Preparation method of high-viscosity hydroxypropyl distarch phosphate
By combining α-amylase hydrolysis and segmented etherification with phytic acid and phosphate crosslinking, the problem of insufficient stability of hydroxypropyl distarch phosphate in traditional processes was solved, and high viscosity and freeze-thaw stable hydroxypropyl distarch phosphate was prepared.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-31
- Publication Date
- 2026-03-31
AI Technical Summary
Traditional hydroxypropyl distarch phosphate production processes struggle to precisely control the diffusion and reaction of chemical reagents within starch granules, resulting in insufficient dynamic stability of the product under high shear stress, repeated freeze-thaw cycles, or extreme pH conditions, leading to decreased viscosity retention and difficulty in meeting the tolerance requirements of different application scenarios.
Starch was hydrolyzed by α-amylase, and epichlorohydrin was added dropwise in stages for etherification. Phytic acid and phosphate were used as crosslinking agents to construct a stable three-dimensional network. The uniformity of hydroxypropyl substitution and the viscosity of the product were improved by stepwise etherification and crosslinking reactions.
It improves the viscosity and freeze-thaw stability of hydroxypropyl distarch phosphate, enhancing the product's tolerance in different application scenarios.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of modified starch technology, specifically relating to a method for preparing high-viscosity hydroxypropyl distarch phosphate. Background Technology
[0002] Hydroxypropyl distarch phosphate (HPDSP), also known as hydroxypropyl distarch phosphate, is a type of starch derivative. Its solid appearance is a white powder, odorless and tasteless, readily soluble in water but insoluble in organic solvents. Its basic structure is the same as acetylated distarch phosphate, except that the hydroxyl group at the C6 position of its glucose residue forms an ether bond with the 2-hydroxypropyl group. The introduction of a hydrophilic hydroxypropyl group into the HPDSP molecule weakens the hydrogen bonding structure within the starch granules, making it easier to absorb water, swell, and gelatinize. The simultaneous introduction of hydroxypropyl ether bonds and phosphate crosslinking bonds in the structure of HPDSP gives the product the dual characteristics of hydroxypropyl starch and phosphate distarch, exhibiting good viscosity stability, shear resistance, transparency, and freeze-thaw stability. It can be used as a thickener, stabilizer, and binder, and is widely applied in non-food industries such as cosmetics, pharmaceutical excipients, papermaking, textiles, and biomaterials.
[0003] The traditional production process of hydroxypropyl distarch phosphate involves the etherification of starch or starch slurry with propylene oxide under alkaline conditions, followed by a phosphate cross-linking reaction, and then producing the finished product through a semi-dry or wet process. However, this traditional process struggles to precisely control the diffusion and reaction of chemical reagents within the starch granules. Propylene oxide reacts violently in a strongly alkaline environment, easily leading to excessive local substitution and increased side reactions, thus affecting the rheological properties of the final product. Consequently, when subjected to high shear forces, repeated freeze-thaw cycles, or extreme pH environments, the internal three-dimensional network lacks effective strength gradient support, resulting in insufficient dynamic stability. This manifests as a significant decrease in viscosity retention, making it difficult to meet the stringent material tolerance requirements of various applications. Summary of the Invention
[0004] The purpose of this invention is to provide a method for preparing high-viscosity hydroxypropyl distarch phosphate to solve the problem of poor stability of hydroxypropyl distarch phosphate.
[0005] The objective of this invention can be achieved through the following technical solutions: This invention provides a method for preparing high-viscosity hydroxypropyl distarch phosphate, comprising the following steps: Step 1, Pretreatment: Use α-amylase to enzymatically hydrolyze starch to obtain enzymatically hydrolyzed starch. Mix the starch and enzymatically hydrolyzed starch, add water and mix, then add sodium sulfate and mix well. Step 2, Etherification: At a temperature of 40℃, sodium hydroxide is added to the reaction system of step 1 to adjust the pH value to 10-11, and epichlorohydrin is added dropwise in stages to carry out the etherification reaction for 3-4 hours. Step 3, cross-linking: Add a phosphorus-containing cross-linking agent to the reaction system of step 2 to carry out the cross-linking reaction and obtain high-viscosity hydroxypropyl distarch phosphate.
