Method for extracting feruloyl arabinoxylan in wheat bran through combination of ultrahigh pressure, high temperature and enzymolysis
The extraction of arabinoxylan from wheat bran by ultra-high pressure-high temperature-enzymatic hydrolysis solves the problems of ester bond destruction and environmental pollution in traditional methods, and realizes the preparation of highly biologically active arabinoxylan with good antioxidant and hypoglycemic effects.
Patent Information
- Application Number
- CN202510816869.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-18
- Publication Date
- 2025-09-23
AI Technical Summary
When extracting arabinoxylan from wheat bran using the traditional dilute alkaline solution method, the ester bond between ferulic acid and arabinose residues is easily destroyed, resulting in reduced biological activity of arabinoxylan and environmental pollution problems.
An ultra-high pressure-high temperature-enzymatic hydrolysis method was adopted. Ultra-high pressure treatment was used to destroy the non-covalent interaction between polysaccharides and cell wall proteins/lignin. High temperature treatment was combined to soften the lignin structure. Xylanase and papain were used for enzymatic hydrolysis. Finally, feruloylarabinoxylan was obtained through precipitation, dialysis and freeze-drying.
The ester bond between ferulic acid and arabinose residues is effectively retained, the biological activity of arabinoxylan is improved, environmental pollution is reduced, and the obtained arabinoxylan has significant antioxidant and hypoglycemic effects.
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of xylan extraction, and in particular to a method for extracting feruloylarabinoxylan from wheat bran by combining ultrahigh pressure, high temperature and enzymatic hydrolysis. Background Art
[0002] Wheat bran, a major by-product of wheat processing, has a huge annual production volume but a low utilization rate. It is often used as a low-value feed or brewing raw material, or even directly discarded. Studies have shown that wheat bran is rich in bioactive polysaccharides, among which arabinoxylans (AX) are the core component of wheat bran polysaccharides. The arabinoxylan backbone is composed of xylose linked by β-(1→4) glycosidic bonds, with side chain arabinose residues linked to the backbone at the O-2 and O-3 positions, forming a complex branched structure. Furthermore, ferulic acid (FA), a natural phenolic acid, can cross-link with arabinose residues through ester bonds, conferring significant antioxidant and hypoglycemic bioactivities to the polysaccharide.
[0003] The significant limitations of traditional wheat bran polysaccharide extraction methods (such as the dilute alkaline solution method) are listed below:
[0004] Chemical bond destruction: Alkaline conditions can easily hydrolyze the ester bond between ferulic acid and Arabic residues, resulting in loss of active ingredients.
[0005] Environmental pollution: The use of chemical reagents produces waste liquid, which is not in line with the trend of green processing.
[0006] Ultra-High Pressure Processing (UHPP), a non-thermal processing technology, provides a revolutionary solution for wheat bran polysaccharide extraction, with the following advantages:
[0007] Selective dissociation mechanism: Pressure (100-600 MPa) is used to destroy the non-covalent interactions (such as hydrogen bonds and hydrophobic interactions) between polysaccharides and cell wall proteins / lignin, while retaining covalent structures such as ferulic acid-arabinose residue ester bonds.
[0008] Activity retention advantage: Low temperature (<40°C) operation avoids degradation of heat-sensitive components and significantly enhances the biological activity of polysaccharides.
