阅读说明：本技术 具有速溶性能的黄原胶的制备方法 (Preparation method of xanthan gum with instant property ) 是由 乞锋辉 杨晓民 刘学珍 脱世华 靳晓伟 于 2020-06-28 设计创作，主要内容包括：本发明属于微生物发酵,特别是指一种具有速溶性能的黄原胶的制备方法。包括将黄原胶生产菌种接种至灭菌后且含有碳源、氮源及必要营养物质的培养液中培养制成含有黄原胶的发酵液,调整制成含有黄原胶的发酵液pH至酸性后高温处理,采用醇提制成黄原胶湿料；将制备的黄原胶湿料中捏合制成膏状物料,捏合过程中加入碳酸盐或碳酸氢盐调整pH；将制备的膏状物料均质、干燥、粉碎,制成具有速溶性能的黄原胶。本发明解决了现有技术存在的黄原胶溶解速度慢的问题,具有所制备的黄原胶产品溶解速度快,黏度及其它主要技术指标不低于现有产品等优点。(The invention belongs to microbial fermentation, and particularly relates to a preparation method of xanthan gum with instant property. Inoculating xanthan gum producing strain into sterilized culture solution containing carbon source, nitrogen source and necessary nutrient substances, culturing to obtain fermentation broth containing xanthan gum, adjusting pH of the fermentation broth containing xanthan gum to acidity, treating at high temperature, and extracting with ethanol to obtain xanthan gum wet material; kneading the prepared xanthan gum wet material into a paste material, and adding carbonate or bicarbonate to adjust the pH value in the kneading process; homogenizing the prepared pasty material, drying, pulverizing, and making into xanthan gum with instant property. The invention solves the problem of slow dissolving speed of the xanthan gum in the prior art, and has the advantages that the dissolving speed of the prepared xanthan gum product is high, the viscosity and other main technical indexes are not lower than those of the prior product, and the like.)

1. A process for preparing xanthan gum with instant solubility includes such steps as inoculating the strain to the culture liquid containing carbon source, nitrogen source and necessary nutrients, culturing to obtain the fermented liquid containing xanthan gum, purifying, drying and pulverizing; the method is characterized in that:

A. adjusting the pH value of the fermentation liquor containing the xanthan gum to acidity, then carrying out high-temperature treatment, and carrying out alcohol extraction to prepare a xanthan gum wet material;

B. kneading the xanthan gum wet material prepared in the step A into a pasty material, and adding carbonate or bicarbonate to adjust the pH value in the kneading process;

C. b, homogenizing, drying and crushing the paste material prepared in the step B to prepare xanthan gum with instant performance;

the xanthan gum producing strain is selected from Xanthomonas campestris Campesris, Xanthomonas campestris Campesris or Xanthomonas campestris Xanthomonas axononsis Axonopodis.

2. The method for preparing xanthan gum with instant property according to claim 1, wherein the step a is that the pH of the fermentation broth containing xanthan gum is adjusted to 3.8-4.5 by acid, then the fermentation broth is heated to 80-95 ℃, the temperature is kept for 10-30 minutes, then the fermentation broth is cooled to 60-70 ℃, alcohol solution is added and stirred until cellulose is separated out, and the xanthan gum wet material is prepared by centrifugation.

3. The method for preparing xanthan gum with instant property according to claim 2, characterized in that the adding amount of the alcoholic solution in step a is not less than 2 times of the total volume of the fermentation broth, the volume percentage concentration of the alcoholic solution is 85% -95%, and the alcoholic solution is selected from ethanol and isopropanol.

4. The method for preparing xanthan gum with instant property according to claim 1, characterized in that step B is to add the wet xanthan gum prepared in step a into a kneader, and adjust the pH of the wet xanthan gum to 6.5-7.5 with carbonate solution or bicarbonate solution with a concentration of 10% -20% by mass while stirring.

5. The method of claim 4, wherein the carbonate or bicarbonate in step B is selected from sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate.

6. The method for preparing xanthan gum with instant dissolving property as claimed in claim 1, wherein the homogenizing condition in step C is that the pasty material prepared in step B is put into a high pressure homogenizing pump for homogenizing, the homogenizing pressure is 15mPa-40mPa, and the homogenizing temperature is 40 ℃ to 50 ℃.

7. The method for preparing xanthan gum with instant property according to claim 1 or 5, wherein the drying condition in step C is boiling drying the homogenized material to water content of 20% -30%, and then microwave drying.

