Buckwheat flour, high-toughness buckwheat noodles and preparation method thereof

Abstract

The invention relates to buckwheat flour, high-toughness buckwheat noodles and a preparation method thereof, and belongs to the technical field of food processing. The buckwheat flour comprises buckwheat flour consisting of sweet buckwheat flour and tartary buckwheat flour, high-gluten wheat flour and vital gluten, and can be used for preparing the high-toughness buckwheat noodles, and the high-toughness buckwheat noodles are obtained by mixing the buckwheat flour with water and then performing layering, aging and drying. The high-toughness buckwheat noodles provided by the invention solve the problems of low toughness and poor taste caused by high content of buckwheat flour, maintain the high content of buckwheat flour, balance the flavor and taste of the buckwheat noodles, and increase the toughness of the noodles. The buckwheat noodles prepared from the buckwheat flour are not added with any additive and edible salt, and have the advantages of being smooth in taste, rich in toughness, high in stretchability, resistant to boiling and not broken on the premise that the original quality of the buckwheat flour is kept.

Description

Technical Field

[0001] The present invention belongs to the technical field of food processing, and in particular relates to a buckwheat flour, a high-tenacity buckwheat noodle and a preparation method thereof. Background Art

[0002] Buckwheat belongs to dicotyledonous plants of the Polygonaceae family, and is mainly divided into two categories: tartary buckwheat (Fagopyrum tataricum) and common buckwheat (Fagopyrum esculentum). Buckwheat flour is rich in flavonoids such as rutin and quercetin, which have strong antioxidant effects and help prevent the occurrence of chronic diseases. At the same time, the contents of vitamin B1 and B2 in buckwheat flour are 3 to 20 times that of wheat flour. Vitamin B1 can protect the nervous system and also promote gastrointestinal peristalsis. The glycemic index (GI) of buckwheat is lower than that of wheat, and it has less impact on blood sugar, making it very suitable for diabetic patients and people on a weight-loss diet. Therefore, foods prepared from buckwheat flour such as buckwheat noodles are increasingly favored by people.

[0003] However, buckwheat protein is mainly composed of water-soluble albumin, salt-soluble globulin and glutenin, and the gluten content is extremely low. After kneading the dough, it has no viscoelasticity and extensibility. Moreover, due to the natural defects of buckwheat, the noodles prepared from buckwheat flour are prone to breakage and have poor stretchability. At the same time, tartary buckwheat is more widely planted and has more applications than common buckwheat, but tartary buckwheat has a strong bitter taste, which often results in poor flavor of the noodles prepared from tartary buckwheat. Therefore, in the current preparation of buckwheat noodles, in order to ensure the taste, the addition ratio of buckwheat flour is often reduced, and the addition amount is generally less than 30%. At the same time, it is necessary to add salt and food additives such as edible gums for improving the quality of the noodles. However, excessive salt and food additives will cause a burden on the body. Therefore, it is of great significance to provide a buckwheat flour with a high buckwheat content, which can be used to prepare buckwheat noodles with high tenacity and good taste without adding any additives and salt. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a buckwheat flour, which is used to prepare high-tenacity buckwheat noodles, and on the basis of ensuring a high content of buckwheat flour and without adding salt or additives, improve the taste, flavor and tenacity of buckwheat noodles.

[0005] The present invention provides a buckwheat flour, which comprises buckwheat flour, high-gluten wheat flour and vital gluten; the buckwheat flour comprises sweet buckwheat flour and tartary buckwheat flour;

[0006] The mass ratio of the buckwheat flour to the high-gluten wheat flour is (5:5) to (6:4); the mass percentage content of the vital gluten in the buckwheat flour is 5% to 10%.

[0007] Preferably, the mass ratio of the sweet buckwheat flour to the tartary buckwheat flour is (0.8 to 1.2):(0.8 to 1.2).

[0008] The present invention also provides an application of the buckwheat flour in the preparation of high-toughness buckwheat noodles.

[0009] The present invention provides a kind of high-toughness buckwheat noodles, which are prepared from the buckwheat flour and water described above.

[0010] Preferably, the mass ratio of the buckwheat flour to water is 100∶(30 - 40).

[0011] The present invention also provides a preparation method of the buckwheat noodles, comprising the following steps:

[0012] Mix the buckwheat flour with water; then press the noodles, age them, and dry them.

[0013] The temperature for aging is 3.8°C - 4.2°C.

[0014] Preferably, the diameter of the noodles during pressing is 1.2 mm - 1.8 mm.

[0015] Preferably, the temperature for pressing is 90°C - 120°C.

[0016] Preferably, the time for aging is 6 h - 12 h.

[0017] Preferably, the temperature for drying is 40°C - 50°C, the humidity is 58% - 62%, and the time is 4 h - 5 h.

