DE1567348A1 - Process for obtaining crystalline glucose - Google Patents

Description

Pofenfanwolf

i ^h lTD ^F üfen ^rüfnPf 1567348 20.5.69

Kowewfraße 20 N 14

Nippon Shiryo Kogyo Co,

Tokushima / Japan

Process for obtaining crystalline glucose

The invention relates to a method for obtaining crystalline glucose by spray drying aqueous glucose solution.

In the USA in particular, corn starch hydrolyzate has hitherto been used mostly converted into dextrose, probably because of the demand for high quality and out of consideration found that the so-called "total sugar system" has economic disadvantages because the heat released during crystallization is not kept under constant control and the crystallization often does not proceed satisfactorily. Furthermore, the mechanical treatment the resulting blocks difficult.

The method of the invention avoids these disadvantages and solves the problem of using glucose in crystallized form excellent quality economically based on the total sugar system to win. It is characterized in that a concentrated glucose solution of high D.E. crystallizes to a stable, pumpable filling compound, the filling compound is crystallized in a stream of hot air Droplets or particles are sprayed and the water still contained in them is then removed.

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Documents (Art. 7 i I Abe.2 No. 1 Clause 3 of the Ärtderunaegt ». Y, 4» 9.196 »

Thereby the distribution and discharge of the released takes place Heat of crystallization takes place in a short time, as the glucose in the transition to the solid state in the form of small particles which has a large surface area, and therefore every glucose droplet or particle during the Spray drying always assume the same temperature, so that the removal of moisture from each Particles and the crystallization always takes place under the same conditions.

Therefore, the obtained according to the invention has crystalline Product a great uniformity, and it can perfectly can be produced continuously without producing any more hydrol and without solid glucose as crystal nuclei as described in British Patent Specification 586,951.

The snow-white crystal-like grains or particles thus obtained can mainly be seen under the microscope recognized as dextrose monohydrate surrounded by tiny crystal droplets. You see in the Magnification like golf balls with cracked surface. The product is extremely sweet, fermentable by yeast, etc. and can be very easily dissolved in water without clumping. Its chemical properties are the same like that of a total sugar of the same D.E.

The filling compound used according to this invention can be made from starch hydrolyzate, which enzymatically with Gluc-Amylase or by other methods preferably to a high D.E. has been hydrolyzed.

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The method according to the invention thus has three Levels up, namely

1) Production of a filling compound that can be pumped and then sprayed,

2) the spray drying of this filling compound under such conditions that crystals between or on the surface of the droplets or particles can arise Chier and in the following also called "spray crystallization" labeled), and

3) the ripening and drying of the particles obtained, which are still somewhat sticky for a few hours the end product no longer cakes.

For the practical implementation of the method according to the invention, a solution of DE 94, preferably higher, first purified by ordinary methods and up to about 7O ⁰ Brix, for example, to 67, concentrated, treated with a small amount of nuclei (the addition of germs can omitted if there is still a crystal residue in the crystallization device), and then converted into filling compound ^{with stirring at a temperature between room temperature and 40 ° C.} The precrystallization only reaches equilibrium in 6 to 24 hours, corresponding to the DE of the solute, so that crystals of suitable size have completely separated from the supersaturated sugar solution. The stable filling material is composed of roughly equal parts of dextrose monohydrate crystals, dissolved sugar and water (based on dry matter).

This filling compound is sufficiently fluid and stable to be able to be pumped without getting into pipelines solidifies due to crystallization or dissolves into a solution due to the frictional heat when pumping.

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The pre-crystallization described can because of the low viscosity and good heat dissipation of the Liquid or the filling compound are carried out continuously, but it is preferable to use several crystallizers to work, which are combined in such a way that the maximum of crystallization is reached in a short time even if the crystallization is very slow. The respective D.E. value must be taken into account here, which influences the rate of crystallization. If the capacity of the crystallizer is too small one often obtains a filling compound with microcrystals, which at higher crystallization rates tends to gel hard and is difficult to pump. Solution is converted back.

If the crystallization apparatus is large enough, however, it is possible to shut down the precrystallization process in this way lead to the fact that one can control the size of the crystals and their distribution or structure. Then it is also possible according to the sprayed drops or particles of the filling compound and the size of the final product Desire to influence. Such a filling compound of suitable consistency can be used in an atomization dryer of any desired Kind of pumped and sprayed there, whereby the size of the droplets or particles e.g. by changing the number of revolutions the atomizer, the amount of the filling compound, etc. can be regulated.

Since the droplets or particles of the filling compound are relatively large crystals in relation to the germs and have an extremely large surface area, their temperature is preferably about the same as

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that of the air stream kept in the dryer, with Consideration for the rapid release of heat and dehydration resulting from the rapid crystallization between or on the surfaces of relatively large crystal cores in the supersaturated phase of the filler mass results during the deposition in the chamber. However, the final drying of the particles must be carried out with care, because a glass-like solid mass is created if the evaporation is too strong.

