Preparation method of soluble modified starch, soluble modified starch and application of soluble modified starch in anti-caking

Abstract

The invention discloses a preparation method of soluble modified starch, the soluble modified starch and an application of the soluble modified starch in resisting caking, the method comprises the following steps: preparing wheat starch or corn starch into starch slurry, and then carrying out acidolysis reaction to obtain wheat starch or corn starch after acidolysis; the wheat starch or the corn starch after acidolysis is prepared into starch slurry, the starch slurry is subjected to an enzymatic hydrolysis reaction to obtain an enzymatic hydrolysis solution, the enzymatic hydrolysis solution is subjected to spray drying to obtain the soluble modified starch, and the soluble modified starch can be used for resisting caking and improving the caking resistance. According to the method, the solubility of the wheat starch or the corn starch can be remarkably improved, the application range of the wheat starch or the corn starch is widened, and the method has important practical significance and economic value.

Description

Technical Field

[0001] This invention relates to the field of soluble modified starch, specifically a method for preparing soluble modified starch, soluble modified starch, and its application in anti-caking. Background Technology

[0002] Starch, as a natural and renewable polymer material, is widely used in food, chemical, and pharmaceutical fields. However, its natural structure has drawbacks such as poor water solubility and limited functional properties, restricting its application in high-end fields. Soluble modified starch, due to its good solubility and stability, can meet the needs of special applications and has become a research hotspot in the field of starch modification. Existing methods for preparing soluble modified starch involve drum drying or extrusion puffing, resulting in good solubility but high viscosity. Maltodextrin has low viscosity and good solubility, but poor anti-caking properties in food powder systems. Summary of the Invention

[0003] This invention provides a method for preparing soluble modified starch, soluble modified starch and its application in anti-caking, to solve the problem of poor anti-caking properties of starch products in food powder systems in the prior art.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for preparing soluble modified starch, the process is as follows: Natural starch paste is subjected to enzymatic hydrolysis to obtain an enzymatic hydrolysis solution, which is then spray-dried to obtain soluble modified starch.

[0005] Furthermore, the natural starch slurry is first subjected to a first enzymatic hydrolysis reaction using a branching enzyme, and then subjected to a second enzymatic hydrolysis reaction using a branching enzyme; wherein the amount of branching enzyme added in the first enzymatic hydrolysis reaction is 0.1% of the weight of the natural starch, and the amount of branching enzyme added in the second enzymatic hydrolysis reaction is 0.2% of the weight of the natural starch.

[0006] Furthermore, the first enzymatic hydrolysis reaction was carried out at a temperature of 80°C and a reaction time of 1 hour using a branching enzyme added at 0.1% of the starch weight.

[0007] Furthermore, the second enzymatic hydrolysis reaction was carried out at a temperature of 70°C and a reaction time of 20 hours, using branching enzyme added at 0.2% of the starch weight.

[0008] Furthermore, after the first enzymatic hydrolysis reaction is completed, the enzymatic hydrolysate obtained from the first enzymatic hydrolysis reaction is subjected to boiling water bath, high temperature sterilization, and cooling in sequence, and then branching enzyme with an addition amount of 0.2% of starch weight is added to carry out a second enzymatic hydrolysis reaction.

[0009] Furthermore, the boiling water bath time after the first enzymatic hydrolysis reaction is 10 minutes; the temperature for high-temperature sterilization is 121℃ and the time is 20 minutes; after sterilization, the temperature is lowered to 70℃, and then branching enzyme with an addition amount of 0.2% of the starch weight is added to carry out the second enzymatic hydrolysis reaction.

[0010] Furthermore, after the second enzymatic hydrolysis reaction is completed, the enzymatic hydrolysis solution obtained from the second enzymatic hydrolysis reaction is boiled in a water bath for 30 minutes.

[0011] Furthermore, before the enzymatic hydrolysis reaction, the natural starch paste is first subjected to an acid hydrolysis reaction to obtain an acid hydrolysis solution, and then the acid hydrolysis solution is neutralized before the enzymatic hydrolysis reaction is carried out.

