Wheat flour, preparation method thereof and fine dried noodles

Abstract

The invention relates to the technical field of grain processing, and discloses wheat flour, a preparation method thereof and fine dried noodles, the grain granularity of the wheat flour is 68-91 [mu] m, the wheat flour is prepared by rolling wheat flour as a raw material through a smooth roller, and compared with refined wheat flour added with bran, the wheat flour is pure white in color and higher in quality, and compared with the refined wheat flour, the wheat flour has the advantages that the grain size is small; the content of fat and dietary fibers is remarkably increased, the content of damaged starch is remarkably reduced, the cooking loss rate and protein digestibility of fine dried noodles prepared from the wheat flour are remarkably reduced, and the fine dried noodles prepared from the wheat flour are better in taste, high in chewiness and low in cooking loss rate and protein digestibility. The risk that obesity and type II diabetes mellitus are increased due to long-term consumption of the refined wheat flour can be avoided.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, in particular to wheat flour and a preparation method thereof, and dried noodles. Background Art

[0002] Wheat is a world grain with the advantages of large planting area and wide distribution range. Wheat is mainly made into flour in China, and flour is used to make a variety of pasta. Wheat is rich in nutrients such as protein, phenolic compounds, vitamins, dietary fiber and minerals, but these nutrients are not evenly distributed in wheat grains. Therefore, in the process of flour processing, the nutrients in wheat flour will be lost to varying degrees, and the higher the processing precision of wheat flour, the more serious the loss of its nutritional components. The traditional wheat noodle industry pursues refined wheat flour that is fine, white, and refined, but refined wheat flour has serious nutritional loss. At the same time, the content of damaged starch in refined wheat flour is high, and long-term consumption will increase the risk of obesity and type 2 diabetes.

[0003] In recent years, consumers have increasingly higher requirements for food health, and refined wheat flour no longer meets the needs of consumers. Therefore, people in this field have proposed methods such as adding coarse grains such as bran germ to refined wheat flour, steam explosion, microwave radiation, extrusion modification and solid-state fermentation to improve the taste and nutrients of wheat flour. For example, a nutritious wheat flour and a production method thereof disclosed in publication number CN114192212B are mixed with bran of a special particle size and wheat macaroni to obtain nutritious wheat flour. However, the above methods all use crude fiber and nutrients to refined wheat flour, and the original nutrients of the wheat flour have been lost. In addition, the wheat flour after adding crude fiber has a darker color and a poorer appearance. Therefore, in order to balance the nutrition and taste of wheat flour, it is necessary to further optimize the wheat flour and its processing technology. Summary of the invention

[0004] In order to overcome the problems in the prior art that refined wheat flour has high nutrient loss and the wheat flour becomes dark in color and easily acidified after adding nutritious crude fiber, the present invention provides wheat flour and a preparation method thereof, and noodles. The wheat flour in the present invention is wheat flour with a particle size of 68-91 μm made by rolling wheat clear flour as a raw material. The wheat flour is white in color and has high nutritional value. The cooking loss rate and protein loss rate of the noodles made from the wheat flour prepared by the present invention are significantly reduced, and the taste of the noodles is significantly improved.

[0005] The specific technical scheme of the present invention is: A wheat flour, the particle size of which is 68-91 μm, is prepared by using wheat pure flour as a raw material and undergoing a smooth roller pressing process.

[0006] The invention provides wheat flour, which is prepared by using wheat purified flour prepared by a powder purification system as a raw material and then subjected to a smooth roller pressing process. The particle size of the wheat is 68-91 μm. Compared with refined wheat flour added with bran, the wheat flour is white in color and has higher quality. Compared with refined wheat flour, the fat and dietary fiber contents are significantly increased, the damaged starch content is significantly reduced, and the cooking loss rate and protein digestibility of pasta prepared by the wheat flour are significantly reduced.

[0007] A method for preparing the wheat flour comprises the following steps: placing the wheat flour under a smooth roller for roller pressing to prepare the wheat flour.

[0008] Preferably, the rolling distance of the smooth roller is 0.04 to 0.08 mm.

