A preparation method and application of low-density resistant dextrin

Abstract

The present application relates to the field of resistant dextrin preparation, and in particular to a preparation method of low-density resistant dextrin and its application. The preparation method of low-density resistant dextrin mainly includes the steps of acidification, alcohol spraying, water dissolution, enzymolysis and saccharification. The low-density resistant dextrin prepared in the present application has excellent granularity, water solubility and transparency, and the overall preparation method has the advantages of less material loss, high preparation efficiency, less dust and high safety. In addition, a large amount of starch residue is effectively avoided during the reaction process, and there is no problem of difficult decolorization. Through the reasonable design of the process, the yield and purity of low-density resistant dextrin are greatly improved, and it has a very excellent market prospect.

Description

Technical Field

[0001] The present application relates to the field of resistant dextrin preparation, and in particular to a preparation method of low-density resistant dextrin and its application. Background Art

[0002] In recent years, with the improvement of people's living standards, various nutrition and health problems have emerged one after another, including obesity, diabetes and cardiovascular diseases, so people have begun to favor low-calorie, high-nutrition health foods and functional foods. Among them, dietary fiber has attracted much attention because dietary fiber will not be degraded by enzymes in the human digestive tract and has beneficial effects such as improving intestinal flora, regulating blood sugar and lowering blood lipids. At the same time, the World Health Organization (WHO) recommends that adults consume an average of 25 grams of dietary fiber per day.

[0003] Resistant dextrin is a non-viscous dietary fiber that cannot be digested in the small intestine, but is fermented by colonic bacteria in the colon, thereby increasing the production of short-chain fatty acids, and is therefore beneficial to the human body. Fermentation of resistant dextrin in the colon has many benefits, such as controlling weight, lowering blood sugar, reducing triglycerides, and regulating appetite. Resistant dextrin has a bland taste and non-sticky texture, and has good development potential in health foods and beverages.

[0004] The acid-heat method is a traditional method for preparing resistant dextrins. This method mainly uses organic acid or inorganic acid as a catalyst. Through high-temperature heating, the main chain of macromolecular starch is broken and decomposed to generate pyrodextrin. Then, after a series of operations, liquefaction enzyme and saccharification enzyme are added in sequence for enzymolysis. Finally, after refining, resistant dextrins are prepared. However, the acid-heat method has many side reactions and is a random transformation mechanism. It is difficult to control the polymerization of the product. In addition, after high-temperature pyrolysis, the obtained pyrodextrin has a low whiteness. After liquefaction and saccharification, the light transmittance of the liquid is poor. The refining process uses a lot of carbon, resulting in large losses and high costs. In addition, the final product is difficult to refine and has a strong bitter taste.

[0005] Therefore, in order to effectively solve the above problems, a method for preparing low-density resistant dextrin is provided in the present application. The low-density resistant dextrin prepared in the present application has excellent granularity, water solubility and transparency, and the overall preparation method has the advantages of less material loss, high preparation efficiency, less dust and high safety. In addition, a large amount of starch residue is effectively avoided during the reaction process, and there is no problem of difficult decolorization. Through the reasonable design of the process, the yield and purity of low-density resistant dextrin are greatly improved, and it has a very excellent market prospect. Summary of the invention

[0006] In order to solve the above problems, the first aspect of the present application provides a preparation method of low-density resistant dextrin, and the preparation method comprises the following steps: S1: adding an acid treatment agent to a starch material, mixing and reacting for 3 to 6 hours, and then drying to a moisture content of ≤3wt%, and then spraying an alcoholizing agent on the starch material, shaking evenly, to obtain a pretreated starch material; S2: subjecting the pretreated starch material to a high-temperature heating treatment to obtain gelatinized starch; S3: cooling the gelatinized starch to room temperature, adding purified water for stirring and washing, removing alcohol and filtering to obtain a crude product; S4: adding deionized water to the crude product; In the step of step 1, a crude solution is prepared and an auxiliary agent is added, the pH value of the crude solution is adjusted to 5.5-6.5, amylase is added, the temperature is raised to 80-100°C and kept warm for 20-30 minutes, then the temperature is cooled to 50-65°C, the pH value is adjusted to 4-4.5, saccharifying enzyme is added, the enzymatic reaction is kept warm for 20-22 hours, the pH value is adjusted to 5.5-6, transaminase is added, the enzymatic hydrolysis is carried out for 6-8 hours, and then the enzyme is inactivated by boiling water; S5: the material after the enzyme inactivation treatment is decolorized and nanofiltered, and finally the low-density resistant dextrin is obtained after ventilation drying at 180-200°C.