[0009] Green and environmentally friendly features: No chemical reagents are required, wastewater discharge is reduced by more than 80%, in line with the concept of sustainable processing. Summary of the Invention
[0010] A problem with the prior art is that the use of a dilute alkaline solution method to extract arabinoxylan from wheat bran easily destroys the ester bond formed between ferulic acid and the arabinose residue, significantly reducing the biological activity of the resulting arabinoxylan. To address this technical problem, the present invention provides a method for extracting feruloylarabinoxylan from wheat bran using a combination of ultrahigh pressure, high temperature, and enzymatic hydrolysis, comprising the following steps:
[0011] (1) the wheat bran is sequentially washed with water, filtered, and enzymatically hydrolyzed with amylase (amylase is added in solid form, accounting for 2% of the mass of the wheat bran, and before the amylase is added, deionized water is added to the filtered wheat bran at a mass ratio of 1:15) to remove starch, and then the enzyme is inactivated to obtain a wheat bran residue;
[0012] (2) drying and pulverizing the wheat bran residue in sequence to obtain wheat bran powder;
[0013] (3) mixing the wheat bran powder with deionized water and subjecting it to ultrahigh pressure extraction to obtain a wheat bran solution;
[0014] (4) subjecting the wheat bran solution to high-temperature extraction to obtain a wheat bran solution I;
[0015] (5) adding xylanase to the wheat bran solution I (xylanase is added in solid form, 0.05-0.06% by weight of the wheat bran powder is added, and the pH of the wheat bran solution I is first adjusted to 4.0-5.5 with a 1 mol / L HCl aqueous solution before adding the xylanase) for enzymatic hydrolysis. After the enzyme is inactivated, the pH of the solution is adjusted to 6.5 with a 1 mol / L NaOH aqueous solution. The solution is then centrifuged and the obtained supernatant is concentrated to 1 / 5 of the original volume to obtain a concentrated solution;
[0016] (6) Anhydrous ethanol is added to the concentrated solution to carry out a precipitation reaction. After the precipitation reaction is completed and allowed to stand, the obtained precipitate is subjected to solid-liquid separation. The obtained solid isolate is sequentially dissolved in water and enzymatically hydrolyzed by papain (papain is added in solid form, 0.3% of the mass of the wheat bran powder). The obtained enzymatic hydrolyzate is then sequentially subjected to enzyme inactivation, dialyzed, and freeze-dried to obtain feruloyl arabinoxylan.
[0017] Preferably, the amylase in step (1) is a high-temperature α-amylase.
[0018] Preferably, the average particle size of the wheat bran powder in step (2) is 50 mesh.
[0019] Preferably, the ultrahigh pressure extraction condition in step (3) is to place the wheat bran solution under 400 MPa and maintain the temperature and pressure at 40° C. for at least 30 minutes.
[0020] Preferably, the high temperature extraction in step (4) is to keep the wheat bran solution at 90° C. for at least 2 hours.
[0021] Preferably, the pH value of xylan hydrolysis is in the range of 4.0-5.5.
[0022] Preferably, the enzymatic hydrolysis temperature in step (5) is 50-55°C.
[0023] Preferably, in the step (6), when adding anhydrous ethanol to the concentrated solution for precipitation reaction, the addition of anhydrous ethanol is stopped after the mass concentration of ethanol in the concentrated solution reaches 80%, and the concentrated solution is then placed at a temperature of 4° C. for at least 12 hours.
[0024] The present invention has the following beneficial effects:
[0025] The present invention uses a combined ultrahigh pressure, high temperature, and enzymatic hydrolysis method to extract ferulic acid, which is not easily destroyed. The ester bond between ferulic acid and the residual arabinose group is also not easily destroyed. The ultrahigh pressure treatment can also destroy the rigid structure of the cell wall. The high temperature (90°C) treatment can soften, migrate, or slightly depolymerize some lignin and further destroy the dense hydrogen bond network between cellulose, hemicellulose, and lignin, thereby effectively destroying the stubborn connection between ferulic acid and the arabinoxylan carrier and between it and the cell wall matrix, significantly increasing the substrate's sensitivity to xylanase. The arabinoxylan ultimately obtained by the present invention has good antioxidant and blood sugar-lowering biological activities. The method of the present invention has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 : Standard curve of ferulic acid concentration.
[0027] Figure 2 : Comparison of ferulic acid content in the arabinoxylan obtained in Example 1 and the arabinoxylan obtained in Comparative Examples 1 and 6.