8. The method of preparing xanthan gum with instant dissolving property as claimed in claim 7, wherein the microwave drying condition is: the rotating speed is 400-600 revolutions per minute and the power is 5-8 watts per gram.

Technical Field

The invention belongs to microbial fermentation, and particularly relates to a preparation method of xanthan gum with instant property.

Background

Xanthan gum is high-viscosity extracellular polysaccharide with wide water solubility, which is obtained by taking Xanthomonas campestris of black rot of cabbage as a producing strain and taking starch as a main raw material through specific biological fermentation, purification, drying and crushing. The xanthan gum has excellent rheological property, good thickening property, acid and alkali resistance, pseudoplasticity and high temperature resistance due to unique molecular structure, can resist high-concentration salt, has emulsifying and suspending properties, is widely applied to industries such as food, medicine, petroleum, textile, casting and the like as a stabilizer, a thickening agent, an emulsifying agent and a suspending agent, and is a biological polysaccharide with the largest production scale and extremely wide application at present.

Xanthan gum is a natural high molecular polysaccharide, has strong hydrophilicity, and can be dissolved in cold water and hot water. Because the xanthan gum has stronger hydrophilicity, the outer layer immediately absorbs a large amount of water when the xanthan gum is added into water, the volume expands into a micelle, the mass transfer process of the water to the inner layer is delayed, and the xanthan gum is easy to form lumps and fish eyes, so that the xanthan gum can not be completely hydrated, the release of the viscosity of the xanthan gum is seriously influenced, and the large-scale application of the xanthan gum in industrial production is influenced. In order to promote dissolution of xanthan gum, it is common to dry-blend xanthan gum with sugar, salt, etc. and then dissolve the xanthan gum, or to promote dissolution of xanthan gum by a method such as raising the dissolution temperature, raising the stirring speed, and extending the soaking time.

The food additive xanthan gum (GB 1886.41-2015) was issued by the national health administration on day 9/22 of 2015, wherein structural formulas, sensory requirements, physicochemical indices (viscosity, shear performance values, etc.), microbiological indices, etc. were defined, and methods for solubility test, gel test, viscosity measurement, and shear performance value measurement were given. The above standard discloses that the dissolution method in xanthan gum viscosity measurement is performed with continuous stirring at 800r/min for 2 hours, because the dissolution rate of the existing xanthan gum is slow. The xanthan gum sample is dissolved in 2 hours, which seriously influences the viscosity detection of the xanthan gum in industrial production and the application of the xanthan gum in various industries.

The prior patent documents retrieved by the applicant include: in order to increase the dissolution rate of xanthan gum particles, the patent document of publication No. CN103074408A utilizes a method of adding a surfactant during the production process to increase the solubility of xanthan gum; in patent publication No. CN101270166A, the dispersion solubility of xanthan gum is improved by making xanthan gum into liquid xanthan gum. However, the above prior art only achieves a certain dispersion effect during the dissolution of xanthan gum, and cannot basically solve the problem of dissolution rate of xanthan gum, and for the above reasons, it is very important to research and develop xanthan gum with instant dissolution function.

Disclosure of Invention

The invention aims to provide a preparation method of xanthan gum with instant property, which adopts the technical means of alcohol extraction after high-temperature treatment of fermentation liquor, pH adjustment in the kneading process by adopting carbonate or bicarbonate, high-temperature homogenization and the like, so that the xanthan gum prepared by the invention meets the viscosity index and the thickening effect, and simultaneously greatly improves the dissolution speed.

The overall technical concept of the invention is as follows:

a process for preparing xanthan gum with instant solubility includes such steps as inoculating the strain to the culture liquid containing carbon source, nitrogen source and necessary nutrients, culturing to obtain the fermented liquid containing xanthan gum, purifying, drying and pulverizing; the method comprises the following steps:

A. adjusting the pH value of the fermentation liquor containing the xanthan gum to acidity, then carrying out high-temperature treatment, and carrying out alcohol extraction to prepare a xanthan gum wet material;

B. kneading the xanthan gum wet material prepared in the step A into a pasty material, and adding carbonate or bicarbonate to adjust the pH value in the kneading process;

C. and C, homogenizing, drying and crushing the paste material prepared in the step B to prepare the xanthan gum with instant property.