[0007] As a preferred solution, the starch material is at least one of carboxymethyl starch, corn amylose, corn amylopectin, and cross-linked starch.

[0008] As a preferred solution, the starch material is a composition of carboxymethyl starch, corn amylose and corn amylopectin.

[0009] As a preferred solution, the mass ratio of the carboxymethyl starch, corn amylose and corn amylopectin is (2-3): (4-5): (0.5-1.5).

[0010] As a preferred solution, the mass ratio of the carboxymethyl starch, corn amylose and corn amylopectin is (2-2.5): (4.5-5): (0.8-1).

[0011] In the present application, the starch combination used above can greatly improve the preparation efficiency of low-density resistant dextrin, and can also effectively reduce the loss of materials, reduce dust, and ultimately improve the preparation product and purity of low-density resistant dextrin. This is mainly because, by adopting the compounding of the above-mentioned starches, carboxymethyl starch and amylopectin can form a bridging structure entangled with the long spiral structure of amylopectin in the starch material system, and the formation of this structure can form a stable colloidal network in the crude solution. The existence of this network can greatly limit the migration speed of starch molecules in the solution and the collision frequency between molecules, thereby forming a stable sol system, avoiding a large amount of precipitation of materials and stratification and precipitation in the subsequent reaction process, thereby improving the overall preparation purity and yield of the product.

[0012] As a preferred solution, the acid treatment agent is at least one of hydrochloric acid, carbonic acid and phosphoric acid.

[0013] As a preferred solution, the amount of the acid treatment agent added is 5-10% of the dry weight of the starch material.

[0014] As a preferred solution, the amount of the acid treatment agent added is 6-8% of the dry weight of the starch material.

[0015] As a preferred solution, the concentration of the acid treatment agent is 0.01-0.02 g / mL.

[0016] As a preferred solution, the alcoholizing agent is anhydrous ethanol.

[0017] As a preferred solution, the amount of the alcoholizing agent added is 20-25% of the dry weight of the starch material.

[0018] As a preferred solution, the temperature of the high temperature heating treatment in S2 is 120-160°C.

[0019] As a preferred solution, the temperature of the high temperature heating treatment in S2 is 130-155°C.

[0020] As a preferred solution, the high temperature heating treatment time in S2 is 40 to 80 minutes.

[0021] As a preferred solution, the time of the high temperature heating treatment in S2 is 55 to 70 minutes.

[0022] As a preferred solution, the concentration of the crude product solution is 20-40 wt%.

[0023] As a preferred solution, the concentration of the crude product solution is 32-38 wt %.

[0024] As a preferred solution, the amount of the auxiliary agent added is 1 to 5 wt % of the crude product solution.

[0025] As a preferred solution, the amount of the auxiliary agent added is 2-3.5 wt % of the crude product solution.

[0026] As a preferred solution, the auxiliary agent is at least one of cocamidopropyl betaine, fatty acid glyceride, polysorbate, sorbitan ester, sodium stearate, sodium lauryl sulfate, and lecithin.

[0027] As a preferred solution, the auxiliary agent is a combination of cocamidopropyl betaine, sodium stearate and sorbitan ester.

[0028] As a preferred solution, the mass ratio of cocamidopropyl betaine, sodium stearate and sorbitol ester is (2-3): (0.5-1.5): (3-4).

[0029] As a preferred solution, the mass ratio of cocamidopropyl betaine, sodium stearate and sorbitol ester is 2.5:1:3.5.