[0018] Advantages of the present invention:

[0019] The buckwheat flour provided by the present invention can be used to prepare high-toughness buckwheat noodles. The addition amount of buckwheat flour is high, providing rich nutritional value, and it is a low-GI food. The combination of tartary buckwheat flour and common buckwheat flour neutralizes the bitterness of tartary buckwheat with the fragrance of common buckwheat, improves palatability, balances the flavor, and improves the roughness of the noodles. The appropriate addition of vital gluten further improves the bitterness of tartary buckwheat and enhances the taste and quality of buckwheat noodles; at the same time, through the synergistic effect of vital gluten and wheat flour, the toughness of buckwheat noodles is improved.

[0020] In the preparation method provided by the present invention, the aging process at a suitable low temperature further increases the tensile property of the noodles. The finally prepared buckwheat noodles with a high buckwheat flour content still achieve the effects of smooth taste, high toughness, high stretchability, and being resistant to boiling without breaking on the basis of without any additives and salt, solving the industry problem of poor taste of noodles with a high buckwheat content. Description of the Drawings

[0021] Figure 1 It is a process flow chart for preparing high-toughness buckwheat noodles in Example 2.

[0022] Figure 2To observe the surface and cross-sectional morphology of buckwheat noodles using an S-3400N scanning electron microscope (SEM); among them, the first row from top to bottom is the surface morphology diagram, and the second row is the cross-sectional morphology diagram; from left to right, the first column is buckwheat noodles with a gluten powder addition of 0%, the second column is buckwheat noodles with a gluten powder addition of 5%, and the third column is buckwheat noodles with a gluten powder addition of 10%.

[0023] Figure 3 Diagram of the soup turbidity of buckwheat noodles with different gluten powder additions after cooking. From left to right, they are buckwheat noodles with a gluten powder addition of 0%, buckwheat noodles with a gluten powder addition of 5%, and buckwheat noodles with a gluten powder addition of 10%.

[0024] Figure 4 Graph of the tensile stress-strain performance of buckwheat noodles with different gluten powder additions.

[0025] Figure 5 Graph of the tensile stress-strain performance of buckwheat noodles with different ratios of buckwheat flour and high-gluten wheat flour.

[0026] Figure 6 Graph of the tensile stress-strain performance of buckwheat noodles aged at different temperatures. Detailed implementation method

[0027] The present invention provides a buckwheat flour, which comprises buckwheat flour, high-gluten wheat flour and gluten powder; the buckwheat flour comprises sweet buckwheat flour and bitter buckwheat flour; the present invention has no special limitation on the sources of the buckwheat flour (sweet buckwheat flour and bitter buckwheat flour), high-gluten wheat flour and gluten powder, and conventional commercially available products in the art can be used.

[0028] In the present invention, the mass ratio of the buckwheat flour to the high-gluten wheat flour is (5:5) to (6:4), preferably 5:5, 5:4.5, 5:4, 6:4.5 or 6:4; the mass percentage content of the gluten powder in the buckwheat flour is 5% to 10% (5 g to 10 g of gluten powder is contained in every 100 g of buckwheat flour), preferably 5%, 6%, 7%, 8%, 9% or 10%. The mass ratio of the sweet buckwheat flour to the bitter buckwheat flour is preferably (0.8 to 1.2):(0.8 to 1.2), more preferably 0.8:1.2, 0.9:1.1, 1:1, 1.1:0.9 or 1.2:0.8.

[0029] In the present invention, it is preferred to mix the bitter buckwheat flour and the sweet buckwheat flour to obtain buckwheat flour, and then mix the buckwheat flour with high-gluten wheat flour and gluten powder to obtain the buckwheat flour. The present invention has no special limitation on the mixing method, and conventional mixing methods in the art can be used.

[0030] The present invention also provides the application of the buckwheat flour in the preparation of high-tenacity buckwheat noodles.

[0031] In the present invention, by compounding sweet buckwheat flour and bitter buckwheat flour into buckwheat flour, it contains both the dietary fiber of sweet buckwheat and the flavonoids of bitter buckwheat, making the nutrition more abundant; at the same time, it improves the palatability of the products prepared from buckwheat flour, balances the flavor, and improves the problem of the rough texture of single buckwheat flour. By adding an appropriate amount of wheat flour and vital gluten, when used to prepare high-tenacity buckwheat noodles, the tensile property of the buckwheat noodles is improved, and the toughness of the buckwheat noodles is enhanced; and the appropriate addition of vital gluten also balances the bitter and astringent taste of the buckwheat noodles, improving the taste and quality of the buckwheat noodles.

