Peanut protein amyloid fiber and preparation method thereof

Abstract

The invention relates to the technical field of peanut functional protein structure application, in particular to a peanut protein amyloid fiber and a preparation method thereof. The method specifically comprises the following steps: (1) mixing peanut meal with an organic solvent, degreasing to obtain degreased peanut powder, and preparing the degreased peanut powder into a degreased peanut powder solution; (2) centrifuging the degreased peanut powder solution for the first time, taking a supernatant, adjusting the pH value, standing, centrifuging for the second time, taking a precipitate, dialyzing, and freeze-drying to obtain peanut protein isolate; (3) hydrating the peanut protein isolate, centrifuging for the third time, taking supernatant to obtain a peanut protein isolate solution, adjusting the pH value, centrifuging for the fourth time, taking supernatant, and filtering to obtain a protein solution; and (4) carrying out fibrosis treatment on the protein solution to obtain the peanut protein amyloid fiber. The preparation method provided by the invention can improve the generation amount of the peanut protein amyloid fiber and increase the length of the fiber, and provides a theoretical basis for the application of the peanut protein amyloid fiber in the food industry.

Description

Technical Field

[0001] The invention relates to the technical field of peanut functional protein structure application, in particular to peanut protein amyloid fiber and a preparation method thereof. Background Art

[0002] Compared with dietary protein from animal sources, dietary protein from plant sources is popular due to its sustainability and health benefits. However, its poor functional properties (such as poor solubility and poor gelation) limit its wide application, so animal-based proteins with good functional properties have become a conventional choice in food development. However, the negative impact of animal protein production on the environment has been more strictly regulated in recent years. Therefore, it is urgent to partially or completely replace animal protein with plant protein.

[0003] Peanut meal is rich in nutrition, low in price, easy to obtain raw materials, high in protein content (50% to 60%), contains a variety of essential amino acids for the human body, and has high bioavailability. It is a high-quality source of plant protein. Peanut protein is often used as a by-product of peanut oil extraction and is mainly used in animal feed, fertilizer, etc., which causes a great waste of protein resources. Peanut meal has a high protein content and can be developed and utilized as an ideal substitute for animal protein. However, its application is limited due to its poor effect in the food field. Protein amyloid fibers have extremely high aspect ratios and high order, which give proteins excellent functional properties. Their unique structure has excellent irreversible interfacial adsorption and anti-aggregation properties, which can further enhance their functional properties. However, in the prior art, there is a lack of preparation methods related to peanut protein amyloid fibers, which limits the large-scale application of peanut protein amyloid fibers. Summary of the invention

[0004] The purpose of the present invention is to provide a method for promoting the formation of peanut protein amyloid fibers mediated by protein concentration in order to solve the problems of low added value of peanut protein in peanut meal, low conversion rate of peanut protein amyloid fibers and poor fiber morphology.

[0005] The method of the invention can improve the conversion rate of peanut protein amyloid fibers, increase the number and length of fibers, and the long fibers have better emulsification and foaming properties, which provides a theoretical basis for the application of peanut protein amyloid fibers in the food industry.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a method for preparing peanut protein amyloid fibers, comprising the following steps:

[0008] (1) mixing peanut meal with an organic solvent and defatting to obtain defatted peanut powder, and preparing a defatted peanut powder solution from the defatted peanut powder;

[0009] (2) centrifuging the defatted peanut powder solution for the first time to obtain the supernatant, adjusting the pH, standing, centrifuging for the second time to obtain the precipitate, dialysis and freeze-drying to obtain peanut protein isolate;

[0010] (3) after hydrating the peanut protein isolate, centrifuging for a third time to obtain a peanut protein isolate solution, adjusting the pH, centrifuging for a fourth time to obtain a supernatant, and filtering to obtain a protein solution;

[0011] (4) The protein solution is subjected to a fibrillation treatment to obtain peanut protein amyloid fibers.

[0012] Preferably, the organic solvent in step (1) is n-hexane or petroleum ether; the mass volume ratio of the peanut meal to the organic solvent is 10 g:40-60 mL; and the number of defatting is 1-3 times, each time for 1-2 hours.