[0030] In the present application, the preparation yield and purity of low-density resistant dextrin can be greatly improved by the selection combination of the above-mentioned auxiliary agents, and the residual phenomenon of a large amount of starch is avoided, and subsequent decolorization is promoted. This is mainly because, the composite joint action of the above-mentioned auxiliary agents can enhance its dispersion effect for starch particles in solution, and contribute to the suitable aggregation of starch particles, and then form a stable sol system, but at the same time, because the overall reaction preparation process presents an acidic environment, it is easy to occur the mutual neutralization of cocamidopropyl betaine and sodium stearate, and the appropriate addition of sorbitol ester can not only promote the generation of sol system, but also can further form a protective liquid phase around betaine, so as to avoid the excessive mutual contact of sodium stearate molecules and betaine molecules in the system, and then stabilize the overall reaction system.

[0031] As a preferred embodiment, the amylase is α-amylase.

[0032] As a preferred solution, the added amount of the α-amylase is 0.03-0.05% of the dry weight of the crude product.

[0033] As a preferred solution, the added amount of the α-amylase is 0.035-0.04% of the dry weight of the crude product.

[0034] As a preferred solution, the added amount of the saccharifying enzyme is 0.05-0.08% of the dry weight of the crude product.

[0035] As a preferred solution, the added amount of the saccharifying enzyme is 0.055-0.065% of the dry weight of the crude product.

[0036] As a preferred solution, the amount of transglycosidase added is 0.025-0.035% of the dry weight of the crude product.

[0037] As a preferred solution, the specific decolorization operation in S4 is: feeding the material after enzyme inactivation treatment to an activated carbon particle column, with a feed concentration of 50-55wt%, a decolorization temperature of 80-100°C, and a feeding speed of 200-250mL / h.

[0038] As a preferred solution, the sugar concentration of the material after nanofiltration treatment is 0.5-0.55 g / 100 mL.

[0039] As a preferred solution, the density of the low-density resistant dextrin is 0.04-0.045 g / cm 3 .

[0040] The second aspect of the present application provides an application of the preparation method of the above-mentioned low-density resistant dextrin, including the application of the low-density resistant dextrin prepared by the preparation method in food addition.

[0041] Beneficial effects:

[0042] 1. A method for preparing low-density resistant dextrin provided in the present application, wherein the prepared low-density resistant dextrin has excellent particle size, water solubility and transparency, and the overall preparation method has the advantages of less material loss, high preparation efficiency, less dust and high safety, and effectively avoids a large amount of starch residue during the reaction process, and there is no problem of difficult decolorization. Through the reasonable design of the process, the yield and purity of low-density resistant dextrin are greatly improved, and it has a very excellent market prospect.

[0043] 2. A method for preparing low-density resistant dextrin provided in the present application can greatly improve the preparation efficiency of low-density resistant dextrin by adopting a starch combination, while also being able to effectively reduce material loss and dust, thereby ultimately improving the preparation product and purity of low-density resistant dextrin; carboxymethyl starch and amylopectin can form a bridging structure entangled with the long spiral structure of amylopectin in the starch material system, and the formation of this structure can form a stable colloidal network in the crude solution. The presence of this network can greatly limit the migration speed of starch molecules in the solution and the collision frequency between molecules, thereby forming a stable sol system, avoiding a large amount of material precipitation and stratification in the subsequent reaction process, thereby improving the overall preparation purity and yield of the product.

[0044] 3. A method for preparing low-density resistant dextrin provided in the present application can greatly improve the preparation yield and purity of low-density resistant dextrin through the selection and combination of auxiliary agents, avoid the residual phenomenon of a large amount of starch, and promote subsequent decolorization; the compounding of the auxiliary agents and their combined action can enhance the dispersion effect of starch particles in the solution, and help the appropriate aggregation of starch particles, thereby forming a stable sol system, but at the same time, because the overall reaction preparation process presents an acidic environment, mutual neutralization of cocamidopropyl betaine and sodium stearate is prone to occur, and the appropriate addition of sorbitol esters can not only promote the formation of the sol system, but also can further form a protective liquid phase around betaine, thereby avoiding excessive mutual contact between sodium stearate molecules and betaine molecules in the system, thereby stabilizing the overall reaction system.

