Low-GI sea-buckthorn coarse cereal noodles and preparation method thereof

Abstract

The invention provides low-GI sea-buckthorn coarse cereal noodles and a preparation method thereof. Raw material powder of the noodles comprises wheat flour, sea-buckthorn powder, highland barley powder, quinoa powder and chickpea powder, the raw materials are mixed with water to prepare dough, and the dough is rolled to prepare the low-GI sea-buckthorn coarse cereal noodles. The optimal compounding amount of the three coarse cereals and the hippophae rhamnoides is determined; by optimizing a dough kneading process, the sea-buckthorn coarse cereal noodles which are good in taste and low in cooking loss are prepared; and carrying out quality analysis and functional characteristic evaluation on the sea-buckthorn coarse cereal noodles. The GI value of the sea-buckthorn coarse cereal noodles is 47.43, the sea-buckthorn coarse cereal noodles are good in quality, the blood glucose generation level after eating can be effectively regulated and controlled, the sea-buckthorn coarse cereal noodles have the anti-oxidation effect, the prepared low-GI sea-buckthorn coarse cereal noodles can hinder digestion of digestive enzymes on the noodles, then the GI value of the noodles is reduced, and the sea-buckthorn coarse cereal noodles are suitable for being eaten by people needing to control blood glucose and lose weight.

Description

Technical Field

[0001] The present invention belongs to the technical field of functional noodle processing, relates to the regulation of the glycemic index of noodles, and specifically relates to a low-GI seabuckthorn whole grain noodle and a preparation method thereof. Background Art

[0002] Diabetes is a comprehensive disease characterized by elevated postprandial blood glucose, accompanied by disorders of protein and fat metabolism. At present, diabetes cannot be completely cured, and patients need to maintain the stability of blood glucose, blood lipids, and body weight through a combination of drug treatment, exercise intervention, and dietary regulation, in order to reduce the occurrence of complications such as cardiovascular diseases, limb necrosis caused by neuropathy, and uremia caused by kidney diseases. Carbohydrates account for a large proportion of the daily diet, and their types and properties directly affect the postprandial blood glucose level. Therefore, dietary regulation is one of the key links for diabetic patients to control blood glucose.

[0003] As one of the traditional staple foods in China, traditional wheat noodles are mainly made from refined wheat flour, with an unbalanced nutritional ratio and a relatively high GI value, which poses challenges in the modern dietary structure. Developing low-GI noodles has become a key direction for balancing traditional food culture and health needs. Whole grains have significant nutritional value and bioactive functions. Among them, unsaturated fatty acids can regulate lipid metabolism and have the effect of reducing blood glucose, thus helping to prevent the occurrence of cardiovascular diseases; dietary fiber can effectively promote intestinal peristalsis, regulate gastrointestinal functions, and reduce cholesterol and glucose levels. For example, flavonoids such as rutin rich in tartary buckwheat have the effects of enhancing capillary permeability, improving vascular elasticity, and promoting insulin secretion, and have application value in the prevention and treatment of metabolic syndrome.

[0004] Seabuckthorn is a "medicinal and edible homologous" berry plant, which has attracted much attention in the fields of food processing and functional foods due to its rich nutrients and functional components. Seabuckthorn contains rich flavonoid compounds, which can effectively reduce myocardial oxygen consumption and increase coronary blood flow, thus improving cardiovascular health.

[0005] At present, there is a relative lack of low-GI noodle products developed for specific consumer groups, and the whole grain noodles sold on the market generally have problems such as product singularity, low whole grain content, and rough texture. Therefore, it is particularly important to develop a low-GI staple noodle suitable for diabetic patients. Summary of the Invention

[0006] In order to solve the common problems existing in whole grain noodles, the present invention provides a low-GI seabuckthorn whole grain noodle and a preparation method thereof. The noodle has relatively high sensory quality and excellent apparent state, and can hinder the digestion of the noodle by digestive enzymes, thereby reducing the GI value of the noodle, and is suitable for people who need to control blood glucose and lose weight.

[0007] To achieve the above technical objectives, the present invention provides a low-GI seabuckthorn multi-grain noodle. The raw material powder of the noodle includes wheat flour, seabuckthorn powder, highland barley flour, quinoa flour, and chickpea flour. The above raw materials are mixed with water to form a dough, and after rolling, a low-GI seabuckthorn multi-grain noodle is obtained.

[0008] The mass ratio of the raw material powder is: wheat flour: highland barley flour: quinoa flour: chickpea flour: seabuckthorn powder = 3.4 - 4.8:1.2 - 2.4:1.4 - 2.6:2.2 - 3.6:0.2 - 1.

[0009] In a preferred technical solution of the present invention, the seabuckthorn powder is obtained by washing, juicing, and filtering seabuckthorn fresh fruits to obtain seabuckthorn juice, adding maltodextrin, and then performing vacuum freeze-drying and passing through a 40 - 100 mesh sieve to obtain a powdery raw material. The addition amount of the maltodextrin is 6% - 12% of the mass percentage of the seabuckthorn juice, and after vacuum freeze-drying and passing through a 40 - 100 mesh sieve, a powdery raw material is obtained; the vacuum freeze-drying is carried out at a material temperature of -45°C to -60°C.

[0010] In a preferred technical solution of the present invention: the mass ratio of each substance in the raw material powder is wheat flour: highland barley flour: quinoa flour: chickpea flour: seabuckthorn powder = 3.5 - 4:1.2 - 1.5:1.5 - 2:2.5 - 3:0.2 - 0.5.

