A processing technology for low-bacteria wheat flour

Abstract

The present invention discloses a processing technology for low-bacteria wheat flour, which belongs to the field of wheat flour production. The process of the present invention aims to significantly reduce the content of microorganisms in the finished flour and improve the sanitary quality and safety of wheat flour by introducing pulsed electric field technology combined with comprehensive optimization of conditioning, grinding, powder cleaning and suction systems. In particular, in the grinding process, the parameters of the grinding roller are dynamically adjusted according to the gluten content and moisture content of the wheat to ensure that the particle size of the ground material is accurately controllable. This process can not only improve the purity of wheat flour, but also achieve a significant sterilization effect through the control of moisture and particle size throughout the entire process. It is suitable for the production of a variety of wheat flour products such as low-gluten, medium-gluten and high-gluten, and provides the food industry with a safe and reliable new method for preparing low-bacteria wheat flour.

Description

Technical Field

[0001] The invention belongs to the field of wheat flour production, and particularly relates to a processing technology for low-bacteria wheat flour. Background Art

[0002] Wheat flour is a widely used basic food ingredient worldwide. One of the major challenges in its production is controlling microbial content. The presence of microorganisms is unavoidable in traditional flour production processes, particularly in the outer layers of the wheat grain (such as the bran and aleurone), where microorganisms are most concentrated. Therefore, effectively reducing microbial content in flour milling has become a core issue for ensuring food safety and improving product quality.

[0003] Existing microbial control technologies typically employ chemical fungicides or physical methods such as high-temperature treatment. While these methods can reduce microbial loads to a certain extent, they have significant limitations. For one thing, chemical treatments can easily lead to product residues, impacting food safety and consumer health. Furthermore, while effective, physical methods such as high-temperature treatment can adversely affect the physical properties of wheat, reducing flour quality.

[0004] At the same time, the traditional flour-making process has limited optimization for key links such as conditioning and purifying, especially in terms of wheat moisture control and the separation of bran and endosperm, which often have deficiencies. In particular, conditioning, as a key link, not only affects the quality of flour, but also plays an important role in microbial control and subsequent processing performance. Traditional conditioning methods mostly rely on static moisture migration or mechanical stirring, but due to their limited physical disturbance effect, the migration speed of moisture inside the wheat grains is often slow and the penetration depth is insufficient. This limitation leads to uneven distribution of moisture in the grains, especially it is difficult to effectively penetrate into the endosperm layer, which in turn causes problems such as poor separation of bran and endosperm and microbial growth.

[0005] However, in the processes reported in existing reports (such as CN103392979A and CN105767072A), the production process of wheat flour has the independence of conditioning, grinding and powder cleaning processes, resulting in a lack of coordination and optimization between the various processes, especially in terms of microbial control, and it is difficult to achieve significant results; moreover, the parameters of the conditioning, grinding roller and suction system are difficult to flexibly adjust according to the characteristics of wheat, resulting in a high microbial content in the finished flour and unstable flour quality.

[0006] Therefore, the existing technical means still have a lot of room for improvement in terms of microbial control, process adaptability and product quality improvement. There is an urgent need for a more refined process method that can ensure the sanitary quality and stability of flour without relying on chemical additives or high-temperature treatment, while improving the physical properties and processing performance of the product. Summary of the Invention

[0007] [Technical Issues]

[0008] Existing methods for preparing low-microbial wheat flour primarily rely on physical or chemical methods to sterilize wheat grains, the milling process, or the finished flour, but there is limited research on optimizing the entire milling process to improve flour quality. The present invention aims to optimize the milling and conditioning processes to achieve a low-microbial effect, providing a method for producing low-microbial wheat flour that does not require chemical treatment. This method is compatible with existing sterilization methods, improves production efficiency, and effectively improves product quality and safety.

[0009] [Technical solution]

[0010] The present invention effectively controls the number of microorganisms in wheat flour and effectively improves the quality and safety of the product through the regulation of the flour process and further joint regulation of the wheat process and flour process. No chemical reagents are added or used in the process, which is a green, environmentally friendly and safe technology.

[0011] The present invention provides a processing technology for low-bacteria wheat flour, comprising the following steps:

[0012] (1) Primary cleaning: The wheat is vacuumed and then screened using a rotary vibrating screen. A circulating air suction system is used to remove light impurities to obtain primary cleaned wheat.

[0013] (2) Cleaning the raw wheat: The cleaned wheat obtained in step (1) is sequentially subjected to screening, air suction, stone removal, and threshing processes to obtain cleaned wheat;

[0014] (3) Tempering treatment: adding sterile water to the cleaned wheat obtained in step (2), using high-frequency vibration waves to assist in tempering, and applying an alternating magnetic field in the tempering chamber to obtain tempered wheat;

[0015] (4) Cleaning of wheat: The wheat after conditioning obtained in step (3) is sequentially processed by a high-efficiency threshing machine → a rotary vibrating screen → a circulating air suction machine → a stone removing machine → a color sorting machine to obtain wheat to be ground into flour;

[0016] (5) Flour making: the wheat to be ground obtained in step (4) is subjected to a flour making process of milling, beating bran and cleaning flour, wherein the flour milling includes a hull milling section (B section), a core milling section (M section), a slag milling section (S section) and a tail milling section (T section), and flour is discharged from the hull milling section and the core milling section by a powder pipe, and the flour is mixed to obtain low-bacteria wheat;

[0017] When the wheat is medium or high gluten wheat, the rolling distance parameters of the hull grinding section are: 1B: 0.48-0.50mm, 2B: 0.26-0.30mm, 3B: 0.16-0.18mm, 4B: 0.08-0.10mm, 5B: 0.02-0.03mm; the rolling distance parameters of the core grinding section are: 1M: 0.018-0.020mm, 2M: 0.015-0.018mm, 3M: 0.014-0.016mm, 4M: 0.012-0.014mm;

[0018] When wheat is low-gluten wheat, the rolling distance parameters of the hull grinding section are: 1B: 0.52-0.58mm, 2B: 0.30-0.35mm, 3B: 0.20-0.25mm, 4B: 0.10-0.15mm, 5B: 0.04-0.06mm; the rolling distance parameters of the core grinding section are: 1M: 0.014-0.016mm, 2M: 0.012-0.014mm, 3M: 0.010-0.012mm, 4M: 0.008-0.010mm.

[0019] In one embodiment of the present invention, the total colony count in the low-bacteria wheat flour does not exceed 1000 CFU / g.

[0020] In one embodiment of the present invention, in step (1), the wheat raw grain is first subjected to 360-degree dust collection before entering the milling process, and then is preliminarily screened through two high-efficiency rotary vibrating screens, and a circulating suction system is used to remove light impurities.

[0021] In one embodiment of the present invention, in step (2), after step (1), the wheat is sequentially processed through a vibrating screen, a stone remover, a thresher, and an air suction device to remove impurities and fine particles. The entire cleaning process includes three screenings, three air suctions, two stone removals, and two threshers. The fully cleaned wheat enters the tempering bin for conditioning.