[0012] A soluble modified starch prepared by the above-mentioned method for preparing soluble modified starch.

[0013] The application of soluble modified starch prepared by the above-mentioned method as an anti-caking raw material in food.

[0014] This invention discloses a mild, efficient, and environmentally friendly method for preparing soluble modified starch. Using natural starch as raw material, a slurry is prepared. The natural starch slurry is then modified by enzymatic hydrolysis with a branching enzyme, significantly increasing the branching degree of the natural starch. The resulting soluble modified starch, obtained through enzymatic hydrolysis followed by cooking, exhibits high solubility, low viscosity, large molecular weight, and small contact area. Therefore, while retaining the natural advantages of natural starch, it also possesses excellent anti-caking properties and can be used as an anti-caking ingredient in food processing to enhance anti-caking performance.

[0015] This invention saves costs, expands the application range of natural starch, increases the added value of natural starch products, and promotes environmental sustainability, thus having significant practical significance and economic value. Attached Figure Description

[0016] Figure 1 This refers to the heat flux at the glass transition temperature of different modified starch samples in the embodiments of the present invention.

[0017] Figure 2 The figure represents the water absorption rate of the sample within 12 hours in the embodiments of the present invention, wherein: Figure A is the wheat starch group, Figure B is the corn starch group, and Figure C is the dextrin group.

[0018] Figure 3 Figure A shows the water absorption rate of the samples within 7 days in the embodiments of the present invention, where: Figure A is the wheat starch group, Figure B is the corn starch group, and Figure C is the dextrin group.

[0019] Figure 4 These are iodine staining of different starch samples in the embodiments of the present invention.

[0020] Figure 5 The whiteness of different starch samples at 10% concentration under cold storage in the embodiments of the present invention is shown.

[0021] Figure 6 The whiteness of different starch samples at 30% concentration under cold storage in the embodiments of the present invention is shown.

[0022] Figure 7 These are the viscosity characteristics of different starch samples at 30% concentration in the embodiments of the present invention, wherein: Figure A is the wheat starch group, Figure B is the corn starch group, and Figure C is the dextrin group.

[0023] Figure 8 This is a diagram showing the experimental results of tomato anti-caking properties in an embodiment of the present invention. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] Example 1

[0026] This embodiment discloses a method for preparing soluble modified starch, using wheat starch or corn starch as the natural starch raw material. The method is as follows: Wheat starch or corn starch was prepared into a 10% starch slurry. Then, branching enzyme Branchzyme was added to the 10% starch slurry to perform two enzymatic hydrolysis reactions. These enzymatic hydrolysis reactions modified the acid-hydrolyzed wheat starch or corn starch by branching. The two enzymatic hydrolysis reactions are as follows: First, branching enzyme was added to a 10% starch slurry at a concentration of 0.1% of the natural starch weight. The first enzymatic hydrolysis reaction was then carried out at 80℃ for 1 hour to obtain the hydrolysate. After the first hydrolysis reaction, the hydrolysate was boiled in a water bath for 10 minutes. After boiling, it was sterilized at 121℃ for 20 minutes. After sterilization, the temperature was lowered to 70℃.

[0027] After cooling, a second enzymatic hydrolysis reaction was carried out by adding branching enzyme at a rate of 0.2% of the weight of natural starch. The second enzymatic hydrolysis reaction was carried out at 70℃ for 20 hours. After the second enzymatic hydrolysis reaction, the resulting enzymatic hydrolysate was boiled in a water bath for 30 minutes.

[0028] Finally, the enzymatic hydrolysis solution obtained from the second enzymatic hydrolysis reaction, after being boiled in a water bath, is spray-dried to obtain soluble modified starch from wheat or corn.

[0029] The soluble modified starch of wheat or corn prepared in this embodiment has a large molecular weight and small contact area, making it more suitable as a food anti-caking raw material compared to small molecule dextrin.