[0011] In a preferred technical solution of the present invention: the raw material powder of the noodle further includes vital wheat gluten, and the addition amount of the vital wheat gluten is 3% - 6% of the total mass of the raw material powder.

[0012] In a preferred technical solution of the present invention: the highland barley flour, quinoa flour, and chickpea flour are respectively obtained by grinding highland barley, quinoa, and chickpeas into powder and passing through a 60 - 80 mesh sieve.

[0013] The present invention also provides a preparation method of the above low-GI seabuckthorn multi-grain noodle, which specifically includes the following steps:

[0014] S1 Grind highland barley, quinoa, and chickpeas into powder respectively and pass through a 60 - 80 mesh sieve to obtain highland barley flour, quinoa flour, and chickpea flour;

[0015] S2 Wash, juice, and filter seabuckthorn fresh fruits in sequence to obtain seabuckthorn juice. Take the seabuckthorn juice and add maltodextrin to obtain a seabuckthorn mixed solution. Vacuum freeze-dry the seabuckthorn mixed solution to obtain seabuckthorn powder, wherein the added mass of the maltodextrin is 6% - 12% of the mass of the seabuckthorn juice;

[0016] S3 takes wheat flour, adds highland barley flour, quinoa flour and chickpea flour prepared in step S1, then adds sea buckthorn powder prepared in step S2, and adds salt and auxiliary materials, mixes and stirs evenly to obtain mixed raw material powder; wherein the mass ratio of highland barley flour: quinoa flour: chickpea flour: sea buckthorn powder is 3.4-4.8: 1.2-2.4: 1.4-2.6: 2.2-3.6: 0.2-1;

[0017] S4: adding water to the mixed flour and mixing to obtain dough, and pressing the dough after proofing to obtain low GI sea buckthorn multi-grain noodles.

[0018] A preferred technical solution of the present invention: in step S2, the sea buckthorn mixed solution is vacuum freeze-dried at a material temperature of -45 to -50°C.

[0019] A preferred technical solution of the present invention: in step S3, the auxiliary material is gluten powder, and its addition amount is 5% of the total mass of the mixed raw material powder.

[0020] A preferred technical solution of the present invention: in step S3, the amount of salt added is 3-5% of the total mass of the mixed raw material powder.

[0021] A preferred technical solution of the present invention is as follows: in step S4, the amount of water added to the dough is 32-44% of the total mass of the mixed raw material flour, and the dough proofing time is 0-20 minutes.

[0022] A preferred technical solution of the present invention: in step S4, the dough after proofing is rolled and cut into strips to obtain low-GI sea buckthorn multi-grain noodles.

[0023] The beneficial effects of the present invention are:

[0024] The present invention selects three kinds of cereals and sea buckthorn powder for compounding, optimizes the processing condition parameters of sea buckthorn cereal noodles through single factor and response surface experiments, and proposes sea buckthorn cereal noodles with relatively high sensory quality and excellent appearance, which can improve abnormal glucose and lipid metabolism to a certain extent.

[0025] The present invention selects highland barley, chickpeas, quinoa, and sea buckthorn as raw materials for making low-GI sea buckthorn multi-grain noodles. By optimizing the dough-kneading process, sea buckthorn multi-grain noodles with a good texture and low cooking loss are produced. Quality analysis and functional property evaluation of the sea buckthorn multi-grain noodles demonstrate that the sea buckthorn multi-grain noodles are rich in dietary fiber and have a complex granular structure, which can hinder the contact between digestive enzymes and starch molecules, delay starch digestion and glucose release, and hinder digestive enzyme digestion of the noodles, thereby lowering the GI value of the noodles. Furthermore, the noodles are suitable for people who need to control blood sugar and lose weight. In addition, special volatile flavor compounds in sea buckthorn can effectively neutralize the beany smell of the multi-grain noodles, improving their flavor acceptance and thus improving the sensory evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is the influence of the water addition amount on the quality of seabuckthorn multi-grain noodles in the embodiments of the present invention;

[0027] Figure 2 It is the influence of the salt addition amount on the quality of seabuckthorn multi-grain noodles in the embodiments of the present invention;

[0028] Figure 3 It is the influence of the proofing time on the quality of seabuckthorn multi-grain noodles in the embodiments of the present invention;

[0029] Figure 4 They are the response surface (A) and contour line (B) of the influence of the salt addition amount and water addition amount on the cooking loss rate of seabuckthorn multi-grain noodles in the embodiments of the present invention;

[0030] Figure 5 They are the response surface (A) and contour line (B) of the influence of the salt addition amount and proofing time on the cooking loss rate of seabuckthorn multi-grain noodles in the embodiments of the present invention;

[0031] Figure 6 They are the response surface (A) and contour line (B) of the influence of the water addition amount and proofing time on the cooking loss rate of seabuckthorn multi-grain noodles in the embodiments of the present invention;

[0032] Figure 7 They are the appearance diagrams of different noodles in the embodiments of the present invention;

[0033] Figure 8 They are the scanning electron microscope diagrams of different noodles in the embodiments of the present invention;

[0034] Figure 9 Analysis of the antioxidant activity of different noodles in the embodiments, DPPH radical scavenging rate (A) and ABTS + radical scavenging rate (B);

[0035] Figure 10 It is the graph of the change in fasting blood glucose of mice after modeling in the embodiments;

[0036] Figure 11 They are the insulin (A) and insulin resistance index (B) of mice after modeling in the embodiments. Detailed implementation manners

[0037] The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0038] Unless otherwise specified, the technical means adopted in the specification are all technical means known in the art. The raw materials used are all commercially available.

