Preparation method of carboxymethyl maltodextrin

Abstract

The invention belongs to the technical field of maltodextrin preparation, and particularly relates to a preparation method of carboxymethyl maltodextrin. Comprising the following steps: (1) adding pullulanase and maltodextrin into a buffer solution, mixing, and reacting while stirring to obtain an enzymatic maltodextrin mixed solution; (2) heating the enzymatic maltodextrin mixed solution for enzyme deactivation, adding a flocculating agent, and carrying out centrifugal filtration to obtain a supernatant; (3) adding sodium hydroxide into the supernate, mixing, reacting to obtain an alkalized maltodextrin solution, and concentrating under reduced pressure to obtain a concentrated solution; (4) adding an alcohol solution of chloroacetic acid into the concentrated solution for dissolving, and after the reaction is finished, filtering to obtain sodium carboxymethyl maltodextrin; and (5) adding sodium carboxymethyl maltodextrin into glycerol, carrying out ultrasonic treatment, adding hydrochloric acid, introducing nitrogen, carrying out aeration reaction, and after the reaction is finished, filtering, cleaning and drying to obtain the carboxymethyl maltodextrin. The method is simple and feasible, reaction conditions are easy to control, reaction is efficient and stable, and the method is suitable for industrialized production.

Description

Technical Field

[0001] The invention belongs to the technical field of maltodextrin preparation, and particularly relates to a method for preparing carboxymethyl maltodextrin. Background Art

[0002] Carboxymethyl maltodextrin is a specially chemically modified maltodextrin with unique properties and a wide range of applications. Carboxymethyl maltodextrin has the following unique properties: Solubility: Due to the chemical modification, the solubility of carboxymethyl maltodextrin is usually better than that of native starch. Stability: Carboxymethyl maltodextrin exhibits good stability under a variety of environmental conditions, such as temperature, pH value, etc. Viscosity: The viscosity of carboxymethyl maltodextrin is usually higher than that of maltodextrin, depending on its degree of substitution and molecular structure. Particle shape: After modification, the particle shape and size of carboxymethyl maltodextrin change significantly, and the particles usually become smaller, rougher, and aggregate. Carboxymethyl maltodextrin has a wide range of applications in many fields, such as the food industry, as a food additive to improve the taste, stability and shelf life of food, and as a substitute for oils and fats in the processing of foods such as baking, candy, and beverages; in the pharmaceutical field, as a drug carrier, stabilizer, etc.; carboxymethyl maltodextrin can also be used in cosmetics, textiles, papermaking and other industries as a thickener, stabilizer or moisturizer.

[0003] Chinese invention patent CN107540750A discloses a method for preparing carboxymethyl maltodextrin, wherein maltodextrin is added to anhydrous ethanol, a dispersant is added, a sealed ultrasonic reaction and a static reaction are performed, and the pressure is quickly released to obtain an expanded maltodextrin alcohol solution; sodium hydroxide is added to the expanded maltodextrin alcohol solution and the solution is slightly boiled and refluxed to obtain an alkalized maltodextrin solution, and chloroacetic acid alcohol solution is slowly added dropwise and pressurized and heated to obtain sodium carboxymethyl maltodextrin; finally, sodium carboxymethyl maltodextrin is added to glycerol for ultrasonic reaction, hydrochloric acid is added, and then filtered, and ethanol is used for multiple washing and drying to obtain carboxymethyl maltodextrin. Although this method has shown certain advantages in the preparation of carboxymethyl maltodextrin, its strict requirements for reaction conditions do bring considerable challenges to actual production, and it is difficult to easily achieve precise control. In addition, the current preparation method of carboxymethyl maltodextrin is relatively scarce, which limits the wide application of maltodextrin in many fields and highlights the urgent need for more efficient preparation methods. Therefore, in order to promote the further development and application of maltodextrin, we urgently need to develop more easy-to-operate, efficient and stable methods for preparing carboxymethyl maltodextrin. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for preparing carboxymethyl maltodextrin, which is simple and feasible, has easy-to-control reaction conditions, is efficient and stable, and is suitable for factory production.

