A high-fiber wheat bran powder product containing slowly digestible starch and resistant starch and preparation method thereof

Abstract

The present invention provides a high-fiber wheat bran powder product containing slowly digestible starch and resistant starch, wherein the total dietary fiber content of the high-fiber wheat bran powder product is 10wt%-50wt%, and the content of the slowly digestible starch accounts for 20wt%-40wt% of the total starch compound content in the high-fiber wheat bran powder product; the content of the resistant starch accounts for 10wt%-20wt% of the total starch content in the high-fiber wheat bran powder product; and the high-fiber wheat bran powder product does not contain an organic solvent. The present invention also provides a preparation method for the high-fiber wheat bran powder product, which uses bran and bran containing flour with low cost as raw materials, while reducing costs, can increase the dietary fiber content of the product and enrich product functionality. At the same time, the method of the present invention is produced using a pure physical method, without the use of additional raw materials such as chemical reagents and enzymes, with low cost, no waste liquid generation, and green environmental protection.

Description

Technical Field

[0001] The invention relates to a high-fiber wheat bran powder product containing slowly digestible starch and resistant starch and a preparation method thereof, and belongs to the technical field of grain production and deep processing. Background Art

[0002] In recent years, the number of diabetes patients in China has exploded. In 2016, the number of people with diabetes in China reached 110 million. What is more noteworthy is that the number of people in my country who are in the pre-diabetes stage, that is, the impaired glucose tolerance stage (postprandial blood sugar is 7.8-11.1 mol / L), has exceeded 300 million. The cause of this problem is closely related to the change in the dietary structure of the Chinese people. The WHO recommends that adults should not consume more than 25 grams of sugar per day. However, at present, the average per capita sugar intake in my country has reached 53.7g per day, which is more than twice the recommended amount. It is recommended that adults consume at least 25g of dietary fiber per day, while the average daily dietary fiber intake of Chinese residents is only 11-14g, which is only about half of the recommended amount. In addition to refined sugar, the intake of fast-digestible starch will also have a great impact on postprandial blood sugar. Starch can be divided into fast-digestible starch (starch that can be digested and absorbed in the small intestine within 20 minutes), slow-digestible starch (starch that can be completely digested and absorbed in the small intestine within 20 to 120 minutes) and resistant starch (cannot be digested and absorbed in the small intestine within 120 minutes, which has little effect on blood sugar fluctuations). In addition to controlling blood sugar, resistant starch and dietary fiber have additional health benefits. Resistant starch is not digested and enters the colon, which can serve as a nutrient source for colon flora. These microorganisms metabolize carbohydrates through fermentation to produce short-chain fats such as butyric acid. Butyric acid has the effects of promoting colon health, reducing the production of amine carcinogens, and inhibiting tumor cells. Thereby reducing the proliferation of intestinal mucosal cells and reducing the risk of colon cancer. Escherichia coli in the intestine can also synthesize pantothenic acid, niacin, riboflavin and other essential life substances for the human body, increasing the nutrients needed by the human body. Resistant starch can also reduce cholesterol content and promote bile secretion and circulation. Resistant starch can also reduce lipid absorption and fatty acid synthesis, effectively reduce the lipid content in the blood and liver, and prevent the formation of fatty liver. Appropriate consumption of dietary fiber can help gastrointestinal motility and promote food digestion and absorption. Dietary fiber is also beneficial for the excretion of feces and prevents constipation. At the same time, dietary fiber has a certain sense of fullness and is also helpful for weight control. Regular supplementation of dietary fiber can not only maintain a healthy physique, but also effectively prevent various diseases such as coronary heart disease.

[0003] Residents in modern society, especially urban residents, have increased their intake of refined rice and noodles, and the proportion of fast-digestible starch has increased, while the proportion of slow-digestible starch, resistant starch and dietary fiber intake is seriously insufficient, which is also one of the important reasons for the high incidence of energy metabolism diseases and obesity. With the transformation and upgrading of consumption, consumers have an increasingly strong demand for healthy and functional food. The development of natural and additive-free food raw materials containing resistant starch and dietary fiber that have a positive effect on blood sugar regulation is one of the important directions for deep processing of grain and oil foods.

