A method for preparing a wheat flour having a digestion resistance function

Abstract

The application discloses a kind of wheat flour preparation method with anti-digestion function;Including the following steps: high-temperature-resistant alpha-amylase, papain and saccharifying enzyme are used to enzymolysis to young leaf of highland barley, the product after enzymolysis is carried out first solid-liquid separation, residue is collected, residue is added to xylanase and cellulase, cooling to room temperature is carried out second solid-liquid separation, ethanol is precipitated in liquid polysaccharide, precipitate is redissolved, dialysis, rotary evaporation concentration after vacuum freeze-drying is obtained polysaccharide;Polysaccharide is dissolved in water to obtain uniform polysaccharide solution, polysaccharide solution is added to wheat flour, stirring is uniformly obtained mixed system, mixed system is heated gelatinization, room temperature cooling, freeze-drying is obtained finished product.The wheat flour prepared based on polysaccharide obtained from enzyme extraction residue can be used to prepare various noodles, such as noodles, bread, steamed buns and the like, which has anti-digestion function, and is an ideal low GI noodle raw material.

Description

Technical Field

[0001] This invention relates to the field of food processing, and more specifically, to a method for preparing wheat flour with anti-digestive properties. Background Technology

[0002] Wheat (Triticum aestivum L.) is one of the most widely cultivated grasses in the world, and along with rice and corn, it is known as one of the "three major grains." It is used as a staple food in many countries and holds an absolute dominant position in food supply. my country is currently the world's largest wheat producer, with approximately 70% of its wheat processed into flour annually. Wheat flour is the main product of the wheat processing industry. Wheat grains consist mainly of three parts from the outside in: bran, endosperm, and germ. The chemical composition and nutrient content of each part differ. The endosperm is the main component of the wheat grain, primarily composed of starch and protein. Typical refining processes remove the aleurone layer and bran to improve the texture and processing properties of the flour, which is then used to make staple foods such as steamed buns and noodles, as well as baked goods such as bread and biscuits. However, when refined flour is digested and absorbed in the human intestines, its glucose content spikes, disrupting the body's blood balance and potentially leading to a series of complications such as diabetes, obesity, and related health issues.

[0003] Starch, comprising approximately 70%-75% of flour, is a primary source of energy for humans and plays a crucial role not only in the quality of wheat flour and its products but also significantly impacts human health. The digestibility of starch is closely related to the body's glycemic response. Englyst has proposed three types of starch based on their bioavailability: rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS). Foods rich in SDS and RS can reduce postprandial glycemic load and maintain stable blood sugar levels. Therefore, developing wheat flour rich in SDS and RS not only significantly enhances the value of wheat flour but also holds great importance for the development of functional foods and the further advancement of the flour processing industry.

[0004] Barley grass, the seedlings of barley when they reach a height of 20-30cm, is a food with both medicinal and culinary uses, recorded in Chinese pharmacopoeias such as *Puji Fang* and *Compendium of Materia Medica*. Barley, also known as naked barley, is a type of barley. Research data shows that young barley leaves have effects such as fat reduction, cancer inhibition, and antioxidant properties. However, there are no reports of using the polysaccharides in young barley leaves to reduce the digestion rate of wheat flour, thus giving it anti-digestive properties and preventing or reducing the risk of obesity, diabetes, and some cardiovascular diseases. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing wheat flour with anti-digestion function. This invention, for the first time, utilizes a combined method of xylanase and cellulase to extract soluble polysaccharides from the residue of young barley leaves. These polysaccharides are mainly composed of arabinoxylan and pectin polysaccharides rich in rhamnose-galacturonic acid polysaccharide type I (RG-I). Among these, arabinoxylan is a branched polymer, and RG-I is also highly branched. In the flour system, the complex entanglement between arabinoxylan and the RG-I-rich pectin polysaccharide forms a network structure, and the gluten proteins in the wheat flour also interact with the polysaccharides, simultaneously encapsulating starch granules, blocking the direct contact between amylase and starch, significantly delaying the starch hydrolysis rate, and synergistically inhibiting starch digestion. Since starch needs to be converted into glucose and enter the bloodstream through the action of amylase, the complexation of this polysaccharide with wheat flour hinders the enzyme's attack on the starch in the wheat flour, reducing the starch digestion rate and thus lowering blood glucose levels.

