BE1018560A3 - SOLID CALCIUM LACTATE OF SUBSTANTIALLY SPHERICAL FORM. - Google Patents

Abstract

Solid calcium lactate in the form of substantially spherical particles, characterized in that it has a particle size such that the majority of the particles have dimensions of between 280 and 550 microns and that it can dissolve rapidly in water.

Description

Solid calcium lactate of substantially spherical form Field of the invention

The present invention relates to a solid calcium lactate composition, in the form of particles of substantially spherical shape, having a particle size such that the majority of the particles have dimensions of between 280 and 550 microns; the present invention also relates to a method for obtaining this type of calcium lactate.

Calcium lactate or calcium hydroxy-2-propanoate is the calcium salt of lactic acid, a natural acid produced by bacterial fermentation on starch or molasses. It exists in different forms: anhydrous, monohydrate, trihydrate and pentahydrate. Calcium lactate has physicochemical characteristics that are particularly well suited for the enrichment of a wide range of food products and for calcium supplementation.

However, whether for supplementation or for fortification of food products, there is a real need for a source of calcium with improved properties, including better resistance to attrition to prevent the formation of fine particles, properties improved flow and in addition that this Ca lactate can be dissolved quickly and completely for easy use and consumption.

Framework of the invention

Calcium, present as a mineral salt in the body, accounts for 2% of body weight. 99% of it is found in the bones and teeth to which it provides rigidity and strength. The remaining percentage (1%) circulates in the blood and contributes to the proper functioning of the nervous and cardiovascular systems. When an insufficient amount of calcium circulates in the blood, it is renewed by the calcium of the bones. The bones thus lose calcium continuously.

To avoid deficiencies, sources of growth delays, bone fragility and osteoporosis, calcium must be "replenished" by food.

Milk and dairy products (infant formulas, cheeses and yogurts) are now the main source of calcium in the diet for many populations. However, many people find it difficult to meet their daily needs via this type of product. Several reasons explain this phenomenon, they are of order: sociological cultural: choice of diets low in fat, vegan diets - physiological: disorders related to dairy products, such as digestive problems and allergies

Several possibilities are well known today for individuals to increase their calcium intake. They are based on a change in diet or consumption of dietary supplements or calcium fortified products.

State of the art

The flow capacity and the percentage of fines of the ingredients used in tablet formulation are important parameters for the production of this dosage form. Indeed, the powders having a high degree of flow capacity offer the advantage of being able to support high production speeds. Similarly, the reduction of electrostatic and pneumatic spraying of fines helps to increase yields and keep rooms and machines clean.

However, most often calcium sources are in the form of a powder having a particle size distribution that is not uniform and contains a large percentage of fine particles. These characteristics limit the flowability of the powder and hence its use in the production of tablets.

Supplementation in the form of calcium powders may also be offered to consumers. These usually contain calcium carbonate or calcium citrate, which is poorly soluble in water. The consumer will usually have to wait patiently for the dissolution of the powder before consuming the product. In the opposite case, the undissolved particles will be able to reduce considerably the organoleptic qualities of the solution as well as its absorption by the organism.

For these reasons, consumers are turning to enriched products. The enrichment of integrating calcium into the composition of certain foods is thus perceived by consumers as an easy way to increase their consumption. To meet these expectations, agri-food industries have a wide range of sources of calcium. The selection of the appropriate source is generally based on different criteria related to the finished product, such as solubility, calcium content, taste and bioavailability. Other criteria relating to the ease of use and the cost of the ingredient are also taken into account. Indeed, the fact of enriching a mineral food product is often a source of increase in the overall cost of production for the industrialist. Calcium salts such as calcium citrate or calcium malate requiring a long dissolution time or a high dissolution temperature are generally sources of additional costs. On the other hand, raw materials containing large quantities of dust are sources of significant losses for the company (the amount of calcium actually delivered to the consumer may therefore be less than hoped).

However, at present, the known compositions comprise in addition to calcium lactate, a significant amount of citrate or malate Ca, but this does not lead despite the desired properties, given their deficiency in terms of solubility in water, but also because of their impact on the taste of the product.

On the other hand, most sources of calcium, including calcium lactate, are in the form of clusters of particles highly sensitive to the attrition phenomenon and can therefore limit its use. The spherical shape has the advantage that it is much more resistant to this phenomenon, thus generating a lower percentage of fines and increasing the rate of dissolution of the ingredient.

The various forms of solid calcium lactate available on the market are generally obtained by mass crystallization followed by grinding or spray-drying and in all cases, the particle size is not adequate, and the forms of granules are far from being substantially spherical, which is not desired to meet the objects of the invention.