[0004] However, in the existing flour deep processing methods, it is usually necessary to introduce chemical reagents such as alcohol during the processing, and the introduction of these chemical reagents not only does not conform to the concept of green, energy saving and environmental protection, but also increases the production cost and environmental load. In addition, although the content of chemical reagents can be reduced as much as possible in the products obtained by the existing processing methods, there will inevitably be chemical reagent residues, which is obviously very unfavorable for products eaten by consumers (including children, teenagers, etc.) as food. Furthermore, if the processing method does not use chemical reagents, there may also be problems with unbalanced content of resistant starch, slowly digestible starch and dietary fiber, making it difficult to obtain a fully functional resistant starch product. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a high-fiber wheat bran powder product containing slowly digestible starch and resistant starch and a preparation method thereof, the method selects wheat bran with a high dietary fiber content as a raw material, considering that the taste of bran without wheat flour is relatively rough and the bitter taste is serious, in order to meet the needs of different consumers, a bran part (powder-containing bran) containing appropriate wheat flour is selected as a raw material, and part of the fast-digestible starch in the wheat flour is converted into slowly digestible starch and resistant starch through high temperature and high pressure treatment, so as to obtain a high-fiber wheat bran powder product containing slowly digestible starch and resistant starch. The method of the present invention adopts bran without wheat flour and bran containing flour as raw materials with lower cost, while reducing costs, it can increase the dietary fiber content of the product and enrich the functionality of the product. At the same time, the method of the present invention uses a pure physical method for production, without the need to use additional chemical reagents, enzymes and other raw materials, with lower costs and no waste liquid generation.

[0006] Specifically, the above object of the present invention is achieved through the following aspects:

[0007] On the one hand, the present invention provides a high-fiber wheat bran powder product containing slowly digestible starch and resistant starch, characterized in that the total dietary fiber content of the high-fiber wheat bran powder product is 10wt%-50wt%, the content of the slowly digestible starch accounts for 20wt%-40wt% of the total starch compound content in the high-fiber wheat bran powder product; the content of the resistant starch accounts for 10wt%-20wt% of the total starch content in the high-fiber wheat bran powder product; and the high-fiber wheat bran powder product does not contain organic solvents.

[0008] In another aspect, the present invention provides a method for preparing a high-fiber wheat bran flour product containing slowly digestible starch and resistant starch, the method comprising the following steps:

[0009] (1) Bran raw material: bran with a flour content of 20wt%-60wt% is selected as the raw material;

[0010] (2) adding water and stirring: adding water to the bran and mixing evenly using a stirring device;

[0011] (3) Standing treatment: allowing the stirred material to stand for a predetermined period of time at room temperature to obtain a tempered material;

[0012] (4) high temperature and high pressure treatment: subjecting the quenched and tempered material to high temperature and high pressure treatment to obtain a recombinant material;

[0013] (5) Optional drying treatment: Optionally, the recombinant material is dried so that the moisture content of the dried material is controlled below 20 wt %;

[0014] (6) Cooling: cooling the recombinant material or the dried material;

[0015] (7) Crushing: crushing the cooled material to obtain a particle size D

[90] of 30-3000 μm;

[0016] Wherein, the method does not include the step of adding an organic solvent.

[0017] Beneficial Effects

[0018] (1) The product of the present invention has obvious cost advantages. The raw materials selected by the present invention are by-products or secondary products in the deep processing of flour, which are low in cost. In addition, no chemical reagents are introduced in the processing process, which is green, energy-saving and environmentally friendly.

[0019] (2) The product obtained by the present invention not only has a certain amount of resistant starch and slowly digestible starch, but also contains a certain amount of dietary fiber (10%-50%), which is more comprehensive in functionality. It not only has a certain effect on blood sugar regulation, but also can help gastrointestinal motility, promote food digestion and absorption, increase satiety and control body weight. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The technical roadmap of the preparation method of the high-fiber wheat bran powder containing resistant starch of the present invention is schematically shown.