[0022] As an embodiment of the present invention, the high-frequency vibration wave assisted conditioning technology in step (3) of the present invention has brought significant improvement to the wheat tempering process through an innovative physical disturbance mechanism. The high-frequency vibration wave assisted conditioning machine is based on the high-frequency vibration wave technology driven by a motor, which can significantly accelerate the penetration of water from the surface layer to the inner layer of wheat, thereby effectively optimizing the moisture distribution during the conditioning process. The high-frequency vibration wave assisted conditioning machine uses a high-speed rotating motor system to stimulate the device shell to generate high-frequency vibration waves. This vibration wave stimulates the movement of water molecules through the rapid switching and action of the physical force field, thereby destroying the moisture tension on the surface of the wheat grains. Through this high-frequency vibration, water can break through the barrier of the wheat surface more quickly and quickly penetrate into the deep endosperm layer, greatly improving the water penetration rate and distribution uniformity.

[0023] Compared to traditional conditioning, high-frequency vibration-assisted conditioning significantly reduces the time moisture remains on the kernel surface through its precisely controlled high-frequency vibrations, reducing the microbial growth environment caused by excessive moisture accumulation on the surface. Furthermore, the physical disturbance of the vibration waves enhances the rate of moisture diffusion, allowing it to more evenly penetrate all layers of the kernel, particularly the hard-to-penetrate core endosperm.

[0024] As one embodiment of the present invention, the high-frequency vibration-assisted conditioning in step (3) uses a Model A device with an operating frequency of 180-200 Hz and a vibration speed of 5800 rpm. The high-speed operation of the motor drives the high-speed vibration of the housing, ensuring that moisture evenly penetrates the endosperm layer of the wheat kernels during the conditioning process, thereby improving the conditioning effect.

[0025] As an embodiment of the present invention, when the tempering object in step (3) is low-gluten wheat, high-frequency vibration waves are used to assist tempering, the tempering time is 4-8 hours, and the tempering moisture is controlled at 14.3±0.2%;

[0026] As an embodiment of the present invention, when the tempering object in step (3) is medium-gluten wheat, high-frequency vibration wave-assisted tempering is performed for 8-12 hours, and then a secondary tempering is performed for 6 hours by a plate-beating water-dampening method, and the tempering moisture is controlled at 14.6±0.2%;

[0027] As an embodiment of the present invention, when the tempering object in step (3) is high-gluten wheat, high-frequency vibration waves are used to assist tempering for 14-18 hours, and then a secondary tempering is performed for 6 hours by the plate-beating water method, and the tempering moisture is controlled at 15.0±0.2%.

[0028] As an embodiment of the present invention, during the secondary conditioning in step (3), the first water addition amount is 80% of the total water addition amount, and the second water addition amount is 20% of the total water addition amount, to ensure that the water gradually penetrates into the wheat endosperm layer to avoid bran rupture and uneven moisture.

[0029] As one embodiment of the present invention, the dampening method employs a dampening machine model FZSQ with a rotational speed of 480 rpm. The curved dampening design allows the wheat to absorb water more evenly during the secondary conditioning process, enhancing the bran's toughness and preventing it from breaking in subsequent processes.

[0030] In one embodiment of the present invention, in step (3), the medium-high gluten wheat is further conditioned through a secondary conditioning process to ensure uniform water penetration and microbial control. Simultaneously, an alternating magnetic field of a certain intensity is applied to the wheat grains during the conditioning process to inhibit microbial growth.

[0031] In one embodiment of the present invention, a secondary conditioning process can improve the precision and uniformity of the conditioning stage. The first watering is performed with a large amount of water for initial moistening, while the second conditioning is further balanced with a small amount of water to penetrate deep into the endosperm. This staged conditioning strategy not only ensures the hierarchical distribution of moisture, but also significantly enhances the toughness of the bran, preventing it from being broken due to excessive fragility during the subsequent flour-making process. The meticulous design of this process makes the separation of bran more thorough during the powder cleaning process, reduces the possibility of bran entering the finished flour, and ultimately improves the purity of the flour and its competitiveness in the high-end market.

[0032] As an embodiment of the present invention, during the tempering process of wheat, high humidity and temperature environment can easily promote the rapid reproduction of microorganisms, especially some bacteria and fungi (such as Escherichia coli and mold), which can cause the corruption and quality deterioration of wheat, increasing food safety risks. Traditional microbial inhibition methods usually rely on chemical treatment or high-temperature disinfection, but these methods may destroy the natural nutrients of wheat or leave chemical residues, which do not meet the high standards of modern consumers for food safety and quality. Alternating magnetic field technology provides a non-thermal, non-chemical method for microbial inhibition. The alternating magnetic field is an electromagnetic field that changes with time. It achieves physical inhibition of microorganisms by continuously changing the direction and intensity of the magnetic field. The alternating magnetic field can induce tiny pores in the cell membrane of microorganisms. This phenomenon is called "electroporation". Under the action of a low-frequency alternating magnetic field (30-100Hz), the permeability of the cell membrane of the microorganism increases, and the flow of ions and molecules inside and outside the cell is disturbed, resulting in an unstable cell environment and ultimately inhibiting the proliferation of microorganisms. The changing frequency of the alternating magnetic field can affect the ion channels and molecular movement in microbial cells, especially the migration of ions such as calcium, sodium, and potassium. The ion imbalance induced by alternating magnetic fields increases reactive oxygen species (ROS) within microbial cells, causing oxidative stress within the cells. These ROS molecules can damage bacterial DNA, proteins, and lipid structures, effectively inhibiting their growth. The oxidative stress and ion imbalance induced by alternating magnetic fields within microbial cells further disrupt cellular metabolic processes, particularly inhibiting DNA replication, RNA transcription, and protein synthesis, ultimately preventing microbial reproduction.

[0033] As an embodiment of the present invention, the alternating magnetic field treatment system in step (3) is modularized by combining multiple magnetic field sources, using multiple alternating magnetic field units. Magnetic field equipment is arranged around the warehouse (such as in the corners) and on the top of the warehouse to ensure uniform magnetic field coverage.

[0034] As an embodiment of the present invention, the electromagnetic field strength used in the alternating magnetic field in step (3) is 1-50 mT, and the frequency is 20-100 Hz. Furthermore, the pulse electric field strength is 10-30 mT, and the frequency is 30-50 Hz.

[0035] In one embodiment of the present invention, in step (3), the wheat obtained in step (2) is subjected to differentiated tempering treatments according to the gluten properties of the wheat:

[0036] This conditioning process rationally regulates moisture distribution, ensuring the physical properties of the wheat kernels meet the requirements of subsequent cleaning and grinding processes. Furthermore, by combining different wheat gluten strengths and aiding conditioning with high-frequency vibration waves, moisture quickly and evenly penetrates the kernels, reducing surface moisture retention and inhibiting microbial growth.