[0006] The objective of this invention is achieved through the following solution:

[0007] This invention provides a method for preparing wheat flour with anti-digestive function, the method comprising the following steps:

[0008] S1. The young leaves of highland barley are enzymatically hydrolyzed with heat-resistant α-amylase, papain and saccharifying enzyme. After solid-liquid separation, the residue is collected. The residue is mixed with water, and xylanase and cellulase are added for enzymatic hydrolysis. After solid-liquid separation, the polysaccharide in the solution is precipitated with ethanol. The precipitate is redissolved, dialyzed, concentrated by rotary evaporation, and then freeze-dried under vacuum to obtain the polysaccharide.

[0009] S2. Dissolve the polysaccharide in water to obtain a polysaccharide solution. Add wheat flour to the polysaccharide solution and stir to obtain a mixed system. Heat the mixed system to gelatinize it, cool it at room temperature, and freeze-dry it to obtain the finished product.

[0010] In one embodiment of the present invention, in step S1, the young barley leaves are mixed with water at a solid-liquid ratio of 1:30-40.

[0011] In one embodiment of the present invention, in step S1, heat-resistant α-amylase is added at a ratio of 200-250 U / g to barley young leaves, and then incubated in a water bath at 70-80°C for 1-2 hours. This step removes starch from the barley young leaves, enzymatically hydrolyzing the starch into dextrin and oligosaccharides.

[0012] In one embodiment of the present invention, after hydrolysis with heat-resistant α-amylase, papain and saccharifying enzyme are added at a ratio of 1000-1500 U / g for papain / barley young leaves and 250-300 U / g for papain / barley young leaves, respectively, and the mixture is incubated in a water bath at 55-65°C for 2-3 hours. After cooling to room temperature, the residue is collected after centrifugation. This hydrolysis step is to remove protein from the barley young leaves, breaking down the protease into soluble peptides, and further hydrolyzing the α-amylase product in the mixture to generate glucose, which is then removed by subsequent centrifugation. Papain and saccharifying enzyme can be added simultaneously or separately.

[0013] In one embodiment of the present invention, step S1, after solid-liquid separation and collection of residue, further includes the steps of drying the residue, pulverizing and sieving it. The residue is dried and then pulverized to a mesh size of 60-80 and sieved. The drying temperature of the residue is 37-40°C, and the drying time is 24-48 hours.

[0014] In one embodiment of the present invention, in step S1, the residue is mixed with water at a solid-liquid ratio of 1:25-30, and xylanase and cellulase are added for enzymatic hydrolysis at pH 5.0-5.5. Specifically, the pH can be adjusted to 5.0-5.5 with 0.561 mol / L hydrochloric acid.

[0015] As one embodiment of the present invention, in step S1, after the residue is mixed with water, xylanase and cellulase are added at a ratio of xylanase / residue = 700-800 U / g and cellulase / residue = 300-400 U / g, respectively, and the mixture is then placed in a water bath at 50-55°C for 3-4 hours. After cooling to room temperature, the mixture is centrifuged.

[0016] As one embodiment of the present invention, the supernatant obtained by centrifugation is precipitated with 3 to 4 times the amount of 95% ethanol.

[0017] In one embodiment of the present invention, in step S1, after the precipitate is re-dissolved in water, polysaccharides with a molecular weight cutoff greater than 3500 Da are dialyzed and concentrated by rotary evaporation and then freeze-dried under vacuum to obtain barley leaf polysaccharide.

[0018] In one embodiment of the present invention, in step S1, the liquid is rotary evaporated at 50-60°C for 0.5-1 h, and the concentrate is freeze-dried under vacuum at -40--50°C for 12-24 h.