[0021] Figure 2 The following are electron microscope photos of bran flour before (left) and after (right) treatment by the method of the present invention at 500 times magnification. Figure 2 (Left) The untreated bran powder starch granules are round, with no wrinkles on the surface and clear boundaries of the starch granules. Figure 2 (Right) In the figure, the surface of individual starch granules in the processed bran powder is wrinkled and damaged, and the larger starch granules present a cross-connected paste structure, with basically no starch granules with clear boundaries. After high temperature and high pressure treatment, the starch has been combined with fat, protein and other structures to achieve the reorganization of different substances in the material and form a combination. DETAILED DESCRIPTION

[0022] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0023] In the present invention, the terms "flour content" and "flour content" can be used interchangeably and refer to the percentage of flour (wheat flour) contained in a sample.

[0024] In the present invention, the term "flour-containing bran" refers to bran containing flour (wheat flour) which has not been completely scraped off the bran.

[0025] In the present invention, the term "room temperature" refers to 20°C to 30°C.

[0026] In some embodiments, the present invention provides a high-fiber wheat bran flour product containing slowly digestible starch and resistant starch, characterized in that the total dietary fiber content of the high-fiber wheat bran flour product is 10wt%-50wt% (for example, 15wt%-45wt%), the content of the slowly digestible starch accounts for 20wt%-40wt% (for example, 20wt%-35wt%) of the total starch compound content in the high-fiber wheat bran flour product; the content of the resistant starch accounts for 10wt%-20wt% (for example, 10wt%-19wt%) of the total starch content in the high-fiber wheat bran flour product; and the high-fiber wheat bran flour product does not contain organic solvents.

[0027] In some embodiments, the total starch content of the high-fiber wheat bran flour product is 30wt%-65wt%, such as 34wt%-65wt%.

[0028] In some embodiments, the fast-digestible starch accounts for 50 wt%-80 wt% (eg, 50 wt%-75 wt%) of the total starch compound content in the high-fiber wheat bran flour product.

[0029] In the present invention, the high-fiber wheat bran powder product does not contain an organic solvent. In some embodiments, the organic solvent includes, but is not limited to, alcohols: methanol, ethanol, isopropanol, etc.; ethers: ethyl ether, propylene oxide, etc.; esters: methyl acetate, ethyl acetate, propyl acetate, etc.

[0030] In another aspect, the present invention provides a method for preparing a high-fiber wheat bran flour product containing slowly digestible starch and resistant starch, the method comprising the following steps:

[0031] (1) Bran raw material: bran with a flour content of 20wt%-60wt% is selected as the raw material;

[0032] (2) adding water and stirring: adding water to the bran and mixing evenly using a stirring device;

[0033] (3) Standing treatment: allowing the stirred material to stand for a predetermined period of time at room temperature to obtain a tempered material;

[0034] (4) high temperature and high pressure treatment: subjecting the quenched and tempered material to high temperature and high pressure treatment to obtain a recombinant material;

[0035] (5) Optional drying treatment: Optionally, the recombinant material is dried so that the moisture content of the dried material is controlled below 20 wt %;

[0036] (6) Cooling: cooling the recombinant material or the dried material;

[0037] (7) Crushing: crushing the cooled material to obtain a particle size D

[90] of 30-3000 μm;

[0038] Wherein, the method does not include the step of adding an organic solvent.

[0039] In some embodiments, in step (1), the bran is wheat bran.

[0040] In some embodiments, in step (1), the bran includes bran without flour and bran containing flour. The method of the present invention uses bran without flour and bran containing flour with lower cost as raw materials, which can increase the dietary fiber content of the product and enrich the functionality of the product while reducing the cost.

[0041] In some embodiments, in step (1), the bran raw material includes but is not limited to the bran components ground from 1B, 2B, 3B, and 4B, wherein the bran powder content is 20wt%-60wt%, preferably 25wt%-40wt%.

[0042] In some embodiments, in step (1), the bran raw material includes but is not limited to one or more of the following: bran flakes on the sieve obtained after being processed by a 1B mill and passing through a sieve with a pore size of 1200 μm, with a powder content of 50-60wt%; bran flakes on the sieve obtained after being processed by a 2B mill and passing through a sieve with a pore size of 1000 μm, with a powder content of 40-50wt%; bran flakes on the sieve obtained after being processed by a 3B mill and passing through a sieve with a pore size of 800 μm, with a powder content of 30-40wt%; bran flakes on the sieve obtained after being processed by a 4B mill and passing through a sieve with a pore size of 600 μm, with a powder content of 20-30wt%; the bran final product after flour separation, with a powder content of 10-20wt%.