[0039] A low-GI seabuckthorn multi-grain noodle provided by Example 1 uses quinoa flour, chickpea flour, highland barley flour, seabuckthorn powder and wheat flour as raw materials, among which wheat flour accounts for 40%, and multi-grain flour and seabuckthorn powder account for 60%. Adjust the proportions of quinoa flour, chickpea flour, highland barley flour and seabuckthorn powder, and determine the optimal formula as wheat flour: highland barley flour: quinoa flour: chickpea flour: seabuckthorn powder = 3.9:1.3:1.9:2.6:0.3.

[0040] The raw material powder of the seabuckthorn multi-grain noodle is prepared by the following method:

[0041] S1. Treatment of multi-grain raw materials: After removing impurities, washing and drying quinoa, chickpeas and highland barley, use a high-speed pulverizer to grind them into powder and pass through an 80-mesh sieve to obtain quinoa flour, chickpea flour and highland barley flour respectively. After separating the obtained raw material powder and packing them in bags, store them at -4°C.

[0042] S2. Treatment of seabuckthorn raw materials: After removing rotten, damaged and broken fruits from fresh seabuckthorn fruits, wash them and beat them into a uniform fruit pulp. Pass through a 100-mesh nylon cloth to obtain seabuckthorn juice. After adding maltodextrin and homogenizing at high speed, pre-freeze for 5 h, vacuum freeze-dry for 24 h. After taking out, use a high-speed pulverizer to grind them into powder and pass through an 80-mesh sieve to obtain seabuckthorn powder. After packing in bags, store them at -4°C; the addition amount of maltodextrin is 8% of the mass of seabuckthorn juice.

[0043] S3. Mix the raw material powders obtained in Step S1 and Step S2 and wheat flour according to the following mass ratio to prepare a mixed raw material powder, and its mass ratio is wheat flour: highland barley flour: quinoa flour: chickpea flour: seabuckthorn powder = 3.9:1.3:1.9:2.6:0.3.

[0044] S4. Add 5% gluten powder to the mixed raw material powder in Step S3, and fix the stirring time at 5 min.

[0045] S5. Fix the salt addition amount at 3%, the proofing time at 10 min, and the water addition gradient at 32%, 35%, 38%, 41%, 44% to obtain doughs with different water contents. After proofing, the doughs are rolled and cut into low-GI seabuckthorn multi-grain noodles with different water contents.

[0046] A low-GI seabuckthorn multi-grain noodle provided by Example 2 has the same raw material powder ratio as that in Example 1. Steps S1 to S4 are the same. In Step S5, fix the water addition amount at 35%, the proofing time at 10 min, and the salt addition gradient at 1%, 2%, 3%, 4%, 5% to obtain doughs with different salt contents. After proofing, the doughs are rolled and cut into low-GI seabuckthorn multi-grain noodles with different salt contents.

[0047] The low GI sea buckthorn multi-grain noodles provided in Example 3 have the same raw material powder ratio as that in Example 1, and steps S1 to S4 are the same. The amount of water added is fixed at 35%, the amount of salt added is 3%, and the proofing time gradient is 0, 5, 10, 15, and 20 minutes to obtain doughs with different proofing times. The proofed dough is rolled and cut into strips to obtain low GI sea buckthorn multi-grain noodles with different proofing times.

[0048] Taking cooking loss rate as the main evaluation index and breaking rate as reference, the effects of different water content, salt content and proofing time on noodle product quality were investigated.

[0049] The cooking loss rate and breaking rate of the noodles prepared in Examples 1 to 3 were measured. The results are as follows: Figures 1 to 3 shown. Figure 1 Figure A shows the cooking loss rate of noodles in Example 1, and Figure B shows the breaking rate of noodles in Example 1. Figure 1 It is shown that when the amount of water added increases from 32% to 35%, the cooking loss rate of noodles gradually decreases. This is because the amount of water added gradually approaches the water absorption capacity of the mixed flour, allowing the gluten protein to fully absorb water and swell and form a continuous gluten network structure. At the same time, the starch granules also absorb water and swell moderately and are wrapped in the gluten network, thereby increasing the elasticity of the noodles, shortening the cooking time, and reducing the cooking loss rate. However, when the amount of water added exceeds 35%, the moisture in the dough exceeds the appropriate range, and the stickiness of the dough dominates, resulting in a significant decrease in the tensile strength of the noodles, the surface of the noodles becoming sticky, and the loss of starch and protein increasing during the cooking process, and the cooking loss rate increasing significantly. Based on the above analysis, three gradients of water addition of 32%, 35% and 38% were selected in the subsequent response surface experiment to further optimize the processing technology of sea buckthorn multi-grain noodles.

