Method for improving quality of wheat flour through static magnetic field treatment and application of method

Abstract

The invention discloses a method for improving the quality of wheat flour and noodles thereof through static magnetic field treatment and application of the method, and belongs to the technical field of food processing. The method comprises the following steps: treating wheat flour in a static magnetic field of 1-15mT for 6-100 hours; the rheological property and the mechanical stirring resistance of the dough of the wheat flour are improved by controlling the treatment of the static magnetic field; hydrophobic amino acids such as gluten egg white amino acid and tyrosine are promoted to be embedded in the protein, so that the protein structure is more aggregated; the texture property and the cooking quality of the wheat noodle product are improved. According to the method, the processing performance of the spring wheat dough and the quality of gluten protein are remarkably improved. In addition, the method for improving the quality of the wheat flour is environment-friendly, harmless to human bodies, low in processing cost and simple to operate, and has industrial application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of food processing, and particularly relates to a method for improving the quality of wheat flour by static magnetic field treatment and application thereof. Background Art

[0002] Wheat is currently the food crop with the highest yield, the widest planting range, rich nutritional components and good processing characteristics. It is also the main source of food. Various flour products made from wheat flour are very popular among consumers. Affected by the geographical environment and climatic conditions, the quality of spring wheat is relatively poor, mainly manifested in low protein content, low gluten content in wheat flour, poor gluten extensibility and viscoelasticity, and weak gluten strength, which affects its processing quality and edible quality, and is regarded as "low-quality" wheat. Due to the high requirements of consumers for food quality, the requirements for flour products have gradually diversified. At the same time, the wheat flour market is becoming increasingly competitive. Therefore, the market demand for the quality of wheat flour is getting higher and higher.

[0003] At present, the methods for improving the quality of wheat flour can be roughly divided into three types: enzyme preparations, chemical methods and physical methods. The physical modification method of wheat flour is relatively safe and has low economic cost, mainly including controlling the production process of wheat flour, adding ingredients already contained in food components to enhance its functionality or nutritional value, and heat treating wheat flour. However, thermal processing technology will reduce the loss of nutrients during food processing to a certain extent. Non-thermal processing technologies mainly include magnetic fields, pulsed electric fields (PEF), ultrasonic (US) high hydrostatic pressure, ultraviolet radiation, etc. In the field of food processing, most of the existing technical research applies magnetic fields to the preservation and freshness of food, thanks to the characteristics that magnetic fields can change the permeability of biological membranes, affect the biochemical reactions of organisms, and inhibit the activity of biological enzymes.

[0004] Low-quality wheat flour, represented by spring wheat flour, has poor quality. Existing methods for improving wheat quality are mostly heat treatment, enzymatic treatment, or chemical methods, which have disadvantages such as nutritional loss, high production energy consumption, and potential safety hazards. It is necessary to develop a quality improvement method to improve the quality of low-quality wheat products, represented by spring wheat. Summary of the invention

[0005] In order to improve the problems of the prior art, the present invention uses a static magnetic field to treat wheat flour. By adjusting the intensity and time of the magnetic field treatment, a method for improving the quality of wheat flour using a static magnetic field is provided, which significantly improves the processing performance of spring wheat dough and the quality of gluten protein.

[0006] The first aspect of the present invention is to provide a method for improving the quality of wheat flour by static magnetic field treatment, wherein the wheat flour is placed in a static magnetic field for 6 to 100 hours, and the magnetic field strength is 1 to 15 mT. Magnetic field treatment is an environmentally friendly and economically friendly technology. It is harmless to the human body and has a low processing cost.

[0007] Furthermore, the wheat includes but is not limited to spring wheat.

[0008] In some embodiments of the present invention, the wheat varieties used are Abo and Gaoyuan 437;

[0009] Further, the steps of improving the quality of wheat flour include:

[0010] S11. Spread the wheat flour flat and seal it in a sealed bag;

[0011] S12. Place the sealed wheat flour in a static magnetic field for 12 to 96 hours with a magnetic field strength of 1 to 10 mT.

[0012] In some embodiments, the step of removing impurities, grinding and removing bran from the wheat grains is further included before step S11; preferably, the step of sieving is further included after the bran is removed. In some embodiments, the sieving step uses a 100-mesh sieve.

[0013] In some embodiments, the method for improving the quality of wheat flour further includes the following steps: cleaning the spring wheat grains, grinding them and removing the bran; sieving the wheat flour and sealing it in a polyethylene sealed bag; and placing the sealed wheat flour in a static magnetic field with a magnetic field strength of 1 to 10 mT for 48 to 96 hours.

