Sandwich buckwheat fine dried noodles and preparation method thereof

Abstract

The invention relates to the technical field of food processing, and particularly discloses sandwiched buckwheat fine dried noodles and a preparation method thereof. The cross section of the sandwich buckwheat fine dried noodles provided by the invention is circular, square or elliptical; the preparation method of the sandwiched buckwheat fine dried noodles comprises the following steps: performing vacuum dough kneading, performing dough floc fermentation, performing calendering, performing dough band fermentation, performing two-pass calendering, performing three-layer composite calendering, performing continuous calendering, performing strip cutting and performing drying. Buckwheat flour, wheat active protein and water are poured into a vacuum dough kneading machine to be kneaded, and the buckwheat flour is obtained; the weight ratio of the buckwheat flour to the wheat active protein is 1: (0.1-0.2); wheat flour and water are poured into a vacuum dough kneading machine for dough kneading, and the wheat flour is obtained. According to the sandwich buckwheat fine dried noodles provided by the invention, perfect balance of nutrition and mouth feel is realized, high content of buckwheat components is ensured, and the problems that traditional buckwheat fine dried noodles are rough in texture and poor in mouth feel are solved.

Description

Technical Field

[0001] The present application relates to the technical field of food processing, and in particular to a kind of sandwich buckwheat noodles and a preparation method thereof. Background Art

[0002] With the gradual improvement of living standards, people have a higher demand for nutrition and health. Buckwheat noodles have attracted widespread attention because they are rich in dietary fiber and a variety of nutrients. However, buckwheat noodles on the market generally have the problem of not taking into account both nutritional functions and taste, which not only affects consumers' purchasing experience, but also limits the further development of buckwheat noodles in the field of healthy food.

[0003] At present, in order to solve the problem of balancing nutrition and taste of buckwheat noodles, the industry usually adopts the following methods: First, add a certain amount of wheat flour to buckwheat flour, but when the amount of wheat flour added is too high, the nutritional function of buckwheat cannot be fully reflected; and when the proportion of buckwheat flour is too high, the noodles made will have rough texture, poor appearance and taste, and even difficult to swallow, which cannot meet the needs of consumers and leads to a low repurchase rate of the product; the second is to try to use additives to improve the taste of buckwheat noodles, but this method may affect the natural properties of the noodles, and the improvement effect is limited.

[0004] Therefore, how to improve the nutritional function of buckwheat noodles while maintaining a good taste and appearance has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] In order to improve the nutritional function of buckwheat noodles while maintaining a good taste and appearance, the present application provides a sandwich buckwheat noodles and a preparation method thereof.

[0006] In the first aspect, the present application provides a sandwich buckwheat noodles, which adopts the following technical solution: A sandwich buckwheat noodle, the cross section of the sandwich buckwheat noodle is round, square or oval; When the cross section of the sandwich buckwheat noodles is circular, the center is the buckwheat circle and the outer layer is the wheat wrapping; When the cross section of the sandwich buckwheat noodles is square, the middle layer is buckwheat sandwich, and the upper and lower layers are covered with wheat; When the cross-section of the sandwich buckwheat noodles is oval, the middle is the buckwheat center and the outer layer is wrapped with wheat.

[0007] The present application provides a buckwheat noodles with a unique sandwich structure, which achieves a perfect balance between nutrition and taste. It not only ensures a high content of buckwheat components but also solves the problems of rough texture and poor taste of traditional buckwheat noodles. Specifically, firstly, the circular, square or oval cross-sectional design endows the noodles with diverse appearances, enhancing the market competitiveness of the product. Secondly, the outer wheat wrapping layer ensures that the noodles have a smooth taste similar to ordinary noodles, meeting the taste needs of consumers, while the inner buckwheat part is rich in dietary fiber and other healthy components, significantly improving the nutritional value of the noodles. In addition, this visual sandwich design allows consumers to intuitively see the presence of buckwheat, enhancing the trust in the naturalness and healthiness of the product. The sandwich buckwheat noodles provided by the present application not only fill the market gap but also provide an innovative solution for the field of healthy foods, with broad promotion value.