For this reason, the moisture is removed from the filler droplets or particles removed to about 13%, about 10% being bound as water of crystallization, and the remainder of about 3% is gradually removed as the crystallization proceeds.

The half-dried sugar particles deposited on the bottom of the dryer have a snow-like appearance Appearance, tend to stick together and form a hard mass under pressure. But by balancing with the relative Humidity, the surface of the droplets reaches a density suitable for crystallization - accordingly their own affinity for moisture creates a certain balance between water attraction and water release - and with a higher ratio of solid substance to liquid it is gradually increased in a few hours due to the growth of the crystal parts after released. In a few hours, the particles turn completely into non-baking crystals converted, with the time from D.E. the filling mass depends. For example, in the case of glucose from D.E. 97% to complete the crystallization, three hours to dry in a stream of air, which is continuous in one pneumatic conveyor system, in one

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rotating dryer or the like. can be done. The end product, which contains about 10% moisture bound as crystal water, consists mainly of dextrose monohydrate and no longer has a tendency to stick or crust, so that it is brought into collecting containers and automatically packed can be.

The method of the invention has other advantages as well. So various additives can be mixed in of course, must not impair the crystallization of glucose, e.g. organic acids, sweeteners, Fruit juices and plant extracts. This gives immediately soluble mixtures which are as homogeneous as they are cannot be achieved by conventional mechanical mixing. The inventive method can also can be applied to the spray-drying of dextrose crystals, which are separated from the hydrol by centrifugation have been.

example 1

Starch hydrolyzate prepared with a DE of 97, according to a conventional method, is purified and concentrated in a known manner to Brix 67 ° and with slow stirring in a crystallizer at 20 ⁰ C., is admixed preferably as crystallization nuclei 0.5% Dextrosemonohydratkristalle (or substances which contain dextrose monohydrate as the main component), calculated on dry matter. The time required until the crystallization is complete is not constant when the equilibrium between the precipitated crystals and the solution saturated at this temperature is established. It depends on the degree of hydrolysis and the purity of the liquid and is usually reached in about 8 hours. The process can be continuous

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be carried out by passing the concentrated liquid through a suitable crystallization device will; Crystallization nuclei do not need to be added.

The filling mass obtained in this way consists of relatively structurally larger crystals in the saturated solution, in a state that allows the mass to be pumped through a line to a spray dryer, which is possible with regard to the liquid state of the mass and its stability. As a result, it can be continuously fed up to the sprayer. The filling mass is dried to small droplets or particles by spraying, which can fall through a stream of air into the "chamber. The temperature of the chamber is regulated to below 50 ^° C. in order to obtain a product which essentially contains dextrose monohydrate but no anhydride which would interfere with the subsequent crystallization of the filler droplets or particles and cause the end product to cake together. ”In the following, an example is given which shows the method in detail, how it can be carried out practically and economically.

At the top of a chamber, which has a diameter of 7700 mm, in its cylindrical part a height of 7700 mm and in its conical part also has a height of 7700 mm, an atomizer with a diameter of 350 mm is arranged, which rotates at 6500 revolutions per minute. In this device 1000 kg of filling compound are sprayed per hour. The air flow blown into the chamber for drying has a temperature of 55 C, but cools by removing the Heat of vaporization and the ingress of cold air

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if5 ° C. The droplets and particles of the filling compound, which fall to the bottom of the chamber contain 13% moisture and are snow-white in appearance. From 1Ö00 kg 770 kg of semi-dried agglomerates are obtained from the filling compound, which consists of 70% monohydrate crystals and 30% consist of a liquid phase. If the product is dried in a stream of air for 3 to 5 hours, it completely crystallizes and can be pneumatically conveyed.

The procedure is shown in, for example, the following table overview:

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33P kg

kg

kg

Glucose
(fixed) Glucose
(guesses I.
Water content IA
I.

Composition of the filling compound

A = crystal water T 33 kg— ¹

kg
Spray crystallization

50p kg

2] 0kg

• in the dryer
! evaporates

Dextrose B ι monohydrate
! (fixed)

concentrated,
Solution ι C (liquid) «

Composition of the semi-dried grains

Crystal water

(50 kg)

H ₂ O (B + O = 13

kg

ater than
Solvent (50kg)
I.

