MXPA99004231A - Method for improving the exploitability and processability of guar endosperm and products obtained using said method - Google Patents

Abstract

The invention relates to a method for improving the exploitability and processability of guar endosperm. According to said method, guar splits are brought into contact with liquid ammonia at an initial pressure which is higher than the atmospheric pressure and at a temperature of at least 25°C, whereby the amount of liquid ammonia is sufficient to moisten at least the surface of the guar splits and the remaining available guar split/liquid ammonia system volume is increased in an explosion-like manner by reducing the pressure by approximately 5 bars, resulting in the sheath of the guar-splits being torn open. Said ammonia-exploded guar splits can be ground more easily than native guar splits.

Description

METHOD FOR IMPROVING EXPLOITATION CAPACITY AND PROCESSING OF ENDOSPERMA GUAR AND PRODUCTS OBTAINED USING SUCH METHOD DESCRIPTIVE MEMORY The invention relates to a method for improving the expiotability and processing of the endosperm of guar and the products obtained therefrom in the form of guar endosperm fragments (guar splits), made to explode with ammonia, guar flour. and guarano powder. Guar flour is used in the food industry as a stabilizer for ice cream and some soft cheeses, as a bulking agent and thickener for sauces and similar products, as well as in the cosmetics industry. In the art, guar flour is used for sizing and stratifying textile products and as a thickening agent for textile printing pastes. A large amount of guar flour is also used in the paper industry as an additive for pulp crusher for the production of stronger papers. The main ingredient of guar flour is guarano. Guarano is a galactomannan, which consists of approximately 36% of D-galactose and 64% of mannose. The mannose units are linked to each other in the form of pyranose β-1, 4-glycosidically to long backbones, to which the galactose units in the form of pyranose are fixed by means of α-1,6-glycosidic bonds. In guarano, every second constituent member of the mañosa of the main chain carries a galactose side group. The average molecular weight of guarano is most times significantly greater than 200,000. Guarana is contained in the endosperm of the guar bean semiamy, Cyamopsis Tetragonoloba, which is widespread in India and has been cultivated on a large scale in the United States since 1944. The endosperm is a food nutrient for the development of the small germ during germination. Since guar is a dicotyledonous plant, two endospermic halves are present in each seed. These endospermic halves surround the small germ and are surrounded on their part by a seed shell, which is usually light brown in color. The endosperm itself consists of a cellular layer, the aleurone, and a substance of nutrition and storage for the small germ, the guarano. The cells of the aleurone layer contain many beads of aleurone, ie many condensed vacuoles of albumin. In the aleurone lines, enzymes are synthesized during the germination of the guar seed and delivered to the endosperm to mobilize the reserve materials. The two predominant enzymatic activities are the activity of a-galactocidase and ß-manasa. The separation of the seed husk and the small germ is technically carried out by crushing and mechanical selection steps. Thus, the different hardness of the ingredients of the seed is used. The various crushing and sieving steps are often combined with other mechanical methods to break the seeds and select the ingredients. There are different kinds of mills which can be used in connection with other methods of roasting or treating the seed with water or acid. In a careful separation of the small germ, special care should be taken in its use for food products. The purified endosperm is sold with the designation "guar splits" (guar fragments). The guar fragments move, usually forming a powder, which is called guar flour or guar gum. In this case, the endosperm envelope containing protein is not separated from the guar fragments. In certain applications, the portion of protein produced through the envelope containing protein does not affect the guar flour. There is therefore a need for a simple and efficient method, according to which the guaran can be isolated very purely from the guar fragments. The grinding of the guar fragments is also related to a high consumption of electrical energy. The grinding conditions also influence the viscosity of the aqueous solution of guarane or its derivatives. There is therefore a need for a method, in which the crushing of the guar fragments is not necessary. Aqueous commercially available guar flour solutions are usually cloudy. Turbidity is caused mainly by the presence of insoluble portions of the endosperm. The derivatives produced from guar flour generally show an improved solubility and clarity of the solution. The improved clarity is due to the derivatization and the solubilization of insoluble impurities of the seed for certain applications, the properties of the derivatized guar flour are also however insufficient. Thus, the carboxymetal guar exhibits a relatively high structure viscosity with a weakly marked Newton range in low portions of shear. In the use of carboxymethylated guar as a thickening agent in textile printing, a poor volatility is adjusted in the products common in commerce. The cause probably lies in an inhomogeneous distribution of substituents, which is due in turn to the derivatizations being carried out in a heterogeneous reaction of the crushed guar fragments. Even by crushing with a very small particle size, this disadvantage can not be completely eliminated. There is therefore a need for a guar product, which is completely soluble or can be derivatized in a homogeneous reaction. The invention is therefore based on the commitment to present proposals with which the aforementioned needs can be met. In particular, the exploitation and processing capacity of the guar endosperm fragments (guar splits) must be improved, as well as the crushing capacity to form guar flour. In addition, it should be possible to isolate pure guarano from the guar fragments in a simple and efficient manner, so that no shredding of the guar fragments is necessary and with which the guarano is completely soluble in water and can be derivatized in a reaction homogeneous According to the invention, this compromise is solved by means of a method for improving the exploitation capacity and processing of the guar endosperm, in which guar endosperm fragments (guar splits) can be contacted with liquid ammonia at a pressure initial high with respect to atmospheric pressure and at a temperature of at least about 25 ° C, wherein the amount of liquid ammonia reaches at least to moisten the surface of the guar endosperm fragments and the volume that is at disposition of the guar / liquid ammonia endosperm fragment system by lowering the pressure by at least about 0.5 MPa (5 bar) explosively and thereby tearing the envelope of the guar endosperm fragments. WO 96/30411 discloses a method for the activation of polysaccharides by the ammonia explosion. In one example, guar flour is treated and exploited with liquid ammonia. WO 96/30411 does not recommend using intact guar endosperm fragments as a starting material, instead of guar flour. In the case of the guar endosperm starting material, it is preferably treated with endosperm fragments which are not essentially ground beforehand, ie, essentially intact guar fragments. In the treatment of guar fragments with liquid ammonia, liquid ammonia can penetrate the envelope surrounding the guar fragments and infiltrate the core of poiisaccharides. In the subsequent explosion, the volume of the ammonia suddenly increases to a high degree. The gaseous ammonia can no longer escape from the envelope quickly enough and results in tearing of the surface of the guar fragments. The guarana contained in the native guar fragments is microcrystalline and exhibits in general a degree of crystallinity of about 20 to 30%. With the action of the liquid ammonia, at least partial expansion of the polysaccharide substance takes place. Intermolecular bridge links with hydrogen between the molecular chains fall apart, since the ammonia molecule competes with the hydroxyl groups of neighboring molecules. With the explosion, an evaporation of the ammonia that is between the molecular chains takes place. The molecular chains whose intermolecular bridging links with hydrogen have been previously discarded, are detached from each other. This results in an unfolding of intervals normally only slightly accessible for the reagents. In particular, the polysaccharide portion is made soluble in water by blasting with ammonia. The guarano in the fragments of guar made to explode is no longer crystalline, but amorphous.