[0008] In a first aspect, the present application provides a method for preparing sandwich buckwheat noodles, adopting the following technical solution: A method for preparing sandwich buckwheat noodles includes the following steps: vacuum kneading, dough floc fermentation, rolling, dough sheet fermentation, secondary rolling, three-layer composite rolling, continuous rolling, cutting into strips, and drying; The vacuum kneading includes: kneading buckwheat dough flocs and kneading wheat dough flocs; Kneading buckwheat dough flocs: Pour buckwheat flour, wheat active protein and water into a vacuum kneading machine for kneading to obtain buckwheat dough flocs; the weight ratio of the buckwheat flour to the wheat active protein is 1:(0.1 - 0.2); Kneading wheat dough flocs: Pour wheat flour and water into a vacuum kneading machine for kneading to obtain wheat dough flocs; In the step of dough floc fermentation, the water content of the dough flocs after fermentation is 30 - 35%.

[0009] The present application provides a preparation method for sandwich buckwheat noodles. This preparation method can produce buckwheat noodles with a unique sandwich structure, effectively solving the problem that it is difficult to balance nutrition and taste in existing buckwheat noodles on the market. First, the present application prepares buckwheat noodle flocs and wheat noodle flocs respectively in a vacuum environment. In particular, by precisely controlling the ratio of buckwheat flour to wheat active protein and the water content of the noodle flocs after proofing, it is possible to improve the water absorption rate, cooking loss rate, and strength of the sandwich buckwheat noodles while maximizing the proportion of buckwheat, meeting the requirements of taste and healthy diet. Then, by proofing and rolling the buckwheat dough and the wheat dough, the stability and layering of the noodle sheet are enhanced. Moreover, multiple rollings of the wheat dough can ensure that the outer dough has sufficient ductility and elasticity, enabling it to form a uniform and smooth outer structure after wrapping the buckwheat dough. Next, by precisely superimposing two layers of wheat noodle sheets and the middle buckwheat noodle sheet, a core design of the buckwheat component is achieved. This not only increases the addition ratio of buckwheat but also avoids the problem of rough taste that may be caused by direct exposure of buckwheat to the outside. This unique three-layer structure design enables the final product to maintain the smooth and delicate appearance of traditional noodles while being rich in highly nutritious buckwheat components inside. Finally, through multiple continuous rolling processes and drying steps, the thickness and moisture content of the noodle sheet are adjusted to improve the overall texture and cooking adaptability of the noodles and extend their shelf life. The sandwich buckwheat noodles obtained by the preparation method of the sandwich buckwheat noodles provided by the present application not only significantly improve in nutritional components, meeting the needs of consumers for a healthy diet, but also are close to ordinary noodles in taste, greatly improving the user experience.

[0010] In some embodiments, the weight ratio of the buckwheat flour to the wheat active protein can be 1:(0.1 - 0.15) or 1:(0.15 - 0.2).

[0011] In a specific embodiment, the weight ratio of the buckwheat flour to the wheat active protein can also be 1:0.1, 1:0.15, or 1:0.2.

[0012] Optionally, the vacuum degree of the vacuum noodle mixer is 0.0 - 0.1 MPa, and the time is 4 - 10 min.

[0013] Optionally, in the noodle floc proofing step, the proofing temperature of the noodle flocs is 20 - 25°C, the humidity is 60 - 70%, and the time is 20 - 30 min; In the noodle sheet proofing step: the proofing temperature of the noodle sheet is 20 - 25°C, the humidity is 70 - 80%, and the time is 25 - 30 min.

[0014] Optionally, the method for preparing the wheat active protein is as follows: water is added to wheat flour with a wet gluten content > 32% and mixed, and then kneaded into a uniform dough with a water content of 45 - 50%, followed by proofing for 20 - 30 min; then water is added to the dough for the first time, and it is stirred and washed for 30 ± 5 min, and the washing water is removed, leaving the gluten mass; then water is added to the gluten mass for the second time, and it is stirred and washed for 30 ± 5 min, and the washing water is removed, leaving the gluten mass; then water is added to the gluten mass for the third time, and it is stirred and washed for 20 ± 5 min, and the washing water is removed, leaving the gluten mass, thus obtaining the wheat active protein; The water addition amount for the first time is 3 times the volume of the dough; the water addition amounts for the second and third times are both 1 time the volume of the dough.

[0015] In the above method for preparing the wheat active protein, during the proofing process of the dough, wheat proteins (gliadin and glutenin) can fully absorb water and expand to form a gluten network, and the gluten network structure has good ductility and elasticity. The first water addition and stirring wash can wash away soluble starch, sugars, and water-soluble impurities, obtaining a viscoelastic gluten mass; the second stirring wash can remove residual non-gluten proteins (such as globulins) and other impurities; the third stirring wash can remove residual substances and water. The wheat active protein prepared in this application, also known as wheat gluten protein, has the functions of improving the nutritional value of food, improving the texture and taste of food, etc., and can increase the viscoelasticity and ductility of the dough during the processing, making the noodles more chewy, smooth, and elastic.