[0030] Example 2

[0031] This embodiment discloses a method for preparing soluble modified starch, also using wheat starch or corn starch as raw material. The process is as follows: Step 1: Prepare a starch slurry with a concentration of 40% by mixing wheat starch or corn starch.

[0032] Then, concentrated hydrochloric acid was added to a 40% starch slurry, and the acid hydrolysis reaction was carried out in a water bath at 50°C. The amount of concentrated hydrochloric acid added was 1% based on the dry starch. The reaction was terminated at 8 h and 16 h, respectively, to obtain wheat or corn acid hydrolysis solutions with reaction times of 8 h and 16 h.

[0033] Next, the acid hydrolysis solution is neutralized with sodium hydroxide solution (10%, w / w), and then the neutralized acid hydrolysis solution is washed and dried in an oven at 42°C. The dried product is ground into powder by a grinder and then the powder is passed through a 100-mesh sieve to obtain acid hydrolyzed wheat starch or corn starch.

[0034] Finally, the acid-hydrolyzed wheat starch or corn starch is made into a starch slurry with a concentration of 10%.

[0035] Step 2: Add branching enzyme Branchzyme to a 10% starch slurry to perform two enzymatic hydrolysis reactions, thereby modifying the branching of acid-hydrolyzed wheat starch or corn starch. The enzymatic hydrolysis process is the same as in Example 1.

[0036] The soluble modified starch of wheat or corn prepared in this embodiment is also suitable as a raw material for anti-caking in food.

[0037] Experimental Example 1 This experimental example 1 measured the properties of various starch samples, including the soluble modified starch prepared in Examples 1 and 2, including: glass transition temperature, hygroscopicity, amylose content, transparency at 0.5% concentration, solubility and dissolution time at 10% concentration, iodine staining, refrigerated whiteness at 10% concentration, refrigerated whiteness at 30% concentration, in vitro digestion, and viscosity. Among these: 1. When determining the glass transition temperature, take 1.0 g of starch sample in an aluminum box, dry it overnight at 60 ℃, and weigh 10 mg of starch sample into a crucible to prepare the test sample. The temperature range of the crucible is 10 ℃-130 ℃, and the heating rate is 10 ℃ / min.

[0038] 2. To determine hygroscopicity, weigh 3.0 g of starch sample and spread it evenly in a transparent petri dish, then place it in a desiccator containing water. Weigh the sample at 0 h, 2 h, 4 h, 6 h, 8 h, 10 h, 12 h, 1 d, 3 d, 5 d, and 7 d, and record the changes in sample weight.

[0039] 3. When determining the amylose content, the internal standard should be RS50 (70), AM (55), or NW (34). The method should refer to GB / T15683-2008.

[0040] 4. When determining the transparency of a 0.5% concentration, a starch sample was prepared into a 0.5% starch slurry. The slurry was heated in a boiling water bath, stirred for 15 min, cooled to 25 °C, and shaken well. The transmittance of the starch paste was then measured at a wavelength of 650 nm using a spectrophotometer.

[0041] 5. When determining the solubility and dissolution time of a 10% concentration, prepare a 10% starch slurry from a starch sample, add it to a rotor, and stir at 1000 r / min until the starch granules are completely dissolved. Record the dissolution time. Dissolution time parameter settings: 20℃, Type B rotor (8 Stir mechanically at 1000 r / min (25 mm). Take 10 mL of the sample solution and heat in a 95 ℃ water bath for 20 min, then centrifuge at 3214 xg for 15 min. Pour the supernatant into a clean aluminum box and dry in an oven at 105 ℃ for 24 h until constant weight is achieved. Solubility (%) = (dry basis of soluble matter in supernatant / dry basis of starch) × 100%.

[0042] 6. When determining the iodine staining, take 10 mL of fully dissolved 10% starch sample solution into a transparent glass sample bottle, add iodine reagent (2% KI - 0.2% I) until the color does not change, and take a picture to record the color of each sample.