[0050] Figure 2 The effect of salt addition on the quality of sea buckthorn multigrain noodles was shown. Figure 2 Figure A shows the cooking loss rate of noodles in Example 2, and Figure B shows the breaking rate of noodles in Example 2. Figure 2It can be seen that when the salt addition is between 1% and 3%, the cooking loss rate and the breaking rate of the noodles show a downward trend. When the salt addition is 3%, the cooking loss rate and the breaking rate reach the lowest values. After adding an appropriate amount of salt, the sodium ions therein can interact with the negative charges on the surface of gluten proteins, promoting the formation of a more ordered and dense three-dimensional network structure by gluten molecules. This strengthened gluten network significantly improves the elasticity and extensibility of the dough, reduces the risk of noodle breakage during processing, and simultaneously reduces the loss of starch granules during cooking, thus effectively reducing the cooking loss rate. However, when the salt addition exceeds 3%, the cooking loss rate and the breaking rate of the noodles gradually increase. This may be because excessive salt destroys the stability of the gluten network structure, resulting in an increase in the cooking loss rate. Therefore, salt addition levels of 3%, 4%, and 5% are selected as the levels for the subsequent response surface experiment to further optimize the processing technology of sea buckthorn multi-grain noodles.

[0051] The influence of proofing time on the quality of sea buckthorn multi-grain noodles is as Figure 3 shown. Figure 3 In Figure A, it is the cooking loss rate of the noodles in Example 3, and in Figure B, it is the breaking rate of the noodles in Example 3. Figure 3 It can be seen that when the proofing time is 15 min, the cooking loss rate of the noodles is the lowest. This may be because a proofing time of 15 min can fully promote the migration of water, enabling the water to uniformly penetrate into the interior of the dough and come into full contact with protein particles, promoting the formation of more disulfide bonds between protein molecules, thereby enhancing the stability and strength of the gluten network structure. As the proofing time extends, the cooking loss rate and the breaking rate gradually decrease, indicating that a longer proofing time helps the water to be more evenly distributed in the dough, enabling the water content in the gluten network to reach equilibrium, thus improving the stability and mechanical properties of the dough. Based on the experimental data, 10 min, 15 min, and 20 min are selected as the three levels of proofing time in the subsequent response surface experiment to further optimize the processing technology parameters of sea buckthorn multi-grain noodles.

[0052] Under the condition that the raw materials and auxiliary materials remain unchanged, according to the results of Examples 1 - 3, three better gradients are selected, namely, the salt addition of 3 - 5%, the water addition of 32 - 38%, and the proofing time of 10 - 20 min, and a response surface test is set up to obtain the following formula:

[0053]

[0054] The doughs with different formulas in the above table are respectively put into the noodle machine 5 times, and the noodle cutting size of the noodle machine is a diameter of 2 mm and a length of 40 cm.

[0055] Through the response surface optimization experimental method, a quadratic polynomial regression equation is established, and its expression is:

[0056] Y = 9.50 + 0.22A - 0.26B - 0.21C + 0.22AB + 0.062AC - 0.36BC + 0.93A 2 + 1.66B 2 + 1.3

[0057] 7C 2

[0058] In the regression model, the P - value < 0.0001, indicating that the model is extremely significant; the P - value of the lack - of - fit term is 0.966 > 0.05, showing that the lack - of - fit term is not significant, indicating that the established model has a high degree of fitting and can better reflect the law of experimental data.

[0059] The influence of the interaction of each factor on the cooking loss rate is shown in Figures 4 to 6 . Through response surface analysis, the influence law of the water addition amount, salt addition amount and proofing time on the cooking loss rate of noodles can be intuitively understood. When the salt addition amount is fixed, the cooking loss rate first decreases and then increases with the increase of the water addition amount. In the interaction between the proofing time and the water addition amount, the influence of the water addition amount on the cooking loss rate is more significant, and the corresponding surface slope is steeper, while the influence of the proofing time is relatively small.

[0060] According to the analysis of Design Expert software, the optimal process conditions for noodles are finally determined as: water addition amount 35.29%, salt addition amount 3.87%, proofing time 15.46 min. At this time, the cooking loss rate of noodles is 9.46%. Combining the experimental operability and actual production experience, the process parameters are adjusted to: water addition amount 35%, salt addition amount 3%, proofing time 15 min. Through the verification experiment, the measured cooking loss rate is 9.37%, which is basically consistent with the theoretical prediction value, indicating that the response surface model has high reliability and practical significance and can effectively guide the process optimization of seabuckthorn multi - grain noodles.

[0061] Then, seabuckthorn multi - grain noodles are prepared according to the formula in Example 1 with the process parameters of water addition amount 35%, salt addition amount 3%, and proofing time 15 min.

[0062] Comparative Example 1: Compared with Example 1, seabuckthorn is not added when preparing the mixed powder. The ratio of raw material powder is wheat flour: highland barley flour: chickpea flour: quinoa flour = 4:1.4:2.6:2; the addition amount of auxiliary materials and the processing technology remain unchanged. The prepared dough is rolled and cut into strips in a noodle machine to obtain pure multi - grain noodles.

[0063] Comparative Example 2: Compared with Example 1, only wheat flour is used when preparing noodles. The addition amount of auxiliary materials and the processing technology remain unchanged. The prepared dough is rolled and cut into strips in a noodle machine to obtain pure wheat noodles.

[0064] The seabuckthorn noodles prepared with the optimal parameters in the above-mentioned Example 1, the pure coarse grain noodles prepared in Comparative Example 1, and the pure wheat noodles prepared in Comparative Example 2 were used for different experiments to study the basic nutritional components, cooking quality, GI value, sensory quality, antioxidant activity, effects on fasting blood glucose in mice, and effects on insulin in mice. The specific experiments are as follows.