[0019] In one embodiment of the present invention, in step S2, 1 to 5 parts of polysaccharide are dissolved in 1000 to 1500 parts of water to obtain a uniform polysaccharide solution.

[0020] In one embodiment of the present invention, in step S2, wheat flour is added to the polysaccharide solution according to the mass ratio of polysaccharide to wheat flour being 1-5:95-99, and the mixture is stirred and mixed to obtain a mixed system.

[0021] As one embodiment of the present invention, in step S2, the mixed system is heated at 90-95°C for 15-20 minutes, gelatinized, cooled at room temperature for 12-24 hours, and then freeze-dried under vacuum at -40--50°C for 12-24 hours to obtain the finished product.

[0022] In step S1 of the present invention, soluble polysaccharides are extracted from the residue of young barley leaves by a combination of xylanase and cellulase, thereby degrading the cellulose and hemicellulose in the residue and degrading the insoluble polysaccharides into soluble polysaccharides, to obtain arabinoxylan and pectin polysaccharides rich in rhamnose galacturonic acid polysaccharide type I (RG-I).

[0023] In step S2 of this invention, the lyophilized polysaccharide is reconstituted with water, dialyzed using a 3500 Da dialysis bag for 36-48 hours, and then precipitated with anhydrous ethanol in a volume 3-4 times that of the extract. The dialysis bag is used to retain polysaccharides with a molecular weight greater than 3500 Da, thus preserving polysaccharides with higher degrees of branching.

[0024] Anti-digestion performance determination: Following the in vitro simulated enzyme hydrolysis method proposed by Englyst et al., the contents of rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS) in the product of the example were determined. Specifically, 4.5 g of trypsin was weighed and mixed with 30 mL of deionized water, and the mixture was slowly and gently shaken for 30 minutes. After centrifugation, the supernatant was collected and mixed evenly with 3.9 mL of saccharifying enzyme to prepare the enzyme solution for later use. 550 mg of sample was weighed into a 50 mL centrifuge tube, 10 mL of deionized water was added, and the centrifuge tube was heated in a boiling water bath at 100 °C for 20 minutes. After cooling, 10 mL of acetate buffer (pH 5.2), 15 glass beads (4-5 mm in diameter), and 0.05 g of guar gum solid were added. The mixture was stirred evenly, and 5 mL of enzyme solution was added. The mixture was immediately placed in a constant temperature water bath at 37 °C and shaken (80 r / min) and the time was recorded. After hydrolysis for 20 and 120 min, 0.5 mL of the hydrolysate was taken out and 20 mL of 80% ethanol was added. The mixture was shaken thoroughly until the amylase was inactivated. The supernatant after centrifugation was used to determine the glucose content at 510 nm using the glucose oxidase method (GOPOD). A standard curve for glucose was prepared and the calculations were as follows:

[0025] Rapidly digestible starch (RDS) content (%) = (G20 - FG) × 0.9 / TS

[0026] Slowly digestible starch (SDS) content (%) = (G120 - G20) × 0.9 / TS

[0027] Resistant starch (RS) content (%) = (TS - RDS - SDS) / TS

[0028] In the formula: FG is the free glucose content in the sample before enzymatic hydrolysis; G20 and G120 represent the glucose content produced after 20 min and 120 min of amylase hydrolysis, respectively; TS represents the total starch content in the sample; and 0.9 is the conversion factor.

[0029] Furthermore, the application of wheat flour prepared by the method described in this invention in low-GI pasta products also falls within the scope of protection of this invention.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] (1) The present invention uses the residue after extracting polysaccharides from barley tender leaf powder as raw material, and uses xylanase and cellulase for secondary extraction to obtain polysaccharides. The polysaccharides have the effect of delaying starch digestion and improving the value of barley tender leaf by-products.