When one speaks of "explosively" in relation to the method according to the invention, then one must consider this concept strictly. Preferably, the explosive increase in volume occurs in the course of a time of less than 1 s, in particular of less than 0.5 s. The ammonia explosion of the method according to the invention can take place therein batchwise or continuously. In the continuous conduction of the method, fragments of endosperm / liquid ammonia are removed, in consideration of an increased amount. The guar endosperm fragments and the liquid ammonia are preferably contacted in a pressure device and the guar / liquid ammonia endosperm fragment system is discharged by transferring to a combustion chamber with a larger volume with respect to the device. Pressure. Preferably, the initial pressure is between about 0.5 and 4.6 MPa (5 and 46 bar) and in particular between about 2.5 and 3.0 MPa (25 and 30 bar). The minimum pressure decrease of 0.5 MPa (5 bar) is critical. If a lower level is applied, then the object of the invention is not achieved. The upper limit value of 4.6 MPa (46 bar) did not give rise to more advantages with its increase. Its application requires a relatively large outlay in appliances, so it is not convenient to expand on practical considerations. With the given pressure frame, the temperature is correlated from approximately 25 to 85 ° C or from 55 to 65 ° C. Preferably, the initial pressure of the guar / liquid ammonia endosperm fragment system is explosively lowered by at least about 1 MPa (10 bar) and in particular by about 3.0 MPa (30 bar). Preferably, the explosion takes place in a combustion chamber which is kept under vacuum. A sufficient amount of ammonia must be compressed to the pressure device such that liquid ammonia is present in accordance with the pressure or temperature conditions required in accordance with the invention and at least the surface of the guar endosperm fragments is wetted. . Preferably, at least about one part by mass of liquid ammonia, in particular at least about two parts by mass and most preferably about 5 to 10 parts by mass, correspond to a bulk part of guar endosperm fragments. of liquid ammonia. The step of the explosion with ammonia of the method according to the invention can be carried out discontinuously or continuously. In the discontinuous driving of the method, the apparatus set essentially exhibits a pressure vessel, which can be filled with the charge to be treated, and a collector or expansion vessel connected through a valve thereto. It can be considered here that the valve exhibits a large internal diameter in the open state, so that in the process of the explosion, the endosperm fragments of guar and exhaust will not stack exclusively ammonia. The expansion vessel exhibits a multiple volume with respect to the pressure vessel, for example the volume of the pressure vessel is 1 liter and the volume of the expansion vessel is 30 liters.