[0065] Test Example 1. Determination of the basic nutritional components of three different noodles

[0066] The seabuckthorn coarse grain noodles of Example 1 were selected as the experimental group, the pure coarse grain noodles of Comparative Example 1 were selected as Control Group 1, and the pure wheat noodles of Comparative Example 2 were selected as Control Group 2. The nutritional components of the noodles in each group were measured respectively, and the test results are shown in Table 1.

[0067] Table 1 Basic nutritional indexes of three different noodles

[0068]

[0069] As can be seen from Table 1, there are significant differences in the basic nutritional components between the two coarse grain noodles and the wheat noodles. The gluten protein content in wheat flour is relatively high, and it can absorb and retain more water during the processing. Therefore, the water content of wheat noodles is significantly higher than that of coarse grain noodles. The ash content reflects the content of minerals and other nutrients in the noodles. Since wheat flour is finely processed and the bran and germ rich in minerals are removed, the ash content of wheat noodles is significantly lower than that of coarse grain noodles. These differences indicate that coarse grain noodles have unique advantages in the composition of nutritional components, especially the contents of minerals and proteins are significantly higher than those of wheat noodles.

[0070] Test Example 2. Appearance display and scanning electron microscopy of three different noodles

[0071] The appearance of the seabuckthorn coarse grain noodles prepared in Example 1, the coarse grain noodles prepared in Comparative Example 1, and the pure wheat noodles prepared in Comparative Example 2 was photographed, as specifically Figure 7 shown; and the scanning electron microscopy (SEM) was used to observe the microscopic structures of the three noodle samples, as specifically Figure 8 shown. After the noodle samples were sputter-coated with gold, they were magnified 500 times to observe the morphological characteristics of their internal network structures.

[0072] Figure 7The three photos in the middle illustrate the appearance characteristics of three noodle recipes. Compared to the two multigrain noodles, the pure wheat noodles exhibited a uniform color and fine texture, displaying typical wheat noodle characteristics. The addition of chickpeas gave the conventional multigrain noodles a yellowish color. Despite the high multigrain content of 60%, the noodles had a slightly rougher texture, which is attributed to the high dietary fiber content and particle size of the multigrain flour. In contrast, the seabuckthorn multigrain noodles were golden yellow. The addition of seabuckthorn not only improved the color of the noodles but also promoted the formation of the gluten network through its functional components, resulting in a finer appearance and more uniform texture. These results demonstrate that the addition of seabuckthorn has a positive effect on improving the appearance quality of multigrain noodles.

[0073] Figure 5 This is a scanning electron microscope (SEM) image of three types of noodles. Figure 8 The distribution of the gluten network structure within the three types of noodles can be clearly seen. All three noodles exhibit pores, likely due to gelatinization and water expansion of starch granules during cooking, which stretches the gluten protein network. However, the gluten network structure of wheat noodles is uniformly connected and intact, exhibiting a high degree of continuity. Compared to wheat noodles, cross-sections of the two multi-grain noodles show significant fractures, with larger and more dispersed pores. This is because the bran components of the multi-grain noodles disrupt the tight connection between starch and protein within the noodles, resulting in a loss of continuity in the gluten network structure. The starch is no longer fully encapsulated within the gluten and gradually leaks outward. Furthermore, the β-glucan contained in highland barley, added to conventional multi-grain noodles, fills the gluten network, weakening its formation and causing the noodles to become loose and more prone to breakage. The addition of sea buckthorn significantly improves the microstructure of the multi-grain noodles. The polysaccharides in sea buckthorn interact with proteins, forming a relatively stable network structure that resists disruption of the gluten network by the multi-grain components. Polysaccharides can improve the structural properties, processing characteristics, and quality of food through non-covalent interactions or covalent bonds between molecules. This mechanism may be an important reason why the microstructure of sea buckthorn multi-grain noodles is superior to that of ordinary multi-grain noodles.

[0074] Experimental Example 3. The cooking quality, GI value and sensory quality of three different noodles were determined. The three noodle samples were the sea buckthorn multigrain noodles prepared in Example 1, the multigrain noodles prepared in Comparative Example 1 and the pure wheat noodles prepared in Comparative Example 2.

[0075] (1) Determination of cooking loss rate: 20 noodles were taken from each of the three types of noodles and boiled in 300 mL of boiling water. When the optimal cooking time was reached, the noodles were removed and the surface was rinsed with distilled water. The noodles were transferred to a beaker together with the noodle soup. After most of the water was evaporated on an electric stove, the beaker was placed in an oven at 105°C and dried to constant weight. The cooking loss rate of the three different types of noodles was calculated according to the following formula:

[0076]

[0077] Where: w1—the total mass of the residue and the beaker after constant weight (g);

[0078] w2—the mass of the empty beaker after constant weight (g); w3—the mass of the uncooked noodles (g).

[0079] (2) Determination of the broken noodle rate: Take 20 noodle samples from each of the three types of noodles, cook them in 300 mL of boiling water, fish them out when the optimal cooking time is reached, and record the number of intact noodles; calculate the cooked broken noodle rates of the three different types of noodles according to the following formulas respectively. The specific formulas are as follows:

[0080]

[0081] Where: N—the number of intact noodles.

