FR2833187A1 - New stable, crystalline organometallic complexes of glycine with metals, e.g. cobalt, magnesium, iron, zinc, manganese or copper, useful as bioavailable metal sources for humans or animals - Google Patents

Abstract

Organometallic complexes (I) of glycine with metals (other than zinc diglycinate chelate), in which the glycine is bonded to the metal the oxygen of at least carboxylate moeity. Independent claims are included for: (i) powders formed from mixtures containing at least one complex (I); (ii) a method for the preparation of (I) in powder form; and (iii) iron sulfate pentahydrate glycinate, obtained by introducing 779 kg of water into a mixer-dryer under vacuum, heating the water to 60 deg C, introducing 2142 kg ferrous sulfate heptahydrate and 579 kg glycine, heating the mixture to 70 deg C under stirring, evaporating under vacuum at 95 deg C and a minimum pressure of 10 mbar, continuing drying until a moisture content of ca. 28% is attained, recovering the powder and milling and/or screening if necessary (all quantities being relative).

Description

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POWDER OLIGO-ELEMENT, METHOD AND DEVICE
FOR ITS MANUFACTURE
The invention relates to products packaged in powder which, by their nature, usually have an inherent hygroscopic character. Examples are the combinations of amino acids and minerals.

 When exposed to moist air, such powdered products take up moisture quickly. In doing so, they become hard, solidify, crust or even become deliquescent. This phenomenon is called caking or deliquescence.

 The invention relates more particularly to water-soluble dispersible powder compounds, based on a product of inherent hygroscopic nature, and intended for a use in which it is desired to be able to homogeneously mix the compound in reduced dose in a substrate, for example in dose in the range of 1 to 1000 grams per tonne.

 The problem is then to have a sufficiently fine powder, the fineness of which remains sufficient during mixing with the substrate. However, under the usual conditions of use, the substrate frequently contains a certain humidity. Mixing is then only possible if the powder has a sufficiently low hygroscopicity so that its grains remain detached and dispersible despite the presence of moisture.

 To date, a limited number of techniques are used to obtain powdered products, the most common of which is spray drying, also called "spray dry".

 Spray drying consists in bringing the concentrated aqueous solution containing the product to be dried in a turbine or nozzles so as to spray this solution into fine droplets in a chamber at high temperature (between 150 and 220 C). There, the water is immediately evaporated, and the very fine particles of product are transported by a stream of air into a cyclone to separate the moist air and the dry product.

 An example of application of spray drying is described in document WO 99 61037, for preparing an additive containing a mixture of a botanical plant, microcrystalline cellulose and calcium carbonate. We thus realize a

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 directly compressible powder composition to form tablets. The document does not concern itself with the possible hygroscopic nature of the products, nor with the means for reducing the hygroscopicity of a pulverulent product.

 Spray drying technology necessarily produces very small spray droplets with very low water content. It does not allow effective selection of the humidity level and the particle size of the finished product. The product obtained has too high a hygroscopicity, which causes caking or deliquescence phenomena.

 Document US 5,840,358 relates to the preparation of a food additive based on lysine for animals. The document mentions the hygroscopic nature of the starting product, which causes its agglomeration and the formation of crusts, and which prevents its mixing with food. To avoid these drawbacks, the document teaches to dry the product in a fluidized bed, in which particles remain in suspension in a stream of air or gas directed from the bottom upwards.

Simultaneously, the product is sprayed in liquid form in the fluidized bed, and comes to recharge the particles, thereby increasing their size, and compacting them individually. Compacted particles are thus produced in layers, similar to an onion, the size of which varies from 100 to 1,500 microns, and preferably from 500 to 1,200 microns. The particle sizes are large, and are suitable for the usual concentrations of the order of 3% for adding lysine to animal feed. But these sizes are too large for products intended to be used in doses of 1 to 1000 grams per tonne. In addition, the fluidized bed process apparently does not allow crystal complexes to be produced.

 Document US 5,213,838 describes the manufacture of a substitute for cooking salt. A mixture of salts in solution is dried under vacuum in a rotary vacuum evaporator to remove most of the water. Before complete drying, the dough is transferred to a hot air drying device to achieve complete drying. Then, the solid obtained is ground. The powder

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 thus obtained obviously has a high hygroscopicity.

To reduce this drawback, the document proposes to coat the salt crystals obtained with a protective layer of a material which does not react to water or to water vapor. The material is sprayed into a fluidized bed of crystalline powder. Examples of materials are phosphoric acid, sulfuric acid, or potassium salts. It is understood that this process requires the introduction of additional components which adversely affect the purity of the final product, and which also adversely affect the solubility of the final product.