The pressure vessel is connected to an intake pipe for ammonia, possibly interposing a device that raises the pressure. For the greatest increase in pressure, an inlet pipe for inert gases, for example nitrogen, may be provided. In a continuous manner, the method could be carried out using a pressure-resistant reactor in the form of a tube or a cylinder, in which the endosperm fragments of guar and the liquid ammonia in the cylinder are contacted. of the reactor and the impregnated material is transported with the aid of a conveyor thread as a plug through the reactor and intermittently extracted through a valve or an appropriate system of pressure locks to a collecting chamber. The contact time between liquid ammonia and guar endosperm fragments is not critical. It is preferably at least about 1 minute, as a rule of 4 to 8 minutes or more. After the explosion, the resulting material generally contains less than about 2% by weight ammonia. The excess ammonia content is not very critical for the subsequent method. A further advantageous further development of the method according to the invention consists in treating the exploded material (with ammonia) with a diluting agent, so that the guarano is essentially directed to the solution and the endosperm envelopes remain essentially unsolvable, the endosperm envelopes are separated and gurano is optionally recovered from the guarano solution.

Preferred eluents for the treatment of ammonia-exploited material are aqueous media, in particular water, or other solvents with comparable solution properties. In the extraction of the material exploited with ammonia, for example with water, the polysaccharide portion of the guar fragments dissolves satisfactorily, while the envelope surrounding the fragments remains unchanged and can be separated according to usual techniques, by example by filtration or centrifugation. The exploded material is treated with the eluent, preferably at a temperature of about 25 to 95 ° C. The aqueous guarano solution can be used as such, for example for the derivatization and homogeneous aqueous phase, or it can be dried after the usual method. Particularly suitable for drying are spray drying or drum drying. The resulting poivo is extraordinarily soluble in water with the formation of very clear solutions. Following the method according to the invention, guarano is then produced as an aqueous solution or extraodinary powder, water solubility, so that in order to give rise to solubility in water no further derivatization is necessary. As desired in the particular case, the derivatization of guarana produced according to the invention results in products with surprisingly improved properties, since homogeneous derivatization products are obtained by means of improved accessibility for the derivatization reagents. Its production is possible with a smaller application of chemical substances and a smaller result of secondary products. The homogeneity of the substituent distribution is thus higher. By the method according to the invention, the guarano does not experience any significant decrease in DP. By means of x-ray diffraction spectra it was found that the guarana, initially at least partially crystalline, is henceforth amorphous. The molecular weight is notably below that of the native starting material. As a framework for the guarano recovered from guar fragments made to explode with ammonia by extraction according to the invention, a molecular weight of about 1.5 to 2.5 million, in particular of about 1.8 to 2.2 million, has to be set. The portion of the guar fragments made to explode with ammonia according to the invention, of water-soluble fraction, are between about 53 and 59% by weight, in particular between about 56 and 66% by weight. If the fragments of guar mined with ammonia obtained according to the invention are subjected to a usual grinding up to a particle size of a little more than about 100 μm, this then results in a further decrease in the molecular weight of the guarana in the crushed material. This results in molecular weight values of about 1.4 to 1.65 million, while the water-soluble portion is 65 to 77% by weight. If they are finally dried from guar fragments and then crushed to a particle size of approximately 100 μm, then a particularly marked decrease in the molecular weight of guarane results. In these cases, its molecular weight is between about 450,000 and 9,000,000, in which case the water-soluble portion is between about 71 and 85% by weight. The fragments of guar obtained according to the invention made to explode with ammonia are further characterized as follows: it shows a shell torn by the explosion with ammonia. This envelope remains after the explosion with essentially chemically unaltered ammonia. The guarano obtained from the guar fragments or recovered from them exhibits enhanced reactivity in chemical reactions, such as in etherification (carboxymethylation), in particular in silylation. The guarano still included is porous and amorphous. The porosity can be described as follows: the ammonia explosion of the guar fragments produces vacuoles (hollow spaces) on the inside of the fragments, which remain in union