[0032] (2) The polysaccharide prepared in this invention is mainly composed of water-soluble arabinoxylan and RG-I pectin polysaccharide. The complex entanglement between the two branched polymers, together with gluten protein, encapsulates starch granules, blocking the direct contact between amylase and starch, significantly delaying the hydrolysis rate of starch, and synergistically inhibiting starch digestion. Since starch needs to be converted into glucose and enter the human bloodstream through the action of amylase, the complexation of this polysaccharide with wheat flour hinders the attack of enzymes on starch in wheat flour, reduces the starch digestion rate, and thus reduces its glycemic index.

[0033] (3) The wheat flour with anti-digestive function prepared by the present invention is an ideal raw material for making low-GI pasta. It can be used to prepare various pasta, such as noodles, bread, steamed buns, etc. It is of great significance for improving the nutritional status of diabetic patients and delaying the occurrence of diabetic complications. It is also suitable for the healthy diet of the general population. Detailed Implementation

[0034] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0035] Example 1

[0036] A method for preparing wheat flour with anti-digestive function, comprising the following steps:

[0037] (1) Preparation of barley tender leaf residue: Barley tender leaves were mixed with water at a solid-liquid ratio of 1:30. 200U of heat-resistant α-amylase was added per gram of barley tender leaves to enzyme and the mixture was incubated at 80℃ for 1 hour. Then, 1000U of papain and 300U of saccharifying enzyme were added and the mixture was incubated at 65℃ for 3 hours for enzymatic hydrolysis. The mixture was cooled to room temperature and centrifuged to collect the residue.

[0038] (2) Preparation of polysaccharides from barley young leaf residue: The residue was mixed with water at a solid-liquid ratio of 1:30. Based on the ratio of residue to enzyme, 700U xylanase and 300U cellulase were added after adjusting the pH to 5.0 with 0.561mol / L hydrochloric acid. The mixture was then incubated in a water bath at 50℃ for 3 hours. After cooling to room temperature, the mixture was centrifuged. The supernatant was precipitated with 3 times the amount of 95% ethanol. The precipitate was reconstituted with water and dialyzed to retain polysaccharides with a molecular weight cutoff greater than 3500 Da. The mixture was then rotary evaporated at 60℃ for 1 hour. The concentrate was freeze-dried under vacuum at -50℃ for 18 hours to obtain barley young leaf residue polysaccharides.

[0039] (3) Preparation of wheat flour with anti-digestive function: 5 parts of barley leaf residue polysaccharide were dissolved in 1000 parts of water to obtain a uniform polysaccharide solution. 95 parts of wheat flour were added to the polysaccharide solution and stirred to obtain a mixed system. The mixed system was heated at 90℃ for 15 min, cooled at room temperature for 12 h, and freeze-dried to obtain the finished product.

[0040] Results: As shown in Table 1, the SDS+RS content of the finished product was 41.50%, which significantly improved the digestibility of the wheat flour compared with the SDS+RS content of the control group (original wheat flour) (24.17%).

[0041] Example 2

[0042] This embodiment relates to a method for preparing wheat flour with anti-digestion function, the steps of which are as follows:

[0043] (1) Preparation of barley young leaf polysaccharide: Barley young leaves were mixed with water at a solid-liquid ratio of 1:30. Based on the ratio of barley young leaves to enzymes, 700U xylanase and 300U cellulase were added after adjusting the pH to 5.0 with 0.561mol / L hydrochloric acid. The mixture was then incubated in a water bath at 50℃ for 3h. After cooling to room temperature, the mixture was centrifuged. The supernatant was precipitated with 3 times the amount of 95% ethanol. The precipitate was redissolved in water and dialyzed to retain polysaccharides with a molecular weight cutoff greater than 3500Da. The mixture was then rotary evaporated at 60℃ for 1h. The concentrate was freeze-dried under vacuum at -50℃ for 18h to obtain barley young leaf polysaccharide.

[0044] (2) Preparation of wheat flour with anti-digestive function: 5 parts of barley tender leaf polysaccharide were dissolved in 1000 parts of water to obtain a uniform polysaccharide solution. 95 parts of wheat flour were added to the polysaccharide solution and stirred to obtain a mixed system. The mixed system was heated at 90℃ for 15 min, cooled at room temperature for 12 h, and freeze-dried to obtain the finished product.