[0032] The present invention provides a high-tenacity buckwheat noodle, which is prepared from the buckwheat flour and water described above. The mass ratio of the buckwheat flour to water is preferably 100∶(30 - 40), more preferably 100∶30, 100∶32, 100∶35, 100∶38 or 100∶40. In the present invention, the masses of the buckwheat flour (sweet buckwheat flour, bitter buckwheat flour), high-gluten wheat flour, vital gluten and buckwheat flour are all calculated based on the dry basis mass.

[0033] The present invention also provides a preparation method of the buckwheat noodles, comprising the following steps:

[0034] Mix the buckwheat flour and water; then press the noodles, age them, and dry them.

[0035] In the present invention, preferably, the buckwheat flour and water are mixed to obtain a mixed material. The present invention has no special limitation on the mixing method, and the conventional mixing methods in the art can be adopted, preferably stirring and mixing. The stirring time is preferably 5 - 10 min, more preferably 5 min, 8 min or 10 min. So that each raw material is uniformly mixed in the mixed material.

[0036] In the present invention, after mixing, the obtained mixture is subjected to strip pressing. The diameter of the strip-pressed noodles is preferably 1.2 mm to 1.8 mm, more preferably 1.2 mm, 1.5 mm or 1.8 mm. In the present invention, the strip pressing preferably uses a twin-screw extruder. The twin-screw extruder can quickly complete the processes of feeding, mixing, cooking and forming on a single production line, with high production efficiency. Moreover, the two screws of the machine mesh with each other during rotation, which can fully stir the material, ensuring the quality and taste of the product. The twin-screw extrusion method can produce noodles with various shapes and structures by changing the shape and size of the die, meeting the different needs of consumers. During the strip pressing process, the spindle frequency of the twin-screw extruder is preferably 10 Hz - 15 Hz, more preferably 10 Hz, 12 Hz, 13 Hz or 15 Hz; the feeding frequency is preferably 10 Hz - 20 Hz, more preferably 10 Hz, 12 Hz, 13 Hz, 15 Hz, 18 Hz or 20 Hz; the temperature of the strip pressing (the temperature of the twin-screw extruder during extrusion and forming) is preferably 90 °C to 120 °C, more preferably 90 °C, 100 °C, 110 °C or 120 °C.

[0037] After strip pressing, it is preferred to cut the strip-pressed noodles. The present invention has no special limitation on the length of the cutting, and it can be cut according to the conventional required length in the art.

[0038] After cutting, the cut noodles are aged. The aging preferably involves allowing the noodles to stand at a certain aging temperature. The aging temperature in the present invention is 3.8 °C to 4.2 °C, preferably 3.8 °C, 3.9 °C, 4.0 °C, 4.1 °C or 4.2 °C. At the aging temperature in the present invention, it can promote the recrystallization of buckwheat starch, enhance the internal network structure of the noodles, form a more stable and orderly structure, improve its toughness and elasticity, thereby enhancing the tensile properties, so that the prepared noodles can withstand greater external forces during stretching without breaking, significantly superior to the effects of normal temperature aging and freezing low-temperature aging. The aging time in the present invention is preferably 6 h to 12 h, more preferably 6 h, 8 h, 10 h or 12 h.

[0039] After the noodles are aged, it is preferred to separate the noodles. Separating the noodles is an operation to keep the noodles from overlapping and sticking to each other. The present invention has no special limitation on the method of separating the noodles, and the conventional operation methods in the art can be used.

[0040] After striping, it is dried. The drying is preferably carried out in a constant temperature and humidity environment. The drying temperature is preferably 40°C to 50°C, more preferably 40°C, 42°C, 45°C, 48°C or 50°C; the drying humidity is preferably 58% to 62%, more preferably 58%, 59%, 60%, 61% or 62%; the drying time is preferably 4h to 5h, more preferably 4h, 4.2h, 4.5h, 4.8h or 5h. Drying under these conditions can not only ensure the effective diffusion of the internal moisture of the noodles to achieve the drying effect, but also reduce the crack rate of the noodles and maintain the good appearance and color state of the noodles. After drying, high-toughness buckwheat noodles are obtained.

[0041] The technical solutions provided by the present invention will be described in detail below in conjunction with the embodiments, but they cannot be understood as limiting the protection scope of the present invention.

[0042] In the following embodiments, unless otherwise specified, they are all conventional methods.

[0043] In the following embodiments, the materials, reagents, etc. used, unless otherwise specified, can all be obtained from commercial channels.

[0044] Example 1

[0045] A kind of buckwheat flour is composed of 225g of sweet buckwheat flour, 225g of bitter buckwheat flour, 450g of high-gluten wheat flour and 100g of vital gluten; the preparation method of the buckwheat flour is: put the sweet buckwheat flour and the bitter buckwheat flour in a container, stir evenly to make buckwheat flour, and then take the high-gluten wheat flour and vital gluten and add them to the container, and stir evenly to obtain buckwheat flour.