[0009] Preferably, the conditions of the roller pressing process include: the roller pressing times are 3 to 5 times. The present invention also provides a preparation method of the above-mentioned wheat flour, which adopts a smooth roller to perform rolling treatment on the wheat flour. The refined wheat flour in the prior art can obtain wheat flour with a high starch content after being subjected to a heavy screening system and a smooth roller / toothed roller rolling treatment. The heavy screening system will separate some wheat residues, wheat cores, small bran and other materials from the wheat flour, so that the crude fiber content in the wheat flour is significantly reduced. The rolling treatment of the smooth roller / toothed roller combination grinds the wheat flour with a larger particle size into wheat flour particles with a particle size of less than 68 μm, but the total starch and damaged starch contents of the wheat flour subjected to the above-mentioned treatment are significantly increased. The increased damaged starch content will significantly increase the digestibility of the wheat flour, resulting in a rapid increase in the blood sugar of the consumer, which is not conducive to human health. In view of the above-mentioned technical problems, the present invention selects the wheat flour produced by the wheat flour cleaning system as a raw material and performs rolling treatment with a smooth roller under specific conditions to obtain wheat flour with a particle size of 68 to 91 μm. The wheat flour is white in color and of higher quality. Compared with refined wheat flour, the fat and dietary fiber contents are significantly increased, and the damaged starch content is significantly reduced.

[0010] A kind of fine noodles, which is made from the wheat flour mentioned above.

[0011] Preferably, the noodles are prepared by the following steps: adding water to wheat flour and kneading the flour to form dough, placing the dough in a sheet press for rolling and pressing to form dough skin, proofing the dough skin and then cutting it into strips to form noodles, and drying the noodles to form noodles.

[0012] Preferably, the moisture content of the wheat flour and the dough is 36-38%.

[0013] Preferably, the conditions for the proofing treatment include: a temperature of 30-35° C. and a humidity of 80-85%.

[0014] Preferably, the conditions for the proofing process also include: a time of 25 to 30 minutes.

[0015] Preferably, the rolling distance of the strip cutting process is 1.2 to 4.0 mm.

[0016] Compared with the prior art, this application has the following technical effects: The invention provides wheat flour, a preparation method and application thereof. The wheat flour is prepared by using wheat pure flour prepared by a powder purification system as a raw material and then subjected to a smooth roller pressing process. The particle size of the wheat is 68-91 μm. Compared with refined wheat flour added with bran, the wheat flour is white in color and has higher quality. Compared with refined wheat flour, the fat and dietary fiber contents are significantly increased, the damaged starch content is significantly reduced, and the cooking loss rate and protein digestibility of pasta prepared from the wheat flour are significantly reduced. DETAILED DESCRIPTION

[0017] The present invention will be further described below in conjunction with the embodiments.

[0018] Embodiment 1: A wheat flour, wherein the particle size of the wheat flour is 68 μm; A method for preparing the above-mentioned wheat flour comprises the following steps: The raw material of wheat granular flour was taken from the powder cleaning system in the homemade flour process. The initial particle size of the sample was 224 μm. It was placed under a smooth roller for continuous grinding. The grinding roller was adjusted to a rolling distance of 0.04 mm and rolled 5 times to obtain wheat flour with a particle size of 68 μm. A kind of dried noodles, comprising the following steps: Accurately weigh 200g of the above wheat flour and add an appropriate amount of distilled water. Use a pin-type dough mixer to knead the dough for 7 minutes to obtain loose dough in good condition, so that the final moisture content of the dough is 37%. Place the dough on a dough press with a rolling distance of 4mm and roll it once. Fold it in half and roll it twice, then put it into a ziplock bag. Then place it in a constant temperature and humidity chamber at a humidity of 85% and a temperature of 35°C to proof for 30 minutes. Finally, roll it through rolling distances of 4.0mm, 3.0mm, 2.0mm, 1.5mm, and 1.0mm in sequence, cut it into strips with a 2mm wide cutter, place the noodles on a drying platform to dry for 7h, and cut them into 20cm long noodles.

