Noodles with low hardness and low digestibility and preparation method thereof

Abstract

The invention discloses noodles with low hardness and low digestibility and a preparation method of the noodles. The noodles comprise the following raw materials: vital gluten and starch; the starch comprises high-amylose wheat starch and waxy wheat starch. The ratio of the vital gluten to the starch is (10-20): (90-80); the ratio of the high amylose wheat starch to the waxy wheat starch is (40-60): (60-40). Due to the fact that the high-amylose wheat starch which is difficult to gelatinize and easy to age and the waxy wheat starch which is easy to gelatinize and difficult to age are contained in a specific proportion, and the vital gluten and the starch are contained in a specific proportion, the taste similar to that of common noodles is kept while the digestion rate is reduced, and the dual requirements of consumers for health and taste are met. Other components do not need to be added, the process is simple and easy to implement, and industrialization is easy to achieve.

Description

Technical Field

[0001] The invention relates to noodles, in particular to noodles with low hardness and low digestibility and a preparation method thereof. Background Art

[0002] With the improvement of living standards and the development of science and technology, the processing precision of noodle products and people's intake of refined noodle products are increasing. The starch in refined noodle varieties is quickly decomposed after ingestion, causing the increase of blood sugar in the human body after a meal. Studies have shown that excessive intake of refined noodle products will increase the risk of chronic diseases such as diabetes, obesity, and cardiovascular disease. As one of the most important noodle products in my country, how to reduce its digestion rate is a common concern of scientific researchers and consumers.

[0003] The digestion rate of starch in noodles is reduced by selecting wheat varieties with high amylose content. Existing patents prepare low GI noodles by adding konjac (CN102123612B), whole grains (CN114698778B, CN115736178B) and other ingredients such as resistant dextrin, resistant starch (CN109619415B). However, the addition of resistant starch or other dietary fiber may cause the taste of noodles to deteriorate, such as increased hardness and poor elasticity. When a high proportion of grains is added, the difficulty of forming the noodles may increase due to lack of gluten strength, while a low proportion of addition cannot achieve the effect of low glycemic rate. Grain noodles prepared by extrusion and puffing have a faster digestion rate due to gelatinization and degradation of starch during the extrusion process.

[0004] At present, breeders have cultivated new varieties of wheat with medium to high amylose content. Although the flour made from this kind of wheat can greatly reduce the digestion rate of starch in noodles, it is rich in resistant starch, but when compounded, it will lead to a series of changes in taste such as increased hardness and poor elasticity, making it difficult to meet the public's diverse demands for noodle taste. Therefore, a method for preparing noodles with low hardness and low digestibility is urgently needed. Resistant starch is a new type of dietary fiber. Because it is difficult to be digested by the small intestine, it can be used by probiotics in the intestine and has good health functions.

[0005] This patent uses naturally derived glutinous wheat and high-amylose wheat, and optimizes the processing technology of noodles through specific proportions of mixing, kneading, maturation, rolling and cutting steps to maintain the taste of noodles while reducing the digestion rate of noodles. The present invention can produce slow-digestion noodles only by matching wheat and flour. Its hardness, elasticity and cohesion are comparable to those of ordinary noodles on the market, while the starch digestion rate and digestibility (estimated GI value 63) are significantly lower than those of ordinary noodles on the market (estimated GI value 98). No other ingredients need to be added, the process is simple and easy, and it is easy to achieve industrial-scale production. Summary of the invention

[0006] The purpose of the present invention is to provide a low-hardness and low-digestibility noodle and a preparation method thereof in view of the shortcomings of the prior art:

[0007] The noodle raw materials include: gluten and starch; the starch includes high-amylose wheat starch and glutinous wheat starch.

[0008] Furthermore, the ratio of gluten to starch is 10-20:90-80; further, 12-16:88-84.

[0009] Furthermore, the ratio of high amylose wheat starch to glutinous wheat starch is 40-80:60-20; further, the ratio of high amylose wheat starch to glutinous wheat starch is 40-60:60-40.

[0010] The specific preparation method includes:

[0011] S1. Weigh high amylose wheat starch, gluten starch and gluten powder according to weight;

[0012] S2, uniformly mixing high amylose wheat starch, gluten starch and gluten to obtain reconstituted flour;

[0013] S3, kneading the reconstituted flour, sodium chloride and water to obtain dough;

[0014] S4, using a dough pressing machine to roll the dough for multiple times to obtain dough sheets;

[0015] S5. Use a strip cutter to cut the dough into noodles.