In the case of mass crystallization followed by grinding, the ingredient obtained is composed of particles having poor handling properties (powdery fines) and flow (grains of irregular shapes in particular).

Spray drying, which consists in spraying a liquid into a mist of fine droplets and bringing these fine droplets into contact with the hot air in a drying chamber, generates, for its part, an ingredient with a rich particle size distribution. in fine powdery and difficult to dissolve.

Despite the good general solubility of calcium lactate, the forms obtained by grinding or by spray drying are difficult to "solubilize" at room temperature because of the large amount of fine particles they contain.

We have already tried to remedy these drawbacks in particular in the description of patent US2008152764 but without significant success.

There is therefore a need to prepare and obtain a solid calcium lactate, in the form of particles whose particle size is such that it very strongly limits the presence of particles whose dimensions are less than 150 microns and that this calcium lactate can be dissolve quickly and easily and this is an object of the present invention

Another object of the invention is also a method for obtaining solid Ca lactate particles, in the form of particles of substantially spherical shape.

Detailed description of the invention

The Applicant has now unexpectedly found that by producing solid calcium lactate, in the form of particles of substantially spherical shape, the particle size of which is such that it very strongly limits the presence of particles whose dimensions are smaller than 150 microns and being able to dissolve rapidly in water, the disadvantages of the compositions of the prior art could be overcome.

In one embodiment of the invention, the concentration of calcium lactate solution that can vary from 20 to 60% by weight is supplied by spray (atomization) in a fluidized bed where the suspension is maintained in suspension. fine particles of calcium lactate. The conditions of air flow (to keep the bed in suspension at the atomizing nozzles), flow rate and concentration of the calcium lactate solution, and temperature are controlled so as to allow growth of the size. particles mainly by layer (onion structure) and not by agglomeration of these fine particles.

In general, according to the process of the invention, Ca lactate concentrations of between 20% and 50% are used, an air temperature at the inlet of the atomization chamber of less than 80 ° C. to obtain particles whose dimensions increase in size but which ultimately have a particle size such that there is 50 to 80% of the particles whose dimensions are between 280 and 550 microns.

A preferred way of using the technology is to produce the spherical calcium lactate beads in two stages. The first (granulation-crystallization) operated at low temperature will consist of forming the porous beads by spraying in a fluidized bed consisting of fine particles and the second to bring it to the desired hygrometry level. This second step may be operated in a fluidized bed or by any other technology known to those skilled in the art. By adapting the temperature and the residence time of the product in the drying chamber (from a few minutes to several hours), it is possible to obtain a calcium lactate in pentahydrate form (between 22 and 27% humidity) or trihydrate (between 15 and 20% moisture) or monohydrate (between 5 and 8% moisture) or anhydrous (less than 3% moisture).

In contrast to the process described in the invention, the spray drying technologies traditionally used call for the use of high incoming air temperatures aimed at rapidly attaining a low product hygrometry. In this case the finished products generally comprise a large part of fines. A variation of the conventional process provides agglomerated products with larger particle sizes. After partial spray drying at inlet air temperatures above 120 ° C, the particles are agglomerated in a porous layer on a conveyor belt dryer. A final step of crushing or crumbling is then necessary to obtain a granulated powder having the desired dimensions.

A preferred route for directly obtaining spherical granulated particles (not requiring agglomeration and then crushing) is the use of a fluidized bed granulation technology. However, this process requires that the particles "floating" in the air of the fluidized bed do not tend to stick together. The use of high temperatures promotes the particle sticking phenomenon and leads to a large caking that can block the installation.

Surprisingly the Applicant has now found that by operating at low temperature, the calcium lactate is allowed to remain in a non-sticky crystalline form and thus ensure good fluidization of the particles.

The Applicant has now found that by applying these conditions, the product thus obtained has improved attrition resistance, flow properties, dissolution rate and bulk density ("aerated" to the contrary of "packed" ") High.

Flow capacity

Flow capacity can be defined as the ability of a powder to flow smoothly under the effect of gravity or any other force. Different methods of measuring the flow of powders have been documented in the literature. Comparative analysis of different analytical methods by JL Ilari (Ilari JL, Flow of the proprieties of industrial dairy powders, Milk Tech 82 (2002) 383-399.) Led to the recommendation of the physical properties analyzer method. Hosokawa. This method, which is particularly well suited to analyzing the flow of dairy powders, can also be applied to calcium lactate powders.