[0019] Embodiment 2: A wheat flour, wherein the particle size of the wheat flour is 80 μm; A method for preparing the above-mentioned wheat flour comprises the following steps: The raw material of wheat granular flour was taken from the powder cleaning system in the homemade flour process. The initial particle size of the sample was 224 μm. It was placed under a smooth roller for continuous grinding. The grinding roller was adjusted to a rolling distance of 0.06 mm and rolled 3 times to obtain wheat flour with a particle size of 80 μm. A kind of dried noodles, comprising the following steps: Accurately weigh 200g of the above wheat flour and add an appropriate amount of distilled water. Use a pin-type dough mixer to knead the dough for 7 minutes to obtain loose dough in good condition, so that the final moisture content of the dough is 37%. Place the dough on a dough press with a rolling distance of 4mm and roll it once. Fold it in half and roll it twice, then put it into a ziplock bag. Then place it in a constant temperature and humidity chamber at a humidity of 85% and a temperature of 35°C to proof for 30 minutes. Finally, roll it through rolling distances of 4.0mm, 3.0mm, 2.0mm, 1.5mm, and 1.0mm in sequence, cut it into strips with a 2mm wide cutter, place the noodles on a drying platform to dry for 7h, and cut them into 20cm long noodles.

[0020] Embodiment 3: A wheat flour, wherein the particle size of the wheat flour is 91 μm; A method for preparing the above-mentioned wheat flour comprises the following steps: The raw material of wheat granular flour was taken from the powder cleaning system in the homemade flour process. The initial particle size of the sample was 224 μm. It was placed under a smooth roller for continuous grinding. The grinding roller was adjusted to a rolling distance of 0.08 mm and rolled 3 times to obtain wheat flour with a particle size of 91 μm. A kind of dried noodles, comprising the following steps: Accurately weigh 200g of the above wheat flour and add an appropriate amount of distilled water. Use a pin-type dough mixer to knead the dough for 7 minutes to obtain loose dough in good condition, so that the final moisture content of the dough is 37%. Place the dough on a dough press with a rolling distance of 4mm and roll it once. Fold it in half and roll it twice, then put it into a ziplock bag. Then place it in a constant temperature and humidity chamber at a humidity of 85% and a temperature of 35°C to proof for 30 minutes. Finally, roll it through rolling distances of 4.0mm, 3.0mm, 2.0mm, 1.5mm, and 1.0mm in sequence, cut it into strips with a 2mm wide cutter, place the noodles on a drying platform to dry for 7h, and cut them into 20cm long noodles.

[0021] Comparative Example 1: A wheat flour, wherein the particle size of the wheat flour is 224 μm; A method for preparing the above-mentioned wheat flour comprises the following steps: The raw material of wheat granular flour was taken from the powder cleaning system in the homemade flour process. The initial particle size of the sample was 224 μm. It was placed under a smooth roller for continuous grinding. The roller rolling distance was adjusted to 0.16 mm and the roller was pressed 0 times to obtain wheat flour with a particle size of 224 μm. A kind of dried noodles, comprising the following steps: Accurately weigh 200g of the above wheat flour and add an appropriate amount of distilled water. Use a pin-type dough mixer to knead the dough for 7 minutes to obtain loose dough in good condition, so that the final moisture content of the dough is 37%. Place the dough on a dough press with a rolling distance of 4mm and roll it once. Fold it in half and roll it twice, then put it into a ziplock bag. Then place it in a constant temperature and humidity chamber at a humidity of 85% and a temperature of 35°C to proof for 30 minutes. Finally, roll it through rolling distances of 4.0mm, 3.0mm, 2.0mm, 1.5mm, and 1.0mm in sequence, cut it into strips with a 2mm wide cutter, place the noodles on a drying platform to dry for 7h, and cut them into 20cm long noodles.

[0022] Comparative Example 2: A wheat flour, wherein the particle size of the wheat flour is 115 μm; A method for preparing the above-mentioned wheat flour comprises the following steps: The raw material of wheat granular flour was taken from the powder cleaning system in the homemade flour process. The initial particle size of the sample was 224 μm. It was placed under a smooth roller for continuous grinding. The grinding roller was adjusted to a rolling distance of 0.1 mm and rolled once to obtain wheat flour with a particle size of 115 μm. A kind of dried noodles, comprising the following steps: Accurately weigh 200g of the above wheat flour and add an appropriate amount of distilled water. Use a pin-type dough mixer to knead the dough for 7 minutes to obtain loose dough in good condition, so that the final moisture content of the dough is 37%. Place the dough on a dough press with a rolling distance of 4mm and roll it once. Fold it in half and roll it twice, then put it into a ziplock bag. Then place it in a constant temperature and humidity chamber at a humidity of 85% and a temperature of 35°C to proof for 30 minutes. Finally, roll it through rolling distances of 4.0mm, 3.0mm, 2.0mm, 1.5mm, and 1.0mm in sequence, cut it into strips with a 2mm wide cutter, place the noodles on a drying platform to dry for 7h, and cut them into 20cm long noodles.