[0013] Preferably, the defatted peanut powder solution in step (1) uses water as solvent, has a concentration of 8-12% (w / v), and a pH of 8-9.

[0014] Preferably, in step (2), the pH is adjusted to 4-5; and the standing time in step (2) is 25-35 minutes.

[0015] Preferably, the dialysis method in step (2) is: dialysis at 3 to 5°C using a dialysis bag with a molecular weight of 3300 to 3700 Da for 65 to 75 hours; the freeze-drying method is: pre-freeze at -75 to -85°C for 10 to 15 hours, and then freeze at -45 to -55°C for 40 to 60 hours.

[0016] Preferably, in step (3), the pH is adjusted to 1.8-2.2; the hydration method is: mixing the peanut protein isolate with water at 3-5°C, adjusting the pH to neutral and then standing for 10-15 hours; the concentration of the protein solution is 10-60 mg / mL.

[0017] Preferably, the method of the fibrosis treatment in step (4) is: placing the protein solution in a water bath at 80-90° C. for 8-12 hours, and then placing it in an ice bath for 8-12 minutes.

[0018] Preferably, step (4) further comprises the steps of dialyzing and freeze-drying the peanut protein amyloid fibers; the dialysis is performed by dialyzing for 40 to 60 hours using an 80 to 120 kDa dialysis bag in water at a pH of 1.8 to 2.2 at 3 to 5°C.

[0019] Preferably, the rotation speeds of the first centrifugation, the second centrifugation, the third centrifugation and the fourth centrifugation are all 7500-8000 rpm, and the time is all 5-20 min; and the ambient temperature during the first centrifugation, the second centrifugation, the third centrifugation and the fourth centrifugation is all 3-5°C.

[0020] The invention also provides peanut protein amyloid fibers prepared by the method for preparing the peanut protein amyloid fibers.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The invention significantly improves the conversion rate of peanut protein amyloid fibers by controlling the protein concentration during fibrillation, and increases the number and length of fibers. The preparation method of the invention improves the conversion rate of peanut protein amyloid fibers by 21.28%, increases the length of fibers, and increases the number of fibers, providing a theoretical basis for the application of peanut protein amyloid fibers in the food industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0024] Figure 1 is a process flow chart of the present invention;

[0025] Figure 2 The effect of protein concentration on the conversion rate of peanut protein amyloid fibrils and ThT fluorescence intensity;

[0026] Figure 3 The effect of protein concentration on the morphology of peanut protein starch fibers. DETAILED DESCRIPTION

[0027] The present invention provides a method for preparing peanut protein amyloid fibers, comprising the following steps:

[0028] (1) mixing peanut meal with an organic solvent and defatting to obtain defatted peanut powder, and preparing a defatted peanut powder solution from the defatted peanut powder;

[0029] (2) centrifuging the defatted peanut powder solution for the first time to obtain the supernatant, adjusting the pH, standing, centrifuging for the second time to obtain the precipitate, dialysis and freeze-drying to obtain peanut protein isolate;

[0030] (3) after hydrating the peanut protein isolate, centrifuging for a third time to obtain a peanut protein isolate solution, adjusting the pH, centrifuging for a fourth time to obtain a supernatant, and filtering to obtain a protein solution;

[0031] (4) The protein solution is subjected to a fibrillation treatment to obtain peanut protein amyloid fibers.

[0032] In the present invention, the organic solvent in step (1) is n-hexane or petroleum ether;

[0033] In the present invention, the mass volume ratio of the peanut meal to the organic solvent in step (1) is 10g:40-60mL; preferably 10g:44-56mL; further preferably 10g:48-52mL; more preferably 10g:50mL.

[0034] In the present invention, the degreasing process in step (1) is performed 1 to 3 times, each time for 1 to 2 hours; preferably, the degreasing process is performed 2 times, each time for 1 to 2 hours; and more preferably, the degreasing process is performed 2 times, each time for 1.5 hours.

[0035] In the present invention, the defatted peanut powder solution in step (1) uses water as solvent, has a concentration of 8-12% (w / v), and a pH of 8-9; preferably, the concentration is 9-11% (w / v), and the pH is 8-9; further preferably, the concentration is 10% (w / v), and the pH is 8-9; more preferably, the concentration is 10% (w / v), and the pH is 8.5.