[0046] Example 2

[0047] A kind of high-toughness buckwheat noodles is prepared from the buckwheat flour obtained in Example 1 and water. The mass ratio of the buckwheat flour to water is 100:30;

[0048] The preparation method of the high-toughness buckwheat noodles is as follows:

[0049] Add water accounting for 30% of the mass of the buckwheat flour (30g of water is added to 100g of buckwheat flour) to the buckwheat flour obtained in Example 1, stir for 8 minutes to mix evenly to obtain a mixed material. Subsequently, the mixed material is immediately poured into a twin-screw feeder. The main shaft frequency of the twin-screw extruder is 12Hz, the feeding frequency is 15Hz, the extrusion molding temperature is 100°C, and the extruded noodle diameter is 1.5mm. After molding, it is cut into sections of 24cm, then put into a 4°C refrigerator for aging for 12h. After aging, it is striped and put into a constant temperature and humidity box at a temperature of 45°C and a humidity of 60% for drying for 4.5h to obtain buckwheat noodles. The preparation flow chart is as Figure 1 shown.

[0050] Example 3

[0051] A buckwheat flour is composed of 237.5 g of sweet buckwheat flour, 237.5 g of bitter buckwheat flour, 475 g of high-gluten wheat flour and 50 g of vital wheat gluten. The preparation method of the buckwheat flour is as follows: Put the sweet buckwheat flour and the bitter buckwheat flour in a container, stir evenly to make buckwheat flour, then take the high-gluten wheat flour and vital wheat gluten and add them to the container, and stir evenly to obtain buckwheat flour.

[0052] Example 4

[0053] A high-tenacity buckwheat noodle is prepared from the buckwheat flour obtained in Example 3 and water, and the mass ratio of the buckwheat flour to water is 100∶30.

[0054] The preparation method of the high-tenacity buckwheat noodle is as follows:

[0055] Add water accounting for 30% of the mass of the buckwheat flour obtained in Example 3 to the buckwheat flour, stir for 8 min to mix evenly to obtain a mixed material. Subsequently, immediately pour the mixed material into a twin-screw feeder. The main shaft frequency of the twin-screw extruder is 12 Hz, the feeding frequency is 15 Hz, the extrusion molding temperature is 100 °C, and the diameter of the extruded noodle is 1.5 mm. After molding, cut it into sections according to 24 cm, then put it into a 4 °C refrigerator for aging for 12 h. After aging, divide it into strips, and put it into a constant temperature and humidity box at a temperature of 45 °C and a humidity of 60% for drying for 4.5 h to obtain buckwheat noodles.

[0056] Example 5

[0057] A buckwheat flour is composed of 190 g of sweet buckwheat flour, 285 g of bitter buckwheat flour, 475 g of high-gluten wheat flour and 50 g of vital wheat gluten. The preparation method of the buckwheat flour is as follows: Put the sweet buckwheat flour and the bitter buckwheat flour in a container, stir evenly to make buckwheat flour, then take the high-gluten wheat flour and vital wheat gluten and add them to the container, and stir evenly to obtain buckwheat flour.

[0058] Example 6

[0059] A high-tenacity buckwheat noodle is prepared from the buckwheat flour obtained in Example 5 and water, and the mass ratio of the buckwheat flour to water is 100∶40.

[0060] The preparation method of the high-tenacity buckwheat noodle is as follows:

[0061] Add water accounting for 40% of the mass of buckwheat flour to the buckwheat flour obtained in Example 5, stir for 5 minutes to mix evenly, and obtain a mixed material. Subsequently, immediately pour the mixed material into a twin-screw feeder. The main shaft frequency of the twin-screw extruder is 10 Hz, the feeding frequency is 10 Hz, the extrusion molding temperature is 90 °C, and the diameter of the extruded noodles is 1.2 mm. After molding, cut according to 24 cm, then put it into a refrigerator at 3.8 °C for aging for 6 h. After aging, separate the strips and put them into a constant temperature and humidity box at a temperature of 40 °C and a humidity of 58% for drying for 4 h to obtain buckwheat noodles.

[0062] Example 7

[0063] A kind of buckwheat flour is composed of 276 g of sweet buckwheat flour, 184 g of tartary buckwheat flour, 460 g of high-gluten wheat flour and 80 g of vital gluten; the preparation method of the buckwheat flour is: put the sweet buckwheat flour and the tartary buckwheat flour in a container, stir evenly to make buckwheat flour, and then take the high-gluten wheat flour and vital gluten and add them to the container, stir evenly to obtain buckwheat flour.