[0005] The technical solution of the present invention is as follows: The preparation method of carboxymethyl maltodextrin of the present invention comprises the following steps: (1) adding pullulanase and maltodextrin into a buffer solution, mixing, and reacting under stirring to obtain an enzyme-modified maltodextrin mixture; (2) heating the enzymatic maltodextrin mixture to inactivate the enzyme, adding a flocculant, and centrifuging to obtain a supernatant; (3) adding sodium hydroxide to the supernatant and mixing, reacting to obtain an alkaline maltodextrin solution, and concentrating under reduced pressure to obtain a concentrated solution; (4) adding chloroacetic acid in alcohol to the concentrated solution to dissolve it, and after the reaction is completed, filtering to obtain sodium carboxymethyl maltodextrin; (5) Sodium carboxymethyl maltodextrin is added to glycerol, and hydrochloric acid is added after ultrasonic treatment, and nitrogen is introduced at the same time for aeration reaction. After the reaction is completed, the mixture is filtered, washed, and dried to obtain carboxymethyl maltodextrin.

[0006] Preferably, in step (1), the mass concentration of maltodextrin is 20-30%, the amount of pullulanase added is 80-150 U / g maltodextrin, the buffer is PBS buffer, the reaction temperature is 50-65°C, the reaction pH is 4.0-6.5, and the reaction time is 1-2 h.

[0007] Preferably, in step (2), the enzyme inactivation temperature is 95-100°C, the time is 20-30 min, and the flocculant is an iron salt, preferably FeCl3.

[0008] Preferably, in step (3), the mass of sodium hydroxide is 80-90% of the mass of maltodextrin, the reaction temperature is 45-60°C, and the reaction time is 0.5-1h; the pressure of reduced pressure concentration is 50-60% of the atmospheric pressure, the temperature is 75-85°C, and the concentrated solution is 10-20% of the volume of the alkalinized maltodextrin solution.

[0009] Preferably, in step (4), the alcohol solution of chloroacetic acid is prepared by adding chloroacetic acid to anhydrous ethanol, the mass concentration of chloroacetic acid is 55-70%, the mass of chloroacetic acid is 40-70% of the mass of maltodextrin, the reaction pressure is 0.5-1.0 MPa, the reaction temperature is 80-90° C., and the reaction time is 0.5-1 h.

[0010] Preferably, in step (5), the mass concentration of sodium carboxymethyl maltodextrin is 30-40%, the ultrasonic frequency is 3-5 kHz, the volume ratio of glycerol to hydrochloric acid is 1:1-1.2, the mass concentration of hydrochloric acid is 35-38%, the flow rate of nitrogen is 20-30 mL / min, the cleaning reagent is ethanol, and the drying temperature is 75-85°C.

[0011] Compared with the prior art, the present invention has the following beneficial effects: The method of the invention is simple and feasible, the reaction conditions are easy to control, the reaction is efficient and stable, and is suitable for factory production.

[0012] (1) The present invention uses pullulanase to hydrolyze the α-1,6-glycosidic bonds in amylopectin to change the chain length and branching structure of maltodextrin. The modified maltodextrin has more active sites and is more likely to react with chloroacetic acid, which is beneficial to the carboxymethylation reaction and improves the reaction efficiency.

[0013] (2) The present invention terminates the activity of pullulanase by inactivating the enzyme by heating, thereby preventing the interference of the enzyme in the subsequent reaction. At the same time, the impurities and unreacted enzyme in the reaction system are removed by adding a flocculant and performing centrifugal filtration, thereby obtaining a pure supernatant, thereby improving the purity of the reaction system, and facilitating the smooth progress of the subsequent reaction and improving the quality of the product.

[0014] (3) The present invention adds sodium hydroxide to cause maltodextrin to undergo an alkalinization reaction, thereby improving its reaction activity; and performs reduced pressure concentration to reduce the interference of water in subsequent reactions, while saving reaction time and cost.