[0028] Figure 3 : In vitro hypoglycemic activity test diagram of the arabinoxylan obtained in Example 1 and the arabinoxylan obtained in Comparative Examples 1 and 6. DETAILED DESCRIPTION
[0029] The present invention will be described in detail below with reference to the following examples. However, it should be understood that the following examples are merely illustrative of the embodiments of the present invention and are not intended to limit the scope of the present invention.
[0030] Example 1
[0031] A method for extracting feruloylarabinoxylan from wheat bran by ultrahigh pressure-high temperature-enzymatic hydrolysis is as follows:
[0032] (1) The wheat bran is sequentially washed, filtered, and hydrolyzed with amylase to remove starch, and then the enzyme is inactivated to obtain a wheat bran residue; during the enzymatic hydrolysis process, the washed and filtered wheat bran is firstly mixed with deionized water in a mass ratio of 1:15, then the pH is adjusted to 6 using a 1 mol / L HCl aqueous solution, and finally amylase accounting for 2% of the weight of the wheat bran is added, wherein the enzymatic hydrolysis temperature is 90°C, the enzymatic hydrolysis time is 2 hours, and the enzyme inactivation is specifically maintained at 100°C for 30 minutes;
[0033] (2) the wheat bran residue is dried and pulverized successively to obtain 50 purpose wheat bran powder;
[0034] (3) Wheat bran powder and deionized water were mixed uniformly in a mass ratio of 1:15, and subjected to ultrahigh pressure extraction to obtain a wheat bran solution. The ultrahigh pressure extraction pressure was 400 MPa, the pressure holding time was 30 min, and the temperature was 40°C;
[0035] (4) subjecting the wheat bran solution to high-temperature extraction to obtain wheat bran solution I, wherein the high-temperature extraction temperature is 90° C. and the holding time is 2 h;
[0036] (5) The pH of the wheat bran solution I was adjusted to 4.0 using a 1 mol / L HCl aqueous solution, and xylanase was added for enzymolysis. After the enzyme was inactivated, the pH of the solution was adjusted to 6.5 using a 1 mol / L NaOH aqueous solution; the enzymolysis temperature was 50° C., the enzymolysis time was 1 h, the enzyme inactivation temperature was 90° C., and the inactivation time was 30 min; the amount of xylanase added was 0.055% of the mass of the wheat bran powder;
[0037] (6) The wheat bran solution I is centrifuged, and the obtained supernatant is reduced to 1 / 5 of the original volume by rotary evaporation to obtain a concentrated solution. Anhydrous ethanol is added to the concentrated solution for precipitation reaction. After the ethanol mass concentration in the concentrated solution reaches 80%, the addition of anhydrous ethanol is stopped, and then the concentrated solution is placed at a temperature of 4°C for low temperature storage for 12 hours. The obtained precipitate is subjected to solid-liquid separation. The obtained solid separated material is dissolved in water to obtain a dispersion. Papain is added to the obtained dispersion for papain enzymolysis. The obtained enzymolysis solution is then enzyme-inactivated, dialyzed, and freeze-dried to obtain arabinoxylan. Papain is added in the form of a solid. First, the pH of the above dispersion is adjusted to 6 using a 1 mol / L HCl aqueous solution. Then, 0.3% of the mass of the wheat bran powder is added to the dispersion. The enzyme is inactivated at a temperature of 90°C for 30 minutes. The dialysis is performed using a 3500Da dialysis bag for 72 hours. Finally, the mixture was freeze-dried at -50°C for 24 h to obtain feruloylarabinoxylan.