[0045] 4. The preparation method of a low-density resistant dextrin provided in the present application has a simple operation method, simple steps, no complicated chemical reactions and obvious corrosion to equipment, can effectively control equipment maintenance and labor costs during large-scale production, and has excellent market application prospects. DETAILED DESCRIPTION

[0046] The following will further explain and demonstrate the technical solutions in the above invention content of this application in the form of specific implementation schemes. The following embodiments are only practical examples used to illustrate and explain the contents of the technical solutions in the specification, and should not limit the scope of the claims to be protected by this application. All technical products based on the technical solutions described in the invention content of this application should be included in the scope to be protected by this application.

[0047] In the following examples, unless otherwise specified, the raw materials are all commercially available products, or can be prepared by methods well known to those skilled in the art.

[0048] Example 1

[0049] Example 1 The first aspect provides a preparation method of low-density resistant dextrin, which comprises the following steps: S1: adding an acid treatment agent to a starch material, mixing and reacting for 5 hours, and then drying to a moisture content of ≤3wt%, and then spraying an alcoholizing agent on the starch material, shaking evenly, to obtain a pretreated starch material; S2: subjecting the pretreated starch material to a high-temperature heating treatment to obtain gelatinized starch; S3: cooling the gelatinized starch to room temperature and adding purified water for stirring and washing, removing alcohol and filtering to obtain a crude product; S4: adding the crude product to deionized water to prepare a crude solution and adding an auxiliary agent, adjusting the pH of the crude solution to 6, adding amylase, heating to 90°C and keeping warm for 25 minutes, then cooling to 60°C, adjusting the pH to 4.4, adding saccharifying enzyme, keeping warm for enzymatic reaction for 20 hours, adjusting the pH to 6, adding transaminase, enzymolysis for 6 hours, and then boiling water inactivating enzyme treatment; S5: decolorizing and nanofiltration the material after the inactivating enzyme treatment, and finally drying it at 200°C under ventilation to obtain low-density resistant dextrin.

[0050] The starch material is a composition of carboxymethyl starch, corn amylose and corn amylopectin; the mass ratio of the carboxymethyl starch, corn amylose and corn amylopectin is 2.2:4.8:1.

[0051] Carboxymethyl starch was purchased from the corresponding starch product sold by Jinan Yuncheng Biotechnology Co., Ltd.

[0052] Corn amylose and corn amylopectin were purchased from the corresponding starch products sold by Wuhan Huaxiang Kejie Biotechnology Co., Ltd.

[0053] The added amount of the acid treatment agent is 6.5% of the dry weight of the starch material; the acid treatment agent is hydrochloric acid; and the concentration of the acid treatment agent is 0.01 g / mL.

[0054] The alcoholizing agent is anhydrous ethanol; the amount of the alcoholizing agent added is 25% of the dry weight of the starch material.

[0055] The temperature of the high temperature heating treatment in S2 is 145° C., and the time of the high temperature heating treatment is 65 min.

[0056] The concentration of the crude product solution is 35 wt %; the amount of the additive added is 2.5 wt % of the crude product solution.

[0057] The auxiliary agent is a composition of cocamidopropyl betaine, sodium stearate and sorbitol ester; the mass ratio of cocamidopropyl betaine, sodium stearate and sorbitol ester is 2.5:1:3.5.

[0058] The amylase was α-amylase, and the amount added was 0.04% of the dry weight of the crude product.

[0059] The amount of saccharifying enzyme added was 0.055% of the dry weight of the crude product.

[0060] The amount of transaminase added was 0.03% of the dry weight of the crude product.

[0061] The specific decolorization operation in S4 is: feeding the material after enzyme inactivation treatment to the activated carbon particle column, the feed concentration is 50wt%, the decolorization temperature is 90°C, and the feeding speed is 250mL / h.

[0062] The sugar concentration of the material after nanofiltration treatment in S4 is 0.52 g / 100 mL.