[0006] Furthermore, the mass ratio of starch to enzymatically hydrolyzed starch is 7-8:2-3.
[0007] Furthermore, the mass ratio of starch to epichlorohydrin is 1g:0.3-0.4g; Epichlorohydrin was added dropwise in stages: 60-70% was added evenly over 0-30 min, and the remaining epichlorohydrin was added evenly over 30-60 min.
[0008] Furthermore, the mass ratio of starch to sodium sulfate is 1g:0.2-0.3.
[0009] Furthermore, the mass ratio of phosphorus-containing crosslinking agent to starch is 0.2-0.3:1.
[0010] Furthermore, the phosphorus-containing crosslinking agent is a mixture of phosphate, phytic acid, and salt phosphate; the phosphate is at least one of sodium trimetaphosphate and sodium hexametaphosphate; the mass ratio of phytic acid to phosphate is 1-2:3.
[0011] Furthermore, after the cross-linking reaction is completed, the pH is adjusted to 7 with hydrochloric acid to terminate the reaction. The subsequent steps include water washing, acid washing, water washing, and drying. The acid washing involves mixing citric acid and malic acid in a 2:1 mass ratio, with a total acid mass fraction of 0.2%. Adding calcium chloride introduces calcium ions, which increases the diffusion rate of phytic acid and improves reaction efficiency. Simultaneously, the introduced calcium ions can be further reduced by the combined acid washing with citric acid and malic acid, minimizing residual metal ions and preventing excessively high conductivity due to residual metal ions, which would reduce the viscosity of hydroxypropyl distarch phosphate.
[0012] Furthermore, the enzymatic hydrolysis of starch includes the following steps: Add starch to phosphate buffer and stir for 30-40 min. Then, steam sterilize at 120℃ for 10-15 min, cool to 40-60℃, add α-amylase, and hydrolyze for 10-30 min. After hydrolysis, inactivate the enzyme in a boiling water bath for 10-20 min. After washing, centrifugation, refrigeration for 1-9 days, drying by forced air, pulverizing, and sieving, the hydrolyzed starch is obtained.
[0013] Furthermore, the pH of the phosphate buffer is 6.8-7, the ratio of starch to phosphate buffer is 1g:5-10mL, and the amount of α-amylase added per 10g of starch is 80-100U.
[0014] Furthermore, the starch is one of potato starch, tapioca starch, and corn starch.
[0015] The beneficial effects of this invention are: This invention provides a method for preparing high-viscosity hydroxypropyl distarch phosphate. In this method, enzymatic pretreatment enhances the reactivity and structural diversity of starch; stepwise etherification improves the uniformity of hydroxypropyl substitution; and synergistic crosslinking of phytic acid and phosphate constructs a more stable three-dimensional network. The prepared hydroxypropyl distarch phosphate exhibits higher viscosity and freeze-thaw stability.
[0016] In the enzymatic pretreatment of this invention, α-amylase can randomly cleave the α-1,4 glycosidic bonds in starch molecules, generating low-molecular-weight dextrins, oligosaccharides, and a small amount of glucose. After enzymatic hydrolysis, the molecular weight of starch decreases, the chain length distribution narrows, and more hydroxyl groups and reducing ends are exposed, increasing the density of reactive sites. When enzymatically hydrolyzed starch is mixed with unhydrolyzed starch, the system contains both long chains providing structural support and short chains enhancing dispersibility and reactivity, which is beneficial for the uniform conduction of subsequent etherification and cross-linking reactions.
[0017] In the etherification reaction of this invention, epichlorohydrin undergoes a ring-opening reaction with the hydroxyl groups of starch under alkaline conditions, introducing hydroxypropyl groups to form hydroxypropyl starch. Stepwise addition avoids molecular aggregation or uneven substitution caused by excessively rapid local reactions, making the etherification reaction milder and more thorough. It also improves the uniformity of hydroxypropyl substitution, enhances the hydration capacity and gelatinization stability of starch, thereby improving the viscosity and freeze-thaw stability of the final product. Detailed Implementation
[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0019] Obviously, the following description is merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios without any inventive effort. Furthermore, it is understood that although the effort involved in such development may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, any changes to design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as insufficient disclosure of the content of this application.
