CN103131027B - Instant gellan gum and its preparation method - Google Patents

Abstract

The invention discloses an instant gellan gum and a preparation method thereof. The gellan gum powder is used as a starting material, and a boiling granulation drying device is used to make an instant gellan gum product. The method comprises the following steps : a) Feeding of gellan gum powder: introduce the purified cold air from the bottom of the fluidized bed of the boiling granulation drying device to keep the raw material in a boiling state; b) Wetting the KCl aqueous solution: spray KCl The aqueous solution wets and granulates the gellan gum powder; c) Spraying the gellan gum solution: After the gellan gum solution of dilute concentration is atomized, it is sprayed evenly from the upper part of the fluidized bed to coat the boiling raw material Gellan gum powder; d) coating; e) drying the granular product to obtain an instant colloidal matrix. The instant gellan gum prepared by the method of the invention is used to solve the problems that the powdery gellan gum in the existing production is difficult to dissolve, easily forms "fish-eye"-like agglomerates during the dissolution process, has a slow dissolution time, and is free from dust.

Description

A kind of instant gellan gum and preparation method thereof

technical field

The invention relates to a gellan gum, in particular to an instant gellan gum; in addition, the invention also relates to a preparation method of the instant gellan gum. It belongs to the preparation of compounds containing sugar residues.

Background technique

Gellan Gum (Gellan Gum) is a Gram-negative bacterium isolated from water lilies—Pseudomonas elodea (Pseudomonas elodea) that is purified by fermentation of carbohydrates and extracted and refined. Polysaccharide colloid, almost white powder, is a new type of fully transparent gel. The gellan gum products in the prior art are mostly powdery.

Gellan gum is a high molecular polysaccharide, and its dissolution process has something in common with other high polymers. The dissolution process of the polymer goes through two stages. First, the solvent molecules penetrate into the polymer to expand the volume of the polymer, that is, the swelling process, and then the polymer is evenly distributed in the solvent to achieve complete dissolution. However, during the dissolution process of gellan gum, there will be a "fish-eye" phenomenon: that is, the glue is in water, and the surface _of the particles forms a gelatinous layer due to water swelling. At this time, the molecular chains have not formed and can freely The movement of random coils, the formation of the colloidal layer delays and hinders the penetration of water molecules into the interior of the glue, and makes the particles cement together to form a block, forming a large group with an initial gel on the surface and a dry core inside. block, so that the swelling and dissolution speed of glue molecules in water is reduced, and the dissolution time is prolonged.

When users use it, small aggregates appear in the gellan gum solution, and "fish eyes" cause some users to have to increase the filtration process to filter them out, resulting in waste of gellan gum and limiting its application field. In addition, the pollution of dust to the environment during the production and use of gellan gum powder is also a problem to be solved.

In order to avoid the agglomeration of powdered gellan gum during the dissolution process, food companies generally need to combine gellan gum with a certain proportion of dry materials such as sugar and salt when the formula and process permit. And mix, and use high-speed mixing equipment. However, in practical applications, there is not necessarily a formula for dry powder ingredients, and equipment conditions are often restricted. Moreover, it is difficult to completely avoid agglomeration even if it is premixed with a certain proportion of dry powder.

Due to the generation of agglomeration, many manufacturers try to achieve the full dissolution of gellan gum by prolonging the stirring time and increasing the stirring speed. However, this long-term high-speed stirring not only easily causes a large amount of air to enter the feed liquid, affecting the stability of the final product, but also has a very adverse effect on many ingredients that are not resistant to high shear.

In view of this, the production of rapidly soluble gellan gum has a great impetus for the application of gellan gum in the food industry. Therefore, urgently need to develop a kind of novel instant type gellan gum product.