[0014] Furthermore, in step S11, the thickness of the wheat flour is ≤10 cm;

[0015] In some embodiments, the wheat flour is spread to a thickness of 1-10 cm;

[0016] In some preferred embodiments, the wheat flour is laid to a thickness of 2 cm;

[0017] Furthermore, in step S12, during the static magnetic field treatment, the temperature of the magnetic field environment is controlled to be 15-35° C. and the frequency to be 0-50 Hz.

[0018] In some embodiments, during the static magnetic field treatment, the temperature of the magnetic field environment is controlled to be 25° C., the frequency is 50 Hz, and the excitation current is 8A.

[0019] In one embodiment of the present invention, in step S12, the static magnetic field treatment step places the sealed wheat flour in a magnetic field incubator test rack for treatment.

[0020] The second aspect of the present invention is to provide wheat flour prepared by the method described above. The quality improvement method provided by the present invention can greatly improve the quality of low-quality wheat represented by spring wheat and expand the scope of application. Studies have shown that the requirements for C2 values ​​of biscuits and cakes are generally in the range of 0.35-0.45N·m. The wheat flour prepared by the method of the present invention can be used in flour products such as biscuits and cakes.

[0021] The third aspect of the present invention is to provide the application of the wheat flour prepared by the method described above in the food field.

[0022] Furthermore, the method is applied to prepare a series of products represented by raw wet noodles, biscuits and cakes.

[0023] Further, when used to prepare raw wet noodles, the preparation method comprises the following steps:

[0024] S21, mixing the wheat flour according to claim 7 with water, kneading for 3-10 minutes to obtain dough, and using a dough press to repeatedly roll the kneaded dough for the first time for 3-10 times to obtain a dough sheet;

[0025] S22, placing the dough obtained in step S1 in a 38° C. proofing box and sealing it to allow the dough to fully absorb water;

[0026] S23, repeatedly rolling the dough after proofing for 2-8 times to make it into a dough with fine texture, flatness and smoothness, and then cutting it into strips.

[0027] In one embodiment of the present invention, the preparation method of the raw wet noodles comprises the following steps: S21, mixing wheat flour and water, kneading the dough for 5 minutes to obtain dough, and using a dough press to repeatedly roll the kneaded dough for the first time to obtain a dough sheet; S22, placing the dough sheet obtained in step S21 in a proofing box and sealing it for proofing, so that the dough can fully absorb water; S23, repeatedly rolling the proofed dough sheet for a second time to make it into a dough sheet with fine texture, flatness and smoothness; and cutting it into noodles.

[0028] Furthermore, in step S21, the mass ratio of wheat flour to water in the dough kneading process is 100:30-100:40;

[0029] In a preferred embodiment, the mass ratio of wheat flour to water is 100:35.

[0030] In one embodiment of the present invention, the first repeated calendering in step S21 is performed 8 times.

[0031] In one embodiment of the present invention, in step S22, the proofing temperature is 38°C, and the proofing time is 20 minutes.

[0032] In one embodiment of the present invention, in step S23, the second repeated calendering is performed four times.

[0033] The beneficial effects of the present invention are at least:

[0034] The method for improving the quality of wheat flour provided by the present invention is easy to operate, has mild conditions, has low energy consumption, and reduces production costs. The improvement method provided by the present invention significantly improves the viscoelasticity of wheat dough and enhances the stability of the dough;

[0035] The improvement method provided by the present invention significantly improves the thermomechanical properties of wheat dough, wherein the gluten weakening valley value (C2) is increased from 0.349 N·m to 0.362 N·m (the higher the gluten weakening valley value, the better the high temperature resistance and stirring property of the gluten);

[0036] The spring wheat flour improved by the present invention can achieve a gluten weakening valley value of 0.362 N·m after being made into dough, which can be applied to flour products such as biscuits and cakes, thereby improving the economic value of low-quality wheat flour.