[0063] Example 2

[0064] Example 2 The first aspect provides a preparation method of low-density resistant dextrin, which comprises the following steps: S1: adding an acid treatment agent to a starch material, mixing and reacting for 5 hours, and then drying to a moisture content of ≤3wt%, and then spraying an alcoholizing agent on the starch material, shaking evenly, to obtain a pretreated starch material; S2: subjecting the pretreated starch material to a high-temperature heating treatment to obtain gelatinized starch; S3: cooling the gelatinized starch to room temperature and adding purified water for stirring and washing, removing alcohol and filtering to obtain a crude product; S4: adding the crude product to deionized water to prepare a crude solution and adding an auxiliary agent, adjusting the pH of the crude solution to 6.2, adding amylase, heating to 95°C and keeping warm for 30 minutes, then cooling to 60°C, adjusting the pH to 4.2, adding saccharifying enzyme, keeping warm for enzymatic reaction for 22 hours, adjusting the pH to 6, adding transaminase, enzymolysis for 6 hours, and then inactivating the enzyme with boiling water; S5: decolorizing and nanofiltration the material after the enzyme inactivation treatment, and finally drying it at 190°C through ventilation to obtain low-density resistant dextrin.

[0065] The starch material is a composition of carboxymethyl starch, corn amylose and corn amylopectin; the mass ratio of the carboxymethyl starch, corn amylose and corn amylopectin is 2.5:4.5:0.8.

[0066] Carboxymethyl starch was purchased from the corresponding starch product sold by Jinan Yuncheng Biotechnology Co., Ltd.

[0067] Corn amylose and corn amylopectin were purchased from the corresponding starch products sold by Wuhan Huaxiang Kejie Biotechnology Co., Ltd.

[0068] The added amount of the acid treatment agent is 6% of the dry weight of the starch material; the acid treatment agent is hydrochloric acid; and the concentration of the acid treatment agent is 0.01 g / mL.

[0069] The alcoholizing agent is anhydrous ethanol; the amount of the alcoholizing agent added is 22% of the dry weight of the starch material.

[0070] The temperature of the high temperature heating treatment in S2 is 145° C., and the time of the high temperature heating treatment is 65 min.

[0071] The concentration of the crude product solution is 35 wt %; the amount of the additive added is 2.5 wt % of the crude product solution.

[0072] The auxiliary agent is a composition of cocamidopropyl betaine, sodium stearate and sorbitol ester; the mass ratio of cocamidopropyl betaine, sodium stearate and sorbitol ester is 2.5:1:3.5.

[0073] The amylase was α-amylase, and the amount added was 0.04% of the dry weight of the crude product.

[0074] The amount of saccharifying enzyme added was 0.055% of the dry weight of the crude product.

[0075] The amount of transaminase added was 0.03% of the dry weight of the crude product.

[0076] The specific decolorization operation in S4 is: feeding the material after enzyme inactivation treatment to the activated carbon particle column, the feed concentration is 50wt%, the decolorization temperature is 90°C, and the feeding speed is 220mL / h.

[0077] The sugar concentration of the material after nanofiltration treatment in S4 is 0.49 g / 100 mL.

[0078] Example 3

[0079] Example 3 The first aspect provides a preparation method of low-density resistant dextrin, which comprises the following steps: S1: adding an acid treatment agent to a starch material, mixing and reacting for 5 hours, and then drying to a moisture content of ≤3wt%, and then spraying an alcoholizing agent on the starch material, shaking evenly, to obtain a pretreated starch material; S2: subjecting the pretreated starch material to a high-temperature heating treatment to obtain gelatinized starch; S3: cooling the gelatinized starch to room temperature and adding purified water for stirring and washing, removing alcohol and filtering to obtain a crude product; S4: adding the crude product to deionized water to prepare a crude solution and adding an auxiliary agent, adjusting the pH of the crude solution to 6, adding amylase, heating to 90°C and keeping warm for 25 minutes, then cooling to 60°C, adjusting the pH to 4.4, adding saccharifying enzyme, keeping warm for enzymatic reaction for 20 hours, adjusting the pH to 6, adding transaminase, enzymolysis for 6 hours, and then inactivating the enzyme with boiling water; S5: decolorizing and nanofiltration the material after the enzyme inactivation treatment, and finally drying it at 200°C under ventilation to obtain low-density resistant dextrin.