Contents of the invention

The technical problem to be solved by the present invention is to avoid the disadvantages of the above-mentioned prior art, and provide a kind of instant gellan gum with large specific surface area and high porosity and its preparation method. The instant gellan gum prepared by the present invention can replace the current commercially available powdered products, and solve the problem that the gellan gum powder (that is, powdered gellan gum) in the prior art is difficult to dissolve, the dissolution speed is slow, and the "" "fish-eye" agglomeration, slow dissolution rate and environmental dust pollution. The instant gellan gum product is suitable for use in the industries of sauces, seasonings, soups, beverages, food and pharmaceuticals.

The usual instant products basically use methods such as freeze-drying or microencapsulation to increase the specific surface of the particles or pre-emulsify the solute before dissolving to quickly disperse the solute. But in essence, this kind is just that the solute is quickly dispersed in the solvent phase, and the dissolution process after dispersion is accelerated through emulsification.

These techniques are only effective for non-viscous colloids that disperse or dissolve very easily in water. When gellan gums are added to water, they immediately start to gain viscosity as they are added, making it difficult for the remaining material that has not been added to disperse without forming clumps.

Through research, the present invention adopts various means to make gellan gum dissolve, so that the swollen glue molecules on the surface are separated from the glue particles quickly to form free-moving random coils, so as to achieve the purpose of instant dissolution at the molecular level. For the rapid dissolution of the sample, the viscosity of the solution increases rapidly.

In order to solve the above-mentioned technical problems, the present invention provides a preparation method of instant gellan gum, which uses gellan gum powder (i.e. powdered gellan gum) as the starting material and adopts a boiling granulation drying device to make it into Instant type gellan gum product, the method comprises the following steps:

a) Feeding of gellan gum powder: introduce the purified cold air from the bottom of the fluidized bed of the fluidized granulation drying device to keep the raw material gellan gum powder in a boiling state;

b) Wetting of KCl aqueous solution: Spray KCl aqueous solution to wet and granulate the raw material gellan gum powder;

c) Spraying gellan gum solution: after the gellan gum solution of dilute concentration is atomized, it is sprayed evenly from the upper part of the fluidized bed to coat the raw material gellan gum powder in boiling state;

d) Coating: Atomized by a high-pressure spray gun, the mist-like droplets formed are sprayed on the gellan gum powder in the fluidized bed. With the help of the viscosity of the gellan gum itself, it collides with water to form small particles. During the boiling granulation process, the granules gradually increase and finally form the required microporous spherical coated granules;

e) drying the granular product to obtain an instant colloidal matrix.

Preferably, after step e), the following steps are also included:

f) Process the granule product to a suitable particle size by sieving with a grading sieve or granulating with a granulator; according to the instant size grading requirements, pass through sieves with corresponding meshes to remove a small amount of ungranulated fine powder and large particles ; You can also use a granulator to obtain the desired particle size;

g) Quality inspection, packaging and storage after passing the test.

Preferably, in step a), the feeding amount of the gellan gum powder is 40%-80% of the production capacity of the fluidized granulation drying equipment used.

Preferably, in step a), the gellan gum powder is high acyl gellan gum or low acyl gellan gum.

Preferably, in step b), after atomizing the KCl solution with a concentration of 0.1% to 3% by mass, it is sprayed evenly from the upper part of the fluidized bed, the spraying time is 20-60 minutes, and the atomization pressure is 0.25-0.5 MPa.

Preferably, in step c), the dosage of the gellan gum solution is 5% to 30% of the weight of the input raw material gellan gum powder, the spraying time is controlled at 20 to 120 minutes, and the atomization pressure is 0.3MPa to 0.6 MPa; the concentration of the gellan gum solution is 0.05% to 0.2% (the concentration of the gellan gum solution refers to the mass percentage concentration of gellan gum in the gellan gum aqueous solution).

Preferably, in step e), when the particle size reaches the process requirement, stop spraying the solution, continue to feed hot air, keep the temperature at 60°C-90°C, and continue drying until the moisture content is ≤13%, and the drying time is 20- 120 minutes.

Preferably, the following steps are added between step b) and step c): After the wetted powder forms particles, the purified cold air is preheated by steam, the temperature of the hot air is 60-90°C, and the steam pressure is 0.4MPa-0.8 MPa.