[0020] However, there may be instances where unnecessary detailed descriptions are omitted. For example, detailed descriptions of well-known matters or repetitive descriptions of essentially the same structure may be omitted. This is to avoid making the following description unnecessarily lengthy and to facilitate understanding by those skilled in the art. Furthermore, the following description is provided to enable those skilled in the art to fully understand this application and is not intended to limit the subject matter of the claims.
[0021] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions, and all technical features and optional technical features of this application can be combined to form new technical solutions.
[0022] The following is a detailed description of a method for preparing high-viscosity hydroxypropyl distarch phosphate according to an embodiment of this application. The specific details are illustrated below with reference to the embodiments.
[0023] Example 1 This embodiment provides a method for preparing high-viscosity hydroxypropyl distarch phosphate, comprising the following steps: Step 1, Pretreatment: Starch is enzymatically hydrolyzed using α-amylase to obtain hydrolyzed starch. The starch and hydrolyzed starch are mixed in a mass ratio of 7:3. The starch and hydrolyzed starch are added to water and mixed to a mass fraction of 25%. Then sodium sulfate is added and mixed evenly, while the temperature is controlled at 0-5℃. The mass ratio of starch to sodium sulfate is 1g:0.2g. The enzymatically hydrolyzed starch is prepared through the following steps: Starch was added to phosphate buffer and stirred for 30 min. It was then steam-sterilized at 120℃ for 10 min, cooled to 40℃, and α-amylase was added for enzymatic hydrolysis for 20 min. After hydrolysis, the enzyme was inactivated by boiling water for 20 min. The starch was washed, centrifuged, and refrigerated at 4℃ for 5 days. It was then dried at 60℃ for 18 h, pulverized, and passed through an 80-mesh sieve to obtain hydrolyzed starch. The pH of the phosphate buffer was 6.8, and the ratio of starch to phosphate buffer was 1 g: 5 mL. The amount of α-amylase added per 10 g of starch was 80 U. The starch was potato starch.
[0024] Step 2, Etherification: At a temperature of 40℃, sodium hydroxide was added to the reaction system from Step 1 to adjust the pH to 11. Epichlorohydrin was added dropwise in stages, and the etherification reaction was carried out for 4 hours. The epichlorohydrin was added dropwise in stages: 65% was added uniformly from 0 to 30 minutes, and the remaining epichlorohydrin was added uniformly from 30 to 60 minutes. The mass ratio of starch to epichlorohydrin was 1g:0.3g. Step 3, Crosslinking: A phosphorus-containing crosslinking agent is added to the reaction system from step 2 to carry out a crosslinking reaction, yielding high-viscosity hydroxypropyl distarch phosphate. The phosphorus-containing crosslinking agent includes phytic acid and phosphate; the phosphate is sodium trimetaphosphate. The mass ratio of the phosphorus-containing crosslinking agent to starch is 0.2:1; the mass ratio of phytic acid to phosphate is 1:3.
[0025] The cross-linking reaction includes the following steps: phosphate is added to the reaction system of the second step and stirred at 40°C for 30 min; calcium chloride and phytic acid, accounting for 0.3% of the starch mass fraction, are added and the reaction is continued to be stirred for 25 min; after the reaction is completed, the pH is adjusted to 7 with hydrochloric acid to terminate the reaction; subsequently, the reaction is carried out in sequence by water washing, acid washing, water washing, and drying; the acid washing is carried out by mixing citric acid and malic acid at a mass ratio of 2:1, with a total acid mass fraction of 0.2%.