[0043] 7. When determining the whiteness of a 10% concentration refrigerated sample, prepare a 10% starch milk from the starch sample. Store it in a 4 ℃ refrigerator, and take photos to record the changes in sample whiteness at 0h, 4h, 8h, 1d, 3d, 5d, and 7d.

[0044] 8. When determining the whiteness of a 30% concentration refrigerated sample, prepare a 30% starch milk from the starch sample. Store it in a 4 ℃ refrigerator, and take photos to record the changes in sample whiteness at 0h, 4h, 8h, 1d, 3d, 5d, and 7d.

[0045] 9. For in vitro digestion assays, mix starch sample (0.1 g, db) with sodium acetate buffer (0.1 M, pH 5.2) in a 50 mL polypropylene centrifuge tube and boil in a water bath for 2 min. The buffer contains amylase (0.775 U) and porcine pancreatic amylase (430.9 U). Incubate the mixture in a 37°C water bath with shaking at 140 rpm. Samples of the digested product are taken at 0 min, 20 min, and 120 min, and glucose analysis is performed using a D-glucose assay kit.

[0046] 10. When determining viscosity, prepare a 20% starch slurry from the starch sample. Heat the starch suspension to 50°C within 1 minute and maintain it at 50°C for 15 minutes, then measure the viscosity of the sample.

[0047] The names of the samples included in the experiment are shown in Table 1, as follows: Table 1. Starch Sample Nomenclature Table

[0048] The branched modified wheat starch WS-BE and branched modified corn starch CS-BE in Table 1 are the soluble modified starches prepared in Example 1. The branched modified acid-hydrolyzed wheat starch WS-AH-8h-BE and WS-AH-16h-BE, and the branched modified acid-hydrolyzed corn starch CS-AH-8h-BE and CS-AH-16h-BE in Table 1 are the soluble modified starches prepared in Example 2. The difference is that WS-AH-8h-BE is obtained by acid hydrolysis of wheat starch for 8 hours in step 1, WS-AH-16h-BE is obtained by acid hydrolysis of wheat starch for 16 hours in step 1, CS-AH-8h-BE is obtained by acid hydrolysis of corn starch for 8 hours in step 1, and CS-AH-16h-BE is obtained by acid hydrolysis of corn starch for 16 hours in step 1.

[0049] Figure 1 Table 2 shows the glass transition temperatures of all experimental samples. Compared with the un-acid-hydrolyzed soluble modified starch samples, the glass transition temperature of the acid-hydrolyzed wheat soluble modified starch samples increased with increasing acid hydrolysis time, while the glass transition temperature of the corn soluble modified starch group was the opposite, but both were higher than those of the un-acid-hydrolyzed soluble modified starch samples. Table 2 is as follows: Table 2 Glass transition temperatures of different modified starch samples

[0050] Figure 2 and Figure 3 The water absorption rates of all experimental samples within 12 hours and 7 days are shown. Compared with the untreated group, the water absorption rates of all modified starch samples increased. However, dextrin, due to its small molecular weight, is more easily exposed to water absorption than the high molecular weight soluble modified starch obtained in the embodiments of this invention.

[0051] Table 3 shows the amylose content of all soluble modified starch samples. The amylose content of the acid-hydrolyzed soluble modified starch samples was higher than that of the unhydrolyzed group, as shown in Table 3 below: Table 3. Amylose content of different modified starch samples

[0052] Table 4 shows the transparency of all modified starch samples. The transparency of the wheat soluble modified starch group decreased with increasing acid hydrolysis time, while the transparency of the corn soluble modified starch group increased significantly with increasing acid hydrolysis time. Table 4 is as follows: Table 4. Transparency of different modified starch samples

[0053] Table 5 shows the solubility and dissolution time of all experimental samples at a 10% concentration. Compared with the unmodified starch samples, all modified starch samples showed good solubility, as shown in Table 5 below: Table 5. Solubility and dissolution time of different modified starch samples at 10% concentration

[0054] Figure 4 The results of iodine staining at a 10% concentration are shown for all modified starch samples. All modified starch samples exhibit the red or purplish-red color characteristic of amylopectin. The red or purplish-red color of the acid-hydrolyzed starch samples is deeper than that of the unhydrolyzed group.