In addition, the present invention also provides an instant gellan gum prepared by the above method.

The preparation method of instant gellan gum of the present invention does not add other ingredients, uses the characteristics of the material itself to granulate, does not change the properties of the material itself, and achieves the purpose of improving its dispersion and hydration performance through physical form changes, and improves the dispersion and hydration of gellan gum. The speed not only solves the technical problem of gellan gum agglomeration, but also increases the dissolution rate rapidly, which significantly improves its application performance.

The instant gellan gum product prepared by the method of the present invention has a loose and porous structure, has better dispersion and faster hydration speed than powdered gellan gum, and avoids the use of ordinary powdered gellan gum. Agglomeration caused by too late to disperse.

Some techniques, such as coating and agglomeration techniques using surfactants and wetting agents with a wide HLB (hydrophilic and lipophilic balance) range, are used for "difficult to disperse" gums. However, the dispersibility of viscous fast-swelling colloids is only improved to some extent, and its disadvantages are: ①It is impossible to mix and stir at low speed without forming agglomerates; ②Many wetting agents and surfactants increase the gellan gum solution. Transparency; ③ wetting agents and surfactants will bring odor.

Instant gellan gum can be dispersed under low-shear conditions, which can reduce the investment in high-speed dispersion equipment and help reduce air entrainment during stirring, which is extremely beneficial to system stability, especially the stability of emulsified systems. It is not only convenient in application, but also saves investment in high-speed mixing equipment.

Compared with the prior art, the present invention has the following beneficial effects:

1. A preparation method of instant gellan gum with large specific surface area and high porosity is provided. The prepared instant gellan gum solves the problems of slow dissolution speed, agglomeration during the dissolution process and dust pollution of the powder type gellan gum in the prior art.

2. Provide a new instant product with good dispersibility and fast dissolution, which solves the agglomeration problem of gellan gum in application, improves its application performance, improves the utilization rate of raw materials, and saves time.

3. The time for the instant gellan gum of the present invention to reach complete hydration is greatly shortened (as shown in Figure 1), it is completely dispersed within 30 seconds, and it can basically reach complete hydration in 3 minutes, in a state of uniform sol, while ordinary powdery gellan gum The glue is agglomerated and not completely dissolved, and it takes at least 30 minutes to be completely hydrated. This difference is even more pronounced in saline and sugar solutions.

4. In the sucrose solution (as shown in FIG. 2 ), the instant gellan gum of the present invention can be completely hydrated to reach the equilibrium viscosity in about 1 minute. The viscosity of ordinary powdered gellan gum releases slowly, and it can be completely hydrated after dispersing for 20 minutes, and basically reaches the highest viscosity.

5. Compared with ordinary powdered gellan gum, instant gellan gum has a faster dispersion and hydration rate, is not easy to agglomerate, and has sufficient hydration. In practical application, it can greatly save time, make full use of feeding materials, reduce material waste, and improve the effectiveness of raw material utilization.

6. The present invention can also avoid the problem of raising dust in the use of powdery gellan gum, thereby improving the use environment of gellan gum.

Description of drawings

The present invention will be described in further detail below in conjunction with accompanying drawing:

Figure 1 is a schematic diagram of the comparison of the dispersion and hydration rates of ordinary powdered gellan gum and the instant gellan gum of the present invention in water.

Fig. 2 is a schematic diagram showing the comparison of dispersion and hydration rates of ordinary powdered gellan gum and the instant gellan gum of the present invention in sucrose solution.

In Figure 1 and Figure 2, the abscissa represents time (unit: min (minute)), and the ordinate represents viscosity (unit: CP (centipoise)).