[0037] In one embodiment of the present invention, in step (4), the wheat treated in step (3) is further cleaned, including threshing, vibrating, stone removal, and color sorting. This process is used to remove impurities and unqualified grains remaining on the surface of the wheat, ensuring that the wheat kernels reach the desired cleanliness and provide suitable raw materials for subsequent grinding.

[0038] In one embodiment of the present invention, in step (5), the wheat treated in step (4) is ground and sieved. The flour making process adopts a process flow of 6 hull mills (6 hulls), 8 core mills (8 cores), 2 slag mills (2 slags), 2 tail mills (2 tails), 2 bran threshing machines (2 bran threshing) and 12 powder purifiers (12 powder purifiers).

[0039] In one embodiment of the present invention, in step (5), the powder pipe 2B of the shell grinding section and the powder pipes 1M, 2M, 3M, and 4M of the core grinding section are specifically selected to discharge powder, and the powder is mixed to obtain low-bacteria wheat flour.

[0040] In one embodiment of the present invention, in step (5), when the wheat is medium-high gluten wheat, the rolling distance parameter is:

[0041] Rolling distance of skin grinding section (section B): 1B: 0.48-0.50mm, 2B: 0.26-0.30mm, 3B: 0.16-0.18mm, 4B: 0.08-0.10mm, 5B: 0.02-0.03mm;

[0042] Center grinding section (M section) rolling distance: 1M: 0.018-0.020mm, 2M: 0.015-0.018mm, 3M: 0.014-0.016mm, 4M: 0.012-0.014mm;

[0043] Slag grinding section (S section) rolling distance: 1S: 0.020-0.024mm, 2S: 0.018-0.020mm;

[0044] Rolling distance of tail mill section (T section): 1T: 0.020-0.022mm.

[0045] In one embodiment of the present invention, in step (5), when the wheat is medium-high gluten wheat, the rolling distance parameters of the hull grinding section and the core grinding section are preferably:

[0046] The skin grinding segment is 1B 0.48mm, 2B 0.28mm, 3B 0.17mm, 4B 0.08mm, 5B 0.03mm; the core grinding segment is 1M 0.018mm, 2M 0.016mm, 3M 0.014mm, 4M 0.013mm.

[0047] In one embodiment of the present invention, in step (5), when the wheat is low-gluten wheat, the rolling distance parameter is:

[0048] Rolling distance of skin grinding section (section B): 1B: 0.52-0.58mm, 2B: 0.30-0.35mm, 3B: 0.20-0.25mm, 4B: 0.10-0.15mm, 5B: 0.04-0.06mm;

[0049] Core grinding section (M section) rolling distance: 1M: 0.014-0.016mm, 2M: 0.012-0.014mm, 3M: 0.010-0.012mm, 4M: 0.008-0.010mm;

[0050] Slag grinding section (S section) rolling distance: 1S: 0.022-0.026mm, 2S: 0.020-0.024mm;

[0051] Rolling distance of tail mill section (T section): 1T: 0.022-0.026mm.

[0052] In one embodiment of the present invention, in step (5), when the wheat is low-gluten wheat, the rolling distance parameters of the hull grinding section and the core grinding section are preferably:

[0053] The skin grinding segment is 1B 0.56mm, 2B 0.33mm, 3B 0.22mm, 4B 0.10mm, 5B 0.04mm; the core grinding segment is 1M 0.014mm, 2M 0.013mm, 3M 0.012mm, 4M 0.010mm.

[0054] In one embodiment of the present invention, the rolling distance of the hull grinding section of low-gluten wheat is slightly larger than that of medium- and high-gluten wheat to ensure the integrity of the endosperm and reduce excessive crushing; the rolling distance of the heart grinding section is appropriately increased than that of medium- and high-gluten wheat to ensure the fineness and grading effect of the material.

[0055] In one embodiment of the present invention, during the grinding process, the hopper suction system is used to separate the fine bran and dust in the mill feed, while reducing the temperature and humidity of the feed, thereby reducing the conditions for microbial growth during the grinding process.

[0056] In one embodiment of the present invention, the hopper suction system includes a suction device, an airflow duct, a dust collecting device and a control system; the suction device is installed on the top or side of the hopper, and sucks away dust, bran and fine impurities from the hopper through negative pressure suction. The suction volume of the suction device is 75-300m 3 / h; the air flow duct transports the inhaled air and impurities to the dust collecting device; the dust collecting device separates impurities through a multi-stage filtration system to keep the air inside the hopper clean.

[0057] In one embodiment of the present invention, the suction volume of the hopper suction device is controlled at 75-300m 3 / h to ensure the cleanliness of the grinding environment and the stability of the quality of wheat flour.

[0058] In one embodiment of the present invention, in terms of the precision of the process design, the present invention has also carried out a technical upgrade of the hopper suction system. By generating a negative pressure environment in the hopper area, dust, bran and fine particles are promptly extracted, which not only prevents the accumulation of particles inside the equipment, but also effectively curbs the reproduction of microorganisms in the flour-making process. This negative pressure suction technology is closely integrated with the entire flour-making process. While ensuring a clean production environment, it enhances the working efficiency of the equipment and extends the service life of the equipment. This system complements the optimization of the powder cleaning process, so that each stage of the production process can minimize the microbial load, further ensuring the hygiene standards and quality stability of the finished flour.

[0059] In one embodiment of the present invention, in the powder cleaning stage, the mesh size and suction volume of the powder cleaning machine are adjusted according to the material particle size, and combined with the hopper suction device in the grinding stage, the low temperature and low humidity environment in the grinding chamber is maintained to finally obtain wheat flour.

[0060] In one embodiment of the present invention, the suction air volume of the powder purifier is 200-1000m 3 / h.

[0061] In one embodiment of the present invention, in step (5), the powder cleaning process is implemented by a four-stage screening system, which classifies large coarse particles, medium coarse particles, small coarse particles, and coarse powder respectively.

[0062] In one embodiment of the present invention, in step (5), the medium and coarse particles obtained during the grinding process are concentrated in the screening and grading screen with a passing sieve number of 36W, and the retained sieve number of the screening and grading is 54W. The corresponding powder purifier is configured with a lower layer head end sieve number sparser than 36 and a lower layer end sieve number denser than 24.

[0063] In one embodiment of the present invention, the powder purifier uses the HFQFD.49x2x3-II model. During the purging process, the screen aperture and air volume are adjusted according to the material particle size and moisture content. The 1P1 lower layer front section screen size is 24, and the rear section screen size is 20; the 2P3 lower layer front section screen size is 36, and the rear section screen size is 28; the 6P lower layer front section screen size is 46, and the rear section screen size is 40.