[0015] (4) The method of the present invention is simple and easy to operate, and the reaction conditions are easy to control. During the entire preparation process, high temperature and high pressure conditions are rarely used, thereby avoiding the destruction of the product by extreme conditions. The reaction is efficient and stable. The reaction efficiency and product quality are improved by the modification of pullulanase and the optimization of subsequent reaction steps. The product has excellent performance, and the prepared carboxymethyl maltodextrin has good stability and viscosity, and is suitable for multiple fields such as food, medicine, and cosmetics, and has broad market application prospects. DETAILED DESCRIPTION

[0016] The present invention is further described below with reference to the examples. All raw materials used in the examples are commercially available unless otherwise specified.

[0017] Example 1 The preparation method of carboxymethyl maltodextrin comprises the following steps: (1) adding pullulanase and maltodextrin into a buffer solution, mixing, and reacting under stirring to obtain an enzyme-modified maltodextrin mixture; The mass concentration of maltodextrin was 20%, the addition amount of pullulanase was 80 U / g maltodextrin, the buffer was PBS buffer, the reaction temperature was 50° C., the reaction pH value was 4.0, and the reaction time was 1 h.

[0018] (2) heating the enzymatic maltodextrin mixture to inactivate the enzyme, adding a flocculant, and centrifuging to obtain a supernatant; The enzyme inactivation temperature was 95°C, the time was 20 min, and the flocculant was FeCl3.

[0019] (3) adding sodium hydroxide to the supernatant and mixing, reacting to obtain an alkaline maltodextrin solution, and concentrating under reduced pressure to obtain a concentrated solution; The mass of sodium hydroxide is 80% of the mass of maltodextrin, the reaction temperature is 45°C, and the reaction time is 0.5h; the pressure of reduced pressure concentration is 50% of the atmospheric pressure, the temperature is 75°C, and the concentrated solution is 10% of the volume of the alkalized maltodextrin solution.

[0020] (4) adding chloroacetic acid in alcohol to the concentrated solution to dissolve it, and after the reaction is completed, filtering to obtain sodium carboxymethyl maltodextrin; The alcohol solution of chloroacetic acid is prepared by adding chloroacetic acid into anhydrous ethanol, the mass concentration of chloroacetic acid is 55%, the mass of chloroacetic acid is 40% of the mass of maltodextrin, the reaction pressure is 0.5 MPa, the reaction temperature is 80° C., and the reaction time is 0.5 h.

[0021] (5) adding sodium carboxymethyl maltodextrin to glycerol, adding hydrochloric acid after ultrasonication, and introducing nitrogen gas for aeration reaction. After the reaction is completed, filtering, washing, and drying to obtain carboxymethyl maltodextrin; The mass concentration of sodium carboxymethyl maltodextrin is 30%, the ultrasonic frequency is 3 kHz, the volume ratio of glycerol to hydrochloric acid is 1:1, the mass concentration of hydrochloric acid is 35%, the flow rate of nitrogen is 20 mL / min, the cleaning reagent is ethanol, and the drying temperature is 75°C.

[0022] Example 2 The preparation method of carboxymethyl maltodextrin comprises the following steps: (1) adding pullulanase and maltodextrin into a buffer solution, mixing, and reacting under stirring to obtain an enzyme-modified maltodextrin mixture; The mass concentration of maltodextrin is 30%, the addition amount of pullulanase is 150 U / g maltodextrin, the buffer is PBS buffer, the reaction temperature is 65° C., the reaction pH value is 6.5, and the reaction time is 2 h.

[0023] (2) heating the enzymatic maltodextrin mixture to inactivate the enzyme, adding a flocculant, and centrifuging to obtain a supernatant; The enzyme inactivation temperature was 100°C, the time was 30 min, and the flocculant was FeCl3.

[0024] (3) adding sodium hydroxide to the supernatant and mixing, reacting to obtain an alkaline maltodextrin solution, and concentrating under reduced pressure to obtain a concentrated solution; The mass of sodium hydroxide is 90% of the mass of maltodextrin, the reaction temperature is 60°C, and the reaction time is 1h; the pressure of reduced pressure concentration is 60% of the atmospheric pressure, the temperature is 85°C, and the concentrated solution is 20% of the volume of the alkalinized maltodextrin solution.