[0043] In some embodiments, in step (2), water of different qualities is added to the bran according to the difference in water content of different materials, preferably purified water for production (also called soft water for production).

[0044] In some embodiments, in step (2), the amount of water added is 0wt%-20wt%, preferably 5wt%-15wt%, relative to the total weight of the raw material, so that the moisture content of the bran material is 10wt%-40%, preferably 20wt%-30wt%.

[0045] In some embodiments, in step (2), after adding water, a stirring device (such as a mixer) is used for uniform mixing, and the mixing time is 1-10 minutes, preferably 2-5 minutes.

[0046] In some embodiments, in step (3), the uniformly stirred material is allowed to stand at room temperature for 0-60 min, preferably 20 min-50 min, so that the fiber, starch and protein in the bran raw material can fully absorb water to obtain a tempered material.

[0047] In some embodiments, in step (4), the high temperature and high pressure treatment is carried out using one of the following equipment: high static pressure equipment, such as a sterilizing pot or a sterilizing kettle; extrusion puffing equipment, such as a single-screw or twin-screw extrusion equipment; superheated steam treatment equipment, such as a boiler or a superheated steam generator, but not limited thereto.

[0048] In some embodiments, in step (4), the treatment temperature of the high temperature and high pressure treatment is 100°C-260°C, preferably 130°C-200°C, the absolute pressure is 1-60MPa, preferably 15-30Mpa, and the treatment time is 0.1-60min.

[0049] In the present invention, the final processing time varies according to the specific intensity of heating provided by different devices and the actual use method of the devices.

[0050] In some embodiments, in step (4), the high temperature and high pressure treatment is performed by high static pressure equipment, and the treatment time is 10-60 minutes, preferably 15-30 minutes; preferably, the high temperature and high pressure treatment is performed by a sterilizing pot at 121°C and 100 kPa for 15 minutes.

[0051] In some embodiments, in step (4), the high temperature and high pressure treatment is carried out by a superheated steam treatment equipment, the treatment time is 0.1-5 min, preferably 0.3-2 min, and further kept warm for 10-20 min; preferably, the high temperature and high pressure treatment is carried out by a superheated steam generator at 130°C and 2.7 MPa for 1 min, and further kept warm for 15 min.

[0052] In some embodiments, in step (4), the high temperature and high pressure treatment is carried out by extrusion equipment, and the treatment time is 0.1-10 min, preferably 0.5-3 min; preferably, the high temperature and high pressure treatment is carried out by twin-screw extrusion equipment at 60°C-140°C for 80s-100s.

[0053] In some embodiments, in step (4), the high temperature and high pressure treatment is carried out by a twin-screw extruder at three heating temperatures of 80°C / 110°C / 140°C for 100s.

[0054] In some embodiments, in step (4), the high temperature and high pressure treatment is carried out by a twin-screw extruder at three heating temperatures of 60°C / 100°C / 130°C for 80 seconds.

[0055] In some embodiments, in step (5), the drying method includes, but is not limited to, natural drying, hot air, microwave, infrared, etc., for example, hot air drying at 80°C so that the moisture content of the dried material is controlled below 20wt%, preferably 8wt%-14wt%.

[0056] In the present invention, the drying step of step (5) is adjusted depending on the process. When the high temperature and high pressure treatment in step (4) is steam treatment, the steam treatment will increase the moisture content of the material, so drying is required; and when the high temperature and high pressure treatment in step (4) is extrusion treatment, the extrusion treatment will reduce the moisture content of the material, and no drying treatment is required.

[0057] In some embodiments, in step (6), the cooling method includes but is not limited to conveyor belt cooling or air flow cooling.

[0058] In some embodiments, in step (6), the cooling time is 10-120 s, preferably 20-40 s; the material temperature is cooled to 20-50°C, preferably 30-40°C.