Detailed ways

Example 1

Using gellan gum powder as the starting material, using a boiling granulation dryer, the operation steps are as follows:

①. Gellan gum powder feeding

The raw material gellan gum powder is put into the fluidized bed, and the feeding amount is 2 kg. The purified air is introduced from the bottom of the fluidized bed of the fluidized granulation drying device, so that the raw material gellan gum powder is in a boiling state;

②. Spray KCl solution

Use a peristaltic pump to atomize the KCl solution with a concentration of 0.2% by mass, and spray it evenly from the upper part of the fluidized bed. The spraying time is 30 minutes, and the atomization pressure is 0.4MPa;

③. Spray gellan gum solution

After the gellan gum solution of dilute concentration is atomized, it is evenly sprayed from the upper part of the fluidized bed to coat the raw material gellan gum powder in a boiling state; 5% of the body weight, the spraying time is controlled at 20 minutes, and the atomization pressure is 0.3MPa; the concentration of the gellan gum solution is 0.05%.

④. Boiling granulation, coating

Atomized by a high-pressure spray gun, the formed mist-like droplets are sprayed on the gellan gum powder on the fluidized bed. With the help of the viscosity of the gellan gum itself, it collides with water and forms a small instant solution. During the boiling granulation process , the instant solution gradually increases, and finally forms the required microporous spherical coated particles;

⑤. Drying

When the particle size reaches the process requirements, stop spraying KCl solution, introduce hot air, and at the same time pass 0.1% gellan gum solution, and keep the temperature at 60°C, continue drying until the moisture content is ≤13%, and the drying time is 60 minutes;

⑥. Screening

According to the classification requirements of instant dissolving size, pass through sieves with corresponding meshes respectively, and sieve out a small amount of ungranulated fine powder and large instant dissolving;

⑦. Quality inspection, packaging and storage after passing the test.

Example 2

Using gellan gum powder as the starting material, using a boiling granulation dryer, the operation steps are as follows:

①. Gellan gum powder feeding

The raw material gellan gum powder is put into the fluidized bed, and the feeding amount is 2 kg. The purified air is introduced from the bottom of the fluidized bed of the fluidized granulation drying device, so that the raw material gellan gum powder is in a boiling state;

②. Spray KCl solution

Use a peristaltic pump to atomize the KCl solution with a concentration of 0.2% by mass, and spray it evenly from the upper part of the fluidized bed. The spraying time is 20 minutes, and the atomization pressure is 0.5MPa;

③. Spray gellan gum solution

After the gellan gum solution of dilute concentration is atomized, it is evenly sprayed from the upper part of the fluidized bed to coat the raw material gellan gum powder in a boiling state; 30% of the body weight, the spraying time is controlled at 120 minutes, and the atomization pressure is 0.6MPa; the concentration of the gellan gum solution is 0.2%.

④. Boiling granulation, coating:

Atomized by a high-pressure spray gun, the formed mist-like droplets are sprayed on the gellan gum powder on the fluidized bed. With the help of the viscosity of the gellan gum itself, it collides with water and forms a small instant solution. During the boiling granulation process , the instant solution gradually increases, and finally forms the required microporous spherical coated particles;

⑤. Drying

When the particle size reaches the process requirements, stop spraying KCl solution, introduce hot air, and at the same time pass 0.1% gellan gum solution, and keep the temperature at 90°C, continue drying until the moisture content is ≤13%, and the drying time is 20 minutes;

⑥. Screening

According to the classification requirements of instant dissolving size, pass through sieves with corresponding meshes respectively, and sieve out a small amount of ungranulated fine powder and large instant dissolving;

⑦. Quality inspection, packaging and storage after passing the test.

Example 3

Using gellan gum powder as the starting material, using a boiling granulation dryer, the operation steps are as follows:

①. Gellan gum powder feeding

The raw material gellan gum powder is put into the fluidized bed, and the feeding amount is 2 kg. The purified air is introduced from the bottom of the fluidized bed of the fluidized granulation drying device, so that the raw material gellan gum powder is in a boiling state;

②. Spray KCl solution

Use a peristaltic pump to atomize the KCl solution with a concentration of 0.2% by mass, and spray it evenly from the upper part of the fluidized bed. The spraying time is 60 minutes, and the atomization pressure is 0.25MPa;

③. Spray gellan gum solution

After the gellan gum solution of dilute concentration is atomized, it is evenly sprayed from the upper part of the fluidized bed to coat the raw material gellan gum powder in a boiling state; 20% of the body weight, the spraying time is controlled at 90 minutes, and the atomization pressure is 0.4MPa; the concentration of the gellan gum solution is 0.1%.