[0055] Figure 5 and Figure 6 The changes in whiteness of all modified samples and dextrin samples after 7 days of storage at 4°C at 10% and 30% concentrations are shown. In the 10% concentration group, the wheat starch sample showed stratification after 1 day of storage, which gradually subsided with increasing acid hydrolysis time; the whiteness of other samples showed no significant change. In the 30% concentration group, all modified starch samples were uniform and stable white gel-like solids with no significant change in whiteness. In the dextrin group, the GLUCIDEX 2 sample was a pale yellow liquid, and the MD10 sample became turbid after 1 day of storage, showing obvious stratification after 3 days.

[0056] Table 6 shows the digestibility characteristics of all experimental samples. Compared with the untreated group, the SDS or RS content of the wheat / corn starch branched modified samples increased, as shown in Table 6 below: Table 6. Digestion characteristics of different modified starch samples

[0057] Figure 7 Table 7 shows the viscosity characteristics of all modified samples. Compared with the un-acid-hydrolyzed group, the viscosity of the acid-hydrolyzed wheat soluble modified starch group increased, while the viscosity of the corn soluble modified starch group decreased with increasing acid hydrolysis time, as shown in Table 7 below: Table 7. Experimental conclusions on viscosity characteristics of different modified starch samples.

[0058] Conclusions of the property determination experiment The soluble modified starch preparation method of this embodiment improves the branching degree of wheat / corn starch by performing branching modification treatment. While improving the physicochemical properties of wheat / corn starch, it retains its natural advantages, saves costs, expands the application range, increases product added value, and promotes environmental sustainability.

[0059] Experiment Example 2 The following experiment on the moisture resistance of tomato powder illustrates the solubility of the soluble modified starch prepared by the methods described in Examples 1 and 2.

[0060] 1. Experimental Materials Formula 1: By weight percentage, tomato powder 18%, maltodextrin (MD10) 27%, white sugar 20%, salt 10%, monosodium glutamate 10%, fructose 5%, citric acid 3%, malic acid 1%, corn starch 5%, silicon dioxide 1%.

[0061] Formula 2: By weight percentage, tomato powder 18%, maltodextrin (MD15) 27%, white sugar 20%, salt 10%, monosodium glutamate 10%, fructose 5%, citric acid 3%, malic acid 1%, corn starch 5%, silicon dioxide 1%.

[0062] Formula 3: By weight percentage, tomato powder 18%, soluble modified starch prepared in Example 1 or Example 2 27%, white sugar 20%, salt 10%, monosodium glutamate 10%, fructose 5%, citric acid 3%, malic acid 1%, corn starch 5%, and silicon dioxide 1%.

[0063] Formula 4: By weight percentage, tomato powder 18%, reconstituted rice flour 27%, white sugar 20%, salt 10%, MSG 10%, fructose 5%, citric acid 3%, malic acid 1%, corn starch 5%, silicon dioxide 1%.

[0064] 2. Experimental Methods Weighing raw materials: Use an electronic balance to accurately weigh each raw material (total weight 300 g) according to each formula to ensure that the amount of each raw material meets the formula requirements.

[0065] Mixing stage: Place all the ingredients for each formula into a clean container and mix them initially to ensure that the components are evenly distributed.

[0066] Packaging stage: Divide the mixture of each formula into three parallel groups and place them into prepared sealed bags. Compact them with a heavy object and leave them at room temperature, observing periodically for clumping.

[0067] 3. Conclusions of the Tomato Powder Moisture Resistance Experiment from Figure 8It can be observed that the degree of clumping, from smallest to largest, is: Formula 3 < Formula 1 < Formula 2 < Formula 4. Furthermore, the degree of clumping in all samples slightly increases with prolonged storage time. Except for Formula 3, which contains tomato powder with added soluble modified starch, the tomato powder in the other three formulas shows a slight darkening in color, indicating that the samples in Formulas 1, 2, and 4 absorbed a large amount of moisture during storage.