The xanthan gum producing strain is the strain available in the market or the preservation institution, and includes but is not limited to the following strains: the xanthan gum producing strain is selected from Xanthomonas campestris, Xanthomonas campestris cam Pestris of black rot of cabbage or Xanthomonas campestris Axonopodis.

The specific technical concept of the invention is as follows:

in order to change the hydrophilic characteristic of the xanthan gum, the preferable technical scheme is that the step A is to adjust the pH value of the prepared fermentation liquor containing the xanthan gum to 3.8-4.5 by acid, then heat the fermentation liquor to 80-95 ℃, keep the temperature for 10-30 minutes, then cool the fermentation liquor to 60-70 ℃, add alcohol solution and stir until fibrous matters are separated out, and centrifuge the xanthan gum wet material. Therefore, partial hydroxyl in the xanthan gum can be converted into carboxyl, and the hydrophilic property of the xanthan gum is effectively improved.

In order to effectively ensure the alcohol extraction of the active ingredients of the xanthan gum, the preferable technical implementation mode is that the adding amount of the alcohol solution in the step A is not less than 2 times of the total volume of the fermentation liquor, the volume percentage concentration of the alcohol solution is 85-95%, and the alcohol solution is ethanol or isopropanol.

In order to form a loose and porous structure in the dried xanthan gum product and facilitate the improvement of the dissolution speed of the xanthan gum product, the preferable technical implementation manner is that the wet xanthan gum prepared in the step A is added into a kneader in the step B, and the carbonate solution or bicarbonate solution with the mass percentage concentration of 10% -20% is used for adjusting the pH value of the wet xanthan gum to 6.5-7.5 while stirring. CO thus released in the neutralization reaction₂Wrapping in the kneaded pasty xanthan gum.

More preferably, the carbonate or bicarbonate in step B is selected from one of sodium carbonate, potassium carbonate, calcium carbonate, sodium bicarbonate and potassium bicarbonate.

In order to change the internal structure of the xanthan gum, the solubility of the prepared xanthan gum is further improved. The preferable technical implementation means is that the homogenizing condition in the step C is that the pasty material prepared in the step C is put into a high-pressure homogenizing pump for homogenizing, the homogenizing pressure is 15mPa-40mPa, and the homogenizing temperature is 40 ℃ to 50 ℃.

More preferably, the drying condition in the step C is boiling drying the homogenized material to a water content of 20% -30%, and then microwave drying.

More preferably, the microwave drying conditions are as follows: the rotating speed is 400-600 revolutions per minute and the power is 5-8 watts per gram.

To verify the technical effect of the present invention, the applicant conducted the following experiments:

measurement of viscosity

The preparation method is carried out by the method described in food additive xanthan gum (GB 1886.41-2015).

Second, dissolution rate test

The dissolution time was observed after complete dissolution according to the solubility test method described in food additive xanthan gum (GB 1886.41-2015).

The invention has the substantive characteristics and obvious technical progress that:

1. the pH of the fermentation liquid is adjusted to be weakly acidic, and the fermentation liquid is subjected to high-temperature treatment at the temperature of 80-95 ℃, so that partial hydroxyl in the xanthan gum is changed into carboxyl, and the hydrophilic performance of the xanthan gum is effectively improved.

2. Adjusting the pH of the xanthan gum wet mass during kneading with a carbonate or bicarbonate, the CO released₂The paste xanthan gum is wrapped in the paste xanthan gum, and loose and porous xanthan gum particles are formed by drying and crushing, so that the dissolution speed of the xanthan gum is improved.

3. The internal structure of the xanthan gum is changed by high-pressure homogenization and microwave drying, and the dissolving performance of the xanthan gum is improved.

4. Through experimental determination by an applicant, the xanthan gum prepared by the method disclosed by the invention has the viscosity of 1670-1770cp (the highest viscosity of 1770cp) according to the viscosity detection method of food safety national standard food additive xanthan gum, is free from agglomeration and fish eye formation after being dissolved in water, is high in dissolution speed, can be completely dissolved in 7 minutes to form a uniform and stable solution, is obviously superior to products prepared by the existing process, and has better industrial adaptability and application prospect.

5. The instant xanthan gum produced by the invention belongs to physical modification, does not change the chemical properties of materials, accords with the food safety law and related laws and regulations, and is suitable for use in the food industry and other industries.

Detailed Description

The present invention is further described with reference to the following examples, which are not intended to limit the scope of the present invention, and the claims are not to be interpreted as limiting the scope of the present invention.