[0016] Optionally, the specific steps of the calendering are as follows: the proofed buckwheat dough and wheat dough are respectively rolled into noodle sheets by a rolling mill, and the thickness of the rolled noodle sheet is 12 - 15 mm; the specific steps of the second-stage calendering are as follows: the proofed wheat noodle sheet is calendered by 2 rolling mills to make the thickness of the noodle sheet 2 - 3 mm.

[0017] Optionally, the specific steps of the three-layer composite calendering are as follows: 2 wheat noodle sheets and 1 buckwheat noodle sheet are subjected to three-layer composite calendering, with the upper and lower layers being wheat noodle sheets and the middle layer being a buckwheat noodle sheet; the thickness of the noodle sheet after three-layer composite calendering is 10 - 12 mm.

[0018] Optionally, the specific steps of the continuous calendering are as follows: the noodle sheet after three-layer composite calendering is continuously calendered by multiple rolling mills and gradually calendered to a thickness of 0.8 - 1.2 mm.

[0019] Optionally, during the three-layer composite calendering, continuous calendering, and strip cutting steps, the ambient temperature is 20 - 25°C, and the humidity is 55 - 65%.

[0020] In this application, by strictly controlling the temperature and humidity in the steps of three-layer composite calendering, continuous calendering and strip cutting within the above ranges, problems such as outer layer cracking, inner layer fracture and poor composite bonding of the sandwiched buckwheat noodles can be effectively avoided, thus ensuring the stable quality of the product.

[0021] Optionally, the drying is carried out successively at different temperatures / humidities in 7 zones, and the temperatures, humidities and drying times of the 7 zones are as follows: Zone 1: temperature 25 - 35°C, humidity 80% - 90%, duration 40 ± 3 min; Zone 2: temperature 34 - 40°C, humidity 85% - 95%, duration 40 ± 3 min; Zone 3: temperature 40 - 45°C, humidity 80% - 90%, duration 45 ± 3 min; Zone 4: temperature 45 - 50°C, humidity 80% - 85%, duration 35 ± 3 min; Zone 5: temperature 40 - 45°C, humidity 70% - 80%, duration 30 ± 3 min; Zone 6: temperature 35 - 40°C, humidity 65% - 75%, duration 30 ± 3 min; Zone 7: temperature 25 - 35°C, humidity 60% - 70%, duration 20 ± 3 min.

[0022] In summary, this application has the following beneficial effects: 1. This application provides a sandwiched buckwheat noodle with a cross-section in a circular, square or oval shape, that is, with a buckwheat filling inside and a wheat wrapping outside. The above sandwiched buckwheat noodle not only ensures a high content of buckwheat components, but also solves the problems of rough texture and poor taste of traditional buckwheat noodles, and can meet the taste requirements of consumers.

[0023] 2. By adding a certain amount of wheat active protein to the internal buckwheat flour in this application, the buckwheat dough can have higher structural strength and toughness, making the sandwiched buckwheat noodle have a good toughness and elastic texture.

[0024] 3. By controlling the humidity in the steps of three-layer composite calendering, continuous calendering and strip cutting within the range of 55 - 65%, and controlling the temperature, humidity and time of drying in 7 zones within a specific range in this application, problems such as outer layer cracking, inner layer fracture and poor composite bonding of the sandwiched buckwheat noodle can be effectively avoided, thus ensuring the stable quality of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a flow chart of the preparation method of the sandwiched buckwheat noodle provided by this application; Figure 2 is a schematic diagram of three-layer composite calendering; Figure 3 It is a schematic cross-sectional view of a sandwich buckwheat noodles. Specific embodiments

