminosilicatos and its use in balanced foods." TECHNICAL PROBLEM The current methods of manufacturing pulverized surface-modified zeolites are either carried out in an aqueous medium, so a subsequent filtration step is required, which is difficult and expensive due to the small particle size of the zeolite used, or, it is carried out without the addition of water, applying high-intensity mechanical energy by means of a high-speed mixer, which is a device with high acquisition and maintenance costs.

Our process does not require a filtration stage since the zeolite remains as a slightly humid powder during the reaction of this with the quaternary salt.

Our process also does not require sophisticated equipment since it can be done in any type of conventional low speed mixer, such as a pallet mixer, batten mixer or pin mixer.

NOVELTY CHARACTERISTICS OF THE INVENTION The invention consists in a method in which no more water is present than that used to manufacture the dispersion of the quaternary ammonium salt, such that the pulverized zeolite is only slightly moistened, preserving the appearance and rheological properties of a powder, without getting to form a paste, a mud, a slurry and much less a dispersion, thus avoiding the need for a filtering operation as part of the process.

In addition, the mixing operation is carried out in low intensity mechanical energy conditions, which allows the use of conventional mixing equipment of low cost of acquisition and maintenance, among which we can mention the mixers of pallets, slats, and of pins, among others.

The present invention is based on the fact that the long-chain quaternary salts, when mixed with water, form a micellar dispersion. When the micelles, in dispersion, come into contact with the surface of the zeolite, they break, since the polar end of the salt is attracted by the surface of the zeolite reacting immediately. The remaining quaternary salt continues in dispersion, free to react with some other acidic site, in that same particle of zeolite or in some other. This process continues, until all the molecules of the organic compound have reacted with an acid site of the zeolite. The addition of reagent beyond this point will form a double layer of reagent, in which the polar end of the quaternary salt will point outwards from the zeolite particle giving it a positive ionic character.

The surface energy and the charge of the zeolite, thus obtained, will depend on the amount of superficial acid sites that have reacted, so that by varying the amount of organic reagent it is possible to change the degree of affinity between the zeolite and the various mycotoxins. .

In our invention, it was decided to manufacture a partially modified surface zeolite capable of sequestering both polar and non-polar mycotoxins. To do this, it was decided to use aflatoxins as representatives of polar mycotoxins and zearalenone as representative I am responsible for or generate m e co m e m e ns not po ars to find an adequate organic reagent.

Sequestration tests were carried out on zeolites manufactured according to the method described in this invention, using different percentages of organic reagent in order to find the optimum quantity with which the product obtained was capable of capturing more than 90% of zearalenone without reducing too much. its ability to sequester aflatoxins, if possible, also more than 90%. The zeolite used was a clinoptilolite of natural origin and the ammonium salt selected was octadecyl dimethyl benzyl ammonium chloride.

The levels of inclusion of the modified zeolite were equivalent to a dose of 2 kg per ton of food contaminated with 2ppm (2gr / ton) of the corresponding mycotoxin.

% Octadecyl dimethyl Efficiency of sequestration Efficiency of sequestration bencil chloride of zearalenone aflatoxins ammonium 0.00 30% 99% 0.25 52% N.D. (*) 0.50 66% N.D. (*) 1.00 80% N.D. (*) 1.50 89% 97% 2.00 94% 96% * Information not determined As can be seen in the table, the optimal addition of octadecyl dimethyl benzyl ammonium chloride is approximately two percent. However, different zeolites will require different reagent additions depending on the number of superficial acid sites they have, that is, depending on the particle size, porosity and cation exchange capacity of the original mineral.

Once a partially modified surface zeolite capable of absorbing aflatoxins and zearalenone at levels higher than 90% was obtained, some other mycotoxins were sequestered, obtaining the following results: Ochratoxin A Er alkaloids Fumonisin Bl Toxin T-2 BEST KNOWN METHOD Our manufacturing process of a modified partial-surface zeolite consists of the following steps: - The optimum amount of reagent for the zeolite in question is determined in laboratory, by trial and error, that is, the amount that allows only partially modifying the surface of the zeolite, so that it is capable of sequestering both aflatoxins as zearalenone.

- A zeolitic material is obtained, either natural or synthetic, with a cation exchange capacity of between 60-200 meq./100 gr. and with a humidity less than or equal to 10%.

- The zeolite is pulverized to a size between 35 and 200 microns.

- A hot dispersion, between 60 - 100 ° C, of a long-chain quaternary ammonium salt, such as octadecyl dimethyl benzyl ammonium chloride, is produced at a concentration of between 6% - 12% solids.

- The zeolite is placed inside a mixer of vanes, slats, pins, or any other conventional mixer, the warm dispersion of a long-chain quaternary ammonium salt, such as octadecyl dimethyl benzyl chloride ammonium on the zeolite while mixing until obtaining a product of homogeneous appearance, that is to say, between five and thirty minutes.

- The material obtained is screened by a mesh with apertures of one millimeter, or smaller, in order to eliminate possible lumps.

- Finally, dry, always at a temperature equal to or less than 100 ° C. It has been determined that drying systems by contact with hot surfaces such as the hot wall rotary kiln are more efficient than air drying systems for drying our product. This is due, of course, to the decrease in the vapor pressure of the water when it is contained in zeolite.