[0038] Example 2
[0039] A method for extracting feruloylarabinoxylan from wheat bran by ultrahigh pressure-high temperature-enzymatic hydrolysis is as follows:
[0040] (1) The wheat bran is washed with water, filtered, and hydrolyzed with amylase to remove starch, and then the enzyme is inactivated to obtain a wheat bran residue; during the enzymatic hydrolysis process, the wheat bran and deionized water are first mixed uniformly in a mass ratio of 1:15, and then the pH is adjusted to 7 using a 1 mol / L HCl aqueous solution, and finally 2% amylase by mass of the wheat bran is added, wherein the enzymatic hydrolysis temperature is 90°C, the enzymatic hydrolysis time is 2h, and the enzyme inactivation is specifically maintained at 100°C for 30min.
[0041] (2) the wheat bran residue is dried and pulverized successively to obtain 50 purpose wheat bran powder;
[0042] (3) Mix wheat bran powder and deionized water in a mass ratio of 1:15 and perform ultrahigh pressure extraction on the mixture to obtain a wheat bran solution. The ultrahigh pressure extraction pressure is 400 MPa, the pressure holding time is 30 min, and the temperature is 40°C;
[0043] (4) performing high-temperature extraction on the wheat bran solution to obtain wheat bran solution I. The high-temperature extraction temperature is 90° C., and the holding time is 2 h;
[0044] (5) The pH of the wheat bran solution I was adjusted to 5.5 using a 1 mol / L HCl aqueous solution, and xylanase was added for enzymolysis. After the enzyme was inactivated, the pH of the wheat bran solution I was adjusted to 6.5 using a 1 mol / L NaOH aqueous solution; the enzymolysis temperature was 50° C., the enzymolysis time was 1 h, the enzyme inactivation temperature was 90° C., and the inactivation time was 30 min; the amount of xylanase added was 0.05% of the mass of the wheat bran powder;
[0045] (6) The bran solution was centrifuged, and the supernatant obtained was reduced to 1 / 5 of its original volume by rotary evaporation to obtain a concentrated solution. Anhydrous ethanol was added to the concentrated solution for precipitation reaction. When the ethanol mass concentration in the concentrated solution reached 80%, the addition of anhydrous ethanol was stopped. The concentrated solution was then placed at 4°C for 12 hours. The obtained precipitate was subjected to solid-liquid separation. The obtained solid separated material was dissolved in water to obtain a dispersion. Papain was added to the obtained dispersion for papain enzymatic hydrolysis. The obtained enzymatic hydrolyzed solution was then deactivated, dialyzed, and freeze-dried to obtain arabinoxylan. Papain was added in solid form. First, the pH of the above dispersion was adjusted to 6 using a 1 mol / L HCl aqueous solution. Then, 0.3% of papain by weight of the wheat bran powder was added to the dispersion. The enzyme was deactivated at 90°C for 30 minutes. The solution was dialyzed using a 3500Da dialysis bag for 72 hours. Finally, the solution was freeze-dried at -50°C for 24 hours to obtain feruloylarabinoxylan.
[0046] Example 3
[0047] A method for extracting feruloylarabinoxylan from wheat bran by ultrahigh pressure-high temperature-enzymatic hydrolysis is as follows:
[0048] (1) The wheat bran is sequentially washed with water, filtered, and hydrolyzed with amylase to remove starch, and then the enzyme is inactivated to obtain a wheat bran residue; during the enzymatic hydrolysis process, the wheat bran and deionized water are firstly mixed uniformly in a mass ratio of 1:15, and then the pH is adjusted to 6 using a 1 mol / L HCl aqueous solution, and finally 2% of the mass of the wheat bran amylase is added, wherein the enzymatic hydrolysis temperature is 90°C, the enzymatic hydrolysis time is 2h, and the enzyme inactivation is specifically maintained at 100°C for 30min.