 The problem proposed by the present invention is to avoid the drawbacks of known products and processes, by proposing water-soluble compounds, and their process for obtaining which, although packaged in fine powder and containing one or more products of inherent hygroscopic nature, have a very low hygroscopicity allowing their stability under the usual conditions of use.

 It is sought in particular to ensure that the pulverulent compound is sufficiently stable in the presence of moisture to be preserved, then mixed homogeneously with a substrate according to reduced doses of the order of 1 to 1000 grams per tonne.

 The invention aims to solve this problem without adding any additional product.

 The idea which is at the basis of the invention is to give the powdered compound an appropriate physical and / or chemical form having in itself a hygroscopicity markedly lower than the starting materials or the similar compounds obtained from starting materials using the methods usually used, without harming the water-soluble nature.

 To achieve these and other objects, the invention provides a compound of one or more products of inherent hygroscopic nature, packaged in powder, such that: - the compound is formed of crystalline grains, - its moisture content is more than 4% by weight, - at most 10% of the grains have a diameter of less than 40 µm, and at most 5% of the grains have a diameter of more than 900 µm.

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 Preferably, the compound has a humidity level of between 5 and 40%.

 Depending on the products contained in the compound, the humidity level is chosen so that the grains are in the solid crystalline phase containing water in an amount close to the amount of saturation.

 According to a possible application, the compound is based on amino acids, minerals and water.

 According to another application, the compound contains water, and at least one member of the family comprising complexes, chelates, proteinates, intense sweeteners, vitamins, flavor enhancers, sodium glutamate , ribonucleotides.

 According to another application, the compound consists of water and a 1: 1 complex of amino acids and one of the metals or metalloids: Cu, Co, Ca, Mg, Mo, Fe, Zn, Se, Cr, Mn.

 The invention also provides a powder packaging process for obtaining the physical and / or chemical form of compounds as defined above. This method of packaging a product of inherent hygroscopic nature into powder comprises the steps: a) putting the product or the ingredients in aqueous solution; b) vacuum drying the aqueous solution by mixing in a vacuum drying installation, at suitable temperature and pressure, until an appropriate humidity level is reached; c) ensuring that the grains of the compound obtained have an appropriate size, by grinding the compound after drying or by a choice of the drying conditions.

 If the grains obtained by drying are too large, the resulting dried compound is ground, so as to produce grains having an appropriate size.

 For certain compounds, the grinding step can be avoided if an appropriate choice of drying conditions makes it possible to obtain the desired particle size.

 In practice, the appropriate humidity level at the end of drying is greater than 4% by weight. Preferably, the rate

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 humidity at the end of drying is between 5% and 40% by weight.

 Depending on the products contained in the solution, the humidity level is chosen so that the grains obtained are in solid crystalline phase containing water in an amount close to the amount of saturation.

 Preferably, the appropriate particle size obtained by drying and after optional grinding is such that at most 10% of the grains have a diameter of less than 40 μm, and at most 5% of the grains have a diameter of more than 900 μm.

 The method according to the invention, as well as examples of compounds, will now be described in relation to the appended figures in which: - Figure 1 schematically illustrates a device for implementing the method according to the invention; - Figure 2 illustrates the three-dimensional chemical structure of a crystal obtained by the process of the invention from zinc sulfate and glycine; - Figure 3 illustrates the three-dimensional arrangement of the crystal complex of Figure 2; - Figure 4 illustrates the three-dimensional chemical structure of a crystalline polymer obtained by the process of the invention from zinc sulfate and glycine; and - Figure 5 illustrates the three-dimensional arrangement of the crystal complex of Figure 4.

 Reference will first be made to FIG. 1, schematically illustrating a device allowing the implementation of the process for manufacturing the compounds according to the invention.

 The device comprises a dryer mixer 1 composed of a sealed conical tank 2, provided with an upper inlet 3 for the reagents, with an upper gas extraction outlet 4, with a lower outlet 5 closed by a valve 6 , and a stirring arm 7 driven in axial rotation 8 by a motor 9.

 The valve 6 is sealed. The upper inlet 3 is closed by a removable waterproof cover. The upper gas extraction outlet 4 is connected by a pipe 10 to a vacuum pump 11 with the interposition of a condenser 12.

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 The conical tank 2 of the dryer mixer 1 is wrapped in a double jacket 13, the intermediate space of which can be traversed by a heat transfer fluid allowing the contents of the dryer mixer 1 to be heated and cooled as desired.