The product will then be ready to be packaged. It is advisable to use packaging that does not allow the entry of moisture or odors since these would be trapped by the material.

EXAMPLE 1 To manufacture a test batch, 100 Kg of natural zeolitic mineral with a 70% clinoptilolite content and a cation exchange capacity of 80 meq / 100 g were used. The ore was dried to a moisture content of 8% and pulverized to a particle size of 90% less than 150 microns.

On the other hand 24 Kg. Of a dispersion of octadecyl dimethyl benzyl ammonium chloride at 8.33% were prepared, using 2 Kg of the salt and 22 kg. of hot water at 90 ° C: The natural zeolite was introduced in a batten mixer working at 14 RPM, the hot dispersion of octadecyl dimethyl benzyl ammonium chloride was sprayed at a rate of approximately 8 l / min and mixing was continued for a further 12 minutes, for a total time of 15 minutes process.

The wet material was screened on a vibrating screen with 1 mm mesh, using rubber balls to disperse the lumps.

The screening material was dried in a rotary oven with hot walls. The drying temperature was controlled between 90 and 100 ° C.

The material was cooled in a rotary cooler and packed in polyethylene bags to prevent contamination.

EXAMPLE 2 A test batch was manufactured similarly to the previous one, this time using a pin blender. 100 Kg. Of natural zeolitic mineral with a 70% clinoptilolite content and a cation exchange capacity of 80 meq / 100 gr. The ore was dried to a moisture of 8% and pulverized to a particle size of 90% less than 150 microns. 24 Kg. Of a dispersion of octadecyl dimethyl benzyl ammonium chloride at 8.33% concentration was prepared, using 2 Kg of the salt and 22 kg. of hot water at 90 ° C.

The natural zeolite was introduced in a pin mixer operating at 60 RPM, the warm dispersion of octadecyl dimethyl benzyl ammonium chloride was sprayed at a rate of approximately 8 lt / min and mixing was continued for an additional 15 minutes, for a total time of 18 minute process.

The wet material was screened on a vibrating screen with 1 mm mesh. Using rubber balls to disperse the lumps.

The screening material was dried in a two-stage fluid drying system with air flows and material to be contrasted. The drying temperature was controlled between 90 and 100 ° C.

The material was packed in polyethylene bags to avoid contamination.

Claims (5)

CLAIMS What we consider novel and consequently is claimed:

1) A process for manufacturing partially modified surface zeolites for use as mycotoxin sequestrants, by reaction between a zeolite and a long chain ammonium quaternary salt preferably containing an aryl group. Characterized by the following steps: a) Determine in laboratory, by trial and error, the optimum amount of reagent for the zeolite to be used, that is, the amount that allows to modify only partially the surface of the zeolite, in such a way that it be able to sequester both aflatoxins and zearalenone. b) Provide a zeolitic material, of natural or artificial origin, pulverized and dry. c) Form a dispersion of a long chain ammonium quaternary salt preferably containing an aryl group. d) Place the zeolite inside a mixer of blades, slats, pins, or any other conventional mixer. e) Mix the zeolite and quaternary ammonium salt dispersion, slowly adding the hot dispersion of the long-chain quaternary ammonium salt over the zeolite. f) Homogenize the previous mixture, continuing mixing for several minutes. g) Screen through a mesh to eliminate possible lumps. h) Dry the partially modified surface zeolite obtained.

2) The process of claim 1, wherein: a) The zeolitic material is dried to a humidity of 10% or less. b) The zeolitic material is pulverized to a size between 35 and 200 microns. c) The quaternary ammonium salt used has a main chain of between 12 and 20 carbons. d) The dispersion of the quaternary salt has a concentration between 6% - 25% solids. e) The dispersion of the quaternary salt is at a temperature between 60 ° C and 100 ° C, f) The dispersion of the quaternary salt is poured uniformly into a rat such that this mixing process takes between 3 and 10 minutes. g) The homogenization time is between 3 and 30 minutes. h) The opening of the screen mesh is between 0.5 and 2 millimeters. i) The drying temperature of the partially modified surface zeolite is less than or equal to 100 ° C.

3) The process of claim 2, wherein: a) The zeolitic material is dried to a humidity of 8%. b) The zeolitic material is pulverized to a size of 150 microns. c) The quaternary ammonium salt used is: octadecyl dimethyl benzyl ammonium chloride. d) The dispersion of the quaternary salt has a concentration of 8%. e) The final concentration of the quaternary salt in the modified zeolite is 2%. f) The dispersion of the quaternary salt is at a temperature between 75 ° C and 90 ° C. g) The mixing time is between 5 and 10 minutes. h) The homogenization time is between 10 and 30 minutes. i) The opening of the screening screen is 1 millimeter. j) The drying temperature of the partially modified surface zeolite is between 60 ° C and 100 ° C.

4) The process of claim 3, wherein: a) The zeolitic material used is a clinoptilolite of natural origin.

5) The process of claim 3, wherein: a) The zeolitic material used is a synthetic zeolite.