④. Boiling granulation, coating:

Atomized by a high-pressure spray gun, the formed mist-like droplets are sprayed on the gellan gum powder on the fluidized bed. With the help of the viscosity of the gellan gum itself, it collides with water and forms a small instant solution. During the boiling granulation process , the instant solution gradually increases, and finally forms the required microporous spherical coated particles;

⑤. Drying

When the particle size reaches the process requirements, stop spraying KCl solution, introduce hot air, and at the same time pass 0.1% gellan gum solution, and keep the temperature at 70°C, continue drying until the moisture content is ≤13%, and the drying time is 120 minutes;

⑥. Screening

According to the classification requirements of instant dissolving size, pass through sieves with corresponding meshes respectively, and sieve out a small amount of ungranulated fine powder and large instant dissolving;

⑦. Quality inspection, packaging and storage after passing the test.

Beneficial effects of the present invention are further elaborated below by test example:

Test instruction

To test the viscosity, use a stirrer in a beaker to test the dispersion and dissolution of the final product in water. Use the following test steps and methods:

Test example one

1. Weigh 394g of water in a 600mL beaker, weigh 6g of instant gellan gum on a balance, and use 6g of ordinary powdered gellan gum for comparison experiments;

2. Place the stirring paddle in the beaker below the liquid surface and above the middle;

3. Start the power supply, the initial speed is 400RPM, pour the powder into the water at a constant speed within 5 seconds, and start the timer; increase the speed according to the viscosity to stir the solution as a whole;

4. Measure the viscosity in a Brookfield viscometer at 60 RPM at exactly 0.5, 1, 2, 3, 5, 10, 20 and 30 minutes. Return the solution to the mixer after each viscosity measurement;

5. Observe the state of the solution.

The test results are shown in Figure 1, which is a schematic diagram of the comparison of the dispersion and hydration rates of ordinary powdered gellan gum and the instant gellan gum of the present invention in water. As can be seen from Fig. 1, under the 400rpm rotating speed, the instant gellan gum of the present invention almost reaches the maximum viscosity in 5 minutes, while the viscosity of ordinary powdered gellan gum hardly changes in the first 5 minutes, and in 20 minutes 80% of the maximum viscosity is reached.

Phenomenon: After the instant gellan gum is poured into the beaker, it can be dispersed in the whole solution within 2 to 5 seconds. The appearance is that the fine crystal balls visible to the naked eye are rotating in the solution, and the solution begins to thicken. Ordinary powder-type gellan gum forms lumps and rotates in the solution. When the viscosity rises to 800cp, there are still a small amount of lumps. It can be seen that compared with ordinary powdered gellan gum, the time for the instant gellan gum of the present invention to reach complete hydration is greatly shortened, it can be completely dispersed within 30 seconds, and can basically reach complete hydration in 3 minutes, showing a uniform sol state.

Test example two

1. Weigh 388g of water in a 600mL beaker, weigh 6g of instant gellan gum and 6g of sucrose on a balance, and use 6g of ordinary powdered gellan gum and 6g of sucrose for comparison experiments;

2. Place the stirring paddle in the beaker below the liquid surface and above the middle;

3. Start the power supply, the initial speed is 400RPM, pour the powder into the water at a constant speed within 5 seconds, and start the timer; increase the speed according to the viscosity to stir the solution as a whole;

4. Measure the viscosity in a Brookfield viscometer at 60 RPM at exactly 0.5, 1, 2, 3, 5, 10, 20 and 30 minutes. Return the solution to the mixer after each viscosity measurement;