 The device further comprises a crusher 14, preferably an explosion-proof crusher, which receives in a hopper 15 the products leaving the lower outlet 5 of the dryer mixer 1, and which grinds them and then transmits them via its outlet 16 to a bagging device not shown.

 During the manufacture of the compounds by a process according to the invention, the products are placed in aqueous solution either outside of the dryer mixer 1, or directly inside of the dryer mixer 1 when possible. The reagents are introduced via the upper inlet 3, at atmospheric pressure, the valve 6 being closed. The upper inlet 3 is closed, the motor 9 is supplied with power to drive the stirring arm 7, the mixture is heated to the appropriate temperature by a passage of heat transfer fluid in the double jacket 13, then the vacuum pump 11 is activated to dry under vacuum while mixing in the dryer mixer 1. The vacuum is broken and the heating is stopped when the appropriate humidity level is obtained in the dryer mixer 1, the powders obtained are transferred either to the grinder 14, and grinds then the powders until the desired particle size is obtained, either directly in a bagging device if the powder has the desired particle size as soon as it leaves the dryer mixer 1.

 The instant from which the appropriate humidity level was obtained can be identified either by analyzing the curve for the speed of extraction of water from the dryer mixer 1, or by taking a sample of compound in the dryer mixer 1 and by controlling its pulverulent appearance and its fluidity.

 We will now describe three examples, and the products obtained.

 In the following examples, the humidity levels were measured by infrared drying, the zinc, calcium or iron levels were measured by absorption spectrometry

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 atomic. The nitrogen level was measured by titration according to Kjehldahl. The particle size was measured by sieving.

EXAMPLE 1
A compound based on zinc sulphate, glycine and water is produced according to the process of the invention.

 80 parts of water (for example 80 kg) are introduced into the drying mixer 1, the water is heated to about 76 ° C. A premix containing 30 parts of glycine and 70 parts of zinc sulfate monohydrate is carried out. The premix is introduced into the hot water contained in the dryer mixer 1, in proportion to 100 parts of mixture for 80 parts of water. The whole is stirred at 830C by actuation of the stirring arm 7. A perfectly clear solution is obtained. Evaporation is started under vacuum while stirring, at a minimum pressure of 10 millibars by actuation of the vacuum pump 11. After 30 minutes, the product has precipitated. It continues to dry for 3 hours while mixing. A product is then obtained in the form of beads and coarse powder, which is recovered and then ground in the mill 14, to obtain an appropriate particle size.

 The drying is stopped when the humidity level is between 18% and 27%, advantageously from 21% to 25% approximately.

The grinding is such that the particle size do is approximately 180 μm, and dio is approximately 100 μm.

 The compound obtained has a zinc content of approximately 20%, a nitrogen content of approximately 4.3%, and a humidity content of approximately 21% to 25%. The density of the compound obtained is 1.0, which is much higher than the density of the compound obtained from the same starting materials with a spray drying process. This higher density, coupled with the coarser particle size obtained by grinding, very advantageously makes it possible to avoid the problems of pulverence.

An analysis of the powder by X-ray powder diffraction has shown that the product obtained has a new chemical structure, consisting of two distinct crystals:
1) a water-soluble complex having the following chemical structure:

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[Zn (glycine) 2 (HzO) 4] 2+ [S04] 2- [Zn (H2O) 6] 2+ [S04] 2-
2) a complex of water-soluble linear organometallic polymer type, the chemical structure of which is as follows: [Zn [(H2O) 2 (SO4) 2] glycine [Zn (H2O) 4] glycine] n
Figure 2 illustrates the three-dimensional chemical structure of the first crystal complex, and Figure 3 illustrates the three-dimensional arrangement of this first crystal complex.

 FIG. 4 illustrates the three-dimensional chemical structure of the second polymer-type complex, and FIG. 5 illustrates the three-dimensional arrangement of this second polymer complex.

 These are new products, no description of which has been given so far. These products are surprisingly the result of the use of the process according to the invention.

 The process makes it possible to obtain a water-soluble crystalline powder consisting of a mixture of crystalline complexes according to the two formulas above.

EXAMPLE 2
Using the process of the invention, a compound based on calcium chloride, methionine and water was produced.

 The compound had a humidity level of between 6% and 8%, advantageously approximately 7%, and a particle size of do = 400 μm approximately and dio = 130 μm approximately.

 In a measured example, the calcium level was about 13%, and the humidity was about 7%.