[0068] Therefore, the soluble modified starch prepared in Example 1 or Example 2 has the best moisture resistance, followed by maltodextrin (MD10), then maltodextrin (MD15), and the powder made from recombinant rice has the most severe clumping and the weakest moisture resistance.

[0069] As can be seen from Experiment 1 and Experiment 2, the soluble modified starch prepared in Examples 1 and 2 of this invention not only has good edible value, but also good anti-caking ability, and therefore can be used as a food anti-caking material.

[0070] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. These embodiments are merely descriptions of preferred embodiments and are not intended to limit the scope or concept of the invention. The specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. Such combinations, as long as they do not violate the spirit of the present invention, should also be considered as part of this disclosure. To avoid unnecessary repetition, the present invention will not further describe the various possible combinations.

[0071] This invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this invention and without departing from the design idea of ​​this invention, all modifications and improvements made by those skilled in the art to the technical solutions of this invention should fall within the protection scope of this invention. The technical content for which protection is sought in this invention has been fully described in the claims.

Claims

1. A method for preparing soluble modified starch, characterized in that, The process is as follows: Natural starch paste is subjected to enzymatic hydrolysis to obtain an enzymatic hydrolysis solution, which is then spray-dried to obtain soluble modified starch.

2. The method for preparing soluble modified starch according to claim 1, characterized in that, First, the natural starch paste is subjected to a first enzymatic hydrolysis reaction using a branching enzyme, and then a second enzymatic hydrolysis reaction is carried out using a branching enzyme. The amount of branching enzyme added in the first enzymatic hydrolysis reaction is 0.1% of the weight of the natural starch, and the amount of branching enzyme added in the second enzymatic hydrolysis reaction is 0.2% of the weight of the natural starch.

3. The method for preparing soluble modified starch according to claim 2, characterized in that, The first enzymatic hydrolysis reaction was carried out at a temperature of 80°C and a reaction time of 1 hour, using branching enzyme added at 0.1% of the starch weight.

4. The method for preparing soluble modified starch according to claim 2, characterized in that, The second enzymatic hydrolysis reaction was carried out at a temperature of 70°C for 20 hours, using branching enzyme added at 0.2% of the starch weight.

5. The method for preparing soluble modified starch according to claim 2, characterized in that, After the first enzymatic hydrolysis reaction is completed, the enzymatic hydrolysate obtained from the first enzymatic hydrolysis reaction is subjected to boiling water bath, high temperature sterilization, and cooling in sequence, and then branching enzyme with an addition amount of 0.2% of starch weight is added to carry out the second enzymatic hydrolysis reaction.

6. The method for preparing soluble modified starch according to claim 5, characterized in that, After the first enzymatic hydrolysis reaction, the boiling water bath time is 10 minutes; the high temperature sterilization time is 121℃ and the time is 20 minutes; after sterilization, the temperature is lowered to 70℃, and then branching enzyme with an addition amount of 0.2% of starch weight is added to carry out the second enzymatic hydrolysis reaction.

7. The method for preparing soluble modified starch according to claim 5, characterized in that, After the second enzymatic hydrolysis reaction is completed, the enzymatic hydrolysis solution obtained from the second enzymatic hydrolysis reaction is boiled in a water bath for 30 minutes.

8. The method for preparing soluble modified starch according to any one of claims 1-7, characterized in that, Before the enzymatic hydrolysis reaction, the natural starch paste is first subjected to an acid hydrolysis reaction to obtain an acid hydrolysis solution. Then, the acid hydrolysis solution is neutralized before the enzymatic hydrolysis reaction is carried out.

9. A soluble modified starch prepared by the method for preparing soluble modified starch as described in any one of claims 1-8.

10. The application of soluble modified starch prepared by the method for preparing soluble modified starch as described in any one of claims 1-8 as an anti-caking raw material in food.

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