5. Observe the state of the solution.

The test results are shown in Figure 2, which is a schematic diagram of the comparison of the dispersion and hydration rates of ordinary powdered gellan gum and the instant gellan gum of the present invention in sucrose solution. As can be seen from Fig. 2, under the rotating speed of 400rpm, the instant gellan gum of the present invention can be completely dissolved in 5 minutes, and can reach the maximum viscosity in 2 minutes. Although ordinary powdered gellan gum is better than that without sugar, the viscosity formation effect is not very obvious. In a sucrose solution, the instant gellan gum of the present invention can be completely hydrated to reach an equilibrium viscosity in about 1 minute. The viscosity of ordinary powdered gellan gum releases slowly, and it can be completely hydrated after dispersing for 20 minutes, and basically reaches the highest viscosity.

Phenomenon: When the sugar-containing instant gellan gum is poured into the beaker, it can be dispersed in the whole solution, and the fine crystal balls visible to the naked eye dissolve in the solution, and the solution becomes thick. Although the dispersibility of sugar-containing common powder gellan gum is improved during the dissolution process, there are still "fish-eye" lumps.

Claims (9)

1. a preparation method for instant type gelling gum, is characterized in that, take gelling gum powder as starting raw material, adopts boiling granulating drying installation, is made into instant type gelling gum product, and the method comprises following operation steps:

A) gelling gum powder feeds intake: the freezing air by raw material gelling gum powder through purifying is introduced from the fluidized-bed bottom of boiling granulating drying installation, makes raw material gelling gum powder in boiling state;

B) the KCl aqueous solution is moistening: spray into the KCl aqueous solution and make the moistening and granulating of raw material gelling gum powder;

C) spray into gelling gum solution: the gelling gum solution of dilute concentration, after atomization, evenly sprays into from fluidized-bed top, in order to the raw material gelling gum powder of dressing boiling state;

D) dressing: through high-pressure spray gun atomization, the vaporific drop forming, be sprayed on the gelling gum powder in fluidized-bed, viscosity by gelling gum itself, after meeting water, collide bonding formation small-particle, in boiling granulating process, particle increases gradually, finally forms the particle of the spherical dressing of needed many micropores;

E) described particulate product is dry, to obtain instant type colloidal stroma.

2. the method for claim 1, is characterized in that, further comprising the steps of after step e):

F) by the method for sizing screen screening or the whole grain of pelletizing machine, process described particulate product to suitable globule size;

G) quality test, qualified rear packing warehouse-in.

3. the method for claim 1, is characterized in that, in step a), and 40%～80% of the boiling granulating drying plant throughput that the charging capacity of described gelling gum powder is employing.

4. the method as described in claim 1 or 3, is characterized in that, step a) in, described gelling gum powder is high acyl gellan gum, or low-acyl gellan gum.

5. the method for claim 1, is characterized in that, in step b), by after the KCl solution atomization of 0.1%～3% mass percent concentration, from fluidized-bed top, evenly sprays into spraying time 20-60 minute, atomizing pressure 0.25-0.5MPa.

6. the method for claim 1, is characterized in that, in step c), the consumption of described gelling gum solution is for dropping into 5%～30% of raw material gelling gum powder weight, and spraying time is controlled at 20～120 minutes, and atomizing pressure is 0.3MPa～0.6MPa; The concentration of described gelling gum solution is 0.05%～0.2%.

7. the method for claim 1, is characterized in that, in step e), when grain diameter reaches after processing requirement, stop spraying into solution, hot blast continues to pass into, and keep temperature 60 C～90 ℃, continue to be dried to moisture content≤13%, 20～120 minutes time of drying.

8. the method for claim 1, it is characterized in that, between step b) and step c), increasing following steps: moistening rear powder forms after particulate, and the freezing air through purifying is after steam preheating, 60～90 ℃ of hot blast temperatures, vapor pressure 0.4MPa～0.8MPa.

9. an instant type gelling gum that adopts claim 1-8 any one method to make.