[0064] Example 8

[0065] A kind of high-toughness buckwheat noodles is prepared from the buckwheat flour obtained in Example 7 and water, and the mass ratio of buckwheat flour to water is 100∶35;

[0066] The preparation method of the high-toughness buckwheat noodles is:

[0067] Add water accounting for 35% of the mass of buckwheat flour to the buckwheat flour obtained in Example 7, stir for 10 minutes to mix evenly, and obtain a mixed material. Subsequently, immediately pour the mixed material into a twin-screw feeder. The main shaft frequency of the twin-screw extruder is 15 Hz, the feeding frequency is 20 Hz, the extrusion molding temperature is 120 °C, and the diameter of the extruded noodles is 1.8 mm. After molding, cut according to 24 cm, then put it into a refrigerator at 4.2 °C for aging for 10 h. After aging, separate the strips and put them into a constant temperature and humidity box at a temperature of 50 °C and a humidity of 62% for drying for 5 h to obtain buckwheat noodles.

[0068] Example 9

[0069] A kind of buckwheat flour is composed of 285 g of sweet buckwheat flour, 285 g of tartary buckwheat flour, 380 g of high-gluten wheat flour and 50 g of vital gluten; the preparation method of the buckwheat flour is: put the sweet buckwheat flour and the tartary buckwheat flour in a container, stir evenly to make buckwheat flour, and then take the high-gluten wheat flour and vital gluten and add them to the container, stir evenly to obtain buckwheat flour.

[0070] Example 10

[0071] A kind of high-toughness buckwheat noodles is prepared from the buckwheat flour obtained in Example 9 and water, and the mass ratio of buckwheat flour to water is 100∶30;

[0072] The preparation method of the high-toughness buckwheat noodles is as follows:

[0073] Add water accounting for 30% of the mass of the buckwheat flour obtained in Example 9 to the buckwheat flour, stir for 8 min to mix evenly to obtain a mixed material. Subsequently, immediately pour the mixed material into a twin-screw feeder. The main shaft frequency of the twin-screw extruder is 12 Hz, the feeding frequency is 15 Hz, the extrusion molding temperature is 100 °C, and the diameter of the extruded noodles is 1.5 mm. After molding, cut it into sections according to 24 cm, then put it into a 4 °C refrigerator for aging for 12 h. After aging, separate the strips and put them into a constant temperature and humidity box at a temperature of 45 °C and a humidity of 60% to dry for 4.5 h to obtain buckwheat noodles.

[0074] Example 11

[0075] A kind of buckwheat flour is composed of 270 g of sweet buckwheat flour, 270 g of bitter buckwheat flour, 360 g of high-gluten wheat flour and 100 g of vital gluten; the preparation method of the buckwheat flour is as follows: Put the sweet buckwheat flour and the bitter buckwheat flour in a container, stir evenly to make buckwheat flour, and then take the high-gluten wheat flour and vital gluten and add them to the container, stir evenly to obtain buckwheat flour.

[0076] Example 12

[0077] A kind of high-toughness buckwheat noodles is prepared from the buckwheat flour obtained in Example 11 and water, and the mass ratio of the buckwheat flour to water is 100∶30;

[0078] The preparation method of the high-toughness buckwheat noodles is as follows:

[0079] Add water accounting for 30% of the mass of the buckwheat flour obtained in Example 11 to the buckwheat flour, stir for 8 min to mix evenly to obtain a mixed material. Subsequently, immediately pour the mixed material into a twin-screw feeder. The main shaft frequency of the twin-screw extruder is 12 Hz, the feeding frequency is 15 Hz, the extrusion molding temperature is 100 °C, and the diameter of the extruded noodles is 1.5 mm. After molding, cut it into sections according to 24 cm, then put it into a 4 °C refrigerator for aging for 12 h. After aging, separate the strips and put them into a constant temperature and humidity box at a temperature of 45 °C and a humidity of 60% to dry for 4.5 h to obtain buckwheat noodles.

[0080] Comparative Example 1

[0081] A kind of buckwheat noodles:

[0082] The difference from Example 2 is only that the high-gluten wheat flour in the buckwheat flour is 500 g, the sweet buckwheat flour is 250 g, the bitter buckwheat flour is 250 g, and the vital gluten is 0 g, and the rest are the same as in Example 2.

[0083] Comparative Example 2

[0084] A kind of buckwheat noodles:

[0085] The difference from Example 2 is only that in the buckwheat flour, there are 485 g of high-gluten wheat flour, 242.5 g of sweet buckwheat flour, 242.5 g of tartary buckwheat flour, and 30 g of vital wheat gluten, and the rest are the same as in Example 2.

[0086] Comparative Example 3

[0087] A kind of buckwheat noodles:

[0088] The difference from Example 2 is only that in the buckwheat flour, there are 425 g of high-gluten wheat flour, 212.5 g of sweet buckwheat flour, 212.5 g of tartary buckwheat flour, and 150 g of vital wheat gluten, and the rest are the same as in Example 2.