[0026] Example 2 This embodiment provides a method for preparing high-viscosity hydroxypropyl distarch phosphate, comprising the following steps: Step 1, Pretreatment: Starch is enzymatically hydrolyzed using α-amylase to obtain hydrolyzed starch. The starch and hydrolyzed starch are mixed at a mass ratio of 8:2. The starch and hydrolyzed starch are then added to water and mixed to a mass fraction of 25%. Sodium sulfate is then added and mixed thoroughly, maintaining the temperature at 0-5℃ throughout the process. The mass ratio of starch to sodium sulfate is 1g:0.2g. The difference between this example and Example 1 lies in the different pretreatment conditions. The enzymatically hydrolyzed starch is prepared through the following steps: Starch was added to phosphate buffer and stirred for 30 min. It was then steam-sterilized at 120℃ for 10 min, cooled to 40℃, and α-amylase was added for enzymatic hydrolysis for 20 min. After hydrolysis, the enzyme was inactivated by boiling water for 20 min. The starch was washed, centrifuged, and refrigerated at 4℃ for 5 days. It was then dried at 60℃ for 18 h, pulverized, and passed through an 80-mesh sieve to obtain hydrolyzed starch. The pH of the phosphate buffer was 6.8, and the ratio of starch to phosphate buffer was 1 g: 5 mL. The amount of α-amylase added per 10 g of starch was 80 U. The starch was potato starch.
[0027] Step 2, Etherification: At a temperature of 40℃, sodium hydroxide was added to the reaction system from Step 1 to adjust the pH to 11. Epichlorohydrin was added dropwise in stages, and the etherification reaction was carried out for 4 hours. The epichlorohydrin was added dropwise in stages: 65% was added uniformly from 0 to 30 minutes, and the remaining epichlorohydrin was added uniformly from 30 to 60 minutes. The mass ratio of starch to epichlorohydrin was 1g:0.3g. Step 3, Crosslinking: A phosphorus-containing crosslinking agent is added to the reaction system from step 2 to carry out a crosslinking reaction, yielding high-viscosity hydroxypropyl distarch phosphate. The phosphorus-containing crosslinking agent includes phytic acid and phosphate; the phosphate is sodium trimetaphosphate. The mass ratio of the phosphorus-containing crosslinking agent to starch is 0.2:1; the mass ratio of phytic acid to phosphate is 1:3.
[0028] The cross-linking reaction includes the following steps: phosphate is added to the reaction system of the second step and stirred at 40°C for 30 min; calcium chloride and phytic acid, accounting for 0.3% of the starch mass fraction, are added and the reaction is continued to be stirred for 25 min; after the reaction is completed, the pH is adjusted to 7 with hydrochloric acid to terminate the reaction; subsequently, the reaction is carried out in sequence by water washing, acid washing, water washing, and drying; the acid washing is carried out by mixing citric acid and malic acid at a mass ratio of 2:1, with a total acid mass fraction of 0.2%.
[0029] Example 3 This embodiment provides a method for preparing high-viscosity hydroxypropyl distarch phosphate, comprising the following steps: Step 1, Pretreatment: Starch is enzymatically hydrolyzed using α-amylase to obtain hydrolyzed starch. The starch and hydrolyzed starch are mixed at a mass ratio of 7:3. The starch and hydrolyzed starch are then added to water and mixed to a mass fraction of 30%. Sodium sulfate is then added and mixed thoroughly, maintaining the temperature at 0-5°C. The mass ratio of starch to sodium sulfate is 1g:0.3g. The difference between this example and Example 1 lies in the different pretreatment conditions. The enzymatically hydrolyzed starch is prepared through the following steps: Starch was added to phosphate buffer and stirred for 30 min. It was then steam-sterilized at 120℃ for 10 min, cooled to 40℃, and α-amylase was added for enzymatic hydrolysis for 20 min. After hydrolysis, the enzyme was inactivated by boiling water for 20 min. The starch was washed, centrifuged, and refrigerated at 4℃ for 5 days. It was then dried at 60℃ for 18 h, pulverized, and passed through an 80-mesh sieve to obtain hydrolyzed starch. The pH of the phosphate buffer was 6.8, and the ratio of starch to phosphate buffer was 1 g: 5 mL. The amount of α-amylase added per 10 g of starch was 80 U. The starch was potato starch.