The Hosokawa apparatus thus makes it possible to measure on the powders seven main physical characteristics relating to their flow properties but also to landslide. The seven characteristics measured are described in the manual published by Hosokawa Micron Corp. (Hosokawa Micromeritics Laboratory, Hosokawa Micron Corp., Osaka, Japan, 1981). Below is a brief description of the measurements taken. - The angle of repose which consists of measuring the angle of a stack of particles previously dispersed by a vibrating screen and collected by a funnel and then deposited on a work plane.

- the angle of fall, which consists in measuring the angle of the same pile of powder after having subjected it to an impact (vertical fall of a fixed height of an object of determined mass) - from the angle of fall and the angle of repose, the difference angle is deduced, - the apparent density (A): the measurement is obtained by weighing a quantity of powder collected in a container of known volume - the packed density (P) : the same weighing is carried out after having mulled the powder (180 vertical drops of the tank of a predefined height); From these two density measurements can be deduced the compressibility C (C = 100 * (P-A) / P) of the powders. Compressibility is a particularly important factor in calculating the flow index. When the compressibility value is greater than 20%, the powder is considered to be "non-flowing".

the spatula angle: the angle of a stack of powder deposited on a spatula is measured, the uniformity: the powder passes through three superposed vibrating screens and the method consists in weighing the quantity of powder retained This parameter is a numerical value obtained by dividing the width of the pores of the sieves passing 60% of the powder through the width of the pores of the sieves passing 10% of the powder. uniformity of the powder is important, the ratio described above is close to 1.

dispersion: a watch glass is placed vertically on a trap on which the powder is deposited. The quantity of powder collected on the watch glass is determined after abrupt opening of the hatch. This characteristic also makes it possible to highlight the presence of fines in the powder. The greater the quantity of powder collected on the watch glass, the lower the quantity of dust and the dispersibility value.

Each measured physical characteristic is assigned an index. The sum of these indexes makes it possible to determine the index of flow or landslide, which corresponds to a degree of flow or landslide.

It has now been found that, by applying the conditions of the invention, a calcium lactate having a high flow index of greater than 80, or even greater than 90, is obtained, which corresponds to a degree of flow described as "fairly good". "Or" very good ". More particularly, the uniformity and the spatula angle of the calcium lactate described in the invention respectively have values of less than 2 and 30 °. A uniformity value> 2 and a spatula angle value> 30 ° decrease the flow index and thus reduce the ease of use of calcium lactate. At present it is these types of product that we meet on the market.

Finally, the calcium lactate described in the invention has a high index of landslide greater than 60, which corresponds to a degree of landslide described as "good enough" and greater than what is currently found on the market. .

Particle size:

Any powder while in motion is subject to the phenomenon of attrition leading to the formation of unwanted residues. In different experiments, it was pointed out that particles having a particle size of less than 100 microns had a slower rate of dissolution in water than particles of size ranging from 150 to 710 microns. In order to increase the dissolution rate of calcium lactate it was therefore important to remove these particles and their formation.

In the known processes, a final step of grinding, crushing or even crumbling of porous agglomerates is used, giving rise to variable shapes that can affect the flow properties of the product and generating a number of fines. The applicant has now found that by eliminating the final step of grinding, crushing or crumbling, and by applying the conditions of the invention, more spheroidal forms are obtained with which the quantity of fines is limited and gets a more interesting particle size.

The attrition phenomenon can be demonstrated by the following method: place 100g ± 0.01 g of the test sample (whose particle size distribution obtained by sieving method is known) on a sieve whose size of the openings of Meshes of the wire cloths is 100 microns and trigger the vibrating screen type Retsch AS200 amplitude 0.95mm / g. The sieving time is fixed at 1 hour.

After stopping the sifter, collect the 100 g of sample thus subjected to the phenomenon of attrition and analyze their particle size distribution using conventional measuring equipment. Compare the particle size distribution obtained after attrition to that obtained before attrition.

The particle size distribution of attrition-sensitive samples evolves as follows: the amount of small particles increases while that of large ones decreases.

Note: Particles smaller than 100 microns are first removed from the sample to be attrition tested. The particle size distribution of the sample before the attrition test takes into account this modification.

The dissolution rate:

The dissolution rate can be determined by the following method: in a volume of demineralized water of 100 ml maintained at 25 ° C. ± 1 ° C. in a 500 ml beaker equipped with a magnet bar rotating at a controlled speed of 400 rpm ± 20 rpm, 5 g ± 0.01 g of calcium lactate sample are introduced. A chronometer is triggered at the precise moment of the addition of the product and stopped as soon as the last visible particle disappears / solubilizes. The dissolution rate is then represented by the time required for the dissolution of the entire sample.