[0036] In the present invention, the pH value in step (2) is adjusted to 4-5, preferably 4.5.

[0037] In the present invention, the standing time in step (2) is 25 to 35 min; preferably 27 to 33 min; more preferably 29 to 31 min; and more preferably 30 min.

[0038] In the present invention, the dialysis method in step (2) is: dialysis at 3-5°C for 65-75h using a dialysis bag with a molecular weight of 3300-3700Da; preferably, dialysis at 4°C for 67-73h using a dialysis bag with a molecular weight of 3400-3600Da; further preferably, dialysis at 4°C for 69-71h using a dialysis bag with a molecular weight of 3500Da; more preferably, dialysis at 4°C for 70h using a dialysis bag with a molecular weight of 3500Da.

[0039] In the present invention, the freeze-drying method in step (2) is: pre-freeze at -75 to -85°C for 10 to 15 hours, and then freeze at -45 to -55°C for 40 to 60 hours; preferably, pre-freeze at -77 to -83°C for 11 to 14 hours, and then freeze at -47 to -53°C for 44 to 56 hours; further preferably, pre-freeze at -79 to -81°C for 12 to 13 hours, and then freeze at -49 to -51°C for 48 to 52 hours; more preferably, pre-freeze at -80°C for 12 hours, and then freeze at -50°C for 50 hours.

[0040] In the present invention, the pH value in step (3) is adjusted to 1.8-2.2; preferably, the pH value is adjusted to 1.9-2.1; and more preferably, the pH value is adjusted to 2.

[0041] In the present invention, the hydration method of step (3) is: mixing the peanut protein isolate with water at 3-5°C, adjusting the pH to neutral and then letting it stand for 10-15 hours; preferably, mixing the peanut protein isolate with water at 4°C, adjusting the pH to neutral and then letting it stand for 11-14 hours; further preferably, mixing the peanut protein isolate with water at 4°C, adjusting the pH to neutral and then letting it stand for 12-13 hours; more preferably, mixing the peanut protein isolate with water at 4°C, adjusting the pH to neutral and then letting it stand for 12 hours.

[0042] In the present invention, the concentration of the protein solution in step (3) is 10 to 60 mg / mL; preferably 20 to 50 mg / mL; more preferably 30 to 40 mg / mL; and more preferably 35 mg / mL.

[0043] In the present invention, the method for the fiberization treatment in step (4) is: placing the protein solution in a water bath at 80-90° C. for 8-12 hours, and then placing it in an ice bath for 8-12 minutes; preferably, placing the protein solution in a water bath at 82-88° C. for 9-11 hours, and then placing it in an ice bath for 9-11 minutes; further preferably, placing the protein solution in a water bath at 84-86° C. for 10 hours, and then placing it in an ice bath for 10 minutes; more preferably, placing the protein solution in a water bath at 85° C. for 10 hours, and then placing it in an ice bath for 10 minutes.

[0044] In the present invention, step (4) further comprises the steps of dialyzing and freeze-drying the peanut protein amyloid fibers;

[0045] In the present invention, the dialysis is: dialysis for 40 to 60 hours in water with a pH of 1.8 to 2.2 at 3 to 5°C using a 80 to 120 kDa dialysis bag; preferably, the dialysis is: dialysis for 44 to 56 hours in water with a pH of 1.9 to 2.1 at 4°C using a 90 to 110 kDa dialysis bag; further preferably, the dialysis is: dialysis for 48 to 52 hours in water with a pH of 2 at 4°C using a 100 kDa dialysis bag; more preferably, the dialysis is: dialysis for 50 hours in water with a pH of 2 at 4°C using a 100 kDa dialysis bag.

[0046] In the present invention, the rotation speeds of the first centrifugation, the second centrifugation, the third centrifugation and the fourth centrifugation are all 7500-8000 rpm, and the time is 5-20 min; preferably, the rotation speed is 7600-7900 rpm, and the time is 10-15 min; further preferably, the rotation speed is 7700-7800 rpm, and the time is 11-14 min; more preferably, the rotation speed is 7800 rpm, and the time is 13 min.

[0047] In the present invention, the environmental temperature during the first centrifugation, the second centrifugation, the third centrifugation and the fourth centrifugation is 3-5°C, preferably 4°C.

