阅读说明：本技术 一种变性淀粉的制造方法 (Method for preparing modified starch ) 是由 冯亚平 王曾键 于 2020-07-06 设计创作，主要内容包括：本发明公开了一种变性淀粉的制造方法,包括如下步骤：S1、调节淀粉浆液的pH＝10-11.5,然后加入次氯酸钠水溶液或过氧化氢水溶液进行反应,然后终止反应得到中间溶液；S2、取中间溶液进行改性反应得到反应液,将反应液干燥得到变性淀粉。本发明先用次氯酸钠或过氧化氢降低淀粉浆液的粘度,然后再进行改性反应,避免了改性过程中淀粉容易糊化膨胀、粘度过高影响改性生产的问题,不需要添加硫酸钠等盐来保持淀粉的半晶体状态和抑制淀粉在反应中膨胀；操作简单,不会产生污水,避免了污染环境和污水处理造成的成本较高的问题。(The invention discloses a method for preparing modified starch, which comprises the following steps: s1, adjusting the pH value of the starch slurry to 10-11.5, adding a sodium hypochlorite aqueous solution or a hydrogen peroxide aqueous solution for reaction, and terminating the reaction to obtain an intermediate solution; and S2, taking the intermediate solution to perform modification reaction to obtain reaction liquid, and drying the reaction liquid to obtain the modified starch. According to the invention, sodium hypochlorite or hydrogen peroxide is used for reducing the viscosity of the starch slurry, and then the modification reaction is carried out, so that the problems that the starch is easy to gelatinize and expand and the viscosity is too high to influence the modification production in the modification process are avoided, and salts such as sodium sulfate and the like are not required to be added for keeping the semi-crystal state of the starch and inhibiting the expansion of the starch in the reaction; the operation is simple, no sewage is generated, and the problems of environmental pollution and high cost caused by sewage treatment are avoided.)

1. A method for producing a modified starch, comprising the steps of:

s1, adjusting the pH value of the starch slurry to 10-11.5, adding a sodium hypochlorite aqueous solution or a hydrogen peroxide aqueous solution for reaction, and terminating the reaction to obtain an intermediate solution;

and S2, taking the intermediate solution to perform modification reaction to obtain reaction liquid, and drying the reaction liquid to obtain the modified starch.

2. The method for producing a modified starch according to claim 1, wherein the reaction temperature is room temperature and the reaction time is 3 to 14 hours in S1.

3. The method for producing a modified starch according to claim 1 or 2, wherein the weight ratio of starch to sodium hypochlorite in S1 is 100: 0.3-5.

4. The method for producing a modified starch according to any one of claims 1 to 3, wherein the weight ratio of starch to hydrogen peroxide in S1 is 100:0.1 to 3.

5. The method for producing a modified starch according to any one of claims 1 to 4, wherein the mass fraction of the starch slurry in S1 is 25 to 45 wt%; preferably, in S1, the solvent of the starch slurry is water.

6. The method for producing a modified starch according to any one of claims 1 to 5, wherein the pH of the modified starch is adjusted to 10 to 11.5 with sodium hydroxide in S1.

7. The method for producing a modified starch according to any one of claims 1 to 6, wherein the reaction is terminated at S1 by adjusting the pH to neutral with sodium thiosulfate.

8. The method for producing a modified starch according to any one of claims 1 to 7, wherein the mass fraction of the aqueous sodium hypochlorite solution in S1 is 8 to 12 wt%; preferably, in S1, the mass fraction of the aqueous hydrogen peroxide solution is 1 to 5 wt%.

9. The method for producing a modified starch according to any one of claims 1 to 8, wherein in S2, the modification reaction is at least one of an acetic acid esterification reaction, a hydroxypropyl etherification reaction, a hydroxyethyl etherification reaction, and an octenyl succinate esterification reaction; preferably, in S2, the modification reaction is at least one of a hydroxypropyl etherification reaction and a hydroxyethyl etherification reaction.

10. The method for producing a modified starch according to any one of claims 1 to 9, wherein in S2, the drying method comprises: spray drying or drum drying.