with the surface behind the channels by the ammonia that escapes in the form of gas. In a dilated state, the fragments are dilated up to three times their volume. The porosity can be determined by means of electronic exploration records, to which the electronic scanning representations that are attached are sent. The molecular weight is in the previously designated frame. The water-soluble portion, which is essentially guarana-based, was also designated in accordance with the above framework. In addition, it has been demonstrated that the dilatability of the guar fragments exploded with ammonia compared to the unexploited native materials increases markedly, which is also valid for the different media, being also water or a mixture of "water more soda" at room temperature or also at elevated temperatures. In measurements at a temperature of 23 ° C in an aqueous medium, it has been shown that the guar fragments obtained according to the invention exhibited a dilation almost 100% larger than the native comparison products after an expansion time of 60 minutes. In a given volume of expansion, this means that these guar fragments obtained according to the invention are achieved in half the time. If drying is not achieved for the separation of the remaining ammonia, in particular cases in relation to the determined use of the guarana, then this remaining ammonia can be separated by that means in an extensive and sufficient manner, while an exchange is carried out for example with isopropanol. In addition, it has been shown that guar fragments made to explode with ammonia exhibit less liquid portion than comparison fragments. In addition, the clarity of the solution of guar fragments made to explode with ammonia is negligibly higher than that of the comparison fragments. This improved transparency suggests that the fragments of guar made to explode with ammonia contain less insoluble materials in water. Another further development of the method according to the invention consists in grinding, in a customary manner, the guar fragments which have been exploited to form guar flour, by means of the explosion with ammonia used according to the invention. It is thus generally preferred that water is added during the grinding process. If there is to be no water present in the particular case in the grinding, then a drying is conveniently added to the grinding. The invention will now be explained in more detail by the following examples.

EXAMPLE 1 300 g of commercially available guar fragments were heated to steam in a 1 liter, double walled autoclave. Next, 500 g of liquid ammonia was pressurized through a valve in an autoclave. By heating the additional steam from the autoclave, the temperature was raised to 66 ° C. with that a pressure of approximately 2 MPa (20 bar) was set inside the autoclave. The system was maintained for 60 s under these conditions. Then, it was distended through the opening of a valve (diameter of the opening: 4 cm) suddenly and completely to a collecting vessel with a volume of 30 liters. The ammonia content of the resulting product in the collecting vessel was approximately 0.8% by weight, relative to guar.

It is observed in figures 1 or 2, that the explosion with ammonia leads to a tearing of the surface of the fragments, whereas in the untreated fragment the smooth and closed surface appears.

EXAMPLE 2 8 g of the guar fragments were made to explode with ammonia in a warm double-walled vessel, which contained 192 g of 50 ° C water. the vessel was equipped with an agitator (drive HEIDOLPH RZR2101), which made it possible to follow the torque of the agitated mass. The agitator used was a surface agitator and was operated at 250 rpm. The development of the torque corresponds to the resistance, which exerts the aqueous solution in the agitator device and therefore to the viscosity of the aqueous solution. The viscosity depends on the amount of dissolved guarana and increases with the increasing concentration of this biopolymer. After 2.5 hours, the development of the torque reaches a plateau. From this you can deduce that you have finished the dilution process. By visual observation, the undiluted particles (endosperm envelopes) are recognized which descend to the lower part of the apparatus, after removing the agitator. The solution above is clear and can be separated by decanting. In the comparative experiments, the untreated guar fragments were shaken in water (commercial form) under the same conditions and the development of the torque continued. In addition, the untreated fragments were stirred in 4% ammonia water at 25 ° C. The respective development of torque is shown in FIG. 3. In the comparative experiments, no significant increase in viscosity is reached. This indicates that no decomposition of untreated guar fragments takes place. Subsequent determinations resulted in the following. By gel chromatography analysis it was determined that other guar fragments made to explode with ammonia contained guaran with a molecular weight of 1,996,000 and a water-soluble potion of 61% by weight. The corresponding values in the comparative fragments have a molecular weight of 278,900 and 51% by weight.