[0049] (2) the wheat bran residue is dried and pulverized successively to obtain 50 purpose wheat bran powder;
[0050] (3) Mix wheat bran powder and deionized water in a mass ratio of 1:15 and perform ultrahigh pressure extraction on the mixture to obtain a wheat bran solution. The ultrahigh pressure extraction pressure is 400 MPa, the pressure holding time is 30 min, and the temperature is 40°C;
[0051] (4) performing high-temperature extraction on the wheat bran solution to obtain wheat bran solution I. The high-temperature extraction temperature is 90° C., and the holding time is 2 h;
[0052] (5) The pH of the wheat bran solution I was adjusted to 5 using a 1 mol / L HCl aqueous solution, and xylanase was added for enzymolysis. After the enzyme was inactivated, the pH of the wheat bran solution I was adjusted to 6.5 using a 1 mol / L NaOH aqueous solution; the enzymolysis temperature was 50° C., the enzymolysis time was 1 h, the enzyme inactivation temperature was 90° C., and the inactivation time was 30 min; the amount of xylanase added was 0.06% of the mass of the wheat bran powder;
[0053] (6) The bran solution was centrifuged, and the supernatant obtained was reduced to 1 / 5 of its original volume by rotary evaporation to obtain a concentrated solution. Anhydrous ethanol was added to the concentrated solution for precipitation reaction. When the ethanol mass concentration in the concentrated solution reached 80%, the addition of anhydrous ethanol was stopped. The concentrated solution was then placed at 4°C for 12 hours. The obtained precipitate was subjected to solid-liquid separation. The obtained solid separated material was dissolved in water to obtain a dispersion. Papain was added to the obtained dispersion for papain enzymatic hydrolysis. The obtained enzymatic hydrolyzed solution was then deactivated, dialyzed, and freeze-dried to obtain arabinoxylan. Papain was added in solid form. First, the pH of the above dispersion was adjusted to 6 using a 1 mol / L HCl aqueous solution. Then, 0.3% of papain by weight of the wheat bran powder was added to the dispersion. The enzyme was deactivated at 90°C for 30 minutes. The solution was dialyzed using a 3500Da dialysis bag for 72 hours. Finally, the solution was freeze-dried at -50°C for 24 hours to obtain feruloylarabinoxylan.
[0054] Comparative Example 1 (Extraction of Wheat Bran Polysaccharides with Traditional Dilute Alkaline Solution)
[0055] (1) The wheat bran is washed with water, filtered, and hydrolyzed with amylase to remove starch, and then the enzyme is inactivated to obtain a wheat bran residue; during the enzymatic hydrolysis process, the wheat bran and deionized water are first mixed uniformly in a mass ratio of 1:15, and then the pH is adjusted to 6 using a 1 mol / L HCl aqueous solution, and finally 2% amylase by mass of the wheat bran is added, wherein the enzymatic hydrolysis temperature is 90°C, the enzymatic hydrolysis time is 2h, and the enzyme inactivation is specifically maintained at 100°C for 30min.
[0056] (2) the wheat bran residue is dried and pulverized successively to obtain 50 purpose wheat bran powder;
[0057] (3) 1 g of the wheat bran powder obtained in step (2) was added to 15 mL of a 1 mol / L sodium hydroxide aqueous solution, and stirred at a constant temperature of 60° C. for 2 h. The pH of the supernatant of the mixed solution was then adjusted to 7 with 37% hydrochloric acid. The supernatant was then centrifuged to obtain a supernatant, which was concentrated to one-fifth of its original volume by rotary evaporation. Anhydrous ethanol was then added to the concentrate for precipitation reaction, and the volume ratio of the concentrate to anhydrous ethanol was 1:4. After the precipitation reaction was completed, the obtained solid isolate was dissolved in water to obtain a dispersion, and 3 mg of papain was added to the obtained dispersion for papain enzymatic hydrolysis. The obtained enzymatic hydrolyzate was then inactivated by enzyme, dialyzed, and freeze-dried to obtain feruloylarabinoxylan.
[0058] Comparative Example 2 is the same as Example 1, except that the pressure of ultrahigh pressure extraction in Comparative Example 2 is 100 MPa, the holding time is 30 min, and the temperature is 40°C.