G
Maturation and drying

26 k ι

post-dried

I I

• I

Z24 4

End product completely solid end product

it — crystal water

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In this case it was found that a better degree of efficiency could be achieved by faster drying than by drying in two stages. If, however, the liquid phase in each droplet or particle is dried too quickly, a crystal agglomerate does not form, but a vitreous mass which is hydroscopic and tends to stick. Therefore, to achieve the desired product, it is necessary that the water content in the droplets is maintained or adjusted to the gradual growth of the crystals under the special conditions on which the movement of the dextrose molecules with regard to the appropriate sugar concentration up to the removal of the free Moisture is retained. In other words, it is appropriate to treat the semi-dried particles in not too low a relative humidity so that the adsorption of the moisture and then the dissolution of the particle surfaces take place at a concentration which is suitable for the formation of crystals, even if due to If it evaporates too quickly in the dryer, an amorphous-glassy skin should have formed around the droplets. This ripening and drying can be carried out continuously in suitable apparatus, for example with drum dryers, belt conveyors or pneumatic devices which can be set to the appropriate values of temperature, relative humidity and speed of the air flow.

Example 2

Dextrose monohydrate is used, which has been separated from a glucose filling mass by centrifugation and has a degree of purity of 99% or better with a very low proportion of oligosaccharides. There is a solution

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this product is very easy to crystallize, it is suitable opt for processing according to the method of the invention. So she will be in a calculated amount of water partially dissolved or with a saturated dextrose solution mixed, so that a filling material is formed, which is made up of approximately equal parts of dextrose monohydrate, dissolved Is made up of dextrose and water. The procedure comes in particular for the production of largely homogeneous products into consideration, in addition to the main ingredient Dextrose monohydrate contain any additives.

Example 3

Starch hydrolyzate from D.E. 97 that after a suitable known processes is cleaned, concentrated in the usual way to M-7 ° Brix density and then brought to crystallization according to the method described in Example 1. At the same time, sweeteners, e.g. 1 to 1.5% sodium cyclohexyl sulfamate as a 10% solution, added, whereby the crystallization of the Dextrose is not hindered. The filling compound is pumped out, sprayed, stored and dried as in Example 1. A non-caking product is obtained with the appearance and calorie content as in Example 1, however thanks to the sweetener that is homogeneously distributed in the individual grains and has a stronger sweetening power than cane sugar.

Example 4

Example 3 is repeated, but the filling compound obtained according to Example 2 is used. One receives a Product with the same benefits.

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Example 5

Filling compound, prepared according to Example 3 or ¹ ^, is mixed with a solid organic acid, for example citric acid, succinic acid or tartaric acid, instead of with a sweetener and then processed in the same way. A granular product is obtained which contains the organic acid distributed in great homogeneity between or on the dextrose monohydrate crystals in each granule.

Example 6

Starch hydrolyzate from D.E. 96 is purified, concentrated and crystallized as in Example 1 or 2, Components of various beverages or foods, e.g. concentrated fruit juices, vegetable juices, coffee extracts or cocoa powder, etc. can be mixed in homogeneously one by one. The spray dried and on top The end product freed from the remaining moisture is immediately soluble or easily dispersed due to the homogeneous properties Distribution of its components in the individual agglomerates.

When preparing the mixtures, care must be taken to ensure that the filler remains flowable and the mixtures can be pumped and sprayed. The water content is on the one hand within certain limits if, for example, high polymers are present that increase the viscosity of the filler compound, but on the other hand to be kept so low that the spray-crystallized and ripened agglomerates solidify. For example, can according to this method, as explained in Example 1 or 2, an orange juice instant powder from a Mixture of the following composition can be produced:

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Glucose filling mass 1000 kg (solids) concentrated orange juice 80 kg sodium cyclohexyl sulfamate 10 kg soluble saccharin ^{3 k} S Orange oil ^{15 kg}

Citric acid 35 kg

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Claims (10)

Claims 1. Process for the production of crystalline glucose by spray drying of aqueous glucose solution, characterized in that a concentrated glucose solution of high D.E. to a stable, Pumpable filler material crystallizes, the filler material in a stream of warm air to form crystal-containing droplets or particles are sprayed and the water still contained in these is then removed. 2. The method according to claim 1, characterized in that the glucose solution is a D.E. has over 9U. 3. The method according to claim 1 or 2, characterized in that the filling compound up to about 70 ° Brix, preferably 67 °, is concentrated. k. Method according to one of the preceding claims, characterized in that the filling compound is kept at a temperature between room temperature and H0 °. 5. The method according to any one of the preceding claims, characterized in that the filling compound by the Spray drying is brought to a water content of about 13% (including crystal water). 6. The method according to any one of the preceding claims, characterized in that the spray drying takes place at a temperature below 50 ^° C. 7. The method according to any one of the preceding claims, characterized in that the by spray drying The resulting glucose droplets or particles are completely dried for several hours at an elevated temperature and be matured. 009848/0267 - 15 - 8. The method according to any one of the preceding claims, characterized in that the filling material contains fruit juices, Plant extracts, coffee extracts and / or cocoa powder can be added. 9. The method according to any one of the preceding claims, characterized in that organic acids are added to the filling compound. 10. The method according to any one of the preceding claims, characterized in that the filling compound sweeteners can be added. 009848/0267