[0023] Comparative Example 3: A wheat flour, wherein the particle size of the wheat flour is 62 μm; A method for preparing the above-mentioned wheat flour comprises the following steps: The raw material of wheat granular flour was taken from the powder cleaning system in the homemade flour process. The initial particle size of the sample was 224 μm. It was placed under a smooth roller for continuous grinding. The grinding roller was adjusted to a rolling distance of 0.02 mm and rolled 3 times to obtain wheat flour with a particle size of 62 μm. A kind of dried noodles, comprising the following steps: Accurately weigh 200g of the above wheat flour and add an appropriate amount of distilled water. Use a pin-type dough mixer to knead the dough for 7 minutes to obtain loose dough in good condition, so that the final moisture content of the dough is 37%. Place the dough on a dough press with a rolling distance of 4mm and roll it once. Fold it in half and roll it twice, then put it into a ziplock bag. Then place it in a constant temperature and humidity chamber at a humidity of 85% and a temperature of 35°C to proof for 30 minutes. Finally, roll it through rolling distances of 4.0mm, 3.0mm, 2.0mm, 1.5mm, and 1.0mm in sequence, cut it into strips with a 2mm wide cutter, place the noodles on a drying platform to dry for 7h, and cut them into 20cm long noodles.

[0024] Comparative Example 4: A wheat flour, wherein the wheat flour is refined wheat flour, and the particle size of the wheat flour is 68 μm; the wheat flour is made by a refined wheat flour processing technology; A kind of dried noodles, comprising the following steps: Accurately weigh 200g of the above wheat flour and add an appropriate amount of distilled water. Use a pin-type dough mixer to knead the dough for 7 minutes to obtain loose dough in good condition, so that the final moisture content of the dough is 37%. Place the dough on a dough press with a rolling distance of 4mm and roll it once. Fold it in half and roll it twice, then put it into a ziplock bag. Then place it in a constant temperature and humidity chamber at a humidity of 85% and a temperature of 35°C to proof for 30 minutes. Finally, roll it through rolling distances of 4.0mm, 3.0mm, 2.0mm, 1.5mm, and 1.0mm in sequence, cut it into strips with a 2mm wide cutter, place the noodles on a drying platform to dry for 7h, and cut them into 20cm long noodles.

[0025] Test example 1: The wheat flour obtained in the above Examples 1 to 3 and Comparative Examples 1 to 5 was tested, and the test items included: protein content, ash content, total starch content, damaged starch content, fat content and dietary fiber content.

[0026] The protein content test method refers to "GB 5009.5-2016 National Food Safety Standard Determination of Protein in Food"; the test steps are: accurately weigh 0.3500g of the above wheat flour sample (equivalent to 30-40mg nitrogen), accurate to 0.001g, into the digestion tube, and then add 0.4g copper sulfate, 6g potassium sulfate and 20mL sulfuric acid to the digestion furnace for digestion; when the temperature of the digestion furnace reaches 420℃, continue digestion for 1h. At this time, the liquid in the digestion tube is green and transparent. After taking it out, cool it to room temperature and implement the process of automatic liquid addition, distillation, titration and recording titration data on the Kjeldahl nitrogen analyzer (add sodium hydroxide solution, hydrochloric acid or sulfuric acid standard solution and boric acid solution containing mixed indicator A or B before use).