Technical Field

The invention relates to the technical field of modified starch, in particular to a method for preparing modified starch.

Background

The natural starch is subjected to proper chemical treatment, and certain chemical groups are introduced to change the molecular structure and the physicochemical properties to generate the starch derivative.

In the production and manufacture of chemically modified starch, particularly when modification is carried out by esterification and etherification reactions, salts such as sodium sulfate, potassium sulfate, sodium chloride, potassium chloride and the like are often used in the reaction process to keep the semi-crystalline state of the starch and inhibit the starch from swelling in the reaction, so that the reaction can be smoothly carried out; however, a large amount of water is used for cleaning starch after reaction, sewage containing salts such as sodium sulfate, potassium sulfate, sodium chloride, potassium chloride and the like brings great pressure to the environment, sewage treatment also brings great investment to enterprises, and production cost is increased.

Disclosure of Invention

Based on the technical problems in the background art, the invention provides a method for manufacturing modified starch, which is characterized in that sodium hypochlorite or hydrogen peroxide is used for reducing the viscosity of starch slurry, then modification reaction is carried out, so that the problems that starch is easy to gelatinize and expand and the viscosity is too high to influence modification production in the modification process are solved, and salts such as sodium sulfate are not required to be added to keep the semi-crystal state of the starch and inhibit the expansion of the starch in the reaction; the operation is simple, no sewage is generated, and the problems of environmental pollution and high cost caused by sewage treatment are avoided.

The invention provides a method for preparing modified starch, which comprises the following steps:

s1, adjusting the pH value of the starch slurry to 10-11.5, adding a sodium hypochlorite aqueous solution or a hydrogen peroxide aqueous solution for reaction, and terminating the reaction to obtain an intermediate solution;

and S2, taking the intermediate solution to perform modification reaction to obtain reaction liquid, and drying the reaction liquid to obtain the modified starch.

Preferably, in S1, the reaction temperature is room temperature and the reaction time is 3-14 h.

Preferably, in S1, the weight ratio of starch to sodium hypochlorite is 100: 0.3-5.

Preferably, in S1, the weight ratio of starch to hydrogen peroxide is 100: 0.1-3.

Preferably, in S1, the mass fraction of the starch slurry is 25-45 wt%.

Preferably, in S1, the solvent of the starch slurry is water.

Preferably, in S1, the pH is adjusted to 10-11.5 with sodium hydroxide.

Preferably, in S1, the reaction is terminated by adjusting the pH to neutral with sodium thiosulfate.

Preferably, in S1, the mass fraction of the sodium hypochlorite aqueous solution is 8-12 wt%.

Preferably, in S1, the mass fraction of the aqueous hydrogen peroxide solution is 1 to 5 wt%.

Preferably, in S2, the modification reaction is at least one of an acetic acid esterification reaction, a hydroxypropyl etherification reaction, a hydroxyethyl etherification reaction, and an octenyl succinate esterification reaction.

Preferably, in S2, the modification reaction is at least one of a hydroxypropyl etherification reaction and a hydroxyethyl etherification reaction.

The methods for modifying starch by acetic esterification, hydroxypropyl etherification, hydroxyethyl etherification and octenyl succinate are conventional in the art.

Preferably, in S2, the drying method includes: spray drying or drum drying, etc.

Has the advantages that:

according to the invention, sodium hypochlorite or hydrogen peroxide is used for reducing the viscosity of the starch slurry, and then the modification reaction is carried out, so that the problems that the starch is easy to gelatinize and expand and the viscosity is too high to influence the modification production in the modification process are avoided, and salts such as sodium sulfate and the like are not required to be added for keeping the semi-crystal state of the starch and inhibiting the expansion of the starch in the reaction; the whole process does not use a large amount of water for cleaning, the reaction is directly dried, the operation is simple, the sewage cannot be generated, and the problems of environment pollution and higher cost caused by sewage treatment are solved.

Detailed Description

The technical solution of the present invention will be described in detail below with reference to specific examples.