[0026] The present application provides a method for preparing sandwich buckwheat noodles, including the following steps (as Figure 1 shown): (1) Vacuum kneading: Kneading buckwheat noodle flocs: Pour buckwheat flour, wheat active protein and water into a vacuum kneading machine, and knead for 4 - 10 min under a vacuum degree of 0.0 - 0.1 MPa to obtain buckwheat noodle flocs; Kneading wheat noodle flocs: Pour wheat flour and water into a vacuum kneading machine, and knead for 4 - 10 min under a vacuum degree of 0.0 - 0.1 MPa to obtain wheat noodle flocs; Among them, the weight ratio of the buckwheat flour to the wheat active protein is 1:(0.1 - 0.2); (2) Floc proofing: Let the kneaded buckwheat noodle flocs and wheat noodle flocs stand and proof at a temperature of 20 - 25 °C and a humidity of 60 - 70% for 20 - 30 min. In this step, it is necessary to ensure that the water content of the proofed buckwheat noodle flocs and wheat noodle flocs is 30 - 35%; (3) Rolling: Roll the proofed buckwheat noodle flocs and wheat noodle flocs into noodle sheets respectively by a rolling mill, and the thickness of the rolled noodle sheet is 12 - 15 mm; (4) Noodle sheet proofing: Place the rolled buckwheat noodle sheet and wheat noodle sheet in a noodle sheet proofing box respectively, and continue to proof at a temperature of 20 - 25 °C and a humidity of 70 - 80% for 25 - 30 min; (5) Second rolling: Roll the proofed wheat noodle sheet through 2 rolling mills to make the thickness of the noodle sheet 2 - 3 mm; (6) Three - layer composite rolling: Perform three - layer composite rolling on 2 wheat noodle sheets and 1 buckwheat noodle sheet, with the upper and lower layers being wheat noodle sheets and the middle layer being a buckwheat noodle sheet (as Figure 2 shown); The thickness of the noodle sheet after three - layer composite rolling is 10 - 12 mm; (7) Continuous rolling: Continuously roll the noodle sheet after three - layer composite rolling through multiple rolling mills, and gradually roll it to a thickness of 0.8 - 1.2 mm.

[0027] (8) Cutting: Cut the continuously rolled noodle sheet into different noodle shapes with cutters of different shapes. The final shapes of the sandwich buckwheat noodles are round (buckwheat in the center, wheat on the outside), square (buckwheat in the middle, wheat on the upper and lower layers, and not wrapped by wheat on the left and right), and oval (buckwheat in the middle, wrapped by wheat on the outside), as follows Figure 3 shown; In the steps of three - layer composite rolling, continuous rolling and cutting, the ambient temperature is 20 - 25 °C and the humidity is 55 - 65%; (9) Drying: Place the wet noodles after cutting into strips in a drying room and dry them successively at different temperatures / humidities in 7 zones so that the moisture content of the noodles is 12 - 13%, obtaining the sandwich buckwheat noodles; among them, the temperatures, humidities and drying times of the 7 zones are as follows: Zone 1: Temperature 25 - 35°C, humidity 80% - 90%, duration 40 ± 3 min; Zone 2: Temperature 34 - 40°C, humidity 85% - 95%, duration 40 ± 3 min; Zone 3: Temperature 40 - 45°C, humidity 80% - 90%, duration 45 ± 3 min; Zone 4: Temperature 45 - 50°C, humidity 80% - 85%, duration 35 ± 3 min; Zone 5: Temperature 40 - 45°C, humidity 70% - 80%, duration 30 ± 3 min; Zone 6: Temperature 35 - 40°C, humidity 65% - 75%, duration 30 ± 3 min; Zone 7: Temperature 25 - 35°C, humidity 60% - 70%, duration 20 ± 3 min.

[0028] In this application, the preparation method of wheat active protein is: Add high-quality wheat flour (wet gluten content > 32%) to a wheat starch gluten washing machine, add water to mix according to the final dough moisture content of 45 - 50% (water temperature is about 20°C), stir for 10 - 15 min to knead into a uniform dough, and let it stand and relax for 20 - 30 min. Then add water 3 times the volume of the dough to the dough for the first time, and stir and wash the dough for 30 min; then remove the washing water, retain the gluten mass, and add water 1 time the volume of the gluten mass to the gluten mass for the second time, stir and wash for 30 min; remove the washing water, retain the gluten mass, and add water 1 time the volume of the gluten mass to the gluten mass for the third time, stir and wash for 20 min, remove the washing water, and the residue is wheat active protein, and control the moisture content to be 60 - 70%.

[0029] In the examples of this application, the buckwheat flour is purchased from Yihai Kerry (Shijiazhuang) Buckwheat Products Co., Ltd., and the rest of the raw materials, solvents, etc. can be obtained through self-making or commercial purchase.

[0030] The following further elaborates on this application in combination with examples, performance detection tests and attached drawings.