[0027] The ash content test method refers to "GB 5009.4-2016 National Food Safety Standard Determination of Ash in Food"; the test steps are: accurately weigh 5.0g of the above wheat flour sample, evenly distribute the sample inside the crucible, do not press it, place the crucible on the high-temperature furnace mouth or on the electric heating plate, half cover the crucible lid, and carefully heat the sample to completely carbonize until there is no smoke under ventilation, then immediately put the crucible into the high-temperature furnace, gradually increase the temperature to 900±25℃, and maintain this temperature until all the remaining carbon disappears. Generally, the ash can be completely ashed in 1 hour, cool to about 200℃, take it out, and put it in a dryer to cool for 30 minutes. Before weighing, if there are carbon particles in the ignition residue, a little water should be dripped into the sample to moisten it to loosen the lumps. Evaporate the water and ignite it again until there are no carbon particles, which means that the ash is completely ashed, and then it can be weighed. Repeat the ignition until the difference between the two weighings before and after does not exceed 0.5mg to be constant weight.

[0028] The total starch content test method adopts the straight chain / branched starch kit for determination; the test steps are as follows: the determination of total starch is selected from the starch content detection kit of Solebow, and the reagents include: reagent 1 (liquid 35mL*1 bottle), reagent 2 (liquid 35mL*1 bottle), reagent 3 (powder*2 bottles), standard (powder*1 tube), standard: add 1mL of distilled water to dissolve it before use, prepare 10mg / mL glucose standard solution, store at 2-8℃ for two weeks, preparation of working solution: take 1 bottle of reagent 3 and add 6.75mL of distilled water before use, then slowly add 38.25mL of concentrated sulfuric acid, stir constantly, and fully dissolve, Standby, unused reagents can be stored at 2-8℃ for one week; Operation steps: Sample processing: weigh about 0.03g sample and grind it in a mortar, add 0.6mL reagent 1, transfer to EP tube after full homogenization, extract in 80℃ water bath for 30min, centrifuge at 3000g for 5min at room temperature, discard supernatant, keep precipitate, add 0.3mL double distilled water to the precipitate, put it in a boiling water bath for gelatinization for 15min (cover tightly to prevent water loss), after cooling, add 0.6mL reagent 2, put it in a boiling water bath for extraction for 15min, shake 3-5 times, cool, centrifuge at 8000g for 15min at room temperature, and take the supernatant for testing. If there is still turbidity after centrifugation, repeat centrifugation and take the supernatant; Determination steps: Preheat the spectrophotometer for more than 30min, adjust the wavelength to 620nm, and adjust the distilled water to zero; adjust the water bath to 95℃. Preparation of standard: dilute 10 mg / mL glucose standard solution to obtain 0.2, 0.1, 0.05, 0.04, 0.03, 0.02, 0.01 mg / mL standard solutions for standby use; determination of standard: take 0.2 mL of standard solution (distilled water as blank) and 1 mL of working solution into EP tube, place in 95°C water bath for 10 min (cover tightly to prevent water loss), cool naturally to room temperature, measure the absorbance of A standard and A blank at a wavelength of 620 nm, calculate ΔA=A standard-A blank, the standard curve only needs to be made 1 to 2 times, take 0.2 mL of sample and 1 mL of working solution into EP tube, place in 95°C water bath for 10 min (cover tightly to prevent water loss), cool naturally to room temperature, and measure the absorbance at a wavelength of 620 nm. Value A determination, ΔA′=A determination-A blank, the blank tube only needs to be done 1 to 2 times; starch content calculation, standard curve drawing: according to the concentration of the standard tube (x, mg / mL) and the absorbance ΔA standard (y, ΔA standard), a standard curve is established, and according to the standard curve, ΔA′ is substituted into the equation to obtain x (mg / mL); starch content calculation: starch content (mg / g mass)=x×V extraction÷W÷1.11×F=0.811x÷W×FV extraction: volume after extraction, 0.9mL; W: sample mass, g; F: sample dilution multiple; 1.11: is the constant for converting the glucose content measured by this method into starch content, that is, the color development of 111μg glucose with anthrone reagent is equivalent to the color displayed by 100μg starch with anthrone reagent.