[0048] The invention also provides peanut protein amyloid fibers prepared by the method for preparing the peanut protein amyloid fibers.

[0049] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0050] Example 1

[0051] Step 1: Preparation of defatted peanut meal: Peanuts are shelled and kernels are taken out, and then pressed in a hydraulic press at room temperature for 30 minutes at 60 MPa to obtain low-temperature peanut meal. The low-temperature peanut meal is crushed with a traditional Chinese medicine grinder, passed through an 80-mesh sieve and stored at 4°C for use; the low-temperature peanut meal is mixed with n-hexane at a mass volume ratio of 10g:40-60mL for defatting to obtain defatted peanut powder; the number of defatting is 1-3 times, each time for 1-2 hours.

[0052] Step 2: Preparation of peanut protein isolate: Take defatted peanut powder and add deionized water at a solid-liquid ratio of 1:10, adjust the pH of the solution to 8.5 with 2M NaOH, stir magnetically at room temperature for 2 hours, then centrifuge at 8000r / min for 10 minutes, collect the supernatant, adjust the pH of the supernatant to 4.5 with 2M HCl, let it stand for 30 minutes, centrifuge at 8000r / min for 10 minutes, collect the precipitate and resuspend it with deionized water, use a dialysis bag with a molecular weight of 3500Da, dialyze at 4°C for 72 hours, replace the dialysate every 8 hours, the dialysate is deionized water, and the protein solution after dialysis is pre-frozen at -80°C for 12 hours, freeze-dried and stored at -20°C for use;

[0053] Example 2

[0054] The peanut protein isolate prepared in Example 1 was dispersed in deionized water to prepare a protein stock solution with a mass fraction of 10% (w / v). The pH of the solution was adjusted to 7.0 with 2M sodium hydroxide, and the solution was fully hydrated at 4°C for 12h after stirring at 25°C. The peanut protein solution was centrifuged at 8000rpm for 20min, the pH of the protein solution was adjusted to 2.0, 8000rpm, and the supernatant was taken and filtered through a 0.45μm filter after centrifugation for 5min. The protein solubility was determined by the Coomassie Brilliant Blue method, and the protein solution was diluted to 10mg / mL. At the same time, the pH value was maintained at 2.0, and the fiberization treatment was carried out at 85°C for 10h. After the heating was completed, the solution was immediately ice-bathed for 10min and dialyzed with a 100kDa dialysis bag, and dialyzed at 4°C for 48h. The dialyzate was pH2.0 deionized water, and then freeze-dried to obtain the peanut protein amyloid fiber HPAFs-10C sample.

[0055] Example 3

[0056] The peanut protein isolate prepared in Example 1 was dispersed in deionized water to prepare a protein stock solution with a mass fraction of 10% (w / v). The pH of the solution was adjusted to 7.0 with a 2M sodium hydroxide solution, and the solution was fully hydrated at 4°C for 12 hours after stirring at 25°C. The peanut protein solution was centrifuged at 8000rpm for 20 minutes, the pH of the protein solution was adjusted to 2.0, and the supernatant was taken after centrifugation at 8000rpm for 5 minutes and filtered through a 0.45μm filter. The protein solubility was determined by the Coomassie Brilliant Blue method, and the protein solution was diluted to 20mg / mL. At the same time, the pH value was maintained at 2.0, and the fiberization treatment was carried out at 85°C for 10 hours. After the heating was completed, the solution was immediately dialyzed with a 100kDa dialysis bag in an ice bath for 10 minutes, and dialyzed at 4°C for 48 hours. The dialyzate was pH2.0 deionized water, and then freeze-dried to obtain the peanut protein amyloid fiber HPAFs-20C sample.