[0082] (3) Determination of the glycemic index (GI) value: Take 1 g of samples from each of the three types of noodles and conduct simulated oral digestion, simulated gastric digestion, and simulated intestinal digestion experiments in sequence to calculate the GI value; the experimental process for each sample is as follows:

[0083] a. Simulated oral digestion: Add 1 g of the sample to 5 mL of PBS buffer solution, after boiling water bath for 5 min, add 5 mL of oral simulated digestive fluid and 1 mL of α-amylase (50 U / mL), and react at 37 °C and 200 r / min for 10 min;

[0084] b. Simulated gastric digestion: After the oral digestion is completed, continue to add 3 mL of gastric digestion simulated fluid and 4 mL of pepsin (6000 U / mL), and react at 37 °C and 200 r / min for 30 min;

[0085] c. Simulated intestinal digestion: After the gastric digestion is completed, continue to add 4 mL of intestinal digestion simulated fluid, 2 mL of trypsin (62.5 U / mL), and 0.2 mL of amyloglucosidase (260 U / mL), and adjust the pH to 7 with 1 mol / L NaOH;

[0086] At 0, 30, 60, 90, 120, 150, and 180 min during the simulated intestinal digestion stage, take 1 mL of the digestive fluid each time, after boiling water bath for 10 min to inactivate the enzyme and cooling, centrifuge at 4 °C and 10000x g for 5 min, take 10 μL of the supernatant, dilute it 50 times, add 1.5 mL of DNS reagent, after boiling water bath for 5 min and cooling, add 4 mL of ultrapure water, let it stand for 20 min, and then measure the absorbance at 540 nm;

[0087] d. The DNS method was used to determine the mass concentration of glucose in the samples. With absorbance as the abscissa and glucose concentration as the ordinate, a glucose standard curve was plotted. The absorbance at each time point was substituted to obtain the glucose content, and the hydrolysis rate of the sample was calculated from the glucose content. HI and eGI were calculated through the hydrolysis rate. The calculation formulas are as follows:

[0088]

[0089] eGI = 8.198 + 0.862HI.

[0090] (4) Sensory evaluations were conducted on three different noodle samples: The sensory evaluation criteria are shown in Table 2.

[0091] Table 2 Sensory evaluation criteria for noodles

[0092]

[0093]

[0094] The cooking quality, GI values, and sensory evaluation results of the three different noodles in Test Example 3 are shown in Table 3.

[0095] Table 3 Cooking quality, GI values, and sensory evaluations of different noodles

[0096]

[0097] It can be seen from the above experimental results that wheat noodles are rich in glutenin and gliadin. These proteins interact with each other after absorbing water during processing, forming a stable gluten network structure, which endows wheat noodles with excellent cooking quality. Therefore, the breaking rate and cooking loss rate of wheat noodles are significantly lower than those of miscellaneous grain noodles. The bioactive substances in seabuckthorn (such as soluble dietary fiber and polyphenolic compounds) can, to a certain extent, compensate for the problem of loose gluten network structure in miscellaneous grain noodles, thereby reducing the breaking rate. However, due to the large amount of water-soluble components in seabuckthorn, they are easily dissolved during cooking, resulting in an increase in the cooking loss rate of seabuckthorn miscellaneous grain noodles.

[0098] The GI value of wheat noodles (71.76) is significantly higher than that of miscellaneous grain noodles, belonging to high-GI products. This is mainly because wheat noodles contain a large amount of amylopectin, whose structure is more easily decomposed by digestive enzymes and rapidly converted into glucose, resulting in a rapid increase in blood sugar. In contrast, seabuckthorn miscellaneous grain noodles are rich in dietary fiber and complex granular structures, which can hinder the contact between digestive enzymes and starch molecules, delay the digestion of starch and the release of glucose. The GI value of seabuckthorn miscellaneous grain noodles is 47.43, which is lower than that of miscellaneous grain noodles and belongs to low-GI foods. In addition, the special volatile flavor substances in seabuckthorn can effectively neutralize the beany smell of miscellaneous grain noodles, improve their flavor acceptance, and thus improve the sensory score.

[0099] Experimental Example 4. Determination of the antioxidant activities of three different types of noodles; the three noodle samples are the seabuckthorn miscellaneous grain noodles prepared in Example 1, the miscellaneous grain noodles prepared in Comparative Example 1, and the pure wheat noodles prepared in Comparative Example 2. The specific experimental process for determining the antioxidant activity of each noodle sample is as follows:

[0100] (1) Sample pretreatment: Weigh 3 g of the freeze-dried powder of the noodle sample, add 50 mL of methanol solution with a volume fraction of 80%, mix well, extract in a water bath at 37 °C for 2 h, then perform ultrasonic extraction for 15 min, centrifuge at 5000 r / min for 15 min, and take the supernatant for use.

[0101] (2) DPPH radical scavenging rate: Take 2 mL each of the sample extract and the DPPH radical methanol solution and mix them, let stand in the dark for 30 min. The control group is the sample solution plus the methanol solution; distilled water is used as the blank group to correct the baseline, and the absorbance value is measured at a wavelength of 517 nm; then calculate the DPPH radical scavenging rate according to the following formula:

[0102]

[0103] In the formula: A0—the absorbance value of distilled water and the DPPH reagent;

[0104] A1—the absorbance value of the sample extract and the DPPH reagent;

[0105] A2—the absorbance value of the sample extract and methanol.

[0106] (2) ABTS + radical scavenging rate: Mix the ABTS solution and the K2S2O8 solution in equal volumes and let stand in the dark for 12 h; dilute the mixed solution with distilled water to make its absorbance value at a wavelength of 734 nm be 0.7 ± 0.02; take 0.4 mL of the sample extract and mix it with 3 mL of the ABTS reagent in the dark, let stand in the dark and avoid light for 6 min, use methanol as the control group, and measure the absorbance value at a wavelength of 734 nm.