[0029] The test method for damaged starch content refers to "GB / T 31577-2015 Grain and Oil Inspection Wheat Flour Damaged Starch Determination Amperemeter Method"; use the instrument's special sample spoon to accurately weigh 1.000±0.100g of the above wheat flour sample. Place the glass reaction cup in the correct position of the instrument and put down the measuring rod. Enter the accurate sample mass (accurate to 0.001g), protein content (dry basis) and moisture value, insert the sample into the sample delivery port of the instrument, and test according to the instrument manual. After the test is completed, record the iodine absorption rate (AI%), UCD and UCDc values. The measurement results are retained to one decimal place, and the same group of samples are tested in parallel three times. After the test is completed, rinse and clean the measuring rod, heater resistor and sample stirrer, wash the reaction cup and dry it. Preparation of reaction solution: weigh 3.0g ± 0.2g boric acid (6.2) and 3.0g ± 0.2g potassium iodide (6.3) respectively, pour them into a dry and clean glass reaction cup of the damaged starch tester, add 120mL ± 0.1mL distilled water or deionized water, and add 1 drop of 0.1mol / L sodium thiosulfate solution, and set aside.

[0030] The determination of moisture content shall refer to "GB / T5497 Determination of moisture content of samples".

[0031] The determination of protein content refers to "GB / T5511 Determination of protein content of samples".

[0032] The fat content test method refers to GB 5009.6-2016 National Food Safety Standard Determination of Fat in Foods; Accurately weigh 3.000g of the above wheat flour sample, accurate to 0.001g, and transfer all of it into the filter paper tube. Place the filter paper tube into the extraction tube of the Soxhlet extractor, connect it to the receiving bottle that has been dried to constant weight, add anhydrous ether or petroleum ether from the upper end of the extractor condenser to two-thirds of the bottle volume, heat it on a water bath, and make the anhydrous ether or petroleum ether reflux and extract continuously (6-8 times / h). Generally, the extraction time is 6-10h. At the end of the extraction, use a frosted glass rod to collect 1 drop of extract. The absence of oil spots on the frosted glass rod indicates that the extraction is complete. Remove the receiving bottle, recover the anhydrous ether or petroleum ether, and evaporate it on a water bath when there is 1-2mL of solvent remaining in the receiving bottle, then dry it at 100±5℃ for 1h, cool it in a desiccator for 0.5h, and then weigh it. Repeat the above operation until constant weight (until the difference between the two weighings does not exceed 2mg).

[0033] The test method for dietary fiber content refers to "GB 5009.88-2023 National Food Safety Standard Determination of Dietary Fiber in Food"; all samples must be homogenized, and the above wheat flour samples must be mixed and set aside for use. Dehydration: weigh an appropriate amount of sample, place it in a 105±2℃ oven to dry for 4h, transfer the sample to a dryer, and weigh the mass after the sample temperature drops to room temperature. According to the mass of the sample before and after drying, calculate the sample mass change factor (f), and after the dried sample is homogenized, place it in a dryer for use; defatting: weigh an appropriate amount of the above wheat flour sample (mc, not less than 50g), place it in a 1000ml conical flask, add 500ml petroleum ether and mix, release gas, shake for 2min, place it for 10min, remove the petroleum ether, and repeat three times. After defatting, mix the sample and dry it, weigh it (md), and calculate the sample mass change factor (f) after treatment. After the sample is averaged, it is placed in a desiccator for use; Desugaring: Weigh an appropriate amount of the above wheat flour sample (mc, not less than 50g), place it in a 1000ml conical flask, add 500ml of 85% ethanol solution, mix well, shake for 2min, remove the ethanol solution part, and repeat 3 times. The desugared wheat flour sample was placed in a 40°C oven and dried overnight, and the sample mass change factor (f) after treatment was calculated by weighing (md). After the sample was averaged, it was placed in a desiccator for use; 2 portions of the above wheat flour samples (m) were accurately weighed to 0.1 mg, the mass difference between the 2 wheat flour samples was ≤0.005 g, and the mass of the wheat flour samples was weighed to be 0.25-3 g; enzymatic hydrolysis: the wheat flour sample was placed in a 400-600 mL tall beaker, 35 mL of 50 mmol / L maleic acid buffer was added, and magnetic stirring was used until it was completely dispersed in the buffer. At the same time, 2 blank samples were prepared and operated simultaneously; amylase enzymatic hydrolysis: 5 mL of pancreatic-α-amylase and amyloglucosidase mixed enzyme solution was added to the tall beaker, stirred slowly, covered with aluminum foil, and placed in a constant temperature shaking water bath at 37°C for continuous shaking. When the temperature rose to 37°C, the timing was started, and the enzymatic hydrolysis was performed for 16 hours. Open the aluminum foil cover, add 3.0ml of 0.75mol / L Tris solution to the wheat flour solution, and adjust the pH of the sample solution to 8.2±0.2. Cover with aluminum foil, place in a 95-100℃ water bath for about 20min, shake the beaker from time to time, take out the beaker and cool it to 60±1℃; Proteolysis: add 100μl protease solution to each beaker, cover with aluminum foil, place in a 60±1℃ water bath and shake for 30min, open the aluminum foil, add 4ml of 2mol / L acetic acid solution while stirring, and adjust the pH to 4.3±0.2 with 1mol / L sodium hydroxide solution or 1mol / L hydrochloric acid solution; Determination of total dietary fiber: Precipitation: add 4 times the volume of 95% ethanol preheated to 60±1℃ to the wheat flour enzymatic hydrolyzate.Take out the beaker, cover with aluminum foil, let it sink at room temperature for 1 to 2 hours, and filter: take the treated crucible, moisten the diatomaceous earth with 15mL 78% ethanol and flatten it, connect it to a vacuum filtration device, extract ethanol to make the diatomaceous earth in the crucible spread flat on the filter plate, transfer the sample ethanol precipitate into the crucible for filtration, use a spatula and 78% ethanol to transfer all the residue in the tall beaker to the crucible, and wash the residue twice with 15mL 78% ethanol;. The test results are shown in Table 1.