[0089] Comparative Example 4

[0090] A kind of buckwheat noodles:

[0091] The difference from Example 2 is only that in the buckwheat flour, there are 400 g of high-gluten wheat flour, 300 g of sweet buckwheat flour, 300 g of tartary buckwheat flour, and 0 g of vital wheat gluten, and the rest are the same as in Example 2.

[0092] Comparative Example 5

[0093] A kind of buckwheat noodles:

[0094] The difference from Example 2 is only that in the buckwheat flour, there are 300 g of high-gluten wheat flour, 350 g of sweet buckwheat flour, 350 g of tartary buckwheat flour, and 0 g of vital wheat gluten, and the rest are the same as in Example 2.

[0095] Comparative Example 6

[0096] A kind of buckwheat noodles:

[0097] The difference from Example 2 is only that in the buckwheat flour, there are 200 g of high-gluten wheat flour, 400 g of sweet buckwheat flour, 400 g of tartary buckwheat flour, and 0 g of vital wheat gluten, and the rest are the same as in Example 2.

[0098] Comparative Example 7

[0099] A kind of buckwheat noodles:

[0100] The difference from Example 2 is only that in the buckwheat flour, there are 100 g of high-gluten wheat flour, 450 g of sweet buckwheat flour, 450 g of tartary buckwheat flour, and 0 g of vital wheat gluten, and the rest are the same as in Example 2.

[0101] Comparative Example 8

[0102] A kind of buckwheat noodles:

[0103] The difference from Example 2 is only that the aging temperature is room temperature (25 - 30 °C), and the rest are the same as in Example 2.

[0104] Comparative Example 9

[0105] A buckwheat noodle:

[0106] The difference from Example 2 is only that the aging temperature is -18°C, and the rest are the same as in Example 2.

[0107] Test Example 1

[0108] The morphology, cooking performance, and sensory indexes of the buckwheat noodles prepared in Example 2 (with a gluten content of 10%), Example 4 (with a gluten content of 5%), and Comparative Example 1 (with a gluten content of 0%) were evaluated and analyzed.

[0109] 1. The surface and cross-sectional morphologies of the buckwheat noodles were observed using an S-3400N scanning electron microscope (SEM). The buckwheat noodles were directly broken, and then their surfaces and fracture cross-sections were photographed at an accelerating voltage.

[0110] The obtained results are shown in Figure 2 . It can be seen from Figure 2 that for the buckwheat noodles in Comparative Example 1 without added gluten, the protein network is sparse and the starch granules are not fully wrapped; for the sample in Example 4 with 5% added gluten, the gluten forms a primary network through the shearing and thermal effects of twin-screw extrusion, cross-links with the starch partially, and the structure is denser than that of the sample without added gluten; for the sample in Example 2 with 10% added gluten, the high content of gluten forms a highly cross-linked continuous protein matrix that wraps the starch granules, and the starch granules are completely embedded in the protein network, with extremely small and uniform pores and a highly dense structure.

[0111] 2. The basic performance indexes of the buckwheat noodles prepared in Example 2, Example 4, and Comparative Example 1 were measured, including the optimal cooking time, cooking breakage rate, cooking loss rate, and water content. The detection methods are as follows:

[0112] (1) Optimal cooking time: Weigh the buckwheat noodles and put them into boiling water. Starting from the 3rd minute, take out one buckwheat noodle every 30 seconds, press it with a glass plate until there is no hard core, and then record the time as the optimal cooking time.

[0113] (2) Cooking breakage rate: Take 20 complete buckwheat noodles and observe the whole number P1 after cooking to the optimal cooking time.

[0114] Breakage rate = (P1 / 20) × 100%

[0115] (3) Cooking loss: Weigh and record the mass M0 of a 500 mL beaker, weigh the original weight M1 of 20 buckwheat noodles, take out the buckwheat noodles after cooking to the optimal cooking time, put the remaining noodle soup into the beaker, and weigh M2 after drying and cooling the beaker containing the noodle soup in an oven at 105°C.

[0116] Cooking loss rate = (M2 - M0) / M1 × 100%

[0117] (4) Moisture content: Take a flat weighing bottle made of clean glass, place it in a drying oven at 105 °C, and tilt the bottle cap on the edge of the bottle. Heat for 1 h, take it out, cover it, place it in a desiccator to cool for half an hour, weigh it, and record the mass m3 of the weighing bottle. Cut the buckwheat noodles as finely as possible, weigh 2 g, put them into this weighing bottle, and record the mass m1 of the weighing bottle and the sample. After weighing, place it in a drying oven at 105 °C, tilt the bottle cap on the edge of the bottle, dry for 2 hours, cover it and take it out, place it in a desiccator to cool for half an hour and then weigh it, and record the mass m2 of the weighing bottle and the dried sample at this time.