[0030] Step 2, Etherification: At a temperature of 40℃, sodium hydroxide was added to the reaction system from Step 1 to adjust the pH to 11. Epichlorohydrin was added dropwise in stages, and the etherification reaction was carried out for 4 hours. The epichlorohydrin was added dropwise in stages: 65% was added uniformly from 0 to 30 minutes, and the remaining epichlorohydrin was added uniformly from 30 to 60 minutes. The mass ratio of starch to epichlorohydrin was 1g:0.3g. Step 3, Crosslinking: A phosphorus-containing crosslinking agent is added to the reaction system from step 2 to carry out a crosslinking reaction, yielding high-viscosity hydroxypropyl distarch phosphate. The phosphorus-containing crosslinking agent includes phytic acid and phosphate; the phosphate is sodium trimetaphosphate. The mass ratio of the phosphorus-containing crosslinking agent to starch is 0.2:1; the mass ratio of phytic acid to phosphate is 1:3.
[0031] The cross-linking reaction includes the following steps: phosphate is added to the reaction system of the second step and stirred at 40°C for 30 min; calcium chloride and phytic acid, accounting for 0.3% of the starch mass fraction, are added and the reaction is continued to be stirred for 25 min; after the reaction is completed, the pH is adjusted to 7 with hydrochloric acid to terminate the reaction; subsequently, the reaction is carried out in sequence by water washing, acid washing, water washing, and drying; the acid washing is carried out by mixing citric acid and malic acid at a mass ratio of 2:1, with a total acid mass fraction of 0.2%.
[0032] Example 4 This embodiment provides a method for preparing high-viscosity hydroxypropyl distarch phosphate. The difference between this embodiment and Example 1 lies in the different enzymatic hydrolysis conditions. Specifically, the enzymatically hydrolyzed starch is prepared through the following steps: Starch was added to phosphate buffer and stirred for 40 min. It was then steam-sterilized at 120℃ for 15 min, cooled to 60℃, and α-amylase was added. Enzymatic hydrolysis was carried out for 30 min, followed by boiling in a water bath for 20 min to inactivate the enzyme. After washing, centrifugation, and refrigeration at 4℃ for 5 days, the starch was dried at 60℃ for 18 h. The resulting product was then pulverized and passed through an 80-mesh sieve to obtain hydrolyzed starch. The pH of the phosphate buffer was 6.8, and the starch-to-phosphate buffer ratio was 1 g:5 mL. The amount of α-amylase added per 10 g of starch was 100 U. The starch was potato starch.
[0033] The remaining raw materials and preparation process are the same as in Example 1.
[0034] Example 5 This embodiment provides a method for preparing high-viscosity hydroxypropyl distarch phosphate, comprising the following steps: Step 1, Pretreatment: Starch is enzymatically hydrolyzed using α-amylase to obtain hydrolyzed starch. The starch and hydrolyzed starch are mixed at a mass ratio of 7:3. The starch and hydrolyzed starch are then added to water and mixed to a mass fraction of 25%. Sodium sulfate is then added and mixed thoroughly, with the temperature controlled at 0-5℃. The mass ratio of starch to sodium sulfate is 1g:0.2g. The hydrolyzed starch is the same as in Example 1. Step 2, Etherification: At a temperature of 40℃, sodium hydroxide was added to the reaction system from Step 1 to adjust the pH to 11. Epichlorohydrin was added dropwise in stages, and the etherification reaction was carried out for 4 hours. The epichlorohydrin was added dropwise in stages: 70% was added uniformly from 0 to 30 minutes, and the remaining epichlorohydrin was added uniformly from 30 to 60 minutes. The mass ratio of starch to epichlorohydrin was 1g:0.3g. The remaining raw materials and preparation steps are the same as in Example 1.