[0064] In the flour milling process of the present invention, the moisture content of wheat entering the mill directly affects the particle size distribution and physical properties of the material. The present invention significantly improves the material morphology during the grinding stage by precisely controlling the moisture content during conditioning, especially when operating under low moisture conditions. Low-moisture conditioning not only ensures that larger particles are obtained during subsequent grinding, thereby allowing the use of larger sieve holes and stronger air volume during the powder cleaning process, but also optimizes the grading effect and ensures the effective separation of bran and endosperm. In addition, under low moisture conditions, the viscosity of the wheat endosperm is significantly reduced during the grinding process, avoiding the phenomenon of material sticking in the pipeline, thereby greatly reducing the risk of microbial growth in the subsequent powder path. The synergistic effect of this series of complex parameters ensures the high cleanliness and stability of the production process. When a low amount of water is added during the conditioning process, the particle size of the material produced by subsequent grinding is often larger. This is because moisture has a significant plasticizing effect on the structure of the wheat grains. Under low moisture conditions, the surface layer and endosperm of the wheat grains maintain a high hardness and toughness, are not easily over-crushed during grinding, and the resulting particles are relatively large. On the contrary, a higher amount of water added will cause the surface and internal structure of the wheat to be over-softened, and the wheat will be easily broken into smaller particles during grinding, affecting the subsequent grading effect.

[0065] When the material particle size is large, using a larger screen aperture and stronger suction during the purging process can achieve more efficient material classification. Larger particles are more easily physically separated through the screen, ensuring effective classification between the bran and endosperm. Improved classification efficiency means a more complete separation of the bran and endosperm, thereby reducing the possibility of bran impurities entering the finished flour. Furthermore, larger particles are more easily and efficiently separated by strong suction, further improving the efficiency of the purging process.

[0066] The process of the present invention aims to significantly reduce the microbial content in finished flour and improve the hygienic quality and safety of wheat flour by introducing pulsed electric field technology combined with comprehensive optimization of the conditioning, grinding, powder cleaning and aspiration systems. The process includes the following steps:

[0067] (1) After the raw grain enters the warehouse, it is cleaned of impurities in sequence through a vibrating screen, a stone remover, and a thresher, and a circulating suction system is used to remove surface impurities and microorganisms. (2) During the conditioning process, the wheat grains are treated by applying an electromagnetic field to inhibit microbial reproduction, and high-frequency vibration waves are used to assist in one or two conditioning processes to ensure that moisture evenly penetrates into the wheat grains. For medium-gluten and high-gluten wheat, two-stage conditioning is used, with the first water addition accounting for 80% and the second water addition accounting for 20% to avoid bran damage and further reduce the risk of microbial proliferation. (3) During the grinding process, the grinding roller parameters (including speed and rolling distance) are dynamically adjusted according to the gluten content and moisture content of the wheat to ensure that the particle size of the ground material is accurately controlled. (4) In the powder cleaning process, the grading and separation effect of the material is further optimized by precisely controlling the mesh size and suction volume of the screen, ensuring efficient separation of bran and endosperm and reducing the conditions for microbial growth. (5) Finally, through the synergistic effect of hopper suction and grinding chamber suction, a low-temperature and low-humidity environment is maintained, further enhancing the inhibition effect on microorganisms. This process not only improves the purity of wheat flour, but also achieves significant sterilization effect through moisture and particle size control throughout the entire process. It is suitable for the production of a variety of wheat flour products such as low-gluten, medium-gluten and high-gluten.

[0068] The present invention provides a low-bacteria wheat flour prepared based on the above processing technology.

[0069] The present invention also provides application of the low-bacteria wheat flour in the processing of flour products.

[0070] [Beneficial Effects]

[0071] Compared with the existing low-bacteria wheat flour production technology, the present invention does not use any fungicides or chemical reagents in production. Relying on process improvements, it achieves a low-bacteria effect by controlling the microorganisms on the surface of wheat grains before entering the mill and strengthening the stripping effect of the bran and endosperm during the flour making process, meeting the requirements of clean labels.

[0072] This invention achieves process optimization in multiple key dimensions, demonstrating significant technical advantages, particularly in microbial load management, product quality stability, and production cost control. First, through precise physical control of the milling process, particularly through systematic improvements in the conditioning and cleaning steps, the invention eliminates reliance on chemical additives, thereby achieving microbial control while reducing the operational risks and additional costs associated with chemical substances.

[0073] Furthermore, the present invention offers significant process adaptability, maintaining relative stability in the production process independent of variables such as the initial microbial load, particle distribution, and moisture content of the raw materials. This independence from raw material characteristics allows for greater process flexibility, enabling it to cope with diverse and complex operating conditions in real-world production environments without the need for frequent adjustments to operating parameters, ensuring product consistency and reducing the complexity of human intervention.

[0074] In terms of improving product quality, the present invention achieves effective separation of the bran and aleurone layer through meticulous optimization of the conditioning and cleaning processes, thereby reducing the activity of polyphenol oxidase (PPO), reducing the risk of flour browning, and ensuring long-term stability of the flour color. Furthermore, the efficient separation of the bran also reduces the ash content in the finished product, improving the purity of the flour. These improvements in quality indicators are achieved through physical means rather than relying on external chemical treatments, thus better aligning with current environmental and health trends in food production.

[0075] In particular, during the conditioning process, the present invention adopts a staged water addition technology. By gradually penetrating water, it avoids excessive water absorption or cracking of the bran during the water addition process, ensures the uniform distribution of water in the wheat grains, and thus optimizes the processing performance of the wheat in the subsequent milling process. This water addition method not only enhances the stability of wheat during the milling process, but also makes moisture control more precise and reduces uncertainty in production. The alternating magnetic field is used to suppress the activity of microorganisms on the surface of wheat grains during conditioning, and the vibration wave assisted conditioning system effectively reduces the reproduction of microorganisms during the conditioning process.

[0076] The cleaning process effectively reduces bran breakage through optimized screen aperture and suction volume, thereby improving flour purity and yield. A hopper suction system further ensures a clean production environment, reducing the risk of dust accumulation and microbial growth. This system stabilizes the flour milling process, extends equipment life, and ensures product hygiene.

[0077] Overall, the present invention achieves control over multiple key parameters in wheat flour production through fine-tuning of physical processes, significantly reducing the microbial content of wheat flour without the addition of any chemical reagents. The total bacterial count in wheat flour processed from the treated wheat is consistently below 1000 CFU / g. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 This is a trend chart showing the effects of different watering methods on the changes in microorganisms on the surface of wheat grains during conditioning. DETAILED DESCRIPTION

[0079] Based on the gaps in the existing technology, the inventor of this case has proposed the present invention after long-term summary and continuous practice.

[0080] The technical solution, implementation process and principle of the present invention are further explained below.

[0081] The technical solution of the present invention is further described in detail below through several embodiments. However, the selected embodiments are only

[0082] It is used to illustrate the present invention, not to limit the scope of the present invention.