[0037] The quality improvement method of the present invention significantly improves the aggregation characteristics of wheat flour gluten protein, the gluten protein structure is in a more aggregated state, and the surface hydrophobicity index is reduced by 33.29%; the prepared noodles reduce the cooking loss rate by 23.9%, increase the elasticity by 8.5%, and significantly improve the quality of the noodles. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings are used to provide a further understanding of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the accompanying drawings:

[0039] Figure 1 The rheological properties of spring wheat dough in Examples 1 to 6 and Comparative Example 1;

[0040] Figure 2 The atomic force microscope morphology images of spring wheat gluten proteins in Examples 1 to 6 and Comparative Example 1 (AG are gluten protein samples prepared from spring wheat flour in Comparative Example 1 and Examples 1 to 6, respectively);

[0041] Figure 3 It is the fluorescence spectra of spring wheat gluten protein in Examples 1 to 6 and Comparative Example 1. DETAILED DESCRIPTION

[0042] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the technical methods in the embodiments of the present invention are described more clearly and completely below. In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but are not limited to the following specific implementation cases. The experimental methods in the following embodiments, unless otherwise specified, are conventional methods in the art.

[0043] Raw materials and reagents in the present invention:

[0044] Abo spring wheat, Northwest Institute of Plateau Biology, Chinese Academy of Sciences (Qinghai, China);

[0045] Plateau 437, Northwest Institute of Plateau Biology, Chinese Academy of Sciences (Qinghai, China);

[0046] 8-Aniline-1-benzenesulfonic acid, glacial acetic acid, sodium dihydrogen phosphate, disodium hydrogen phosphate, sodium chloride, etc., were purchased from Sinopharm Chemical Reagent Co., Ltd. All chemical reagents were of analytical grade.

[0047] The instruments and equipment in the present invention include: electronic analytical balance (AX224ZH / E), Ohaus Instrument (Changzhou) Co., Ltd.; high-speed centrifuge (LXJ-IIB), Shanghai Anting Scientific Instrument Factory; ultraviolet spectrophotometer (UV-3200), Shanghai Mepta Instrument Co., Ltd.; fluorescence spectrometer (F7000), Hitachi, Japan; experimental mixer (Mixolab2), Chopin Technology, France; rotational rheometer (MCR302), Anton Paar, Austria; atomic force microscope (Dimension FastScan), Bruker, Germany; physical property analyzer (TA.XTPlus), SMS, UK.

[0048] Test method:

[0049] 1. Dough performance test

[0050] (1) Determination of thermomechanical properties

[0051] The standard “Chopin” mixing tester is used + " protocol was used to determine the thermomechanical properties of wheat flour dough. The experimental parameters were: moisture base 14% (wet basis), dough mass 75g, target torque 1.1Nm±0.05Nm, rotation speed 80r / min; the measurement process included three stages: the dough forming stage was carried out at a constant temperature of 30℃ for 8min, the heating stage increased at a rate of 4℃ / min to 90℃, maintained at 90℃ for 7min, and then the cooling stage decreased at a rate of 4℃ / min to 50℃, and maintained at 50℃ for 5min.

[0052] (2) Rheological properties measurement

[0053] Prepare fresh dough, press a 5g dough sample from rest into a 2mm dough sheet, and select a PP50 probe. After the sample is loaded, gently scrape off the excess edges, set the test gap to 2mm, and the temperature to 25°C. Perform a strain sweep test from 0.001% to 100% at a frequency of 1Hz to determine the linear viscoelastic region of the dough. Perform a frequency sweep experiment in the range of 0.01Hz to 100Hz at a constant strain of 0.01%. Determine the difference between the storage modulus and the loss modulus of the fresh dough, which are abbreviated as G′ and G″, respectively.

[0054] 2. Performance test of gluten protein

[0055] Preparation of gluten protein:

[0056] Weigh 60g of wheat flour, add 30mL of 20g / L sodium chloride (NaCl) solution, mix at room temperature for 3min to form dough. After standing for 15min, wash with 20g / L NaCl solution until gluten is formed. Then wash the gluten with sufficient deionized water until NaCl is completely removed. After freeze drying, high-speed intermittent grinding for 30s and pass through a 60-mesh sieve.

[0057] (1) Observation of gluten protein microstructure

[0058] The gluten protein sample (0.01 mg) was dissolved in 0.5 mol / L glacial acetic acid solution (1 mL) to prepare a 0.01 mg / mL sample solution. 10 μL of the mixture was deposited on an AFM mica sheet and quickly air-dried at 25 °C to evaporate the solvent. After the sample sheet was placed on the instrument operating table, each sample was scanned in 6 different areas at a resonant frequency of 2 kHz and an elastic modulus of 0.4 N / m, with an area range of 2×2 μm. AFM images were analyzed using NanoScope Analysis software.