[0035] Example 6 This embodiment provides a method for preparing high-viscosity hydroxypropyl distarch phosphate, comprising the following steps: Step 1, Pretreatment: Starch is enzymatically hydrolyzed using α-amylase to obtain hydrolyzed starch. The starch and hydrolyzed starch are mixed at a mass ratio of 7:3. The starch and hydrolyzed starch are then added to water and mixed to a mass fraction of 25%. Sodium sulfate is then added and mixed thoroughly, with the temperature controlled at 0-5℃. The mass ratio of starch to sodium sulfate is 1g:0.2g. The hydrolyzed starch is the same as in Example 1. Step 2, etherification: Same as in Example 1; Step 3, Crosslinking: A phosphorus-containing crosslinking agent is added to the reaction system from step 2 to carry out a crosslinking reaction, yielding high-viscosity hydroxypropyl distarch phosphate. The phosphorus-containing crosslinking agent includes phytic acid and phosphate; the phosphate is sodium trimetaphosphate. The mass ratio of the phosphorus-containing crosslinking agent to starch is 0.3:1; the mass ratio of phytic acid to phosphate is 2:3.
[0036] The crosslinking reaction includes the following steps: phosphate is added to the reaction system of the second step and stirred at 40°C for 30 min; calcium chloride and phytic acid, accounting for 0.3% of the starch mass fraction, are added, and the reaction is continued to be stirred for 25 min; after the reaction is completed, the pH is adjusted to 7 with hydrochloric acid to terminate the reaction; subsequently, the reaction is carried out in sequence as water washing, acid washing, water washing, and drying; the acid washing is performed by mixing citric acid and malic acid at a mass ratio of 2:1, with a total acid mass fraction of 0.2%. The phosphorus-containing crosslinking agent in this example is different from that in Example 1.
[0037] Example 7 This embodiment provides a method for preparing high-viscosity hydroxypropyl distarch phosphate, comprising the following steps: Step 1, Pretreatment: Starch is enzymatically hydrolyzed using α-amylase to obtain hydrolyzed starch. The starch and hydrolyzed starch are mixed at a mass ratio of 7:3. The starch and hydrolyzed starch are then added to water and mixed to a mass fraction of 25%. Sodium sulfate is then added and mixed thoroughly, with the temperature controlled at 0-5℃. The mass ratio of starch to sodium sulfate is 1g:0.2g. The hydrolyzed starch is the same as in Example 1. Step 2, etherification: Same as in Example 1; Step 3, Crosslinking: A phosphorus-containing crosslinking agent is added to the reaction system from step 2 to carry out a crosslinking reaction, yielding high-viscosity hydroxypropyl distarch phosphate. The phosphorus-containing crosslinking agent is a phosphate; the phosphate is sodium trimetaphosphate. The mass ratio of the phosphorus-containing crosslinking agent to starch is 0.2:1.
[0038] The crosslinking reaction includes the following steps: phosphate is added to the reaction system in the second step and stirred at 40°C for 55 minutes. After the reaction is completed, the pH is adjusted to 7 with hydrochloric acid to terminate the reaction. The subsequent steps are water washing, acid washing, water washing, and drying. The acid washing is performed by mixing citric acid and malic acid in a mass ratio of 2:1, with a total acid mass fraction of 0.2%. In this embodiment, phytic acid was not added to the phosphorus-containing crosslinking agent.
[0039] Example 8 This embodiment provides a method for preparing high-viscosity hydroxypropyl distarch phosphate, comprising the following steps: Step 1, Pretreatment: Starch is enzymatically hydrolyzed using α-amylase to obtain hydrolyzed starch. The starch and hydrolyzed starch are mixed at a mass ratio of 7:3. The starch and hydrolyzed starch are then added to water and mixed to a mass fraction of 25%. Sodium sulfate is then added and mixed thoroughly, with the temperature controlled at 0-5℃. The mass ratio of starch to sodium sulfate is 1g:0.2g. The hydrolyzed starch is the same as in Example 1. Step 2, etherification: Same as in Example 1; Step 3, Crosslinking: A phosphorus-containing crosslinking agent is added to the reaction system from step 2 to carry out a crosslinking reaction, yielding high-viscosity hydroxypropyl distarch phosphate. The phosphorus-containing crosslinking agent includes phytic acid and phosphate; the phosphate is sodium trimetaphosphate. The mass ratio of the phosphorus-containing crosslinking agent to starch is 0.2:1; the mass ratio of phytic acid to phosphate is 1:3.