[0059] Comparative Example 3 is the same as Example 1, except that the pressure of ultrahigh pressure extraction in Comparative Example 3 is 500 MPa, the holding time is 30 min, and the temperature is 40°C.
[0060] Comparative Example 4 is the same as Example 1, except that the pressure of ultrahigh pressure extraction in Comparative Example 4 is 400 MPa, the holding time is 30 min, and the temperature is 60°C.
[0061] Comparative Example 5 is the same as Example 1, except that the pressure of ultrahigh pressure extraction in Comparative Example 5 is 400 MPa, the holding time is 30 min, and the temperature is 4°C.
[0062] Comparative Example 6 is the same as Example 1, except that the high-temperature extraction step is not included in Comparative Example 6. The method for extracting feruloylarabinoxylan from wheat bran is as follows:
[0063] (1) The wheat bran is sequentially washed, filtered, and hydrolyzed with amylase to remove starch, and then the enzyme is inactivated to obtain a wheat bran residue; during the enzymatic hydrolysis process, the washed and filtered wheat bran is firstly mixed with deionized water in a mass ratio of 1:15, then the pH is adjusted to 6 using a 1 mol / L HCl aqueous solution, and finally amylase accounting for 2% of the weight of the wheat bran is added, wherein the enzymatic hydrolysis temperature is 90°C, the enzymatic hydrolysis time is 2 hours, and the enzyme inactivation is specifically maintained at 100°C for 30 minutes;
[0064] (2) the wheat bran residue is dried and pulverized successively to obtain 50 purpose wheat bran powder;
[0065] (3) Wheat bran powder and deionized water were mixed uniformly in a mass ratio of 1:15, and subjected to ultrahigh pressure extraction to obtain a wheat bran solution. The ultrahigh pressure extraction pressure was 400 MPa, the pressure holding time was 30 min, and the temperature was 40°C;
[0066] (4) The pH of the wheat bran solution was adjusted to 4.0 using a 1 mol / L HCl aqueous solution, and xylanase was added for enzymatic hydrolysis. After the enzyme was inactivated, the pH of the solution was adjusted to 6.5 using a 1 mol / L NaOH aqueous solution; the enzymatic hydrolysis temperature was 50°C, the enzymatic hydrolysis time was 1 h, the enzyme inactivation temperature was 90°C, and the inactivation time was 30 min; the amount of xylanase added was 0.055% of the mass of the wheat bran powder;
[0067] (5) The bran solution was centrifuged, and the supernatant obtained was reduced to 1 / 5 of its original volume by rotary evaporation to obtain a concentrated solution. Anhydrous ethanol was added to the concentrated solution for precipitation reaction. When the ethanol mass concentration in the concentrated solution reached 80%, the addition of anhydrous ethanol was stopped. The concentrated solution was then placed at 4°C for 12 hours. The obtained precipitate was subjected to solid-liquid separation. The obtained solid separated material was dissolved in water to obtain a dispersion. Papain was added to the obtained dispersion for papain enzymatic hydrolysis. The obtained enzymatic hydrolyzed solution was then enzyme-inactivated, dialyzed, and freeze-dried to obtain arabinoxylan. Papain was added in solid form. First, the pH of the above dispersion was adjusted to 6 using a 1 mol / L HCl aqueous solution. Then, 0.3% of papain by weight of the wheat bran powder was added to the dispersion. The enzyme was inactivated at 90°C for 30 minutes. The solution was dialyzed using a 3500Da dialysis bag for 72 hours. Finally, the solution was freeze-dried at -40°C for 24 hours to obtain feruloylarabinoxylan.
[0068] Comparative Example 7 is the same as Example 1, except that the temperature of high-temperature extraction in step (4) of Comparative Example 7 is 120° C. and the extraction time is 30 min.