The calcium lactate described in the invention has the particularity of being both robust enough to provide good resistance to attrition and porous than to allow rapid dissolution (dissolution rate less than 3 minutes).

Examples

The following examples are given for the purpose of illustrating the invention, without limiting its scope.

Example 1

A calcium lactate pentahydrate powder was prepared in two separate steps.

In the first step, a 32% calcium lactate solution was sputtered in a fluidized granulator continuously fed with fines. The bottom sieve of the fluidized bed has a surface of 0.45 m 2. The air temperature at the inlet of the atomization chamber can fluctuate but remains between 52 and 55 ° C. The incoming air flow is adjusted to 1700 m3 / h.

At the end of this first stage of the process a wet product is obtained in the form of substantially spherical particles.

Then, in a second step of the process, the wet particles obtained in the first step are subjected to a heat treatment making it possible to bring the calcium lactate to the desired hygrometry level. This second step takes place within a fluidized bed. for which the incoming air temperature is 125 ° C.

At the end of the second stage of the process, a product is always obtained in the form of substantially spherical particles and having a moisture content of about 23%, and whose physicochemical properties are shown in Table 1 and whose particle size distribution is repeated. in Table 2.

By way of comparative example, a calcium lactate powder was prepared according to a usual method and a powder was obtained in the physicochemical properties shown in Table 1 and whose particle size distribution is given in Table 2. .

Table 1

Table 2

The calcium lactate described in the invention has a particle size such that one has 50 to 80% of the particles whose dimensions are between 280 and 550 microns. Comparatively, the calcium lactate obtained according to the state of the art has, for its part, a particle size such that one has more than 55% of particles whose dimensions are between 0 and 280 microns

Example 2

Two samples of calcium lactate were produced in a test cell from a 40% calcium lactate solution according to the method described in Example 1 above. The only parameter that has varied is the temperature of the air entering during the first stage, the latter being respectively at 52 and 80 ° C.

The physicochemical analyzes of the two samples are shown in Table 3 below:

Table 3

Example 3

Calcium lactate samples were prepared to determine the rate of dissolution. For this purpose, 5 g of each of the particle size ranges studied were taken, it being understood that for the particle size range from 0 to 100 microns, a sample obtained according to the usual method was taken. The dissolution rates as a function of particle size distribution are presented in Table 4 below:

Table 4

A powder containing few particles smaller than 100 microns such as the product described in the invention will therefore tend to have a lower dissolution rate.

Example 4

The particle size distributions of the samples of calcium lactate having been subjected to an attrition phenomenon according to the principle described above are presented in Table 5 below.

Table 5;

Unlike the calcium lactate obtained according to the state of the art, the calcium lactate described in the invention (product 1 and product 2) does not generate particles smaller than 100 microns when it is subjected to an attrition phenomenon. . It has a lower susceptibility to attrition than the calcium lactate obtained according to the state of the art.

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Claims (9)

1. Solid calcium lactate in the form of substantially spherical particles, characterized in that it has a particle size such that the majority of the particles have dimensions of between 280 and 550 microns and can dissolve rapidly in water 2. solid calcium lactate, in the form of substantially spherical particles according to claim 1 characterized in that the particles have a particle size distribution such that the percentage of particles having a size less than 280 microns does not exceed 40%. j 3. Substantially spherical particles of calcium lactate according to claims 1 or 2, characterized in that the particles exhibit high resistance to attrition 4. Calcium lactate according to one of claims 1 to 3 characterized in that the spherical beads have a dissolution rate <3 minutes. 5. Process for obtaining solid calcium lactate, in the form of substantially spherical particles and whose particle size is such that the majority of the particles have dimensions of between 280 and 550 microns, characterized in that, (i) in a first step subjecting a calcium lactate solution to spraying in a fluidized bed granulator at an inlet air temperature of <80 ° C; (ii) recovering substantially spherical wet particles of calcium lactate, and (iii) in a second step subjecting said wet particles to heat treatment in a fluidized bed at an incoming air temperature <165 ° vs. ; 6. Method according to claim 5 characterized in that during the first step, is introduced a calcium lactate solution of concentration between 20 and 60% in the granulator. 7. Process according to claim 5, characterized in that the air temperature entering the granulator is between 50 and 75 ° C. 8. Method according to claim 5 characterized in that the air temperature entering the second stage is between 110 and 160 ° C 9. Process according to claim 5, characterized in that the moisture content of the calcium lactate particles obtained in the first step does not exceed 45%.