[0059] (2) Endogenous fluorescence spectrum of gluten protein

[0060] Dissolve 100 mg of gluten protein sample in 0.01 mol / L pH 7.4 phosphate buffer to prepare a 5.0 mg / mL suspension. Vortex for 3-5 minutes, centrifuge at 25°C, 8000 r / min for 10 minutes, and take the supernatant for fluorescence spectrum scanning.

[0061] (3) Determination of surface hydrophobicity of gluten protein

[0062] Weigh 0.4g of gluten protein sample and dissolve it in 15mL phosphate buffer (10mM, pH 7.4), vortex mix, centrifuge at 15℃, 8000r / min for 10min, take the supernatant and dilute it into gluten protein solutions of different concentrations (0.005%, 0.01%, 0.01%, 0.05%, 0.1%). Take 4mL of gluten protein solutions of different concentrations and add 20μL of 8.0mM ANS solution respectively, incubate at room temperature for 30min, and quickly measure the fluorescence intensity at an excitation wavelength of 390nm and an absorption wavelength of 470nm.

[0063] 3. Determination of noodle cooking characteristics

[0064] (1) Cooking time: Cut the dough into noodles (7 cm × 0.8 cm × 0.1 cm), then measure 450 mL of distilled water and boil it in a pot. Adjust the power of the induction cooker to 1400 W, put in 20 accurately weighed fresh wet noodles, and press the timer at the same time. Within 3 minutes, take a noodle every 30 seconds, put it between two layers of transparent glass plates, and gently squeeze it to observe whether the white core in the middle of the noodle has disappeared. After cooking for 3 minutes, randomly sample the noodles every 15 seconds and observe them in the same way as above. The time when the white core of the fresh wet noodles just disappears is the optimal cooking time.

[0065] (2) Water absorption rate of noodles: Take 15g of noodles and put them into 300mL of boiling water. Cook until the optimal cooking time. Then take them out and use filter paper to absorb the water on the surface of the cooked noodles. Weigh and record. Where: W A : Water absorption index of fresh wet noodles, %; M1: Mass of fresh wet noodles after cooking, g; M2: Mass of fresh wet noodles before cooking, g; W: Water content of fresh wet noodles, %.

[0066]

[0067] (3) Cooking loss rate: Take 15g of fresh wet noodles, then put the noodles into 300mL of boiling water and cook until the optimal cooking time. Then take them out and pour the remaining noodle soup into a 500mL beaker that has been weighed and recorded. Place the beaker on an infrared electric heating stove to evaporate the water. Stop heating when the remaining noodles are less than 10mL. Then place the beaker in a 105℃ forced air drying oven and dry until constant weight is reached. Calculate the cooking loss rate of the noodles. Where, C L : cooking loss rate of fresh wet noodles, %; M: mass of residual dry matter in noodle soup, g; G: mass of fresh wet noodles before cooking, g; W: moisture content of fresh wet noodles, %.

[0068]

[0069] (4) Determination of noodle texture characteristics

[0070] After the fresh noodles are cooked to the optimal cooking time, they are taken out and cooled to room temperature. The middle section is taken for texture profile analysis test. The P / 50 probe is selected and the test parameters are set as follows: the height of the sample rising to the sample surface is 15mm; the deformation percentage is 75%; the detection speed is 60mm / min; the starting force is 0.1N, and the interval time is 2s. Each sample is tested 6 times in parallel.

[0071] Example 1

[0072] A method for improving wheat flour quality by static magnetic field treatment comprises the following steps:

[0073] (1) selecting whole spring wheat with full grains and no mildew, disease or insect pests, cleaning the spring wheat grains, removing bran and grinding them into flour;

[0074] (2) passing the spring wheat flour treated in step (1) through a 100-mesh sieve, and the sieved flour is considered clean if there is no residue on the sieve;

[0075] (3) Spread the spring wheat flour treated in step (2) flatly and seal it in a polyethylene bag so that it is evenly distributed in the polyethylene sealed bag with a thickness of 2 cm, ensuring that there is no bulging in the bag due to gas;

[0076] (4) The spring wheat flour was placed in a magnetic field incubator experimental area at 25°C, a magnetic field strength of 3 mT, a frequency of 50 Hz, and an excitation current of 8 A for 48 h.