[0040] The cross-linking reaction includes the following steps: phosphate is added to the reaction system of the second step and stirred at 40°C for 30 min; calcium chloride and phytic acid, accounting for 0.3% of the starch mass fraction, are added, and the reaction is continued to be stirred for 25 min; after the reaction is completed, the pH is adjusted to 7 with hydrochloric acid to terminate the reaction; subsequently, the mixture is washed with water and dried. Acid washing was not performed in this example.
[0041] Comparative Example 1 The difference between this comparative example and Example 1 is that enzymatically hydrolyzed starch is not added. To ensure the same amount, the enzymatically hydrolyzed starch is replaced with potato starch. The other raw materials and preparation process are the same as in Example 1.
[0042] Comparative Example 2 The difference between this comparative example and Example 1 lies in the second etherification process, specifically: Step 2, Etherification: At a temperature of 40°C, sodium hydroxide was added to the reaction system from Step 1 to adjust the pH to 11, and epichlorohydrin was added to carry out the etherification reaction for 4 hours; the mass ratio of starch to epichlorohydrin was 1g:0.3g; that is, epichlorohydrin was added directly in this comparative example, which is different from the segmented addition method in Example 1; the remaining raw materials and preparation process are the same as in Example 1.
[0043] Comparative Example 3 The difference between this comparative example and comparative example 2 is that enzymatically hydrolyzed starch is not added. To ensure the same amount, the enzymatically hydrolyzed starch is replaced with potato starch. The other raw materials and preparation process are the same as those in comparative example 2.
[0044] Test case Performance tests were performed on Examples 1-8 and Comparative Examples 1-3; Viscosity test: The viscosity was measured using a viscometer.
[0045] The samples prepared in Examples 1-8 and Comparative Examples 1-3 were mixed with water to form an emulsion with a mass fraction of 6%; rotation speed: 75 r / min; torque: 700 cmg; heating (cooling) rate: 3 °C / min. Measurement procedure: Prepare 460 mL of the 6% emulsion, stir well, and transfer to a Brabender viscosity measuring cup. Start heating at 30 °C, increase the temperature to 92 °C at a rate of 3 °C / min, hold for 15 min, then cool to 55 °C at a rate of 3 °C / min and hold for 15 min. Record the peak viscosity.
[0046] Freeze-thaw stability test: Samples prepared in Examples 1-8 and Comparative Examples 1-3 were mixed with water at a ratio of 3g:60mL and gelatinized in a boiling water bath for 20 minutes, stirring constantly for the first 5 minutes to prevent caking. After complete gelatinization, the test tube was removed, cooled to room temperature, and poured into a plastic centrifuge tube with a known mass of m1. The mass was measured as m2, and the tube was frozen for 24 hours. After thawing naturally for 6 hours, one tube was centrifuged at 4000 rpm for 20 minutes, and the supernatant was discarded. This freezing-centrifugation-discarding-supernatant-liquid-returning cycle was repeated 4 times, and the mass was measured as m3. The water separation rate was calculated using the following formula: Water separation rate = Freeze-thaw stability refers to the stability of an emulsion when subjected to alternating freezing and thawing. It is expressed by the water separation rate. The higher the water separation rate, the worse the freeze-thaw stability, and vice versa.
[0047] The results are shown in Table 1: Table 1 As shown in Table 1, the hydroxypropyl distarch phosphate prepared by this invention exhibits higher peak viscosity and better freeze-thaw stability. Furthermore, comparing Examples 1 and 7, introducing phytic acid into existing crosslinking agents (phosphates) is more beneficial for improving the freeze-thaw resistance of hydroxypropyl distarch phosphate. Phytic acid is a natural polyphosphate compound containing multiple phosphate groups, which can undergo esterification reactions with multiple hydroxyl groups in starch molecules to form a three-dimensional network structure. Phosphates (such as sodium trimetaphosphate), as traditional crosslinking agents, form phosphate ester bonds with starch, enhancing the stability of the particle structure. When used in combination, phytic acid provides more crosslinking points and a more flexible crosslinking network, while phosphate strengthens local crosslinking intensity. The synergistic effect of both can construct a more uniform and stronger starch gel structure.