[0034] Table 1 Test results As shown in Table 1, Examples 1 to 3 and Comparative Examples 1 to 3 respectively roll wheat flour into wheat flour with different particle sizes, and the results show that there is no significant difference in the protein, ash, total starch, fat and dietary fiber of different particle sizes of wheat flour after rolling, and the difference in the damaged starch content is significant. The damaged starch content of Examples 1 to 3 is 4.29-10.56%. Comparative Example 1 is wheat flour that has not been rolled, and its damaged starch content is only 0.61%, which is significantly lower than that of Examples 1 to 3; Comparative Example 2 is wheat flour that is rolled once with a rolling distance of 0.1mm, and its damaged starch content is only 1.14%, which is significantly lower than that of Examples 1 to 3; Comparative Example 3 is wheat flour that is rolled 3 times with a rolling distance of 0.02mm, and its damaged starch content is 13.29%, The content of protein in comparative example 4 is not significantly different from that in the wheat flour of examples 1 to 3, but its ash content, total starch content, fat content and dietary fiber content are significantly lower than those in the wheat flour of examples 1 to 3. In addition, the damaged starch in comparative example 4 is significantly higher than that in examples 1 to 3. The above results show that the wheat flour of a specific particle size prepared by treating wheat flour with different rolling wheels with different rolling distances and different rolling times can maintain the damaged starch in the healthy range of 4 to 10% under the premise that the nutrients such as protein, ash, total starch and fat remain unchanged. Compared with refined wheat flour, the damaged starch content is significantly reduced and the dietary fiber content is significantly increased, which significantly reduces the nutrient loss of refined wheat flour and the high damaged starch content. Long-term consumption will increase the risk of obesity and type 2 diabetes.

[0035] Test example 2: The dried noodles prepared in Examples 1 to 3 and Comparative Examples 1 to 5 were tested, and the test items included hardness, elasticity, cohesion, chewiness, cooking loss rate and protein digestibility; The test method for hardness, elasticity, cohesion and chewiness includes the following steps: put the cooked fresh wet noodles in cold water for 1 minute and then take them out, absorb the excess water with gauze, place three noodle samples in parallel on the test platform, use the HDP / PFS probe of the TA-XT Plus texture analyzer, and set the program parameters: 2.0mm / s before the test, 0.08mm / s during the test, and 10mm / s after the test, trigger force 5g; deformation degree 70%. According to the TPA curve, the hardness, adhesion, elasticity, recovery, chewiness and cohesion indicators are obtained. The sample is measured 7 times repeatedly. The test method of cooking loss rate is as follows: select 21 fresh wet noodles, weigh them and record them as M1, put them in a beaker filled with 500mL distilled water and cook them until the optimal cooking time, then take out the noodles; continue to heat the remaining water in the beaker to evaporate most of the water, then dry them in an oven at 105℃ to constant weight, record their weight M2, repeat 3 times for each sample, Where: M1 is the mass of 21 raw noodles before cooking, and is the moisture content of the raw noodles; Test method for protein loss rate: 18.00 g of raw noodles were placed in 500 mL of boiling water and boiled for the optimal cooking time. Then, the noodle soup was boiled continuously to ensure that the cooking time of the fresh wet noodle samples was consistent. The protein content in the noodle soup was determined by the Kjeldahl nitrogen determination method. The test results are shown in Table 2.