[0083] For the convenience of explanation, the powder purifiers involved in sampling in the embodiments and comparative examples are two-way powder purifiers, one for the front middle road and the other for the back road, and the wheat flour sampling point is a representative powder outlet point in the front middle road of the flour path.

[0084] Method for determination of microbial count: The total colony count in wheat flour was determined in accordance with GB 4789.2-2016.

[0085] Determination of ash content: using the incineration method, refer to GB / T 5505-2008.

[0086] Flour yield determination: After tempering the wheat grains, grind them in a test mill and collect the flour from each powder tube. Calculate the percentage of the flour weight to the weight of the wheat grains.

[0087] Determination of damaged starch content in wheat flour: The damaged starch content of flour was determined according to AACC method 76-33.01 using an SDmatic French Chopin damaged starch meter. The results were expressed as UCD values.

[0088] Example 1

[0089] (1) The purchased medium-gluten wheat is subjected to 360-degree vacuuming in the grain unloading pit, initially screened through two high-efficiency rotary vibrating screens, and light impurities are removed using a two-pass circulating air suction system before entering the original grain silo;

[0090] (2) The medium-gluten wheat after the initial cleaning in (1) is cleaned in multiple steps, including passing through a vibrating screen, circulating suction, stone remover, thresher, vibrating screen again, suction, stone remover, thresher, and finally vibrating screen and circulating suction, for a total of 3 screenings, 3 suctions, 2 stone removers, and 2 threshers;

[0091] (3) The medium-gluten wheat cleaned in (2) was tempered using sterile water and high-frequency vibration waves for 16 hours at a frequency of 190 Hz. The amount of water added was adjusted according to the moisture content of the raw grain to achieve a final moisture content of 14.6%. During the entire tempering process, an alternating magnetic field was applied in the wheat conditioning bin with a magnetic field strength of 10 mT and a frequency of 30 Hz.

[0092] (4) Cleaning the medium-gluten wheat after tempering in (3), specifically, the process is carried out in the following order: high-efficiency rubbing machine → rotary vibrating screen → circulating air suction → stone removal machine → color sorter, and finally enters the grinding process;

[0093] (5) During the grinding process, a milling process of 6 skins, 8 hearts, 2 residues, 2 tails, 2 brans and 12 clear powders is adopted. After the materials are ground, graded and sieved, 1M-4M and 2B powder pipes are selected to discharge the powder and mix the powder to obtain wheat flour. The hopper suction volume is 300m 3 / h, the air volume of powder purifier 1 is 500m 3 / h, the mesh size of the first section of the lower layer is 36, and the mesh size of the last section of the lower layer is 28; the air volume of the powder purifier 2 is 300m 3 / h, the mesh size of the lower head section is 46, and the mesh size of the lower tail section is 40. The grinding roller pitch parameters are as follows: shell grinding section 1B 0.48mm, 2B 0.28mm, 3B 0.17mm, 4B 0.08mm, 5B 0.03mm; core grinding section 1M 0.018mm, 2M 0.016mm, 3M 0.014mm, 4M 0.013mm; slag grinding section pitch: 1S: 0.022mm, 2S: 0.019mm; tail grinding section pitch: 1T: 0.021mm.

[0094] Example 2

[0095] (1) The purchased low-gluten wheat is subjected to 360-degree vacuuming in the grain unloading pit, initially screened through two high-efficiency rotary vibrating screens, and light impurities are removed using a two-pass circulating air suction system before entering the original grain silo;

[0096] (2) The low-gluten wheat after the initial cleaning in (1) is cleaned in multiple steps, including passing through a vibrating screen, circulating suction, stone remover, thresher, vibrating screen again, suction, stone remover, thresher, and finally vibrating screen and circulating suction, for a total of 3 screenings, 3 suctions, 2 stone removers, and 2 threshers;

[0097] (3) The low-gluten wheat cleaned in (2) was tempered using sterile water and high-frequency vibration waves for 6 hours at a frequency of 190 Hz. The amount of water added was adjusted according to the moisture content of the raw grain to achieve a final moisture content of 14.3%. During the entire tempering process, an alternating magnetic field was applied in the wheat conditioning bin with a magnetic field strength of 30 mT and a frequency of 50 Hz.

[0098] (4) Cleaning the low-gluten wheat after conditioning in (3), specifically, the process is carried out in sequence of high-efficiency rubbing machine → rotary vibrating screen → circulating air suction → stone remover → color sorter, and finally enters the grinding process;

[0099] (5) During the grinding process, a milling process of 6 skins, 8 hearts, 2 residues, 2 tails, 2 brans and 12 clear powders is adopted. After the materials are ground, graded and sieved, 1M-4M and 2B powder pipes are selected to discharge the powder and mix the powder to obtain wheat flour. The hopper suction volume is 300m 3 / h, the air volume of powder purifier 1 is 500m 3 / h, the mesh size of the first section of the lower layer is 36, and the mesh size of the last section of the lower layer is 28; the air volume of the powder purifier 2 is 300m 3 / h, the mesh size of the lower head section is 46, and the mesh size of the lower tail section is 40. The grinding roller pitch parameters are as follows: shell grinding section 1B 0.56mm, 2B 0.33mm, 3B 0.22mm, 4B 0.10mm, 5B 0.04mm; core grinding section 1M 0.014mm, 2M 0.013mm, 3M 0.012mm, 4M 0.010mm; slag grinding section rolling pitch: 1S: 0.022mm, 2S: 0.020mm; tail grinding section rolling pitch: 1T: 0.022mm.

[0100] Example 3

[0101] (1) The purchased high-gluten wheat is subjected to 360-degree vacuuming in the grain unloading pit, initially screened through two high-efficiency rotary vibrating screens, and light impurities are removed using a two-pass circulating air suction system before entering the original grain silo;

[0102] (2) The high-gluten wheat after the initial cleaning in (1) is cleaned in multiple steps, including passing through a vibrating screen, circulating suction, stone removal machine, thresher, passing through a vibrating screen again, suction, stone removal machine, thresher, and finally through a vibrating screen and circulating suction, for a total of 3 screenings, 3 suctions, 2 stone removals, and 2 threshers;

[0103] (3) The high-gluten wheat after cleaning in (2) was tempered. First, sterile water was used to perform high-frequency vibration wave-assisted tempering for 16 hours, with a water content of 80%. Then, the wheat was tempered by watering on a beating plate for 6 hours, with a water content of 20%, so that the final moisture content of the wheat reached 15.0%. During the entire tempering process, an alternating magnetic field was applied in the wheat tempering bin with a magnetic field intensity of 30 mT and a frequency of 50 Hz.