[0059] In some embodiments, in step (6), the cooling includes flattening the treated material to a thickness of about 1 cm at room temperature and naturally cooling it for 20 minutes.

[0060] In some embodiments, in step (6), the cooling includes placing the processed material on a conveyor belt and cooling it naturally for 2 minutes.

[0061] In some embodiments, in step (7), the pulverizing method includes but is not limited to pulverizing using a cyclone mill, a hammer mill, a disc mill, a pin mill, a ball mill, etc.

[0062] In some embodiments, in step (7), the particle size D

[90] of the pulverized material is 30-3000 μm (eg, 245 μm-1000 μm), preferably 80-600 μm.

[0063] In some embodiments, the method of the present invention comprises the steps of:

[0064] (1) Bran raw material: bran with different powder contents (flour content) is selected as the raw material, wherein the bran powder content is 20wt%-60wt%, preferably 25wt%-40wt%;

[0065] (2) Adding water and stirring: according to the difference in water content of different materials, different masses of purified water for production are added to the bran. After adding water, use a stirring device to mix evenly;

[0066] (3) Standing treatment: After stirring evenly, the raw materials are fully stood at room temperature to allow the fiber, starch, and protein of the bran raw materials to fully absorb water to obtain a tempered material;

[0067] (4) High temperature and high pressure treatment: using specific equipment to provide high temperature and high pressure treatment, after which the reconstituted material is obtained. The high temperature and high pressure treatment equipment includes but is not limited to: high static pressure equipment, such as autoclaves and sterilizers; extrusion equipment, such as single-screw and twin-screw extrusion equipment; superheated steam treatment equipment, such as boilers and superheated steam generators;

[0068] (5) Drying: The recombinant material after high temperature and high pressure treatment is optionally dried. The drying methods include but are not limited to natural sun drying, hot air, microwave, infrared, etc., so that the moisture content of the dried material is controlled below 20%;

[0069] (6) Cooling: Cooling the material using methods including but not limited to conveyor belt cooling or air flow cooling;

[0070] (7) Grinding: Grinding the cooled material, including but not limited to using a cyclone mill, hammer mill, disc mill, pin mill, ball mill, etc., wherein the particle size D

[90] of the pulverized material is 30-3000 μm, preferably 80-300 μm;

[0071] Wherein, the method does not include the step of adding an organic solvent.

[0072] The preparation method of the invention comprises the following steps: conditioning wheat bran raw materials with different powder contents, subjecting them to high temperature and high pressure treatment and crushing them, so that the total dietary fiber content of the finally obtained wheat bran powder is 10wt%-50wt%, the slowly digestible starch accounts for 20wt%-40wt% of the total starch compound content; the resistant starch content accounts for 10wt%-20wt% of the total starch content, and the high-fiber wheat bran powder product does not contain an organic solvent.

[0073] Example

[0074] The present invention is further described in detail by way of examples below. These examples are merely illustrative and should not be construed as limiting the scope of the present invention. All technical solutions and variations thereof implemented based on the above content of the present invention fall within the scope of the present invention.

[0075] In the following examples, unless otherwise specified, the % mentioned refers to wt %.

[0076] Among them, the raw materials and equipment used in the following examples are as follows: bran raw material (COFCO Haijia (Xiamen) Flour Industry Co., Ltd.); high pressure sterilizer (LDZF-30KB, Shanghai Shen'an Medical Equipment Factory); steam generator (3KW superheater, Nobel Steam Generator (Guangdong) Technology Co., Ltd.); twin-screw extruder (FT75-28D, Jinan Zhennuo Machinery Co., Ltd.).

[0077] Test Method

[0078] 1. Total dietary fiber: refer to GB 5009.88-2014 National Food Safety Standard - Determination of dietary fiber in food.

[0079] 2. Total starch compounds: refer to GB 5009.9-2016 National Food Safety Standard - Determination of starch in foods.