[0031] Example 1 Example 1 provides a preparation method of sandwich buckwheat noodles, including the following steps: (1) Vacuum kneading: Mix buckwheat noodle flocs: Pour 50 kg of buckwheat flour, 7.5 kg of wheat active protein and 23 kg of water into a vacuum kneading machine, knead the dough at a vacuum degree of 0.1 MPa for 8 min to obtain buckwheat noodle flocs; and wheat dough flakes: Pour 25 kg of wheat flour and 10 kg of water into a vacuum dough mixer, and knead the dough for 8 minutes under a vacuum degree of 0.1 MPa to obtain wheat dough flakes; (2) Dough flake proofing: Let the kneaded buckwheat dough flakes and wheat dough flakes stand and proof for 30 minutes at a temperature of 25 °C and a humidity of 65%. The water content of the proofed buckwheat dough flakes and wheat dough flakes is 30%; (3) Rolling: Roll the proofed buckwheat dough flakes and wheat dough flakes into noodle sheets respectively through a rolling mill. The thickness of the rolled noodle sheets is 13 ± 1 mm; (4) Noodle sheet proofing: Place the rolled buckwheat noodle sheet and wheat noodle sheet in a noodle sheet proofing box respectively, and continue to proof for 30 minutes at a temperature of 25 °C and a humidity of 70%; (5) Second rolling: Roll the proofed wheat noodle sheet through a rolling mill for 2 passes to make the thickness of the noodle sheet 2.5 ± 0.2 mm; (6) Three-layer composite rolling: Conduct three-layer composite rolling on 2 wheat noodle sheets and 1 buckwheat noodle sheet. The upper and lower layers are wheat noodle sheets, and the middle layer is a buckwheat noodle sheet (as Figure 2 shown); The thickness of the noodle sheet after three-layer composite rolling is 11 ± 0.5 mm; (7) Continuous rolling: Conduct multi-pass continuous rolling on the noodle sheet after three-layer composite rolling, and gradually roll it to a thickness of 0.8 - 1.2 mm.

[0032] (8) Slicing: Cut the noodle sheet after continuous rolling into noodle strips with a circular cross-section (buckwheat in the center and wheat on the outside) through a circular cutter.

[0033] During the steps of three-layer composite rolling, continuous rolling and slicing, the ambient temperature is 25 °C and the humidity is 60%; (9) Drying: Place the wet noodles after slicing in a drying room and dry them successively at different temperatures / humidities in 7 zones to make the moisture content of the noodles 12% and obtain the sandwiched buckwheat noodles; Among them, the temperature, humidity and drying time of the 7 zones are as follows: Zone 1: Temperature 30 °C, humidity 85%, duration 40 min; Zone 2: Temperature 35 °C, humidity 90%, duration 40 min; Zone 3: Temperature 45 °C, humidity 85%, duration 45 min; Zone 4: Temperature 50 °C, humidity 80%, duration 35 min; Zone 5: Temperature 45 °C, humidity 75%, duration 30 min; Zone 6: Temperature 40 °C, humidity 70%, duration 30 min; Zone 7: Temperature 30 °C, humidity 65%, duration 20 min.

[0034] Example 2-3 Examples 2-3 respectively provide a method for preparing sandwich buckwheat noodles.

[0035] The difference between the above examples and Example 1 is that in the preparation of the buckwheat dough in step (1), the addition amount of wheat active protein is as shown in Table 1 below.

[0036] Table 1 Addition amount of wheat active protein in the preparation of buckwheat dough in step (1) Example 4 Example 4 provides a method for preparing sandwich buckwheat noodles.

[0037] The difference between the above example and Example 1 is that the water addition amount in the (1) vacuum dough mixing step is adjusted so that after the (2) dough floc waking step, the water content of both the buckwheat dough flocs and the wheat dough flocs is 35%.

[0038] Example 5 Example 5 provides a method for preparing sandwich buckwheat noodles.

[0039] The difference between the above example and Example 1 is that the environmental humidity in the three-layer composite rolling, continuous rolling and strip cutting steps is 55%.

[0040] Example 6 Example 6 provides a method for preparing sandwich buckwheat noodles.

[0041] The difference between the above example and Example 1 is that the environmental humidity in the three-layer composite rolling, continuous rolling and strip cutting steps is 65%.

[0042] Example 7 Example 7 provides a method for preparing sandwich buckwheat noodles.