[0045] Implementation results: As shown in Table 1, the SDS+RS content of the finished product of Example 2 is 25.91%, which is significantly lower than that of Example 1, indicating that its digestibility is lower than that of Example 1. Compared with the control group (original wheat flour), there is no significant difference in digestibility, indicating that Example 2 did not improve the digestibility of wheat flour.

[0046] Example 3

[0047] This embodiment relates to a method for preparing wheat flour with anti-digestion function. The method is the same as that in Embodiment 1, except that in the preparation of barley young leaf residue polysaccharide, after the precipitate is re-dissolved in water, it is not dialyzed, and the polysaccharide with a molecular weight greater than 3500 Da is not retained. It is directly rotary evaporated at 60°C for 1 hour, and the concentrate is freeze-dried under vacuum at -50°C for 18 hours to obtain barley young leaf residue polysaccharide.

[0048] Results: As shown in Table 1, the SDS+RS content of the finished product of Example 3 was 30.11%. Compared with the control group (original wheat flour), there was no significant difference in SDS content, but the RS content was slightly higher than that of the control group, indicating that Example 3 improved the digestibility of wheat flour to a small extent. However, the SDS+RS content was significantly lower than that of Example 1, indicating that its digestibility was lower than that of Example 1.

[0049] Example 4

[0050] This embodiment relates to a method for preparing wheat flour with anti-digestive function. The method is the same as in Example 1, except that in the preparation of barley young leaf residue polysaccharide, the residue is mixed with water at a solid-liquid ratio of 1:30. Based on the ratio of residue to enzyme per gram, 700U xylanase is added after adjusting the pH to 5.0 with 0.561mol / L hydrochloric acid and then placed in a water bath at 50℃ for 3 hours. After cooling to room temperature, the mixture is centrifuged, and the supernatant is precipitated with 3 times the amount of 95% ethanol. After redissolving the precipitate with water, polysaccharides with a molecular weight cutoff greater than 3500 Da are dialyzed and retained. The mixture is then rotary evaporated at 60℃ for 1 hour, and the concentrate is freeze-dried under vacuum at -50℃ for 18 hours to obtain barley young leaf residue polysaccharide.

[0051] Implementation results: As shown in Table 1, the SDS+RS content of the finished product of Example 4 is 32.5%. Compared with the control group (original wheat flour), the SDS content is lower than that of the control group, while the RS content is significantly higher than that of the control group, indicating that Example 4 has improved the digestibility of wheat flour to a certain extent; however, the SDS+RS content is significantly lower than that of Example 1, indicating that its digestibility is lower than that of Example 1.

[0052] In this embodiment, the polysaccharide yield reaches the optimal range when the amount of xylanase reaches 700-800 U / g. When the amount of xylanase is further increased, the yield begins to decrease because when xylanase is excessive, the soluble polysaccharides in the barley young leaf residue are degraded into smaller molecule sugars. These smaller molecule sugars cannot be precipitated during alcohol precipitation or are not retained during dialysis, thus leading to a decrease in yield.

[0053] Example 5

[0054] This embodiment relates to a method for preparing wheat flour with anti-digestive function. The method is the same as in Example 1, except that in the preparation of barley young leaf residue polysaccharide: the residue is mixed with water at a solid-liquid ratio of 1:30. Based on the ratio of residue to enzyme per gram, the pH is adjusted to 5.0 with 0.561 mol / L hydrochloric acid, and 300 U of cellulase is added. The mixture is then heated in a water bath at 50°C for 3 hours, cooled to room temperature, and centrifuged. The supernatant is precipitated with 3 times the amount of 95% ethanol. The precipitate is reconstituted with water, and polysaccharides with a molecular weight cutoff greater than 3500 Da are retained by dialyzing. The mixture is then rotary evaporated at 60°C for 1 hour, and the concentrate is freeze-dried under vacuum at -50°C for 18 hours to obtain barley young leaf residue polysaccharide.