[0036] Table 2 Test results of dried noodles As shown in Table 2, the prepared wheat flour is made into noodles in the present invention, and the performance of the noodles is tested. Through the analysis of the results of the noodles of Examples 1 to 3 and Comparative Examples 1 to 3, it is found that as the particle size of the wheat flour decreases, the hardness of the noodles is also continuously reduced, and when the particle size of the wheat flour is reduced to 68 μm, the hardness of the noodles does not change significantly; as the particle size of the wheat flour continues to decrease, the elasticity of the noodles continues to increase, and when the particle size of the wheat flour is reduced to 68 μm, the elasticity of the noodles reaches the best, and the elasticity of the noodles will decrease as the particle size of the wheat flour continues to decrease; as the particle size of the wheat flour continues to decrease, the cohesion of the noodles continues to increase, and when the particle size of the wheat flour is reduced to 80 μm, the cohesion of the noodles does not change significantly; as the particle size of the wheat flour continues to decrease, the chewiness of the noodles continues to increase, and when the particle size of the wheat flour is reduced to 68 μm, the chewiness of the noodles increases. When the particle size of wheat flour continues to decrease, the chewiness of noodles will decrease. In addition, as the particle size of wheat flour decreases, the cooking loss rate and protein digestibility of noodles continue to increase. Comparative Example 4 is a refined wheat flour prepared by the prior art. By comparing the results of Comparative Example 4 with those of Example 1, it is found that compared with the noodles prepared from the refined wheat flour of the same particle size and the wheat flour provided by the present invention, the hardness is significantly increased, the cohesion is significantly reduced, and the cooking loss rate and protein digestibility are significantly improved. The above results indicate that, compared with the noodles prepared from the refined wheat flour of the prior art, the noodles prepared from the wheat flour provided by the present invention have a better taste and a lower cooking loss rate and protein digestibility, and can avoid the risk of obesity and type 2 diabetes caused by long-term consumption of refined wheat flour.

[0037] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent transformation made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A wheat flour, characterized in that: The wheat flour has a particle size of 68-91 μm, and is prepared by using wheat pure flour as a raw material and undergoing a smooth roller pressing process.

2. A method for preparing wheat flour according to claim 1, characterized in that: The following steps are involved: The wheat flour from the powder cleaning system is placed under a smooth roller for roller pressing to produce wheat flour.

3. The method for preparing wheat flour according to claim 2, characterized in that: The rolling distance of the smooth roller is 0.04-0.08 mm.

4. The method for preparing wheat flour according to claim 2, characterized in that: The conditions of the roller pressing treatment include: the number of roller pressing times is 3 to 5 times.

5. A kind of noodles, characterized in that: The noodles are made from the wheat flour according to claim 1.

6. The dried noodles according to claim 5, characterized in that: The fine noodles are prepared by the following steps: adding water to wheat flour and kneading the flour to form dough, placing the dough in a sheet press to perform rolling and pressing to form dough skin, proofing the dough skin and then cutting it into strips to form noodles, and drying the noodles to form the fine noodles.

7. The dried noodles according to claim 6, characterized in that: The moisture content of the wheat flour and the dough is 36-38%.

8. The dried noodles according to claim 6, characterized in that: The conditions for the proofing treatment include: a temperature of 30-35° C. and a humidity of 80-85%.

9. The dried noodles according to claim 6 or 8, characterized in that: The conditions for the proofing process also include: a time of 25 to 30 minutes.

10. The dried noodles according to claim 6, characterized in that: The rolling distance of the strip cutting process is 1.2-4.0 mm.

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