 For this, 96 parts of water were introduced into the dryer mixer 1. The water was stirred in the dryer mixer 1. A premix was made of 57 parts of methionine and 43 parts of anhydrous calcium chloride, and introduced the 100 parts of premix into the 96 parts of water contained in the dryer mixer 1. The mixture was heated and stirred for 30 minutes at a temperature of 90. The solution obtained was perfectly clear.

 Evaporation under vacuum was then started with stirring, with a minimum pressure of 10 millibars. Drying with

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 stirring was carried out for 5 hours at a temperature of approximately 500C.

 This resulted in a product in the form of large hard balls, which was ground using the grinder 14. The particle size was approximately dso = 400 μm, and dio = approximately 130 μm.

EXAMPLE 3
With the process of the invention, a compound based on iron sulfate II, glycine and water was produced.

 The powder had a humidity level of between 17 and 24%, advantageously around 20%, and a particle size dso of approximately 120 μm and dio of approximately 50 μm.

 In a measured example, the iron level was around 19%, the nitrogen level around 4.5% and the humidity level around 20%.

 For this, 40 parts of water were introduced into the mixer-dryer 1. The water was heated to 40 ° C., then 75 parts of iron sulfate II heptahydrate and 20 parts of glycine were added. The mixture was stirred for 30 minutes at a temperature of 45 C. The solution obtained was perfectly clear.

 Evaporation under vacuum was then started, with a minimum pressure of 10 millibars. Drying with stirring was carried out for 11 hours.

 The result was a product in the form of beads and a coarse mass of powder. The product was ground in the grinder 14, to obtain a particle size dso of approximately 120 μm, and dio of approximately 50 μm.

EXAMPLE 4
Using the process of the invention, a compound based on manganese sulfate, glycine and water was produced.

 For this, 450 parts of water were introduced into the dryer mixer 1, the water was stirred and heated to 50 ° C. 190 parts of manganese sulfate monohydrate were introduced, which caused an exothermic reaction. 84 parts of glycine were added, and the whole was heated to 80 C. The evaporation under vacuum was started with stirring, at a minimum pressure of 10 millibars per actuation

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de la pompe à vide 11, en maintenant le manteau chauffant du mélangeur sécheur 1 à une température de 100 C. On a poursuivi le séchage pendant une durée suffisante jusqu'à obtenir un produit sous forme de billes d'environ 1 cm de diamètre, que l'on a broyé pour obtenir une poudre blanc rosâtre léger.

of the vacuum pump 11, maintaining the heating mantle of the dryer mixer 1 at a temperature of 100 C. The drying was continued for a sufficient time until a product in the form of beads of approximately 1 cm in diameter, which was ground to a light pinkish white powder.

 The compound obtained had a moisture content of 5.9%.

 In the four examples above, a free-flowing crystalline powder was obtained, perfectly stable to humidity: a test was carried out in a humidifier, at 250 ° C. and 100% humidity. The powder was not altered after three days. In addition, the powder was completely water-soluble, perfectly homogeneous.

 The present invention is not limited to the embodiments which have been explicitly described, but it includes the various variants and generalizations thereof contained in the field of claims below.

Claims (27)

 CLAIMS 1 - Composed of one or more products of inherent hygroscopic nature, packaged in powder, characterized in that: - the compound is formed of crystalline grains, - its humidity is greater than 4% by weight, - 10% at most grains have a diameter of less than 40 µm, and at most 5% of the grains have a diameter of more than 900 µm.  2-A compound according to claim 1, characterized in that its humidity is between 5% and 40%.  3-Compound according to one of claims 1 or 2, characterized in that the grains are in solid crystalline phase containing water in an amount close to the amount of saturation.  4-Compound according to any one of claims 1 to 3, based on amino acids, minerals and water.  5-Compound according to any one of Claims 1 to 3, characterized in that it contains water and at least one of the members of the family comprising the complexes, the chelates, the proteinates, the intense sweeteners, vitamins, flavor enhancers, sodium glutamate, ribonucleotides.  6-Compound according to any one of claims 1 to 3, characterized in that it consists of water and a 1: 1 complex of amino acids and one of the metals or metalloids: Cu, Co , Ca, Mg, Mo, Fe, Zn, Se, Cr, Mn.  7-A compound according to any one of claims 1 to 3 based on zinc sulfate, glycine and water.  8-A compound according to claim 7, characterized in that it has a humidity level between 18 and 27%, advantageously from 21% to 25% approximately, and a particle size dso = 180 µm approximately and dio = 100 µm approximately .  9-Compound according to one of claims 7 or 8, characterized in that it has a zinc content of approximately 20%, a nitrogen content of approximately 4.3% and a moisture content of 21% to About 25%.  10-Compound according to any one of Claims 1 to 9, having the following chemical structure: <Desc / Clms Page number 12>  [Zn (glycine) 2 (HzO) 4] 2+ [S04] 2- [Zn (H2O) 6] 2+ [S04] 2-.  11-Compound of linear organometallic polymer type according to any one of Claims 1 to 9, the chemical structure of which is as follows:

 [Zn [(H2O) 2 (S04) 2] glycine [Zn (H2O) 4] glycinejn. 12-Water-soluble crystalline powder consisting of a mixture of crystalline compounds according to claims 10 and 11. 13-A compound according to any one of claims 1 to 3 based on calcium chloride, methionine and water.  14-Compound according to claim 13, characterized in that it has a humidity level between 6% and 8%, advantageously about 7%, and a particle size dgo = 400 µm approximately and dio = 130 µm approximately.  15-Compound according to one of claims 13 or 14, characterized in that it has a calcium level of approximately 13% and a humidity level of approximately 7%.  16-A compound according to any one of claims 1 to 3 based on iron sulfate II, glycine and water.  17-A compound according to claim 16, characterized in that it has a humidity level between 17% and 24%, advantageously about 20%, and a particle size dso = 120 µm approximately and dio = 50 µm approximately.  18-Compound according to one of claims 16 or 17, characterized in that it has an iron content of approximately 19%, a nitrogen content of approximately 4.5% and a moisture content of approximately 20% .  19-A method of packaging a product of inherent hygroscopic nature into powder, comprising the steps: a) putting the product or the ingredients in aqueous solution, b) vacuum drying the aqueous solution by mixing in a vacuum drying installation ( 1), at suitable temperature and pressure, until an appropriate humidity level is reached, c) ensuring that the grains of the compound obtained have an appropriate size, by grinding the compound after drying or by a choice of the conditions of drying.  20-A method according to claim 19, characterized in that the resulting dried compound is ground, so as to produce <Desc / Clms Page number 13>  grains of an appropriate size from larger grains resulting from drying.  21-Method according to one of claims 19 or 20, characterized in that the humidity at the end of drying is greater than 4% by weight.  22-A method according to claim 21, characterized in that the humidity level at the end of drying is between 5% and 40% by weight.  23-A method according to any one of claims 19 to 22, characterized in that the size of the grains at the end of drying and after possible grinding is such that at most 10% of the grains have a diameter less than 40 µm, and 5% at most the grains have a diameter greater than 900 μm.  24-A method according to any one of claims 19 to 23, characterized in that the grains at the end of drying have a solid crystalline structure.  25-A method according to any one of claims 19 to 24, characterized in that: - 80 parts of water are introduced into a drying mixer (1) under vacuum and the water is heated to approximately 76 ° C., - a premix of glycine and zinc sulphate monohydrate, in respective proportions of 30 parts and 70 parts, - the premix is introduced into hot water, in proportion to 100 parts of premix for 80 parts of water, - the mixture is stirred '' at 83 C, - it is evaporated at a minimum pressure of 10 millibars while stirring for approximately 3 h 30, - the resulting dried product is ground, to obtain a particle size of approximately dso = 180 μm and dio = 100 μm .  26-A method according to any one of claims 19 to 24, characterized in that: - 96 parts of water are introduced into a drying mixer (1) under vacuum, and the water is stirred; - a premix of 57 parts of methionine and 43 parts of anhydrous calcium chloride is carried out, <Desc / Clms Page number 14>  - the premix is introduced into the water contained in the dryer mixer (1), in proportions of 100 parts of premix for 96 parts of water, - the whole is stirred for 30 minutes while heating to 90 ° C., - evaporated under vacuum at a minimum pressure of 10 millibars while stirring for 5 hours at approximately 50 ° C., the resulting dried product is ground, to obtain a particle size of approximately dso = 400 μm and dio = 130 μm.  27-A method according to any one of claims 19 to 24, characterized in that: - 40 parts of water are introduced into a dryer mixer (1), and the water is heated to around 40 C; - 75 parts of iron sulfate II heptahydrate and 20 parts of glycine in hot water are added; - the whole is stirred for 30 minutes at 45 ° C; - Evaporated under vacuum at a minimum pressure of 10 millibars, for 11 hours; the mixture produced is ground to obtain a particle size of approximately dso = 120 μm and dio = 50 μm.