[0055] Results: As shown in Table 1, the SDS+RS content of the finished product of Example 5 was 33.09%. Compared with the control group (original wheat flour), there was no significant difference in SDS content, but the RS content was higher than that of the control group, indicating that Example 5 improved the digestibility of wheat flour to a certain extent. However, the SDS+RS content was significantly lower than that of Example 1, indicating that its digestibility was lower than that of Example 1.

[0056] In this embodiment, the optimal yield is achieved by adding 300-400U of cellulase. When cellulase is added in excess, the enzymatic hydrolysis is excessive, and more polysaccharides are converted into small oligosaccharides with low molecular weight. These oligosaccharides cannot be precipitated during alcohol precipitation or are not retained during dialysis, resulting in a lower yield and a failure to exert a good anti-digestion effect.

[0057] Example 6

[0058] This embodiment relates to a method for preparing wheat flour with anti-digestion function. The method is the same as that in embodiment 1, except that: in the preparation of wheat flour with anti-digestion function, 5 parts of barley tender leaf residue polysaccharide is dissolved in 1000 parts of water to obtain a uniform polysaccharide solution. 95 parts of wheat flour are added to the polysaccharide solution, stirred and mixed to obtain a mixed system. No heating is performed. After centrifugation, the product is freeze-dried to obtain the finished product.

[0059] Implementation results: As shown in Table 1, the SDS+RS content of the finished product of Example 6 was 27.18%. Compared with the control group (original wheat flour), there was no significant difference in the digestibility. This indicates that Example 2 did not improve the digestibility of wheat flour and was significantly lower than that of Example 1, indicating that its digestibility was lower than that of Example 1.

[0060] Comparative Example 1

[0061] This comparative example relates to a method for preparing wheat flour with anti-digestive function. The method is the same as that in Example 1, except that the preparation of barley leaf polysaccharides is different. The steps are as follows: Barley tender leaves are mixed with water at a solid-liquid ratio of 1:30. Based on the ratio of barley tender leaves to enzymes, 200U of heat-resistant α-amylase is added and the mixture is incubated at 80℃ for 1 hour. Simultaneously, 1500U of papain and 300U of glucoamylase are added and incubated at 65℃ for 2 hours for enzymatic hydrolysis. After cooling to room temperature, the pH is adjusted to 5.0 with 0.561mol / L hydrochloric acid. Then, based on the ratio of barley tender leaves to enzymes, 1400U of xylanase and 600U of cellulase are added and incubated at 55℃ for 3 hours. After cooling to room temperature, the mixture is centrifuged. The supernatant is precipitated with three times the volume of 95% ethanol. The precipitate is reconstituted with water, and polysaccharides with a molecular weight cutoff greater than 3500 Da are dialyzed. The mixture is then rotary evaporated at 60℃ for 1 hour. The concentrated solution is freeze-dried under vacuum at -50℃ for 18 hours to obtain barley tender leaf polysaccharides.

[0062] Results: Table 1 shows that the SDS+RS content of Comparative Example 1 was 23.88%, and the RDS content was 76.12%. Compared with the control group (original wheat flour), there was no significant difference in digestibility, indicating that Comparative Example 1 did not improve the digestibility of wheat flour. This is because the barley leaf polysaccharides obtained in this comparative example are mainly oligosaccharides, such as xylooligosaccharides, glucose, and water-soluble β-glucan. These have low molecular weights and cannot form a complex network structure to encapsulate starch granules, thus hindering amylase attack. Furthermore, the glucose in the barley leaf polysaccharides slightly increases the glucose content in the finished product. During the digestibility test, the glucose in the system slightly increases the RDS content. Therefore, there was no significant difference in digestibility.