[0104] (4) Cleaning the high-gluten wheat after conditioning in (3), specifically, the process is carried out in the following order: high-efficiency threshing machine → rotary vibrating screen → circulating air suction → stone removal machine → color sorter, and finally enters the grinding process;

[0105] (5) During the grinding process, a milling process of 6 skins, 8 cores, 2 slags, 2 tails, 2 bran beaters, and 12 purifiers was adopted. After the materials were ground, classified, and sieved, 1M-4M and 2B powder pipes were selected for powder discharging and mixing to obtain wheat flour. The hopper suction volume was 300 m3 / h, the purifier 1 air volume was 500 m3 / h, the lower layer head section screen number was 36, and the lower layer end section screen number was 28; the purifier 2 air volume was 300 m3 / h, the lower layer head section screen number was 46, and the lower layer end section screen number was 40. The grinding roller pitch parameters were referenced to Example 1.

[0106] Example 4

[0107] (1) The purchased medium-gluten wheat is subjected to 360-degree vacuuming in the grain unloading pit, initially screened through two high-efficiency rotary vibrating screens, and light impurities are removed using a two-pass circulating air suction system before entering the original grain silo;

[0108] (2) The medium-gluten wheat after the initial cleaning in (1) is cleaned in multiple steps, including passing through a vibrating screen, circulating suction, stone remover, thresher, vibrating screen again, suction, stone remover, thresher, and finally vibrating screen and circulating suction, for a total of 3 screenings, 3 suctions, 2 stone removers, and 2 threshers;

[0109] (3) The medium-gluten wheat after cleaning in (2) was tempered. First, sterile water was used to perform high-frequency vibration-assisted tempering for 10 hours, with a water content of 80%. Then, the wheat was tempered by beating and watering for 6 hours, with a water content of 20%, so that the final moisture content of the wheat reached 14.6%. During the entire tempering process, an alternating magnetic field was applied in the wheat tempering bin with a magnetic field intensity of 30 mT and a frequency of 50 Hz.

[0110] (4) Cleaning the medium-gluten wheat after tempering in (3), specifically, the process is carried out in the following order: high-efficiency rubbing machine → rotary vibrating screen → circulating air suction → stone removal machine → color sorter, and finally enters the grinding process;

[0111] (5) During the grinding process, a milling process of 6 skins, 8 cores, 2 slags, 2 tails, 2 bran beaters, and 12 purifiers was adopted. After the materials were ground, classified, and sieved, 1M-4M and 2B powder pipes were selected for powder discharging and mixing to obtain wheat flour. The hopper suction volume was 300 m3 / h, the purifier 1 air volume was 500 m3 / h, the lower layer head section screen number was 36, and the lower layer end section screen number was 28; the purifier 2 air volume was 300 m3 / h, the lower layer head section screen number was 46, and the lower layer end section screen number was 40. The grinding roller pitch parameters were referenced to Example 1.

[0112] Example 5

[0113] Referring to Example 4, the only difference is that in step (3), an alternating magnetic field is applied in the wheat silo during the entire tempering process, the magnetic field strength is 10 mT, the frequency is 50 Hz, and the air volume of the powder purifier 1 in (5) is 200 m3 / h, and the air volume of the powder purifier 2 is 100 m3 / h. 3 / h.

[0114] Example 6

[0115] Referring to Example 4, the only difference is that in step (3), an alternating magnetic field is applied in the wheat tempering bin during the entire tempering process, the magnetic field strength is 30 mT, and the frequency is 20 Hz. In step (5), the mesh number of the lower head section of the powder purifier 1 is 40, and the mesh number of the lower end section is 32; the mesh number of the lower head section of the powder purifier 2 is 50, and the mesh number of the lower end section is 44.

[0116] Example 7

[0117] Refer to Example 4, the only difference is that in step (3), an alternating magnetic field is applied in the wheat tempering bin during the entire tempering process, the magnetic field strength is 50mT, the frequency is 50Hz, and the hopper suction volume in step (5) is 75m 3 / h.

[0118] Comparative Example 1

[0119] The same method as in Example 1 was used, except that the alternating magnetic field was not applied during the conditioning process. The corresponding wheat flour product was obtained while keeping all other conditions unchanged.

[0120] Comparative Example 2

[0121] Referring to Example 1, the only difference is that the dampening method in step (3) is replaced by plate dampening instead of high-frequency vibration wave assisted conditioning, and the conditioning time is 26 hours. Other things remain unchanged to obtain the corresponding wheat flour product.

[0122] Comparative Example 3

[0123] Referring to Example 1, the only difference was that the roller pitch parameters of the shell grinding section and the core grinding section were: shell grinding section 1B 0.44mm, 2B 0.24mm, 3B 0.13mm, 4B 0.06mm, 5B 0.02mm, and core grinding section 1M 0.014mm, 2M 0.012mm, 3M 0.01mm, 4M 0.009mm. The corresponding wheat flour product was produced while keeping all other parameters unchanged.

[0124] Comparative Example 4

[0125] Referring to Example 1, the only difference was that the roller pitch parameters of the shell grinding section and the core grinding section were: shell grinding section 1B 0.52mm, 2B 0.30mm, 3B 0.16mm, 4B 0.09mm, 5B 0.04mm, and core grinding section 1M 0.018mm, 2M 0.012mm, 3M 0.013mm, 4M 0.0120mm. The corresponding wheat flour product was produced while keeping all other parameters unchanged.

[0126] Comparative Example 5

[0127] Referring to Example 1, the only difference was that the roller pitch parameters of the shell grinding section and the core grinding section were: shell grinding section 1B 0.54mm, 2B 0.32mm, 3B 0.19mm, 4B 0.09mm, 5B 0.04mm, and core grinding section 1M 0.018mm, 2M 0.012mm, 3M 0.013mm, 4M 0.0120mm. The corresponding wheat flour product was obtained while keeping all other parameters unchanged.

[0128] The microbial content of the wheat flour products and intermediate materials obtained in each embodiment and comparative example was measured, and the results are shown in Table 1.

[0129] Table 1. Microbial content of wheat flour and intermediate materials in various examples and comparative examples

[0130]

[0131]

[0132] “—” indicates not detected.

[0133] Example 8

[0134] Another batch of low-gluten wheat was selected, and the conditioning step in step (2) was adjusted with reference to Example 2. Other conditions remained unchanged, and the microbial content on the surface of the obtained grains and the quality characteristics of the flour after the test mill were measured.

[0135] The test was repeated three times in parallel and the average value was calculated. The results are shown in Table 2.

[0136] Table 2. Effects of conditioning methods on changes in microorganisms on the surface of low-gluten wheat grains during conditioning and on the quality characteristics of wheat flour after milling.

[0137]

[0138] Note: "Tempering time of 0h" refers to wheat grains that are taken out immediately after water treatment and are not stored in a wheat bin; "dry wheat" refers to wheat grains that have not been water treated.

[0139] Example 9

[0140] Another batch of medium-gluten wheat was selected, and the conditioning step in step (2) was adjusted with reference to Example 1. Other conditions remained unchanged, and the microbial content on the surface of the obtained grains was measured. The obtained wheat grains were ground with a test mill and the flour extraction rate and ash content were measured.