[0080] 3. Determination of fast digestible, slow digestible and resistant starch content:

[0081] The in vitro digestibility was determined according to the research method of Englyst et al. with appropriate modifications. 200 mg of starch sample was suspended in 15 mL of phosphate buffer (0.2 mol / L, pH 5.2), 5 glass beads were added, and the mixture was placed in a 37°C water bath for 5 min, after which 5 mL of mixed enzyme (290 U / mL of porcine pancreatic α-amylase and 50 U / mL of amyloglucosidase) was added. The mixture was shaken in a 37°C shaker (speed of 150 r / min) for a certain period of time (20 and 120 min), 0.5 mL of supernatant was taken in a 10 mL centrifuge tube, and 4.5 mL of anhydrous ethanol was added thereto. The absorbance of the sample was determined at a wavelength of 540 nm using the 3,5-dinitrosalicylic acid (DNS) colorimetric method.

[0082] The calculation formula is:

[0083] RDS(%)=(G 20 -FG)×0.9 / TS

[0084] SDS(%)=(G 120 -G 20 )×0.9 / TS

[0085] RS(%)=(TS-RDS-SDS) / TS

[0086] Where FG is the glucose content in the undigested sample, G 20 and G 120 They represent the glucose content produced after 20 min and 120 min of amylase hydrolysis reaction respectively; TS represents the total starch content in the sample; and 0.9 is the conversion factor.

[0087] Embodiment 1:

[0088] (1) Select bran flakes (powder content 50-60wt%) on the sieve (1200μm) after 1B mill as raw material.

[0089] (2) Add water and stir: Add 5% of soft water for production and use a mixer to mix evenly for 3 minutes.

[0090] (3) Standing treatment: After stirring evenly, the raw materials are allowed to stand at room temperature for 20 minutes.

[0091] (4) High temperature and high pressure treatment: The material is subjected to high temperature and high pressure treatment at 121°C (100 kPa) for 15 min in an autoclave to obtain a reconstituted material.

[0092] (5) Drying: The treated material is dried with hot air at 80°C. The moisture content of the dried material is 13.23%.

[0093] (6) Cooling: Spread the material at room temperature to a thickness of about 1 cm and cool naturally for 20 minutes.

[0094] (7) Crushing: Use a disc mill to crush the cooled material to a particle size D

[90] of 1000 μm.

[0095] Table 1 Dietary fiber and starch content of materials before and after treatment in Example 1

[0096]

[0097] Note: The total dietary fiber and total starch contents in the table are percentages of the total raw materials, and the contents of the other three starches are percentages of the total starch content.

[0098] Embodiment 2:

[0099] (1) The bran flakes (with a powder content of about 40-50 wt%) on the sieve (1000 μm) after 2B grinding are used as raw materials.

[0100] (2) Add water and stir: Add 10% of soft water for production and use a mixer to mix evenly for 1 minute.

[0101] (3) Standing treatment: After stirring evenly, the raw materials are allowed to stand at room temperature for 30 minutes.

[0102] (4) High temperature and high pressure treatment: Use superheated steam treatment (130°C, 2.7 MPa), pass hot steam through the reaction vessel for 1 min, and keep warm for 15 min.

[0103] (5) Drying: The treated material is dried with hot air at 80°C to a moisture content of 12.23%.

[0104] (6) Cooling: Spread the material at room temperature to a thickness of about 1 cm and cool naturally for 20 minutes.

[0105] (7) Crushing: Use a hammer mill to crush the cooled material to a particle size D

[90] of 523 μm.

[0106] Table 2 Dietary fiber and starch content of materials before and after treatment in Example 2

[0107]

[0108]

[0109] Note: The total dietary fiber and total starch contents in the table are percentages of the total raw materials, and the contents of the other three starches are percentages of the total starch content.

[0110] Embodiment 3:

[0111] (1) The bran flakes (with a powder content of about 30-40 wt%) on the sieve (800 μm) from the 3B mill are used as raw materials.

[0112] (2) Add water and stir: Add 20% of soft water for production and use a mixer to mix evenly for 2 minutes.

[0113] (3) Standing treatment: After stirring evenly, the raw materials are allowed to stand at room temperature for 50 minutes.

[0114] (4) High temperature and high pressure treatment: twin-screw extruder was used for extrusion treatment, the three-stage heating temperatures were 80°C / 110°C / 140°C, and the treatment time was 100s.

[0115] (5) Cooling: Place the processed material on a conveyor belt and allow it to cool naturally for 3 minutes.