[0107]

[0108] Where: A0—the absorbance value of methanol and ABTS reagent; A—the absorbance value of the sample extract and ABTS reagent. The measurement results in Test Example 4 are as Figure 9 shown. The antioxidant activities of coarse grain noodles (DPPH scavenging rate of 21.13% and ABTS+ scavenging rate of 40.75%) and seabuckthorn coarse grain noodles (DPPH scavenging rate of 31.48% and ABTS + scavenging rate of 47.55%) are significantly higher than those of wheat noodles. This difference is attributed to the fact that there are fewer natural antioxidants in wheat flour, and some components are lost due to high temperature during the processing. In contrast, ordinary coarse grain noodles can effectively scavenge free radicals because they are rich in natural antioxidants such as dietary fiber and phytic acid. The DPPH and ABTS + free radical scavenging rates of seabuckthorn coarse grain noodles are significantly higher than those of ordinary coarse grain noodles and wheat noodles. This phenomenon is closely related to the rich flavonoids and polyphenolic compounds in seabuckthorn. During the noodle processing, cellulose may be depolymerized, releasing more flavonoids and polyphenolic substances. Therefore, the addition of seabuckthorn can increase the flavonoids and polyphenolic substances in the noodles. These compounds are natural antioxidants and have a certain scavenging effect on DPPH and ABTS + free radicals.

[0109] Test Example 5. Effects of three different noodles on fasting blood glucose in mice. The specific experimental process is as follows:

[0110] Forty male ICR mice were selected. After 1 week of adaptive feeding, 10 mice were randomly selected as the normal group, and the remaining 30 were used as the experimental group and fed a 45% high-fat diet. During this period, the mice had free access to water. After 4 weeks of high-fat diet intervention, the experimental group mice were intraperitoneally injected with a 40 mg / kg STZ solution for 3 consecutive days. Two weeks after the injection of the STZ solution, the experimental group mice were fasted for 12 h (without water restriction), and blood was collected from the tail. The fasting blood glucose value was measured using a handheld blood glucose meter. If the fasting blood glucose value ≥ 11.1 mmol / L, it was determined that the type 2 diabetes (T2DM) model was successfully established. On the premise of ensuring that the blood glucose and body weight of the mice were similar, the successfully modeled mice were randomly divided into three groups, with 10 mice in each group, namely the diabetic group mice, the pure wheat noodle intervention group, and the seabuckthorn coarse grain noodle intervention group mice.

[0111] The seabuckthorn coarse grain noodles prepared in Example 1 and the pure wheat noodles prepared in Comparative Example 2 were made into feeds and used for dietary intervention of the mice for 6 weeks; the diabetic group mice continued to be fed a 45% high-fat diet for 6 weeks. Taking the time point when the T2DM model was successfully constructed as the 0 week, the fasting blood glucose was measured once a week. 12 h before the measurement, the mice were fasted but not water-restricted. The tail blood sampling method was used, and a handheld blood glucose meter was used to measure the fasting blood glucose value of the mice to detect the change in blood glucose level. The measurement results are as Figure 10As shown. Before the intervention, the fasting blood glucose values of the mice in each modeling group were basically the same. Figure 10 Figure 10 shows the changes in the fasting blood glucose values of the mice in each group after successful modeling. The blood glucose of the mice in the normal group was relatively stable, remaining between 5.8 and 6.6; while in the diabetic group, due to the injection of STZ, some pancreatic islet cells were damaged, and the pancreatic β cells secreted insufficient insulin, unable to effectively control blood glucose stability, and the blood glucose could reach up to 30.4. After the intervention with wheat noodles, the fasting blood glucose was 21.3; compared with the wheat noodle group, the seabuckthorn multi-grain noodle group significantly reduced the fasting blood glucose value (18.4), making it gradually tend to the normal level. This effect may be attributed to the polyphenols rich in seabuckthorn, which can reduce oxidative stress reactions, improve insulin sensitivity, thereby promoting the recovery of insulin secretion and controlling blood glucose levels.

[0112] Experimental Example 6. Effects of Three Different Noodles on Insulin in Mice

[0113] Referring to the intervention method in Experimental Example 5, after the intervention, the mice were fasted but allowed to drink water for 12 h, blood was collected from the orbital cavity. After the blood was collected and allowed to clot at room temperature for 60 min, it was centrifuged at 3000 rpm for 20 min at 4°C, and the supernatant was aspirated and stored in a 2 mL EPP tube for use at 4°C.

[0114] The insulin (INS) was measured using a kit, and the insulin resistance coefficient was calculated:

[0115]

[0116] The calculation results are as Figure 8 shown. Insulin is the only endocrine hormone secreted by pancreatic islet β cells that can lower blood glucose, and it plays a key role in maintaining normal metabolism and blood glucose stability, while inhibiting glycogenolysis and gluconeogenesis processes. Serum insulin concentration and insulin resistance index (HOMA-IR) are important indicators for evaluating pancreatic islet β cell function. As Figure 11 can be seen, the serum insulin level (40.06 mmol / L) of the mice in the diabetic model group was significantly higher than that of the normal control group (30.07 mmol / L) (p < 0.05), indicating a decrease in insulin sensitivity. After the intervention with wheat noodles, the insulin level was 38.6 mmol / L, showing no significant difference from the diabetic model group, indicating that wheat noodles have a poor ability to improve insulin levels; after the intervention with seabuckthorn multi-grain noodles, the serum insulin level of the mice decreased to 34.87 mmol / L, and the insulin resistance index decreased synchronously to 31.93 mmol / L. This improvement is related to the AMPK signaling pathway activated by seabuckthorn polysaccharides, indicating that seabuckthorn multi-grain noodles significantly improved insulin resistance in diabetic mice by enhancing insulin signal transduction.