[0069] Performance Testing
[0070] 1. The ferulic acid content of the arabinoxylans obtained in Examples 1-3 of the present invention and Comparative Examples 1-7 was determined by the following method:
[0071] (1) Drawing of the standard curve of ferulic acid
[0072] Weigh 30 mg of ferulic acid standard, add it to a 100 mL volumetric flask, dilute to volume with 80% methanol aqueous solution to obtain a ferulic acid standard solution with a concentration of 500 μg / mL, take 9 test tubes, dilute to 100 μg / mL, 150 μg / mL, 200 μg / mL, 250 μg / mL, 300 μg / mL, 350 μg / mL, 400 μg / mL, 450 μg / mL, 470 μg / mL, respectively, and filter with a 0.45 μm microporous filter membrane for liquid chromatography detection. The detection conditions are: the mobile phase is acetonitrile containing 0.1% acetic acid, the flow rate is 0.4 mL / min, the column temperature is 27 ° C, the ultraviolet detection wavelength is 320 nm, and the standard curve is drawn as shown in the instructions. Figure 1 shown.
[0073] (2) Determination of ferulic acid content in wheat bran polysaccharides
[0074] 30 mg of wheat bran polysaccharide was weighed and added to 5 mL of a 2 mol / L NaOH aqueous solution. The mixture was stirred and reacted overnight under nitrogen protection. 2 mol / L HCl was then added to adjust the pH. When the pH was less than 2, the reaction was stopped. An equal volume of ether was then added for extraction 2-3 times. The ether layer was evaporated to remove the ether. Finally, the remaining product was dissolved in an 80% methanol aqueous solution and filtered through a 0.45 μm microporous filter membrane for liquid chromatography detection. The detection conditions were: acetonitrile containing 0.1% acetic acid as the mobile phase, a flow rate of 0.4 mL / min, a column temperature of 27°C, and a UV detection wavelength of 320 nm.
[0075] The ferulic acid contents in the arabinoxylans obtained in Examples 1-3 and Comparative Examples 1-8 were 10.45 mg / g, 9.80 mg / g, 10.02 mg / g, 1.67 mg / g, 8.63 mg / g, 8.74 mg / g, 9.29 mg / g, 9.76 mg / g, 7.38 mg / g, and 9.91 mg / g, respectively. The test results of Example 1 and Comparative Example 1 are shown in the attached specification. Figure 2 The test results show that the ferulic acid content in Example 1 is significantly better than that in Comparative Example 1.
[0076] 2. In vitro hypoglycemic activity assay of wheat bran polysaccharides
[0077] (1) Establishment of HepG2 cell hypoglycemic model
[0078] During the experiment, we first used the MTT method to test the effect of different concentrations of insulin on the viability of HepG2 cells. -5 , 10 -6 , 10 -7 , 10 -8 and 10 -9 mol / L were used in subsequent experiments. Subsequently, we screened out the insulin concentration with the lowest glucose consumption in the cells among the above five concentrations based on the effect of different insulin concentrations on HepG2 cells. The results showed that the concentration of 10 -5 mol / L. Next, we determine the 10 -5 Based on the insulin concentration of 100 mol / L, we further explored the optimal duration of its action on HepG2 cells. Through multiple experimental comparisons, we determined that the optimal duration of insulin action on cells at this concentration is 24 hours. Finally, based on factors such as insulin concentration and action time obtained from the previous series of experiments, we determined the optimal duration of this experimental model, providing stable and reliable experimental conditions for subsequent research.
[0079] (2) Determination of hypoglycemic activity of wheat bran polysaccharides in vitro
[0080] An appropriate amount of wheat bran polysaccharide was weighed and dissolved in deionized water to prepare a 1 mg / mL polysaccharide solution, which was filtered through a 0.22 μm sterile filter membrane and added to HepG2 cells in an established hypoglycemic model. Glucose consumption was detected after 24 hours.