[0116] (6) Crushing: Use a cyclone mill to crush the cooled material to a particle size D

[90] of 308 μm.

[0117] Table 3 Dietary fiber and starch content of materials before and after treatment in Example 3

[0118]

[0119] Note: The total dietary fiber and total starch contents in the table are percentages of the total raw materials, and the contents of the other three starches are percentages of the total starch content.

[0120] Embodiment 4:

[0121] (1) The bran flakes (with a powder content of about 20-30 wt%) on the sieve (600 μm) after being ground by 4B mill are used as raw materials.

[0122] (2) Add water and stir: Add 15% of soft water for production and use a mixer to mix evenly for 3 minutes.

[0123] (3) Standing treatment: After stirring evenly, the raw materials are allowed to stand at room temperature for 30 minutes.

[0124] (4) High temperature and high pressure treatment: twin-screw extrusion equipment is used for extrusion treatment, the three-stage heating temperatures are 60°C / 100°C / 130°C, and the treatment time is 80s.

[0125] (5) Cooling: Place the processed material on a conveyor belt and allow it to cool naturally for 2 minutes.

[0126] (6) Crushing: Use a cyclone mill to crush the cooled material to a particle size D

[90] of 247 μm.

[0127] Table 4 Dietary fiber and starch content of materials before and after treatment in Example 4

[0128]

[0129] Note: The total dietary fiber and total starch contents in the table are percentages of the total raw materials, and the contents of the other three starches are percentages of the total starch content.

[0130] The embodiments of the present invention have been described in detail above. It is obvious to those skilled in the art that many modifications and changes can be made without departing from the basic spirit of the present invention. All these changes and improvements are within the scope of protection of the present invention.

Claims

1. A method for preparing a high-fiber wheat bran powder product containing slowly digestible starch and resistant starch, the method comprising the following steps: (1) Bran raw material: The following bran was selected as raw material: bran flakes obtained by processing in a 3B mill and passing through a sieve with a pore size of 800 μm, with a powder content of 30-40 wt%; (2) Adding water and stirring: After adding water to the bran, use a stirring device to mix evenly, wherein: Relative to the total weight of the raw materials, the amount of water added was 20wt%, and the mixing time was 2min; (3) Standing treatment: The stirred material is allowed to stand at room temperature for 50 minutes to allow the fiber, starch and protein in the bran raw material to fully absorb water and obtain a tempered material; (4) High temperature and high pressure treatment: subjecting the quenched and tempered material to high temperature and high pressure treatment to obtain a reconstituted material, wherein the high temperature and high pressure treatment is performed by a twin-screw extruder at three heating temperatures of 80°C / 110°C / 140°C for 100s; (5) Cooling: placing the recombinant material on a conveyor belt to cool for 3 minutes; (6) Crushing: The cooled material is crushed using a cyclone mill. The particle size D[90] of the crushed material is 308 μm. Wherein, the method does not include the step of adding an organic solvent; Among them, the total dietary fiber content of the high-fiber wheat bran powder product is 30.7wt%, the content of the slowly digestible starch accounts for 34.9% of the total starch compound content in the high-fiber wheat bran powder product, and the content of the resistant starch accounts for 10.7wt% of the total starch content in the high-fiber wheat bran powder product; and the high-fiber wheat bran powder product does not contain organic solvents.

2. The method of claim 1, wherein: The organic solvents include alcohols, ethers and esters.

3. The method of claim 2, wherein: The alcohols include methanol, ethanol, and isopropanol; the ethers include ethyl ether; and the esters include methyl acetate, ethyl acetate, and propyl acetate.

4. A high-fiber wheat bran powder product containing slowly digestible starch and resistant starch prepared by the method according to any one of claims 1 to 3, wherein: The total dietary fiber content of the high-fiber wheat bran powder product is 30.7wt%, the content of the slowly digestible starch accounts for 34.9wt% of the total starch compound content in the high-fiber wheat bran powder product, and the content of the resistant starch accounts for 10.7wt% of the total starch content in the high-fiber wheat bran powder product; and the high-fiber wheat bran powder product does not contain organic solvents.

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