[0080] The starch material is a composition of carboxymethyl starch, corn amylose and corn amylopectin; the mass ratio of the carboxymethyl starch, corn amylose and corn amylopectin is 2.2:4.8:1.

[0081] Carboxymethyl starch was purchased from the corresponding starch product sold by Jinan Yuncheng Biotechnology Co., Ltd.

[0082] Corn amylose and corn amylopectin were purchased from the corresponding starch products sold by Wuhan Huaxiang Kejie Biotechnology Co., Ltd.

[0083] The added amount of the acid treatment agent is 6.5% of the dry weight of the starch material; the acid treatment agent is hydrochloric acid; and the concentration of the acid treatment agent is 0.01 g / mL.

[0084] The alcoholizing agent is anhydrous ethanol; the amount of the alcoholizing agent added is 25% of the dry weight of the starch material.

[0085] The temperature of the high temperature heating treatment in S2 is 145° C., and the time of the high temperature heating treatment is 65 min.

[0086] The concentration of the crude product solution is 35 wt %; the amount of the additive added is 2.5 wt % of the crude product solution.

[0087] The auxiliary agent is a composition of cocamidopropyl betaine, sodium stearate and sorbitol ester; the mass ratio of cocamidopropyl betaine, sodium stearate and sorbitol ester is 3:0.8:3.2.

[0088] The amylase was α-amylase, and the amount added was 0.04% of the dry weight of the crude product.

[0089] The amount of saccharifying enzyme added was 0.055% of the dry weight of the crude product.

[0090] The amount of transaminase added was 0.03% of the dry weight of the crude product.

[0091] The specific decolorization operation in S4 is: feeding the material after enzyme inactivation treatment to the activated carbon particle column, the feed concentration is 50wt%, the decolorization temperature is 90°C, and the feeding speed is 250mL / h.

[0092] The sugar concentration of the material after nanofiltration treatment in S4 is 0.50 g / 100 mL.

[0093] Comparative Example 1

[0094] The specific implementation of this comparative example is basically the same as that of Example 1, except that the mass ratio of cocamidopropyl betaine, sodium stearate and sorbitol ester is 4:1:0.5.

[0095] Comparative Example 2

[0096] The specific implementation of this comparative example is basically the same as that of Example 1, except that the mass ratio of cocamidopropyl betaine, sodium stearate and sorbitol ester is 1:3:2.

[0097] Comparative Example 3

[0098] The specific implementation of this comparative example is basically the same as that of Example 1, except that the mass ratio of carboxymethyl starch, corn amylose and corn amylopectin is 0.5:5.5:0.1.

[0099] Comparative Example 4

[0100] The specific implementation of this comparative example is basically the same as that of Example 1, except that the mass ratio of carboxymethyl starch, corn amylose and corn amylopectin is 5:0.5:1.5.

[0101] Comparative Example 5

[0102] The specific implementation of this comparative example is basically the same as that of Example 1, except that the starch material is carboxymethyl starch and amylopectin, and the mass ratio of the two is 1:1.

[0103] Comparative Example 6

[0104] The specific implementation of this comparative example is basically the same as that of Example 1, except that the auxiliary agent is a composition of fatty acid glyceride, sodium stearate and lecithin, with a mass ratio of 2.5:1:3.5.

[0105] Comparative Example 7

[0106] The specific implementation of this comparative example is basically the same as that of Example 1, except that the starch material is a composition of carboxymethyl starch, corn amylose and cross-linked starch, with a mass ratio of 2.2:4.8:1.

[0107] Performance Evaluation

[0108] Density of resistant dextrin: Low-density resistant dextrin was prepared by the methods of the embodiments and comparative examples, and the final product was subjected to a density test. The resistant dextrin sample was weighed and the gram weight was recorded. The sample was placed in a volumetric bottle that had been dried and weighed in advance, and distilled water was injected to fully dissolve the resistant dextrin. After dissolution, the excess solution was drained to the scale line to ensure that the solution just filled the specified volume. Density = (total mass after the sample solution was filled - container mass) / standard volume. The average value of 10 measured results was recorded in Table 1.