[0141] The test was repeated three times in parallel and the average value was calculated. The results are shown in Table 3.

[0142] Table 3. Effects of conditioning methods on changes in microorganisms on the surface of medium-gluten wheat grains during conditioning and on the quality characteristics of wheat flour after milling.

[0143]

[0144] Example 10

[0145] Another batch of high-gluten wheat was selected, and the conditioning step in step (2) was adjusted with reference to Example 3. Other conditions remained unchanged, and the microbial content on the surface of the obtained grains was measured.

[0146] The test was repeated three times in parallel and the average value was calculated. The results are shown in Table 4.

[0147] Table 4. Effects of conditioning methods on changes in microorganisms on the surface of high-gluten wheat grains during conditioning and on the quality characteristics of wheat flour after milling.

[0148]

[0149]

[0150] Example 11

[0151] Referring to Example 1, the air suction volume of the hopper in the grinding step in step (5) was adjusted, and other conditions remained unchanged. The microbial content on the surface of the resulting grains was measured. The results are shown in Table 5.

[0152] Table 5. Effect of hopper suction on microbial growth during grinding (CFU / g)

[0153]

[0154] Effect analysis:

[0155] Combined with Example 1 and Comparative Examples 3-5, the grinding roller parameters, especially the parameters of the front skin grinding roller and the core grinding roller, have a significant impact on the microorganisms of wheat flour. A specific grinding roller spacing can significantly increase the bacterial content of wheat flour. This may be because a grinding roller spacing that is too small will lead to a greater scraping effect on the bran, causing some bran to break and mix into the flour, increasing the amount of fine bran debris in the subsequent material, making subsequent material grading more difficult, and increasing the ash content and microbial content of the wheat flour. At the same time, a too small grinding roller spacing will also increase the damaged starch content of the wheat flour. The specific results are shown in Table 6:

[0156] Table 6

[0157] Sample name ash content UCD (Ultra-Destructive Starch Content) Example 1 0.48 23.4 Comparative Example 3 0.53 26.8

[0158] However, if the spacing between the grinding rollers is too large, the grinding rollers will have poor scraping effect on the bran and poor endosperm crushing effect, resulting in a low flour yield; at the same time, it will affect the particle size of the wheat flour. Excessive wheat flour particle size may affect the quality of noodle products.

[0159] Further,

[0160] Combining the data of Examples 1-3, Examples 8-10, Comparative Example 2 and Tables 1-4, it can be concluded that the dampening method has a crucial influence on inhibiting the growth of microorganisms on the surface of wheat grains during the tempering process, and also has a significant effect on reducing the wheat tempering time. Especially for high-gluten wheat grains, when the plate dampening process is adopted, the microbial growth rate is significantly higher than that of wheat grains using the high-frequency vibration wave assisted tempering process. This phenomenon shows that the high-frequency vibration wave assisted tempering process has obvious advantages, which can significantly shorten the time required for tempering, accelerate the migration of water to the interior of the wheat grains, thereby reducing the retention of surface moisture and inhibiting the growth of microorganisms. In addition, at the same time, the flour extraction rate and ash content of wheat tempered with the assistance of high-frequency vibration waves are better than those of conventional plate dampened wheat, which can ensure the sanitary quality and stability of the flour while effectively improving the physical properties and processing performance of the product.

[0161] The advantages of high-frequency vibration-assisted conditioning can be understood from two key perspectives: First, the mechanical disturbance effect of vibration accelerates the uniform distribution of moisture across the wheat surface, reducing localized excess moisture accumulation and thus preventing the rapid proliferation of microorganisms under these favorable conditions. Second, vibration accelerates the dynamic process of moisture penetration, allowing moisture to migrate more quickly into the wheat kernel, reducing surface moisture retention time and thus effectively reducing the growth rate of surface microorganisms.

[0162] Further analysis of the performance of different wheat varieties during the conditioning process revealed that within the same conditioning time, the growth rate of microorganisms on the surface of wheat grains showed significant varietal differences: low-gluten wheat < medium-gluten wheat < high-gluten wheat. This phenomenon can be attributed to the differences in water requirements of different wheat varieties during conditioning. Low-gluten wheat has a lower water requirement before milling, and accordingly, less water is added. Therefore, the retention time of moisture on its surface is shorter, which is not conducive to the growth and reproduction of microorganisms. For medium-gluten and high-gluten wheat, due to their higher water requirement before milling, a relatively large amount of water is added during the dampening process, and the rate at which moisture on the surface of the grains migrates to the interior is relatively slow, resulting in the surface moisture being maintained at conditions suitable for microbial growth for a long time.

[0163] Based on the data from Examples 1-7 and Comparative Example 1, applying an alternating magnetic field during the preparation process can effectively inhibit microbial growth. The ideal parameters for microbial inhibition are a magnetic field intensity of 30-50 mT and a magnetic field frequency of 50 Hz. Excessively high magnetic field intensities or frequencies have little inhibitory effect on microorganisms and may even adversely affect flour quality. Furthermore, when combined with high-frequency vibration conditioning, the electromagnetic field's inhibitory effect on microbial growth is even more pronounced under conditions of low water activity.

[0164] Combining the data from Examples 4 and 7 and Table 5, the hopper suction system significantly impacts the microbial content of the mill chamber material and the resulting flour. Specifically, as the suction volume increases, the microbial content in the material shows a clear downward trend. This phenomenon demonstrates that a higher suction volume not only more effectively removes large dust particles and bran from the material, but also removes some moisture from the material and reduces the temperature within the mill chamber, fundamentally eliminating the conditions for microbial growth.

[0165] From the trend of microbial changes in the feed roller material, it can be clearly seen that as the hopper suction volume increases, the number of microorganisms in the incoming material gradually decreases, which shows that the negative pressure of the suction system has a positive effect on the inhibition of microorganisms on the surface of the material. Especially on the lower grinding chamber material, the suction volume reaches 300m 3 / h, the number of microorganisms in the material is significantly lower than that in the feed roller material. However, when the suction volume is reduced, the number of microorganisms in the lower grinding chamber material gradually approaches or even exceeds that in the feed roller material. This phenomenon reveals that the key role of the suction system is not limited to surface particle cleaning, but also includes intervention in the microbial ecology of the entire system.

[0166] This significant trend can be attributed to the synergistic effect of the grinding chamber suction and hopper suction systems. The negative pressure generated by grinding chamber suction alone has limited dust removal capacity, making it difficult to effectively expel air containing dust and microorganisms into the Shakeron. While the negative pressure within the grinding chamber can somewhat slow the accumulation of microorganisms, it is insufficient to completely remove microbial carriers from the dust. However, through its organic integration with the hopper suction system, the two form a complete airflow channel, ensuring the complete removal of dust and microbial carriers. Therefore, the hopper suction system not only strengthens the negative pressure effect within the grinding chamber but also achieves efficient dust removal, cooling, and microbial inhibition by enhancing air flow.