[0048] According to the comparison between Example 1 and Comparative Examples 1-3, it can be seen that the introduction of enzymatic hydrolysis of starch and stepwise etherification can synergistically improve the viscosity and freeze-thaw stability of hydroxypropyl distarch phosphate.
[0049] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0050] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A method for preparing high-viscosity hydroxypropyl distarch phosphate, characterized in that, Includes the following steps: Step 1, Pretreatment: Use α-amylase to enzymatically hydrolyze starch to obtain enzymatically hydrolyzed starch. Mix the starch and enzymatically hydrolyzed starch, add water and mix, then add sodium sulfate and mix well. Step 2, Etherification: At a temperature of 40℃, sodium hydroxide is added to the reaction system of step 1 to adjust the pH value to 10-11, and epichlorohydrin is added dropwise in stages to carry out the etherification reaction for 3-4 hours. Step 3, cross-linking: Add a phosphorus-containing cross-linking agent to the reaction system of step 2 to carry out the cross-linking reaction and obtain high-viscosity hydroxypropyl distarch phosphate.
2. The method for preparing high-viscosity hydroxypropyl distarch phosphate according to claim 1, characterized in that, The mass ratio of starch to enzymatically hydrolyzed starch is 7-8:2-3.
3. The method for preparing high-viscosity hydroxypropyl distarch phosphate according to claim 1, characterized in that, The mass ratio of starch to epichlorohydrin is 1g:0.3-0.4g; Epichlorohydrin was added dropwise in stages: 60-70% was added evenly over 0-30 min, and the remaining epichlorohydrin was added evenly over 30-60 min.
4. The method for preparing high-viscosity hydroxypropyl distarch phosphate according to claim 1, characterized in that, The mass ratio of starch to sodium sulfate is 1g:0.2-0.
3.
5. The method for preparing high-viscosity hydroxypropyl distarch phosphate according to claim 1, characterized in that, The mass ratio of phosphorus-containing crosslinking agent to starch is 0.2-0.3:
1.
6. The method for preparing high-viscosity hydroxypropyl distarch phosphate according to claim 5, characterized in that, The phosphorus-containing crosslinking agent is a mixture of phosphate, phytic acid and salt phosphate; the phosphate is at least one of sodium trimetaphosphate and sodium hexametaphosphate; the mass ratio of phytic acid to phosphate is 1-2:
3.
7. The method for preparing high-viscosity hydroxypropyl distarch phosphate according to claim 1, characterized in that, After the crosslinking reaction is completed, the pH is adjusted to 7 with hydrochloric acid to terminate the reaction. The subsequent steps are water washing, acid washing, water washing, and drying. The acid washing is performed by mixing citric acid and malic acid in a mass ratio of 2:1, with a total acid mass fraction of 0.2%.
8. The method for preparing high-viscosity hydroxypropyl distarch phosphate according to claim 1, characterized in that, The enzymatic hydrolysis of starch includes the following steps: Add starch to phosphate buffer and stir for 30-40 min. Then, steam sterilize at 120℃ for 10-15 min, cool to 40-60℃, add α-amylase, and hydrolyze for 10-30 min. After hydrolysis, inactivate the enzyme in a boiling water bath for 10-20 min. After washing, centrifugation, refrigeration for 1-9 days, drying by forced air, pulverizing, and sieving, the hydrolyzed starch is obtained.
9. The method for preparing high-viscosity hydroxypropyl distarch phosphate according to claim 1, characterized in that, The pH of the phosphate buffer is 6.8-7, and the ratio of starch to phosphate buffer is 1g:5-10mL; the amount of α-amylase added per 10g of starch is 80-100U.
10. A method for preparing high-viscosity hydroxypropyl distarch phosphate according to claim 1 or 8, characterized in that, The starch is one of potato starch, tapioca starch, and corn starch.