[0117] As can be seen from the above embodiments and tests, the low-GI seabuckthorn multi-grain noodles in the present invention not only have a small cooking loss rate and a low GI value, but also have a certain effect on regulating blood sugar, and are very suitable for people who need to control blood sugar and lose weight to eat.

[0118] The above embodiments are only illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention, and all should fall within the protection scope of the present invention.

Claims

1. A low-GI seabuckthorn multi-grain noodle, characterized in that: The raw material powder of the noodles includes wheat flour, seabuckthorn powder, highland barley flour, quinoa flour and chickpea flour. The above raw materials are mixed with water to make dough, and after rolling, low-GI seabuckthorn multi-grain noodles are obtained. The mass ratio of each substance in the raw material powder is as follows: Wheat flour: Highland barley flour: Quinoa flour: Chickpea flour: Seabuckthorn powder = 3.4 - 4.8: 1.2 - 2.4: 1.4 - 2.6: 2.2 - 3.6: 0.2 - 1.

2. The low-GI seabuckthorn multi-grain noodles according to claim 1, characterized in that: The seabuckthorn powder is obtained by washing, juicing and filtering seabuckthorn fresh fruits to get seabuckthorn juice, adding maltodextrin and then carrying out vacuum freeze-drying and passing through a 40 - 100 mesh sieve to obtain a powdery raw material. The addition amount of the maltodextrin is 6% - 12% of the mass percentage of the seabuckthorn juice, and after vacuum freeze-drying and passing through a 40 - 100 mesh sieve, a powdery raw material is obtained; the vacuum freeze-drying is carried out at a material temperature of -45°C to -60°C.

3. A low-GI seabuckthorn multi-grain noodle according to claim 1 or 2, characterized in that, The mass ratio of each substance in the raw material powder is as follows: Wheat flour: Highland barley flour: Quinoa flour: Chickpea flour: Seabuckthorn powder = 3.5 - 4: 1.2 - 1.5: 1.5 - 2: 2.5 - 3: 0.2 - 0.

5.

4. A low-GI seabuckthorn whole grain noodle according to claim 1 or 2, characterized in that: The raw material powder of the noodles further includes wheat gluten powder, and the addition amount of the wheat gluten powder is 3% - 6% of the total mass of the raw material powder.

5. A low-GI seabuckthorn coarse grain noodle according to claim 1 or 2, characterized in that: The highland barley flour, quinoa flour and chickpea flour are respectively powdery raw materials obtained by grinding highland barley, quinoa and chickpeas into powder and passing through a 60 - 80 mesh sieve.

6. A method for preparing the low-GI seabuckthorn miscellaneous grain noodles according to any one of claims 1 to 4, characterized in that, Specifically, it includes the following steps: S1 Grind highland barley, quinoa and chickpeas into powder respectively and then pass through a 60 - 80 mesh sieve to obtain highland barley flour, quinoa flour and chickpea flour. S2 Wash, juice and filter seabuckthorn fresh fruits in sequence to obtain seabuckthorn juice. Take the seabuckthorn juice and add maltodextrin to obtain a seabuckthorn mixture. The seabuckthorn powder obtained after vacuum freeze-drying the seabuckthorn mixture, wherein the added mass of the maltodextrin is 6% - 12% of the mass of the seabuckthorn juice. S3 Take wheat flour, add the highland barley flour, quinoa flour and chickpea flour prepared in step S1, then add the seabuckthorn powder prepared in step S2, and add salt and auxiliary materials and mix and stir evenly to obtain a mixed raw material powder; wherein the mass ratio of the highland barley flour: quinoa flour: chickpea flour: seabuckthorn powder is 3.4 - 4.8: 1.2 - 2.4: 1.4 - 2.6: 2.2 - 3.6: 0.2 - 1. S4 Add water to the mixed powder to mix and obtain dough. After proofing, roll it to obtain low-GI seabuckthorn multi-grain noodles.

7. The preparation method of a low-GI seabuckthorn whole grain noodle according to claim 5, characterized in that: In step S2, the seabuckthorn mixture is vacuum freeze-dried at a material temperature of -45 to -50°C.

8. The preparation method of a low-GI seabuckthorn miscellaneous grain noodle according to claim 5, characterized in that, In step S3, the auxiliary material selected is wheat gluten powder, and its addition amount is 5% of the total mass of the mixed raw material powder; in step S3, the addition amount of salt is 3% - 5% of the total mass of the mixed raw material powder.

9. The preparation method of a low-GI seabuckthorn miscellaneous grain noodle according to claim 5, characterized in that: In step S4, the water addition amount for kneading the dough is 32% - 44% of the total mass of the mixed raw material powder, and the proofing time of the dough is 0 - 20 min.

10. The preparation method of a low-GI seabuckthorn miscellaneous grain noodle according to claim 5, characterized in that: In step S4, the proofed dough is rolled and cut into strips to obtain low-GI seabuckthorn multi-grain noodles.

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