[0057] Example 4

[0058] The peanut protein isolate prepared in Example 1 was dispersed in deionized water to prepare a protein stock solution with a mass fraction of 10% (w / v). The pH of the solution was adjusted to 7.0 with a 2M sodium hydroxide solution, and the solution was fully hydrated at 4°C for 12h after stirring at 25°C. The peanut protein solution was centrifuged at 8000rpm for 20min, the pH of the protein solution was adjusted to 2.0, 8000rpm, and the supernatant was taken and filtered through a 0.45μm filter after centrifugation for 5min. The protein solubility was determined by the Coomassie Brilliant Blue method, and the protein solution was diluted to 40mg / mL. At the same time, the pH value was maintained at 2.0, and the fiberization treatment was carried out at 85°C for 10h. After the heating was completed, the solution was immediately dialyzed with a 100kDa dialysis bag in an ice bath for 10min, and dialyzed at 4°C for 48h. The dialyzate was pH2.0 deionized water, and then freeze-dried to obtain the peanut protein amyloid fiber HPAFs-40C sample.

[0059] Example 5

[0060] The peanut protein isolate prepared in Example 1 was dispersed in deionized water to prepare a protein stock solution with a mass fraction of 10% (w / v). The pH of the solution was adjusted to 7.0 with a 2M sodium hydroxide solution, and the solution was fully hydrated at 4°C for 12h after stirring at 25°C. The peanut protein solution was centrifuged at 8000rpm for 20min, the pH of the protein solution was adjusted to 2.0, 8000rpm, and the supernatant was taken and filtered through a 0.45μm filter after centrifugation for 5min. The protein solubility was determined by the Coomassie Brilliant Blue method, and the protein solution was diluted to 60mg / mL. At the same time, the pH value was maintained at 2.0, and the fiberization treatment was carried out at 85°C for 10h. After the heating was completed, the solution was immediately dialyzed with a 100kDa dialysis bag in an ice bath for 10min, and dialyzed at 4°C for 48h. The dialyzate was pH2.0 deionized water, and then freeze-dried to obtain the peanut protein amyloid fiber HPAFs-60C sample.

[0061] Comparative Example 1

[0062] The peanut protein isolate prepared in Example 1 was dispersed in deionized water to prepare a protein stock solution with a mass fraction of 10% (w / v). The pH of the solution was adjusted to 7.0 with 2M sodium hydroxide, and the solution was fully hydrated at 4°C for 12 hours after stirring at 25°C. The peanut protein solution was centrifuged at 8000rpm for 20min to adjust the pH of the protein solution to 2.0. After centrifugation at 8000rpm for 5min, the supernatant was taken and filtered through a 0.45μm filter. The protein solubility was determined by the Coomassie Brilliant Blue method, and the protein solution was diluted to 10mg / mL. At the same time, the pH value was maintained at 2.0, and then freeze-dried to obtain the UPPIs-10C sample.

[0063] Experimental Example 1

[0064] The Th T (Thioflavin T) fluorescence intensity and fiber conversion rate of the peanut protein amyloid fibers prepared in Examples 2 to 5 were tested. The microscopic morphology of the peanut protein amyloid fibers prepared in Examples 2 to 5 and the peanut protein isolate obtained in Comparative Example 1 was analyzed using an atomic force microscope.

[0065] (1) ThT fluorescence intensity and fiber conversion rate

[0066] ThT fluorescence intensity: 16 mg Th T was dissolved in 10 mL phosphate buffer (10 mM, pH 7.4) to prepare Th T working solution. 160 μL of the diluted sample was mixed with 4 mL Th T working solution and reacted for 5 min. The Th T fluorescence intensity of the sample with an excitation wavelength of 420 nm and an emission wavelength of 485 nm was measured by a spectrophotometer. The fluorescence intensity of the Th T working solution was used as the background.

[0067] (2) Fiber conversion rate: The freeze-dried fiber sample was diluted with Wahaha water (pH 2.0) to 10 mg / mL. Then 1 mL of the diluted sample was placed on a 100 kDa centrifugal filter, 19 mL of pH 2.0 water was added, and the filtrate was collected after centrifugation at 5000 g and 4 °C for 20 min. After each centrifugation, pH 2.0 water was added to the tube to wash the retained solution until no protein was detected in the washed retained solution. All filtrates were mixed, and their total volume was measured with a measuring bucket, and the protein concentration was determined by the Bradford method. The formula for calculating the original fiber conversion rate is as follows:

[0068]

[0069] Where m0 represents the amount of total protein and non-aggregated peptides, c1 and v1 represent the protein concentration and volume of the filtrate

[0070] (3) Atomic force microscopy analysis

[0071] The lyophilized fibril samples of Examples 2 to 5 and Comparative Example 1 were dissolved in deionized water (pH 2.0), and a few drops of the fibril solution were dispersed on a new mica disk. After the fiber solution was completely dried, the sample on the mica sheet was scanned with an atomic force microscope to capture all AFM images. All AFM images were processed and analyzed using Nanoscope Analysis software v1.9 and FiberApp software. The obtained ThT fluorescence intensity and fiber conversion rate are shown in Figure 2 The atomic force microscopy analysis obtained is shown in Figure 3 shown.