[0081] The hypoglycemic activity of the polysaccharides extracted from Example 1 and Comparative Example 1 was tested in HepG2 cells. The test results are shown in the attached specification. Figure 3 As shown. It can be seen that the hypoglycemic activity of the wheat bran polysaccharide extracted by Example 1 of the present invention is better than that of Comparative Example 1. When the concentration of the wheat bran polysaccharides extracted by the two different methods is 1 mg / mL, the wheat bran polysaccharide extracted by this method has a higher glucose consumption and better hypoglycemic activity. It can also be reflected that the wheat bran polysaccharide extracted by Example 1 of the present invention is higher in purity and better in activity than the wheat bran polysaccharide extracted by Comparative Example 1.
[0082] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.
Claims
1. A method for extracting feruloylarabinoxylan from wheat bran by ultrahigh pressure-high temperature-enzymatic hydrolysis, characterized in that: The following steps are involved: (1) the wheat bran is sequentially washed, filtered, and hydrolyzed with amylase to remove starch, and then the enzyme is deactivated to obtain a wheat bran residue; (2) drying and pulverizing the wheat bran residue in sequence to obtain wheat bran powder; (3) mixing the wheat bran powder with deionized water and subjecting it to ultrahigh pressure extraction to obtain a wheat bran solution; (4) subjecting the wheat bran solution to high-temperature extraction to obtain a wheat bran solution I; (5) adding xylanase to the wheat bran solution I for enzymolysis, inactivating the enzyme, adjusting the solution pH to 6.5 using an alkaline solution, and then centrifuging the solution. The obtained supernatant is concentrated to reduce the volume to 1 / 5 of the original volume to obtain a concentrated solution; (6) adding anhydrous ethanol to the concentrated solution to carry out a precipitation reaction; after the precipitation reaction is completed and allowed to stand, the obtained precipitate is subjected to solid-liquid separation; the obtained solid isolate is sequentially dissolved in water and hydrolyzed by papain; the obtained hydrolyzate is then sequentially subjected to enzyme inactivation, dialysis, and freeze-drying to obtain feruloylarabinoxylan; 2. The method for extracting feruloylarabinoxylan from wheat bran by ultrahigh pressure-high temperature-enzymatic hydrolysis according to claim 1, characterized in that: The amylase in step (1) is a high-temperature α-amylase.
3. The method for extracting feruloylarabinoxylan from wheat bran by ultrahigh pressure-high temperature-enzymatic hydrolysis according to claim 1, characterized in that: The average particle size of the wheat bran powder in step (2) is 50 meshes.
4. The method for extracting feruloylarabinoxylan from wheat bran by ultrahigh pressure-high temperature-enzymatic hydrolysis according to claim 1, characterized in that: The ultrahigh pressure extraction condition in step (3) is to place the mixed solution of wheat bran powder and deionized water at 400 MPa and keep it at 40° C. for at least 30 minutes.
5. The method for extracting feruloylarabinoxylan from wheat bran by ultrahigh pressure-high temperature-enzymatic hydrolysis according to claim 1, characterized in that: The high temperature extraction in step (4) is to keep the wheat bran solution at 90° C. for at least 2 hours.
6. The method for extracting feruloylarabinoxylan from wheat bran by ultrahigh pressure-high temperature-enzymatic hydrolysis according to claim 1, characterized in that: The pH range of xylan hydrolysis is 4.0-5.
5.
7. The method for extracting feruloylarabinoxylan from wheat bran by ultrahigh pressure-high temperature-enzymatic hydrolysis according to claim 1, characterized in that: The enzymatic hydrolysis temperature in step (5) is 50-55°C.
8. The method for extracting feruloylarabinoxylan from wheat bran by ultrahigh pressure-high temperature-enzymatic hydrolysis according to claim 1, characterized in that: In step (6), during the precipitation reaction of adding anhydrous ethanol to the concentrated solution, the addition of anhydrous ethanol is stopped after the mass concentration of ethanol in the concentrated solution reaches 80%, and the concentrated solution is then placed at a temperature of 4° C. for at least 12 hours.