[0077] The method for preparing raw wet noodles comprises the following steps:

[0078] 100 parts of spring wheat flour treated with a static magnetic field are mixed with 35 parts of water, and the dough is kneaded for 5 minutes to obtain a dough. The kneaded dough is repeatedly rolled 8 times for the first time using a dough press to obtain a dough sheet. The dough sheet is sealed and proofed in a 38°C proofing box for 20 minutes to allow the dough to fully absorb water. The proofed dough sheet is repeatedly rolled 4 times for a second time to make it a fine, smooth and flat dough sheet. The fine, smooth and flat dough sheet is cut into noodles. The thickness of the noodles is about 1.5 mm, and the width of the noodles is about 8 mm.

[0079] Example 2

[0080] The difference between Example 2 and Example 1 is that the static magnetic field related parameters in the wheat flour quality modification method are different.

[0081] A method for improving wheat flour quality by static magnetic field treatment comprises the following steps:

[0082] (1) selecting whole spring wheat with full grains and no mildew, disease or insect pests, cleaning the spring wheat grains, removing bran and grinding them into flour;

[0083] (2) passing the spring wheat flour treated in step (1) through a 100-mesh sieve, and the sieved flour is considered clean if there is no residue on the sieve;

[0084] (3) Spread the spring wheat flour treated in step (2) flatly and seal it in a polyethylene bag so that it is evenly distributed in the polyethylene sealed bag with a thickness of 2 cm, ensuring that there is no bulging in the bag due to gas;

[0085] (4) The spring wheat flour was placed in a magnetic field incubator experimental area at 25°C, a magnetic field strength of 6 mT, a frequency of 50 Hz, and an excitation current of 8 A for 48 h.

[0086] The preparation method of raw wet noodles is the same as that of Example 1.

[0087] Example 3

[0088] The difference between Example 3 and Example 1 is that the static magnetic field related parameters in the wheat flour quality modification method are different.

[0089] A method for improving wheat flour quality by static magnetic field treatment comprises the following steps:

[0090] (1) selecting whole spring wheat with full grains and no mildew, disease or insect pests, cleaning the spring wheat grains, removing bran and grinding them into flour;

[0091] (2) passing the spring wheat flour treated in step (1) through a 100-mesh sieve, and the sieved flour is considered clean if there is no residue on the sieve;

[0092] (3) Spread the spring wheat flour treated in step (2) flatly and seal it in a polyethylene bag so that it is evenly distributed in the polyethylene sealed bag with a thickness of 2 cm, ensuring that there is no bulging in the bag due to gas;

[0093] (4) The spring wheat flour was placed in a magnetic field incubator experimental area at 25°C, a magnetic field strength of 10 mT, a frequency of 50 Hz, and an excitation current of 8 A for 48 h.

[0094] The preparation method of raw wet noodles is the same as that of Example 1.

[0095] Example 4

[0096] The difference between Example 4 and Example 1 is that the static magnetic field related parameters in the wheat flour quality modification method are different.

[0097] A method for improving wheat flour quality by static magnetic field treatment comprises the following steps:

[0098] (1) selecting whole spring wheat with full grains and no mildew, disease or insect pests, cleaning the spring wheat grains, removing bran and grinding them into flour;

[0099] (2) passing the spring wheat flour treated in step (1) through a 100-mesh sieve, and the sieved flour is considered clean if there is no residue on the sieve;

[0100] (3) Spread the spring wheat flour treated in step (2) flatly and seal it in a polyethylene bag so that it is evenly distributed in the polyethylene sealed bag with a thickness of 2 cm, ensuring that there is no bulging in the bag due to gas;

[0101] (4) The spring wheat flour was placed in a magnetic field incubator experimental area at 25°C, with a magnetic field strength of 3 mT, a frequency of 50 Hz, and an excitation current of 8 A for 96 h.

[0102] The preparation method of raw wet noodles is the same as that of Example 1.

[0103] Example 5

[0104] The difference between Example 5 and Example 1 is that the static magnetic field related parameters in the wheat flour quality modification method are different.

[0105] A method for improving wheat flour quality by static magnetic field treatment comprises the following steps:

[0106] (1) selecting whole spring wheat with full grains and no mildew, disease or insect pests, cleaning the spring wheat grains, removing bran and grinding them into flour;

[0107] (2) passing the spring wheat flour treated in step (1) through a 100-mesh sieve, and the sieved flour is considered clean if there is no residue on the sieve;

[0108] (3) Spread the spring wheat flour treated in step (2) flatly and seal it in a polyethylene bag so that it is evenly distributed in the polyethylene sealed bag with a thickness of 2 cm, ensuring that there is no bulging in the bag due to gas;

[0109] (4) The spring wheat flour was placed in a magnetic field incubator experimental area at 25°C, a magnetic field strength of 6 mT, a frequency of 50 Hz, and an excitation current of 8 A for 96 h.