[0043] The difference between the above example and Example 1 is that in the drying step, the temperature, humidity and drying time in 7 zones are as follows: Zone 1: temperature 35°C, humidity 80%, duration 40 min; Zone 2: temperature 40°C, humidity 85%, duration 40 min; Zone 3: temperature 40°C, humidity 85%, duration 45 min; Zone 4: temperature 45°C, humidity 80%, duration 35 min; Zone 5: temperature 40°C, humidity 80%, duration 30 min; Zone 6: temperature 35°C, humidity 65%, duration 30 min; Zone 7: temperature 30°C, humidity 60%, duration 20 min.

[0044] Example 8 Example 8 provides a method for preparing sandwich buckwheat noodles.

[0045] The difference between the above example and Example 1 is as follows: in the drying step, the temperature, humidity and drying time of 7 zones are as follows: Zone 1: temperature 45°C, humidity 90%, duration 40 min; Zone 2: temperature 45°C, humidity 85%, duration 40 min; Zone 3: temperature 40°C, humidity 80%, duration 45 min; Zone 4: temperature 40°C, humidity 70%, duration 35 min; Zone 5: temperature 35°C, humidity 60%, duration 30 min; Zone 6: temperature 30°C, humidity 55%, duration 30 min; Zone 7: temperature 20°C, humidity 50%, duration 20 min.

[0046] Example 9 Example 9 provides a method for preparing sandwich buckwheat noodles.

[0047] The difference between the above example and Example 1 is as follows: the drying step is carried out successively at different temperatures / humidities in 3 zones, and the temperature, humidity and drying time of the 3 zones are as follows: Zone 1: temperature 25°C, humidity 95%, duration 30 min; Zone 2: temperature 40°C, humidity 80%, duration 50 min; Zone 3: temperature 20°C, humidity 50%, duration 20 min; Comparative Example 1 Comparative Example 1 provides a method for preparing sandwich buckwheat noodles.

[0048] The difference between the above comparative example and Example 1 is as follows: in the preparation of buckwheat dough in step (1), the addition amount of wheat active protein is 0.

[0049] Comparative Example 2 Comparative Example 2 provides a method for preparing sandwich buckwheat noodles.

[0050] The difference between the above comparative example and Example 1 is as follows: adjust the water addition amount in the (1) vacuum dough mixing step, so that after the (2) noodle floc waking step, the water content of both buckwheat noodle flocs and wheat noodle flocs is 25%.

[0051] Comparative Example 3 Comparative Example 3 provides a method for preparing sandwich buckwheat noodles.

[0052] The difference between the above comparative example and Example 1 is that the environmental humidity in the three-layer composite rolling, continuous rolling and noodle cutting steps is 45%.

[0053] Comparative Example 4 Comparative Example 4 provides a method for preparing sandwich buckwheat noodles.

[0054] The difference between the above comparative example and Example 1 is that the environmental humidity in the three-layer composite rolling, continuous rolling and noodle cutting steps is 75%. Under the above parameters, it is found that the dough sheets are prone to adhesion and roller marks during the three-layer composite rolling, and it is also easy to cause the problem of rapid reproduction of microorganisms in the workshop.

[0055] Performance detection test (2) Physical and chemical property evaluation The sandwich buckwheat noodles obtained from Examples 1-9 and Comparative Examples 1-4 were tested for various physical and chemical indexes, and the results are shown in Table 2 below.

[0056] (1) Water absorption rate and cooking loss rate: Refer to the standard for noodles (LS / T 3212-2021 Noodles). The specific steps are as follows: Weigh 10 g (dry weight) of sandwich buckwheat noodles and put them into a stainless steel basin containing 500 mL of boiling water. Heat with an induction cooker and keep the water in a slightly boiling state. After cooking for 5 min until cooked, take out the noodles and let them stand for 5 min (at this time, the water on the surface of the noodles is completely drained). Weigh the mass of the cooked noodles and calculate the water absorption rate. Each sample is repeated 5 times and the average value is taken. The calculation formula for the water absorption rate is as follows: Water absorption rate = (mass of cooked noodles - dry weight of uncooked noodles before cooking) / dry weight of uncooked noodles before cooking × 100% Evaporate the noodle soup on the induction cooker until almost dry, then continue to dry it in an oven at 105 °C until constant weight. Weigh the dry weight of the noodle soup and calculate the cooking loss rate. Each sample is repeated 5 times and the average value is taken. The calculation formula for the cooking loss rate is as follows: Cooking loss rate = dry weight of noodle soup / dry weight of uncooked noodles before cooking × 100% Note: The greater the water absorption rate of the noodles, the worse the cooking resistance of the noodles; the greater the cooking loss rate of the noodles, the worse the cooking performance of the noodles.