[0118] Moisture content = (m1 - m2) / (m1 - m3) × 100%

[0119] The results are shown in Table 1. It can be seen from Table 1 that the buckwheat noodles without adding vital wheat gluten are loose in structure during cooking, and water penetration and thermal effects are likely to cause local stress concentration, leading to fracture. With the increase in the content of vital wheat gluten, the cooking breakage rate gradually decreases and there are significant differences; the solid content in the cooking soup also decreases (consistent with the phenomenon of reduced turbidity of the soup after cooking), resulting in a decrease in cooking loss and significant differences. With the increase in the content of vital wheat gluten, the optimal cooking time also increases.

[0120] Table 1 Effects of the addition amount of vital wheat gluten on the basic properties of buckwheat noodles

[0121] Gluten content / % Rate of broken strips during cooking / % Cooking time Cooking loss rate / % Water content / % 0 <![CDATA[41.5±2.12 a > 11 min 30 s <![CDATA[19.36±0.52 a > <![CDATA[10.22±0.18 b > 5 <![CDATA[19±1.41 b > 12 min 10 s <![CDATA[15.64±0.20 b > <![CDATA[9.8±0.04 b > 10 <![CDATA[2.5±0.71 c > 13 min 30 s <![CDATA[13.18±0.45 c > <![CDATA[8.9±0.32 c >

[0122] Note: The values are expressed as mean ± standard deviation (n = 3), and different letters in the same column between different groups indicate significant differences (p < 0.05).

[0123] 3. Cook the buckwheat noodles until the optimal cooking time (the optimal cooking time is 11 min 30 s when 0% vital wheat gluten is added, 12 min 10 s when 5% vital wheat gluten is added, and 13 min 30 s when 10% vital wheat gluten is added), and pour the buckwheat noodle soup into a 100 mL beaker to observe the soup turbidity situation.

[0124] The results are as Figure 3 shown. The higher the addition amount of vital wheat gluten, the fewer the suspended particles in the soup and the lower the turbidity, indicating that the higher the addition amount of vital wheat gluten, the more significant the wrapping effect on starch granules and the less the starch dissolution amount.

[0125] 4. Sensory evaluation of buckwheat noodles with different addition amounts was conducted. The evaluation method is as follows: A sensory evaluation panel consisting of 5 laboratory members evaluated the appearance roughness and glossiness, smoothness and hardness, color and uniformity, elasticity and taste of buckwheat noodles. After each evaluation, the members were required to rinse their mouths with water, and they were not allowed to exchange opinions. Finally, the comprehensive evaluation of the 5 members was selected as the evaluation result of the buckwheat noodles in this group.

[0126] The sensory evaluation results are shown in Table 2. As can be seen from Table 2, with the increase of gluten content, not only the appearance and elasticity of buckwheat noodles can be improved, but also the flavor of buckwheat noodles can be effectively balanced, so that the taste is improved. The buckwheat noodles prepared by the present invention have high toughness, smoothness, soft mouthfeel, and the quality of fresh buckwheat flavor. This is the result of the combined action of sweet buckwheat flour, bitter buckwheat flour, high-gluten wheat flour and gluten.

[0127] Table 2 Sensory evaluation of buckwheat noodles with different amounts of gluten added

[0128]

[0129] Test Example 2

[0130] The stress-strain curve of noodle stretching is an important indicator for examining the tensile properties of noodles. The greater the maximum stress, the higher the strength, but high strength does not mean high toughness, so people usually pay more attention to the magnitude of the tensile strain of noodles. The higher the strain value, the wider and higher the stress-strain curve, which means the better the tensile properties of noodles.

[0131] The tensile stress-strain properties of buckwheat noodles prepared in Example 2 (10% gluten addition), Example 4 (5% gluten addition), Comparative Example 1 (0% gluten addition), Comparative Example 2 (3% gluten addition), and Comparative Example 3 (15% gluten addition) were analyzed by texture analyzer (TPA) at the optimal cooking time (11min30s for 0% gluten addition, 11min50s for 3% gluten addition, 12min10s for 5% gluten addition, 13min30s for 10% gluten addition, and 15min20s for 15% gluten addition). The tensile fixture probe was A / TG, the probe distance was 10mm, and the trigger mode was displacement mode, and the tensile stress-strain properties of buckwheat noodles under the optimal cooking state were analyzed.

[0132] The results are as follows Figure 4 As shown. Figure 4 It can be seen that when the amount of gluten added increases to 3%, 5%, and 10%, the tensile strain of buckwheat noodles also increases. However, when gluten is added to 15%, excessive gluten addition causes the noodles to easily break when stretched, and the tensile strain decreases significantly.