[0110] The preparation method of raw wet noodles is the same as that of Example 1.

[0111] Example 6

[0112] The difference between Example 6 and Example 1 is that the static magnetic field related parameters in the wheat flour quality modification method are different.

[0113] A method for improving wheat flour quality by static magnetic field treatment comprises the following steps:

[0114] (1) selecting whole spring wheat with full grains and no mildew, disease or insect pests, cleaning the spring wheat grains, removing bran and grinding them into flour;

[0115] (2) passing the spring wheat flour treated in step (1) through a 100-mesh sieve, and the sieved flour is considered clean if there is no residue on the sieve;

[0116] (3) Spread the spring wheat flour treated in step (2) flatly and seal it in a polyethylene bag so that it is evenly distributed in the polyethylene sealed bag with a thickness of 2 cm, ensuring that there is no bulging in the bag due to gas;

[0117] (4) The spring wheat flour was placed in a magnetic field incubator experimental area at 25°C, a magnetic field strength of 10 mT, a frequency of 50 Hz, and an excitation current of 8 A for 96 h.

[0118] The preparation method of raw wet noodles is the same as that of Example 1.

[0119] Example 7

[0120] The difference between Example 7 and Example 4 is that the wheat variety used is Plateau 437.

[0121] Example 8

[0122] The difference between Example 8 and Example 5 is that the wheat variety used is Plateau 437.

[0123] Example 9

[0124] The difference between Example 9 and Example 6 is that the wheat variety used is Plateau 437.

[0125] Comparative Example 1

[0126] The difference between Comparative Example 1 and Example 1 is that no magnetic field is applied in step (4).

[0127] Comparative Example 2

[0128] The difference between Comparative Example 2 and Comparative Example 1 is that the wheat variety used is Plateau 437.

[0129] 1. Analysis of dough related properties:

[0130] After dough was prepared using the wheat flour treated in the example and the wheat flour of the comparative example according to the method for preparing raw wet noodles, the relevant properties of the dough were studied.

[0131] 1. Dynamic rheological properties of dough

[0132] Effects of magnetic field treatment on rheological properties of spring wheat dough Figure 1 The dynamic rheological properties of dough in the linear viscoelastic region can be used to track the structural and physicochemical properties of dough, study the functions of its components, and effectively predict the behavior of dough during processing and the quality of the final product.

[0133] With the increase of angular frequency, the G' of most samples is greater than G" (i.e. tanδ <1), indicating that spring wheat dough exhibits obvious solid-phase behavior; with the increase of frequency, the G' and G" of the dough increase, indicating that spring wheat dough has a certain frequency dependence. The dough should contain both strong covalent bonds and relatively weak non-covalent bonds, such as hydrogen bonds, and may also contain some weaker other forces, such as molecular entanglement. Figure 1 It can be seen that the magnetic field treatment increases the storage modulus (G') and loss modulus (G") of the dough of the embodiment, indicating that the magnetic field treatment enhances the stability of the dough of the embodiment compared with the comparative example, and enhances the interaction between molecules in the dough structure.

[0134] 2. Thermomechanical properties of dough

[0135] The effect of magnetic field treatment on the mixing characteristics of spring wheat dough is shown in Table 1. The raw materials of Examples 1-6 and Comparative Example 1 are Abo spring wheat; the raw materials of Examples 7-9 and Comparative Example 2 are Plateau 437.

[0136] Compared with Comparative Example 1, in Examples 1-6, as the magnetic field intensity increases, the viscosity index remains unchanged, and the viscosity disintegration value (C3-C4), gluten weakening valley value C2, peak viscosity C3, maintained viscosity C4, and endpoint viscosity C5 all increase to varying degrees; as the magnetic field treatment time increases, the viscosity index decreases, the viscosity characteristics do not change much, and the gluten weakening valley value C2 increases.

[0137] The size of the gluten weakening valley C2 value reflects the high temperature stirring resistance of gluten, and is related to the content and quality of gluten. The disintegration value reflects the shear resistance of dough at high temperature. The lower the disintegration value, the better the shear resistance of the sample and the better the thermal paste stability. The C3, C4, and C5 values ​​represent the gelatinization characteristics of starch in the dough. The C3 peak viscosity value reflects the balance point between the increase in viscosity caused by swelling and polymer escape and the decrease in viscosity caused by rupture and polymer rearrangement. C3 shows the ability of the mixture to bind water, which is related to the quality of the final product. The peak viscosity of starch gelatinization is related to its water absorption and expansion ability. It shows that magnetic field treatment has a certain effect on the water absorption and expansion ability and regeneration characteristics of the dough, and improves the mechanical stirring resistance and thermal paste stability of the dough. Among them, the comprehensive performance of the thermomechanical properties of Example 6 is the best.