[0063] Table 1. Digestibility characteristics of wheat flour

[0064] Rapidly digestible starch (RDS) (%) Slowly digestible starch (SDS) (%) Resistant starch (RS) (%) control group <![CDATA[75.83±2.30 ab ]]> <![CDATA[3.49±0.84 a ]]> <![CDATA[20.68±1.47 f ]]> Example 1 <![CDATA[58.50±2.82 e ]]> <![CDATA[4.89±1.12 a ]]> <![CDATA[36.61±2.26 a ]]> Example 2 <![CDATA[74.09±1.78 bc ]]> <![CDATA[2.29±0.34 ab ]]> <![CDATA[23.62±1.64 d ]]> Example 3 <![CDATA[69.89±1.78 c ]]> <![CDATA[3.39±0.93 a ]]> <![CDATA[26.72±1.45 d ]]> Example 4 <![CDATA[67.50±1.81 d ]]> <![CDATA[1.40±0.39 b ]]> <![CDATA[31.10±1.42 b ]]> Example 5 <![CDATA[66.91±1.38 d ]]> <![CDATA[3.24±0.58 a ]]> <![CDATA[29.85±1.14 bc ]]> Example 6 <![CDATA[72.82±1.25 cd ]]> <![CDATA[2.44±0.10 ab ]]> <![CDATA[24.74±1.17 e ]]> Comparative Example 1 <![CDATA[76.12±1.83 a ]]> <![CDATA[3.32±0.71 a ]]> 20.56±1.12f

[0065] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A method for producing a wheat flour having a digestion resistance function, characterized by, The method comprises the following steps: S1, the high temperature resistant alpha-amylase, papain and glucoamylase are used for enzymolysis of the young leaves of highland barley, and after solid-liquid separation, the residue is collected, the residue is mixed with water, xylanase and cellulase are added for enzymolysis, and after solid-liquid separation, polysaccharide in the solution is precipitated by ethanol, the precipitate is redissolved, dialyzed, concentrated by rotary evaporation, and then vacuum freeze-dried to obtain polysaccharide; S2, the polysaccharide is dissolved in water to obtain a polysaccharide solution, and the polysaccharide solution is added with wheat flour, stirred and uniformly mixed to obtain a mixed system, and after the mixed system is heated and gelatinized, it is cooled at room temperature and freeze-dried to obtain a finished product; In step S1, the young leaves of highland barley are mixed with water at a solid-liquid ratio of 1:30-40; 70-80 DEG C water bath is added for 1-2 h according to the high temperature resistant alpha-amylase / highland barley = 200-250 U / g; after the high temperature resistant alpha-amylase is enzymolyzed, 55-65 DEG C water bath is added for 2-3 h according to the papain / highland barley = 1000-1500 U / g and the glucoamylase / highland barley = 250-300 U / g, and then the residue is collected after centrifugation; after the residue is mixed with water, 50-55 DEG C water bath is added for 3-4 h according to the xylanase / residue = 700-800 U / g and the cellulase / residue = 300-400 U / g, and then the residue is centrifuged after cooling to room temperature; the supernatant obtained by centrifugation is precipitated by 3-4 times of 95% ethanol; polysaccharide with a molecular weight greater than 3500 Da is dialyzed; the concentrated solution is vacuum freeze-dried at-40--50 DEG C for 12-24 h; and the obtained polysaccharide is mainly composed of arabinoxylan and pectin polysaccharide rich in rhamnose galacturonic acid polysaccharide type I (RG-I).

2. The production method according to claim 1, characterized by, In step S1, the residue is mixed with water at a solid-liquid ratio of 1:25-30, and xylanase and cellulase are added for enzymolysis at pH 5.0-5.

5.

3. The production method according to claim 1, characterized by, In step S2, 1-5 parts of the polysaccharide are dissolved in 1000-1500 parts of water to obtain a uniform polysaccharide solution; 95-99 parts of wheat flour are added, stirred and uniformly mixed to obtain a mixed system, the mixed system is heated at 90-95 DEG C for 15-20 min, and cooled at room temperature for 12-24 h.

4. Application of the wheat flour prepared by the method according to any one of claims 1-3 in low GI noodles.