EXAMPLE 3 The influence of the trituration and, eventually, the intercalated drying with regard to the molecular weight of the guarana in the obtained guarana flour as well as the portion of water-soluble fraction must be determined here. Thus, native guar fragments were used, as well as guar fragments made to explode with ammonia, according to example 2. In one case, they were crushed only at a mean particle diameter of more than 100 μm. This took place in a so-called criomolino under moderate conditions, as well as adding liquid nitrogen. In addition, the experiment was carried out, in which the grinding took place at an average particle diameter of approximately 100 μm, where it was dried at a temperature of 40 ° C overnight in a vacuum drying cabinet. According to this the evident data result by the following chart: PICTURE I O Observations: 1) Moderate cryotryping took place with the addition of liquid nitrogen to a particle diameter > 100μm 2) A drying at 40 ° C overnight at 0 vacuum took place here first. A moderate cryotritration followed with the addition of liquid nitrogen to a mean particle size of 100 μm.

Claims (10)

NOVELTY PE THE INVENTION CLAIMS

1. - Method for improving the exploitation and processing capacity of the guar endosperm, in which guar endosperm fragments (Guar spiits) are brought into contact with liquid ammonia at a high initial pressure with respect to atmospheric pressure and at a temperature of at least about 25 ° C, in which the amount of the ammonia is at least liquid for the use of the surface of the guar endosperm fragments and the volume available to the system of fragments of guar is explosively increased. Guar / liquid ammonia endosperm decreasing the pressure by at least 0.5 MPa (5 bar) and thus tearing the envelope of the guar endosperm fragments.

2. Method according to claim 1, further characterized in that the explosive increase in volume is carried out in the course of a time of less than 1 s.

3. Method according to claim 1 or 2, further characterized in that the guar endosperm fragments and liquid ammonia are contacted in a pressure device and the system of guar / liquid ammonia endosperm fragments is distended by Transfer to a combustion chamber with larger volume with respect to the pressure device.

4. Method of conformity to at least one of claims 1 to 3, further characterized in that the initial pressure is set between approximately 0.5 and 4.6 MPa (5 and 46 bar).

5. Method according to claim 3 or 4, further characterized in that the temperature is set in the pressure device before the explosive increase in volume between about 25 and 85 ° C.

6. Method of conformity to at least one of the preceding claims, further characterized in that the initial pressure is explosively reduced by at least about 1 MPa (10 bar).

7. Method of conformity to at least one of the preceding claims, further characterized in that at least one mass portion of liquid ammonia is applied to a bulk portion of guar endosperm fragments.

8. Method of compliance according to at least one of the preceding claims, further characterized in that the exploded material is treated with an eluent, so that the guarano is essentially included in the solution and the endosperm envelopes remain essentially insoluble. they separate the endosperm envelopes and guarano is optionally recovered from the guarano solution.

9. - Method according to claim 8, further characterized in that an aqueous eluent is used, in particular water.

10. Method according to claim 8 or 9, further characterized in that the exploded material is treated at a temperature of about 25 to 95 ° C with the eluent. 1. Method according to one of claims 8 to 10, further characterized in that the endosperm envelopes are separated by filtration or centrifugation. Method according to one of claims 8 to 11, characterized in that guarana is recovered by spray drying. 13. Powder guarana, obtainable by the method according to one of claims 8 to 12. 14. Method according to claim 1, further characterized by grinding the material exploded with ammonia to form guar flour. 15.- Endosperm fragment of guar (Guar spiits), made to explode with ammonia, obtained by the method of compliance with at least one of claims 1 to 7. 16.- Guar flour, obtainable by the method in accordance with Claim 14