[0138] The experimental results of Examples 7-9 and Comparative Example 2 further verified the above conclusions.

[0139] Table 1 Thermomechanical properties of spring wheat dough in different embodiments and comparative examples

[0140]

[0141] 2. Test results of gluten protein related properties:

[0142] The wheat flour prepared in Examples 1 to 6 and Comparative Example 1 was made into gluten protein, and the relevant properties of the gluten protein were tested. The results are as follows:

[0143] 1. Observation of gluten protein microstructure

[0144] Atomic force microscopy (AFM) is a powerful tool for detecting the fine structure and surface morphology of gluten protein, with the advantages of high resolution and non-destructive detection. AFM can provide the original state of the surface structure of macromolecules to the greatest extent.

[0145] The two-dimensional scanning image, three-dimensional scanning image and surface overall morphology analysis of gluten protein are shown in the figure. Figure 2 As shown. Compared with the comparative example, the surface of the gluten protein in the embodiment is rougher, and the root mean square roughness and surface height of the embodiment increase. As the magnetic field treatment time and treatment intensity increase, this change is more significant. After 96 hours of treatment under 10mT magnetic field conditions, the root mean square roughness increases from 0.169nm of the original gluten protein to 0.571nm. Hillock-like substances of different sizes appear in the morphology, which are mainly caused by macromolecular aggregates of gluten in gluten protein. The formation of disulfide bonds between gluten and alcohol-soluble proteins in spring wheat flour treated with a magnetic field causes the aggregation of gluten protein, affecting the functional properties of gluten protein, thereby affecting the processing quality of spring wheat flour, and improving the toughness and processing strength of the dough, which corresponds to the results of the thermomechanical properties of the dough.

[0146] 2. Spectral analysis of changes in the microenvironment of amino acid residues in gluten protein

[0147] The measurement of fluorescence spectrum is based on the amino acid residues in the protein, including three natural chromophores: phenylalanine, tyrosine and tryptophan, especially the tryptophan group. Therefore, the effect of magnetic field treatment on the tertiary structure of wheat gluten protein can be analyzed with the help of fluorescence absorption spectroscopy technology.

[0148] like Figure 3 As shown, compared with the comparative example, the fluorescence intensity of the embodiment is significantly reduced, and its maximum emission wavelength is slightly blue-shifted. This may be because the continuous discharge of high-energy particles during the magnetic field treatment promotes the attraction of hydrophobic residues, causing protein aggregation and embedding amino acids such as tryptophan and tyrosine inside the protein.

[0149] 3. Analysis of surface hydrophobicity of gluten protein

[0150] Surface hydrophobicity is an important indicator of protein non-covalent bonds, which is necessary to maintain the stability of its tertiary structure. The surface hydrophobicity index H0 is an indicator to measure the number of hydrophobic groups on the protein surface in contact with the polar water environment.

[0151] As shown in Table 2, the gluten protein in each example is lower than that in the comparative example H0, and the reduction effect of gluten protein in Examples 6 and 9 is more significant, especially in Example 6, which is reduced by 33.29%. This may be because the magnetic field treatment promotes hydrophobic amino acids such as tryptophan and tyrosine to be more buried inside the protein, reducing the hydrophobicity of the protein surface, making the protein structure more aggregated.

[0152] Table 2 Surface hydrophobic properties of spring wheat gluten proteins in different embodiments and comparative examples

[0153]

[0154] 3. Determination of the quality of fresh noodles prepared in Examples 1 to 6 and Comparative Example 1

[0155] 1. Steaming quality of noodles

[0156] The results of the noodle cooking characteristics of different embodiments and comparative examples are shown in Table 3. It can be seen that the cooking loss rates of different embodiments are lower than those of the comparative examples, and the water absorption rates are higher than those of the comparative examples. Among them, the cooking characteristics of Example 6 are the best. From the perspective of protein in wheat flour, the cooking quality of noodles is mainly related to the protein content and quality in wheat flour and the degree of protein wrapping of starch. Magnetic field treatment makes the network structure of gluten protein more compact, limits the dissolution of starch, reduces the cooking loss rate of noodles, and thus promotes the improvement of noodle cooking characteristics.