[0057] (2) Breaking stress: The TA-XT2i texture analyzer was used to measure the breaking stress of the sandwich buckwheat noodles. The test parameters were set as follows: Select the A / SFR probe; the pre-measurement speed is 3 mm / s, the measurement speed is 1 mm / s, and the post-measurement speed is 3 mm / s. Each sample is repeated 5 times and the average value is taken.

[0058] (3) Natural breakage rate and cooked breakage rate: The natural breakage rate and cooked breakage rate of the sandwiched buckwheat noodles were detected according to the LS / T 3212-2014 standard.

[0059] Table 2 Detection results of the physical and chemical indexes of the sandwiched buckwheat noodles obtained in Examples 1-9 and Comparative Examples 1-4 According to the detection results in Table 2, the water absorption rate of the sandwiched buckwheat noodles obtained in Examples 1-9 of this application was 113.66-118.33%, the cooking loss rate was 6.22-8.23%, and the breaking stress was 7.11-8.72 N·mm -2 , the natural breakage rate was 0-0.3%, and the cooked breakage rate was 0-0.5%; while the water absorption rate of the sandwiched buckwheat noodles obtained in Comparative Examples 1-4 was 88.15-95.13%, the cooking loss rate was 9.33-11.27%, and the breaking stress was 6.09-7.83 N·mm -2 , the natural breakage rate was 0-1.3%, and the cooked breakage rate was 0-0.7%. Therefore, it shows that when the weight ratio of buckwheat flour to wheat active protein in this application is controlled within the range of 1:(0.1-0.2), and in the noodle floc waking step, the water content of the noodle floc after waking is controlled within the range of 30-35%, the obtained sandwiched buckwheat noodles have good boilability, good cooking performance, and good toughness, and are not prone to breakage under natural conditions and after being cooked.

[0060] (2) Sensory evaluation Forty sensory evaluation personnel of the patent were selected and randomly divided into 4 groups, with 10 people in each group; then the sandwiched buckwheat noodles obtained in Examples 1-3 and Comparative Example 1 were cooked in boiling water for 4-6 minutes respectively, and each group of personnel tasted 1 kind of sandwiched buckwheat noodles and carried out sensory scoring on the sandwiched buckwheat noodles according to the standards shown in Table 3, and the average integer value was taken for each group. The results are shown in Table 4 below.

[0061] Table 3 Sensory scoring items and standards for sandwiched buckwheat noodles Table 4 Sensory scoring table of the sandwiched buckwheat noodles obtained in Examples 1-9 and Comparative Examples 1-4 According to the test results in Table 4, the sensory scores of the sandwich buckwheat noodles obtained in Examples 1-9 were 90-95 points. For the sandwich buckwheat noodles of Comparative Example 1, due to the absence of wheat active protein, their elasticity and toughness were poor, and their sensory evaluation was only 76 points; for the sandwich buckwheat noodles of Comparative Example 2, the water content of the noodle flocs after waking was too low, resulting in slightly poor gluten of the noodles; for the sandwich buckwheat noodles of Comparative Example 3, the environmental humidity in the steps of three-layer composite rolling, continuous rolling and noodle cutting was too low, affecting the surface smoothness of the noodles and resulting in poor elasticity and hardness; for the sandwich buckwheat noodles of Comparative Example 4, the environmental humidity in the steps of three-layer composite rolling, continuous rolling and noodle cutting was too high, which would affect the continuity of production, and the various physical and chemical indexes of the products were slightly reduced, but had no significant impact on the taste. Therefore, it shows that adding wheat active protein to buckwheat flour in this application, controlling the weight ratio of buckwheat flour to wheat active protein within the range of 1:(0.1-0.2), controlling the water content of the noodle flocs after waking to be 30-35%, and in the steps of three-layer composite rolling, continuous rolling and noodle cutting, the environmental temperature is 20-25°C and the humidity is 55-65%, can obtain sandwich buckwheat noodles with smooth texture, good taste and excellent flavor.

[0062] Although the present invention has been described in detail above with general descriptions and specific embodiments, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. A sandwiched buckwheat noodles, characterized in that, The cross-section of the sandwiched buckwheat noodles is circular, square or oval; When the cross-section of the sandwiched buckwheat noodles is circular, the middle is the buckwheat center, and the outer layer is wrapped with wheat; When the cross-section of the sandwiched buckwheat noodles is square, the middle layer is the buckwheat filling, and the upper and lower layers are covered with wheat; When the cross-section of the sandwiched buckwheat noodles is oval, the middle is the buckwheat center, and the outer layer is wrapped with wheat.