[0109] Product purity: Low-density resistant dextrin was prepared by the method of the embodiment and the comparative example, and the purity of the final product was tested by high performance liquid chromatography. The average value of 10 measured results was recorded in Table 1.

[0110] Transmittance: The low-density resistant dextrin was prepared by the method of the embodiment and the comparative example, and the transmittance of the resistant dextrin was tested according to the method disclosed in the TGDL1-2019 standard. The average value of 10 measured results was recorded in Table 1.

[0111] Table 1

[0112]

[0113]

[0114] From the examples and comparative examples of the present application and the data results in Table 1, it can be seen that the resistant dextrin prepared by Examples 1 to 3 by adopting the necessary technical solutions defined in the present application can achieve excellent results in terms of low density, light transmittance and product purity. This is mainly because the compounding of specific starches and the addition of specific compounding aids in the present application help the reaction system to form a more stable sol-network system, which enhances the reaction efficiency while avoiding excessive particle aggregation and over-reaction. Comparative Examples 1 to 7, because they do not adopt the necessary technical solutions, are significantly worse than Examples 1 to 3 in the corresponding performance tests, which further proves the importance of the technical solutions defined in the present application for their technical effects.

Claims

1. A method for preparing low-density resistant dextrin, characterized in that: The preparation method comprises the following steps: S1: adding an acid treatment agent to a starch material, mixing and reacting the material for 3 to 6 hours, and then drying the material to a moisture content of ≤3wt%, and then spraying an alcoholizing agent on the starch material, and evenly shaking the material to obtain a pretreated starch material; S2: subjecting the pretreated starch material to a high-temperature heating treatment to obtain gelatinized starch; S3: cooling the gelatinized starch to room temperature, adding purified water, stirring and washing the gelatinized starch, removing alcohol, and filtering to obtain a crude product; S4: adding the crude product to deionized water to prepare a crude product solution, and adding an auxiliary agent, adjusting The pH of the crude solution is adjusted to 5.5-6.5, amylase is added, the temperature is raised to 80-100°C and kept for 20-30 minutes, then cooled to 50-65°C, the pH is adjusted to 4-4.5, saccharifying enzyme is added, the enzymatic reaction is kept for 20-22 hours, the pH is adjusted to 5.5-6, transaminase is added, the enzymatic hydrolysis is carried out for 6-8 hours, and then the enzyme is inactivated by boiling water; S5: the material after the enzyme inactivation treatment is decolorized and nanofiltered, and finally the low-density resistant dextrin is obtained after ventilation drying at 180-200°C; The acid treatment agent is at least one of hydrochloric acid and phosphoric acid; The amount of the acid treatment agent added is 5-10% of the dry weight of the starch material; The concentration of the acid treatment agent is 0.01-0.02 g / mL; The alcoholizing agent is anhydrous ethanol; The amount of the alcoholizing agent added is 20-25% of the dry weight of the starch material; The temperature of the high temperature heating treatment in S2 is 120-160° C.; the time of the high temperature heating treatment in S2 is 40-80 minutes; The concentration of the crude product solution is 20-40wt%; The starch material is a composition of carboxymethyl starch, corn amylose and corn amylopectin; the mass ratio of the carboxymethyl starch, corn amylose and corn amylopectin is (2-3): (4-5): (0.5-1.5); The auxiliary agent is a composition of cocamidopropyl betaine, sodium stearate and sorbitol ester; The mass ratio of the cocamidopropyl betaine, sodium stearate and sorbitol ester is (2-3): (0.5-1.5): (3-4).

2. The method for preparing low-density resistant dextrin according to claim 1, characterized in that: The amount of the acid treatment agent added is 6-8% of the dry weight of the starch material.

3. The method for preparing low-density resistant dextrin according to claim 1, characterized in that: The temperature of the high temperature heating treatment in S2 is 130-155°C.

4. The method for preparing low-density resistant dextrin according to claim 1, characterized in that: The time of the high temperature heating treatment in S2 is 40 to 80 minutes.

5. An application of the method for preparing low-density resistant dextrin according to any one of claims 1 to 4, characterized in that: The invention comprises application of the low-density resistant dextrin prepared by the preparation method in food addition.

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