[0157] Table 3 Cooking characteristics of spring wheat noodles in different embodiments and comparative examples

[0158]

[0159] 2. Texture characteristics of noodles

[0160] The test results of noodle texture properties of different embodiments and comparative examples are shown in Table 4. It can be seen that compared with the comparative example, the viscosity, elasticity, hardness and chewiness of the noodle samples of different embodiments are improved to a certain extent. Generally speaking, noodles with high hardness and elasticity are more popular with consumers, indicating that magnetic field treatment can effectively improve the texture properties of spring wheat noodle products, among which the noodle texture properties of Example 6 are the best.

[0161] Table 4 Texture characteristics of spring wheat noodles in different embodiments and comparative examples

[0162]

[0163] In summary, the method for improving the quality of wheat flour provided by the present invention belongs to the non-thermal processing technology in physical modification. By using a static magnetic field to treat wheat flour and adjusting the intensity and time of the magnetic field treatment, the processing performance of spring wheat dough and the quality of gluten protein are significantly improved by the method of the present invention. The method of the present invention is environmentally friendly, harmless to the human body, and has a low processing cost.

[0164] The improvement method provided by the present invention significantly improves the viscoelasticity of wheat dough, enhances the stability of dough, and improves the thermomechanical properties and the aggregation properties of wheat flour gluten protein (the gluten protein structure is in a more aggregated state). The gluten weakening valley value is increased from 0.349 N·m to 0.362 N·m; it can be applied to flour products such as biscuits and cakes to improve the economic value of low-quality wheat flour;

[0165] The present invention further uses the improved wheat flour to prepare raw wet noodles; improves the texture characteristics and cooking quality of wheat noodle products; reduces the surface hydrophobicity index by 33.29%; reduces the cooking loss rate by 23.9%; improves the hardness, viscosity, elasticity and chewiness of the noodles, wherein the elasticity is increased by 8.5%, significantly improving the quality of the noodles. The method of improving the quality of wheat flour by using a static magnetic field of the present invention is simple to operate and has industrial application prospects.

[0166] The embodiments provided above are not intended to limit the scope of the present invention, and the steps described are not intended to limit the execution order thereof. Those skilled in the art may make obvious improvements to the present invention in combination with existing common knowledge, which also fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for improving the quality of wheat flour, characterized in that: The wheat flour is placed in a static magnetic field for 12 to 100 hours, wherein the magnetic field strength is 1 to 15 mT.

2. The method for improving the quality of wheat flour according to claim 1, characterized in that: The wheat includes but is not limited to spring wheat.

3. The method for improving the quality of wheat flour according to claim 1, characterized in that: The processing steps include: S11. Spread the wheat flour flat and seal it in a sealed bag; S12. Place the sealed wheat flour in a static magnetic field for 12 to 96 hours with a magnetic field strength of 1 to 10 mT.

4. The method for improving the quality of wheat flour according to claim 3, characterized in that: Before step S11, the steps of removing impurities from the wheat grains, grinding the wheat grains, and removing the bran are also included; Preferably, the method further comprises a sieving step after removing the bran.

5. The method for improving the quality of wheat flour according to claim 3, characterized in that: In step S11, the thickness of the wheat flour is ≤10 cm; And / or, in step S12, during the static magnetic field treatment, the temperature of the magnetic field environment is controlled to be 15-35° C. and the frequency to be 0-50 Hz.

6. Wheat flour prepared by any one of the methods of claims 1-5.

7. Use of the method according to any one of claims 1 to 5 or the wheat flour according to claim 7 in the food field.

8. The use according to claim 7, characterized in that: Including but not limited to being used for preparing raw wet noodles, biscuits, and cakes.

9. The use according to claim 8, characterized in that: The preparation method of the raw wet noodles comprises the following steps: S21, mixing the wheat flour according to claim 6 with water, kneading for 3-10 minutes to obtain dough, and using a dough press to repeatedly roll the kneaded dough for the first time for 3-10 times to obtain a dough sheet; S22, placing the dough obtained in step S1 in a proofing box at 30-40° C. and sealing it to allow the dough to fully absorb water; S23, repeatedly rolling the dough after proofing for 2-8 times to make it into a dough with fine texture, flatness and smoothness, and then cutting it into strips.

10. The use according to claim 9, characterized in that: The mass ratio of wheat flour to water in the dough kneading process is 100:30-100:40.

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