[0133] Test Example 3

[0134] Analyze the stress-strain properties of buckwheat noodles with different compounding ratios of buckwheat flour and high-gluten wheat flour, namely Comparative Example 1 (buckwheat flour: high-gluten wheat flour = 5:5), Comparative Example 4 (buckwheat flour: high-gluten wheat flour = 6:4), Comparative Example 5 (buckwheat flour: high-gluten wheat flour = 7:3), Comparative Example 6 (buckwheat flour: high-gluten wheat flour = 8:2), and Comparative Example 7 (buckwheat flour: high-gluten wheat flour = 9:1) during stretching. To ensure a high content of buckwheat flour in the finished noodles, at least 50% of buckwheat flour was selected for compounding. Analyze the stress-strain properties of buckwheat noodles during stretching using a texture analyzer (TPA) at the optimal cooking time (for buckwheat flour: high-gluten wheat flour = 5:5, the optimal cooking time is 11 min 30 s; for buckwheat flour: high-gluten wheat flour = 6:4, the optimal cooking time is 11 min 10 s; for buckwheat flour: high-gluten wheat flour = 7:3, the optimal cooking time is 10 min 50 s; for buckwheat flour: high-gluten wheat flour = 8:2, the optimal cooking time is 10 min 30 s; for buckwheat flour: high-gluten wheat flour = 9:1, the optimal cooking time is 10 min 15 s). The stretching fixture probe is A / TG, the probe distance is 10 mm, the triggering mode is displacement mode, and analyze the stress-strain properties of buckwheat noodles during stretching in the optimal cooking state.

[0135] The results are shown in Figure 5 . It can be seen from Figure 5 that as the content of buckwheat flour increases, the tensile strain of buckwheat noodles gradually decreases, and the tensile properties are higher when the ratio of buckwheat flour to high-gluten wheat flour is 5:5 and 6:4.

[0136] Test Example 4

[0137] Analyze the tensile properties of buckwheat noodles prepared under different aging conditions, namely Example 2 (aged at 4°C), Comparative Example 8 (aged at room temperature), and Comparative Example 9 (aged at -18°C). Analyze the stress-strain properties of buckwheat noodles during stretching using a texture analyzer (TPA) at the optimal cooking time (the optimal cooking time for each group of buckwheat noodles is 13 min 30 s). The stretching fixture probe is A / TG, the probe distance is 10 mm, the triggering mode is displacement mode, and analyze the stress-strain properties of buckwheat noodles during stretching in the optimal cooking state.

[0138] The results are as shown in Figure 6 . It can be seen from Figure 6It can be seen that the tensile strain of buckwheat noodles is the largest at 4°C. While at -18°C, the tensile properties of buckwheat noodles are the lowest. Aging under the condition of 4°C promotes the recrystallization of buckwheat starch, enhances the internal network structure of the noodles, forms a more stable and ordered structure, improves its toughness and elasticity, thereby enhancing the tensile properties, enabling the product to withstand greater external forces without breaking during stretching. Although aging at room temperature does not require additional equipment, aging at ambient temperature results in surface cracking of buckwheat noodles, affecting the aging effect. Aging at -18°C reveals that the formation of ice crystals destroys the gluten network, and at the same time, the low temperature delays the aging process, making the aging time longer. Therefore, aging buckwheat noodles at 4°C can achieve the optimal tensile properties of buckwheat noodles.

[0139] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A buckwheat flour, characterized in that, The buckwheat flour includes buckwheat powder, high-gluten wheat flour and vital wheat gluten; the buckwheat powder includes sweet buckwheat powder and bitter buckwheat powder; The mass ratio of the buckwheat powder to the high-gluten wheat flour is (5:5) to (6:4); the mass percentage content of the vital wheat gluten in the buckwheat flour is 5% to 10%.

2. The buckwheat flour according to claim 1, characterized in that, The mass ratio of the sweet buckwheat powder to the bitter buckwheat powder is (0.8 to 1.2):(0.8 to 1.2).

3. Use of the buckwheat flour according to claim 1 or 2 in the preparation of high-tenacity buckwheat noodles.

4. A buckwheat noodle with high toughness, characterized in that, Prepared from the buckwheat flour according to claim 1 or 2 and water.

5. The buckwheat noodles according to claim 4, wherein The mass ratio of the buckwheat flour to water is 100:(30 to 40).

6. The preparation method of the buckwheat noodles according to claim 4 or 5, characterized in that Comprises the following steps: Mix the buckwheat flour with water; then press the strips, age, and dry; The temperature of the aging is 3.8°C to 4.2°C.

7. The preparation method according to claim 6, wherein, The diameter of the noodles during pressing is 1.2 mm to 1.8 mm.

8. The preparation method according to claim 6, characterized in that, The temperature of the pressing is 90°C to 120°C.

9. The preparation method according to claim 6, wherein, The time of the aging is 6 h to 12 h.

10. The preparation method according to claim 6, characterized in that, The temperature of the drying is 40°C to 50°C, the humidity is 58% to 62%, and the time is 4 h to 5 h.

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