[0167] From the comparison of Example 1 and Example 4, it can be seen that the conditioning conditions have an important influence on the material classification effect in the subsequent flour milling process and the separation effect of the bran in the flour milling process. The separation effect of the wheat purifier after the second watering is better than that of the wheat after the first watering. This is because the internal moisture distribution of the wheat grains after the second watering is more uniform. At the same time, the wheat grains are tempered with the assistance of high-frequency vibration waves and then watered by beating, which can increase the speed of moisture migration and reduce the retention time of moisture on the surface of the wheat grains, so that the microbial reproduction rate in the conditioning process after the second beating is greatly reduced. At the same time, the bran surface is tougher after the second watering and is not easily broken into finer fragments during grinding. In this way, the wheat can maintain the toughness of the bran at a lower water addition amount. At the same time, the synergistic effect of this modulation method and a certain grinding roller spacing makes the particle size of the material after grinding larger, and combined with the specific purifier screen configuration, the grading effect of the purifier is greatly enhanced. The low-bacteria effect of the finished flour is ensured.

[0168] The embodiments provided above are not intended to limit the scope of the present invention, nor are the steps described to limit their execution order. Any obvious improvements to the present invention made by those skilled in the art in combination with existing common knowledge shall fall within the scope of protection defined by the claims of the present invention.

Claims

1. A processing technology for low-bacteria wheat flour, characterized in that: The steps include: (1) Primary cleaning: The wheat is vacuumed and then screened using a rotary vibrating screen. A circulating air suction system is used to remove light impurities to obtain primary cleaned wheat. (2) Cleaning the raw wheat: The cleaned wheat obtained in step (1) is sequentially subjected to screening, air suction, stone removal, and threshing processes to obtain cleaned wheat; (3) Tempering treatment: adding sterile water to the cleaned wheat obtained in step (2), using high-frequency vibration waves to assist in tempering, and applying an alternating magnetic field in the tempering chamber to obtain tempered wheat; (4) Cleaning of wheat: The wheat after conditioning obtained in step (3) is sequentially processed by a high-efficiency threshing machine → a rotary vibrating screen → a circulating air suction machine → a stone removing machine → a color sorting machine to obtain wheat to be ground into flour; (5) Flour making: the wheat to be ground obtained in step (4) is subjected to a flour making process of grinding, beating bran and cleaning flour, wherein the flour grinding includes a hull grinding section, a core grinding section, a slag grinding section and a tail grinding section, and the hull grinding section and the core grinding section are selected to discharge flour through a powder pipe, and the flour is mixed to obtain low-bacteria wheat flour; When the wheat is medium or high gluten wheat, the rolling distance parameters of the hull grinding section are: 1B: 0.48-0.50mm, 2B: 0.26-0.30mm, 3B: 0.16-0.18mm, 4B: 0.08-0.10mm, 5B: 0.02-0.03mm; the rolling distance parameters of the core grinding section are: 1M: 0.018-0.020mm, 2M: 0.015-0.018mm, 3M: 0.014-0.016mm, 4M: 0.012-0.014mm; When wheat is low-gluten wheat, the rolling distance parameters of the hull grinding section are: 1B: 0.52-0.58mm, 2B: 0.30-0.35mm, 3B: 0.20-0.25mm, 4B: 0.10-0.15mm, 5B: 0.04-0.06mm; the rolling distance parameters of the core grinding section are: 1M: 0.014-0.016mm, 2M: 0.012-0.014mm, 3M: 0.010-0.012mm, 4M: 0.008-0.010mm.

2. The processing technology according to claim 1, characterized in that: In the step (3), Low-gluten wheat is tempered with high-frequency vibration waves for 6-8 hours; Medium-gluten wheat is tempered with high-frequency vibration waves for 8-12 hours; or high-frequency vibration waves are used for secondary tempering followed by watering on a beating plate for 6 hours; After high-gluten wheat is tempered with the aid of high-frequency vibration waves for 14-18 hours, it is tempered again for 6 hours by beating and watering.

3. The processing technology according to claim 2, characterized in that: During the secondary tempering process, the first water addition accounts for 80% and is completed through the high-frequency vibration wave system; the second water addition accounts for 20% and is completed through watering on the plate.

4. The processing technology according to claim 1, characterized in that: In the step (3), the electromagnetic field intensity during the alternating magnetic field treatment is 1-50 mT and the frequency is 20-100 Hz.

5. The processing technology according to claim 1, characterized in that: In the step (3), the moisture content of the low-gluten wheat after conditioning reaches 14.3±0.2%, the moisture content of the medium-gluten wheat reaches 14.6±0.2%, and the moisture content of the high-gluten wheat reaches 15.0±0.2%.

6. The processing technology according to claim 1, characterized in that: In the step (5), a flour making process is adopted which includes 6 shell mills, 8 core mills, 2 slag mills, 2 tail mills, 2 bran beaters and 12 flour purifiers.

7. The processing technology according to claim 1, characterized in that: In the step (5), the 2B powder pipe of the shell grinding section and the 1M, 2M, 3M and 4M powder pipes of the core grinding section are specifically selected to produce flour, and the flour is mixed to obtain low-bacteria wheat flour.

8. The processing technology according to claim 1, characterized in that: In the step (5), When the wheat is medium-high gluten wheat, the rolling distance parameters are as follows: rolling distance of the shell grinding section 1B: 0.48-0.50mm, 2B: 0.26-0.30mm, 3B: 0.16-0.18mm, 4B: 0.08-0.10mm, 5B: 0.02-0.03mm; rolling distance of the core grinding section 1M: 0.018-0.020mm, 2M: 0.015-0.018mm, 3M: 0.014-0.016mm, 4M: 0.012-0.014mm; rolling distance of the slag grinding section 1S: 0.020-0.024mm, 2S: 0.018-0.020mm; rolling distance of the tail grinding section 1T: 0.020-0.022mm; When the wheat is low-gluten wheat, the rolling distance parameters are: rolling distance of the shell grinding section 1B: 0.52-0.58mm, 2B: 0.30-0.35mm, 3B: 0.20-0.25mm, 4B: 0.10-0.15mm, 5B: 0.04-0.06mm; rolling distance of the core grinding section 1M: 0.014-0.016mm, 2M: 0.012-0.014mm, 3M: 0.010-0.012mm, 4M: 0.008-0.010mm; rolling distance of the slag grinding section 1S: 0.022-0.026mm, 2S: 0.020-0.024mm; rolling distance of the tail grinding section 1T: 0.022-0.026mm.

9. Low-bacteria wheat flour obtained by the processing technology according to any one of claims 1 to 8.

10. Use of the low-bacteria wheat flour according to claim 9 in the processing of flour products.

Images