[0072] Comparative analysis of the above examples revealed that compared with the unfibrillated peanut protein, the fibrillated groups formed amyloid fibers. In addition, compared with the fibers formed at a protein concentration of 10 mg / mL, increasing the protein concentration (20, 40, 60 mg / mL) increased the fiber conversion rate, and the proportion of fibers with a length of 200 to 400 nm increased. At a concentration of 40 mg / mL, fibers greater than 400 nm appeared. As the protein concentration continued to increase to 60 mg / mL, the proportion of fibers greater than 400 nm increased. Increasing protein concentration promotes the formation of β-folded structures (see Figure 3), the fiber quantity and fiber length increase, which improves the application prospects of peanut protein isolate.

[0073] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing peanut protein amyloid fibers, characterized in that: The steps include: (1) mixing peanut meal with an organic solvent and defatting to obtain defatted peanut powder, and preparing a defatted peanut powder solution from the defatted peanut powder; (2) centrifuging the defatted peanut powder solution for the first time to obtain the supernatant, adjusting the pH, standing, centrifuging for the second time to obtain the precipitate, dialysis and freeze-drying to obtain peanut protein isolate; (3) after hydrating the peanut protein isolate, centrifuging for a third time to obtain a peanut protein isolate solution, adjusting the pH, centrifuging for a fourth time to obtain a supernatant, and filtering to obtain a protein solution; (4) The protein solution is subjected to a fibrillation treatment to obtain peanut protein amyloid fibers.

2. The preparation method according to claim 1, characterized in that: The organic solvent in step (1) is n-hexane or petroleum ether; the mass volume ratio of the peanut meal to the organic solvent is 10 g:40-60 mL; the number of degreasing is 1-3 times, each time for 1-2 hours.

3. The preparation method according to claim 1, characterized in that: The defatted peanut powder solution in step (1) uses water as solvent, has a concentration of 8-12% (w / v) and a pH of 8-9.

4. The preparation method according to claim 1, characterized in that: In step (2), the pH is adjusted to 4-5; and the standing time is 25-35 minutes.

5. The preparation method according to claim 1, characterized in that: The dialysis method in step (2) is: dialysis at 3-5°C using a dialysis bag with a molecular weight of 3300-3700Da for 65-75h; the freeze-drying method is: pre-freeze at -75--85°C for 10-15h, and then freeze at -45--55°C for 40-60h.

6. The preparation method according to claim 1, characterized in that: In step (3), the pH is adjusted to 1.8-2.2; the hydration method is: mixing the peanut protein isolate with water at 3-5°C, adjusting the pH to neutral and then standing for 10-15 hours; the concentration of the protein solution is 10-60 mg / mL.

7. The preparation method according to claim 1, characterized in that: The method of the fibrosis treatment in step (4) is: the protein solution is placed in a water bath at 80-90° C. for 8-12 hours, and then placed in an ice bath for 8-12 minutes.

8. The preparation method according to claim 1, characterized in that: Step (4) also includes the steps of dialyzing and freeze-drying the peanut protein amyloid fibers; the dialysis is: dialyzing for 40 to 60 hours using an 80 to 120 kDa dialysis bag in water at a pH of 1.8 to 2.2 at 3 to 5°C.

9. The preparation method according to claim 1, characterized in that: The rotation speeds of the first, second, third and fourth centrifugations are all 7500-8000 rpm, and the time is all 5-20 min; the ambient temperature during the first, second, third and fourth centrifugations is all 3-5°C.

10. Peanut protein amyloid fibers prepared by the method for preparing peanut protein amyloid fibers according to any one of claims 1 to 9.

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