2. A method for preparing a sandwiched buckwheat noodles, characterized in that, It includes the following steps: Vacuum dough kneading, dough floc waking, rolling, dough sheet waking, secondary rolling, three-layer composite rolling, continuous rolling, cutting into strips, drying; The vacuum dough kneading includes: kneading buckwheat dough flocs and kneading wheat dough flocs; Kneading buckwheat dough flocs: Pour buckwheat flour, wheat active protein and water into a vacuum dough kneading machine to knead the dough to obtain buckwheat dough flocs; the weight ratio of the buckwheat flour to the wheat active protein is 1:(0.1-0.2); Kneading wheat dough flocs: Pour wheat flour and water into a vacuum dough kneading machine to knead the dough to obtain wheat dough flocs; In the step of waking the dough flocs, the water content of the dough flocs after waking is 30-35%.

3. The preparation method of the sandwiched buckwheat noodles according to claim 2, characterized in that, The vacuum degree of the vacuum dough kneading machine is 0.0-0.1 MPa, and the time is 4-10 min.

4. The preparation method of the sandwiched buckwheat noodles according to claim 2, characterized in that, In the step of waking the dough flocs, the waking temperature of the dough flocs is 20-25 °C, the humidity is 60-70%, and the time is 20-30 min; In the step of waking the dough sheet, the waking temperature of the dough sheet is 20-25 °C, the humidity is 70-80%, and the time is 25-30 min.

5. The preparation method of the sandwiched buckwheat noodles according to claim 2, characterized in that, The preparation method of the wheat active protein is: Add water to wheat flour with a wet gluten content > 32% and mix, knead into a uniform dough with a water content of 45-50%, and then let it wake for 20-30 min; then add water to the dough for the first time, stir and wash for 30±5 min, remove the washing water, and retain the gluten mass; then add water to the gluten mass for the second time, stir and wash for 30±5 min, remove the washing water, and retain the gluten mass; then add water to the gluten mass for the third time, stir and wash for 20±5 min, remove the washing water, and retain the gluten mass, thus obtaining the wheat active protein; The water addition amount for the first time is 3 times the volume of the dough; the water addition amounts for the second and third times are both 1 time the volume of the dough.

6. The preparation method of the sandwiched buckwheat noodles according to claim 2, characterized in that, The specific steps of the rolling are: Roll the woken buckwheat dough and wheat dough into dough sheets respectively by a rolling mill, and the thickness of the dough sheet after rolling is 12-15 mm; the specific steps of the secondary rolling are: Perform 2-pass rolling on the woken wheat dough sheet to make the thickness of the dough sheet 2-3 mm.

7. The preparation method of the sandwiched buckwheat noodles according to claim 2, characterized in that, The specific steps of the three-layer composite rolling are: Perform three-layer composite rolling on 2 wheat dough sheets and 1 buckwheat dough sheet, with the upper and lower layers being wheat dough sheets and the middle being a buckwheat dough sheet; the thickness of the dough sheet after three-layer composite rolling is 10-12 mm.

8. The preparation method of the sandwiched buckwheat noodles according to claim 2, characterized in that, The specific steps of the continuous rolling are: Continuously roll the dough sheet after three-layer composite rolling through multiple rolling mills, and gradually roll it to a thickness of 0.8-1.2 mm.

9. The preparation method of the sandwiched buckwheat noodles according to claim 2, characterized in that, In the steps of three-layer composite rolling, continuous rolling and cutting into strips, the ambient temperature is 20-25 °C, and the humidity is 55-65%.

10. The preparation method of the sandwiched buckwheat noodles according to claim 2, characterized in that, The drying is carried out successively at different temperatures / humidities in 7 zones. The temperatures, humidities and drying times of the 7 zones are as follows: Zone 1: Temperature 25~35°C, humidity 80%-90%, duration 40±3 min; Zone 2: Temperature 34~40°C, humidity 85%-95%, duration 40±3 min; Zone 3: Temperature 40~45°C, humidity 80%-90%, duration 45±3 min; Zone 4: Temperature 45~50°C, humidity 80%-85%, duration 35±3 min; Zone 5: Temperature 40~45°C, humidity 70%-80%, duration 30±3 min; Zone 6: Temperature 35~40°C, humidity 65%-75%, duration 30±3 min; Zone 7: Temperature 25~35°C, humidity 60%-70%, duration 20±3 min.

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