[0025] (4) adding chloroacetic acid in alcohol to the concentrated solution to dissolve it, and after the reaction is completed, filtering to obtain sodium carboxymethyl maltodextrin; The alcohol solution of chloroacetic acid is prepared by adding chloroacetic acid into anhydrous ethanol, the mass concentration of chloroacetic acid is 70%, the mass of chloroacetic acid is 70% of the mass of maltodextrin, the reaction pressure is 1.0 MPa, the reaction temperature is 90° C., and the reaction time is 1 hour.

[0026] (5) adding sodium carboxymethyl maltodextrin to glycerol, adding hydrochloric acid after ultrasonication, and introducing nitrogen gas for aeration reaction. After the reaction is completed, filtering, washing, and drying to obtain carboxymethyl maltodextrin; The mass concentration of sodium carboxymethyl maltodextrin is 40%, the ultrasonic frequency is 5 kHz, the volume ratio of glycerol to hydrochloric acid is 1:1.2, the mass concentration of hydrochloric acid is 38%, the flow rate of nitrogen is 30 mL / min, the cleaning reagent is ethanol, and the drying temperature is 85°C.

[0027] Example 3 The preparation method of carboxymethyl maltodextrin comprises the following steps: (1) adding pullulanase and maltodextrin into a buffer solution, mixing, and reacting under stirring to obtain an enzyme-modified maltodextrin mixture; The mass concentration of maltodextrin was 25%, the addition amount of pullulanase was 120 U / g maltodextrin, the buffer was PBS buffer, the reaction temperature was 60° C., the reaction pH was 5.0, and the reaction time was 1.5 h.

[0028] (2) heating the enzymatic maltodextrin mixture to inactivate the enzyme, adding a flocculant, and centrifuging to obtain a supernatant; The enzyme inactivation temperature was 95°C, the time was 25 min, and the flocculant was FeCl3.

[0029] (3) adding sodium hydroxide to the supernatant and mixing, reacting to obtain an alkaline maltodextrin solution, and concentrating under reduced pressure to obtain a concentrated solution; The mass of sodium hydroxide is 85% of the mass of maltodextrin, the reaction temperature is 55°C, and the reaction time is 1h; the pressure of reduced pressure concentration is 55% of the atmospheric pressure, the temperature is 80°C, and the concentrated solution is 15% of the volume of the alkalized maltodextrin solution.

[0030] (4) adding chloroacetic acid in alcohol to the concentrated solution to dissolve it, and after the reaction is completed, filtering to obtain sodium carboxymethyl maltodextrin; The alcohol solution of chloroacetic acid is prepared by adding chloroacetic acid into anhydrous ethanol, the mass concentration of chloroacetic acid is 60%, the mass of chloroacetic acid is 60% of the mass of maltodextrin, the reaction pressure is 1.0 MPa, the reaction temperature is 85° C., and the reaction time is 0.5 h.

[0031] (5) adding sodium carboxymethyl maltodextrin to glycerol, adding hydrochloric acid after ultrasonication, and introducing nitrogen gas for aeration reaction. After the reaction is completed, filtering, washing, and drying to obtain carboxymethyl maltodextrin; The mass concentration of sodium carboxymethyl maltodextrin is 35%, the ultrasonic frequency is 4 kHz, the volume ratio of glycerol to hydrochloric acid is 1:1.1, the mass concentration of hydrochloric acid is 35%, the flow rate of nitrogen is 25 mL / min, the cleaning reagent is ethanol, and the drying temperature is 80°C.

[0032] Comparative Example 1 Refer to Example 1, except that no reduced pressure concentration was performed.

[0033] Comparative Example 2 Refer to Example 1, except that the added amount of pullulanase is 50 U / g maltodextrin.

[0034] Comparative Example 3 Reference Example 1, except that the mass of chloroacetic acid is 20% of the mass of maltodextrin.

[0035] Comparative Example 4 Reference Example 1, except that the mass of sodium hydroxide is 50% of the mass of maltodextrin.

[0036] The carboxymethyl maltodextrin of Examples 1-3 and Comparative Examples 1-4 and the raw material maltodextrin were subjected to performance tests. The results are shown in Table 1.

[0037] Table 1 Performance comparison of carboxymethyl maltodextrin and raw material maltodextrin in Examples 1-3 and Comparative Examples 1-4

[0038] As can be seen from Table 1, the yield of carboxymethyl maltodextrin obtained by the preparation method of the present invention in Examples 1-3 is significantly higher than that in Comparative Examples 1-4. Carboxymethyl maltodextrin introduces a carboxymethyl group on the basis of maltodextrin, changes the original molecular structure, increases hydrophilicity and reactivity, further enhances its stability, and also improves viscosity. Due to the special physical and chemical properties of carboxymethyl maltodextrin, it will have a wider application prospect in the fields of food, medicine, cosmetics, etc.

Claims

1. A method for preparing carboxymethyl maltodextrin, characterized in that: The following steps are involved: (1) adding pullulanase and maltodextrin into a buffer solution, mixing, and reacting under stirring to obtain an enzyme-modified maltodextrin mixture, wherein the amount of pullulanase added is 80-150 U / g maltodextrin; (2) heating the enzymatic maltodextrin mixture to inactivate the enzyme, adding a flocculant, and centrifuging to obtain a supernatant; (3) adding sodium hydroxide to the supernatant and mixing, reacting to obtain an alkaline maltodextrin solution, and concentrating under reduced pressure to obtain a concentrated solution, wherein the mass of the sodium hydroxide is 80-90% of the mass of the maltodextrin; (4) adding chloroacetic acid in alcohol to the concentrated solution to dissolve it. After the reaction is completed, filtering is performed to obtain sodium carboxymethyl maltodextrin, wherein the mass of chloroacetic acid is 40-70% of the mass of maltodextrin. (5) Sodium carboxymethyl maltodextrin is added to glycerol, and hydrochloric acid is added after ultrasonic treatment, and nitrogen is introduced at the same time for aeration reaction. After the reaction is completed, the mixture is filtered, washed, and dried to obtain carboxymethyl maltodextrin.

2. The method for preparing carboxymethyl maltodextrin according to claim 1, characterized in that: In step (1), the mass concentration of maltodextrin is 20-30%, the reaction temperature is 50-65°C, the reaction pH is 4.0-6.5, and the reaction time is 1-2h.

3. The method for preparing carboxymethyl maltodextrin according to claim 1, characterized in that: In step (2), the enzyme inactivation temperature is 95-100°C, the time is 20-30 minutes, and the flocculant is iron salt.

4. The method for preparing carboxymethyl maltodextrin according to claim 1, characterized in that: In step (3), the reaction temperature is 45-60°C and the reaction time is 0.5-1h.

5. The method for preparing carboxymethyl maltodextrin according to claim 1, characterized in that: In step (3), the pressure of reduced pressure concentration is 50-60% of the atmospheric pressure, the temperature is 75-85° C., and the concentrated solution is 10-20% of the volume of the alkalinized maltodextrin solution.

6. The method for preparing carboxymethyl maltodextrin according to claim 1, characterized in that: In step (4), the alcohol solution of chloroacetic acid is prepared by adding chloroacetic acid into anhydrous ethanol, and the mass concentration of chloroacetic acid is 55-70%.

7. The method for preparing carboxymethyl maltodextrin according to claim 1, characterized in that: In step (4), the reaction pressure is 0.5-1.0 MPa, the reaction temperature is 80-90° C., and the reaction time is 0.5-1 h.

8. The method for preparing carboxymethyl maltodextrin according to claim 1, characterized in that: In step (5), the mass concentration of sodium carboxymethyl maltodextrin is 30-40%.

9. The method for preparing carboxymethyl maltodextrin according to claim 1, characterized in that: In step (5), the volume ratio of glycerol to hydrochloric acid is 1:1-1.2, and the mass concentration of hydrochloric acid is 35-38%.

10. The method for preparing carboxymethyl maltodextrin according to claim 1, characterized in that: In step (5), the flow rate of nitrogen is 20-30 mL / min, and the cleaning reagent is ethanol.

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