[0016] Furthermore, S5 performs proofing operation before cutting into strips.

[0017] Preferably, the noodles have a thickness of 2 mm and a width of 2 mm.

[0018] Furthermore, the noodles are dry noodles or wet noodles; the water content of the dry noodles is 5-14.5%; the water content of the wet noodles is 50-75%.

[0019] Furthermore, the noodles may or may not contain salt, sodium carbonate or sodium bicarbonate.

[0020] Beneficial technical effects: Because it contains a specific proportion of high-amylose wheat starch that is difficult to gelatinize and easy to age, and glutinous wheat starch that is easy to gelatinize and difficult to age, and a specific proportion of gluten and starch, which together make the physical and chemical properties of starch show significant differences. The noodles have a lower starch digestion rate than noodles made from high-amylose starch flour, while the hardness is reduced and the elasticity is increased, thereby achieving simultaneous improvement in taste and nutritional value. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1This is the starch digestion curve of noodle samples with 12% gluten content.

[0022] Figure 2 This is the starch digestion curve of noodle samples with 16% gluten content.

[0023] Figure 3 The percentage of resistant starch content in noodle samples with different starch compositions and gluten contents.

[0024] Figure 4 The hardness changes of noodle samples with different starch compositions and gluten contents.

[0025] Figure 5 Elasticity changes of noodle samples with different starch compositions and gluten contents.

[0026] Figure 6 Protein encapsulation of gluten in noodles with different starch compositions and gluten contents DETAILED DESCRIPTION

[0027] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with embodiments, and the contents mentioned in the implementation modes are not intended to limit the present invention.

[0028] Example 1

[0029] A noodle with low hardness and low digestibility and a preparation method thereof:

[0030] The noodle raw materials include: gluten and starch; the starch includes high-amylose wheat starch and glutinous wheat starch.

[0031] Furthermore, the ratio of gluten to starch is 10:90.

[0032] Furthermore, the ratio of high amylose wheat starch to glutinous wheat starch is 40:60.

[0033] Example 2

[0034] A noodle with low hardness and low digestibility and a preparation method thereof:

[0035] The noodle raw materials include: gluten and starch; the starch includes high-amylose wheat starch and glutinous wheat starch.

[0036] Furthermore, the ratio of gluten to starch is 20:80.

[0037] Furthermore, the ratio of high amylose wheat starch to glutinous wheat starch is 60:40.

[0038] Example 3

[0039] A noodle with low hardness and low digestibility and a preparation method thereof:

[0040] The noodle raw materials include: gluten and starch; the starch includes high-amylose wheat starch and glutinous wheat starch.

[0041] Furthermore, the ratio of gluten to starch is 12:88.

[0042] Furthermore, the ratio of high amylose wheat starch to waxy wheat starch is 50:50.

[0043] Example 4

[0044] A noodle with low hardness and low digestibility and a preparation method thereof:

[0045] The noodle raw materials include: gluten and starch; the starch includes high-amylose wheat starch and glutinous wheat starch.

[0046] Furthermore, the ratio of gluten to starch is 16:84.

[0047] Furthermore, the ratio of high amylose wheat starch to glutinous wheat starch is 60:40.

[0048] Example 5

[0049] A noodle with low hardness and low digestibility and a preparation method thereof:

[0050] The noodle raw materials include: gluten and starch; the starch includes high-amylose wheat starch and glutinous wheat starch.

[0051] Furthermore, the ratio of gluten to starch is 15:85.

[0052] Furthermore, the ratio of high amylose wheat starch to glutinous wheat starch is 40:60.

[0053] Test example

[0054] The glucose content obtained by digesting starch in the noodles prepared by the present invention is measured, and the specific steps are as follows:

[0055] 1. Preparation of enzyme preparations:

[0056] Pepsin solution: Dissolve 50 mg pepsin (3200-4500 U / mg) in 50 mL 0.02 M HCl solution. Preheat to 37°C before use after fully dissolved.

[0057] Pancreatin / amyloglucosidase mixed solution: Dissolve 20 mg pancreatin (16 U / mg) and 1 mL amyloglucosidase (3000 U / mL) in 79 mL 0.2 mol / L sodium acetate buffer (0.2 M, pH 6.0). After fully dissolved, preheat to 37 °C before use.

[0058] 2. When the gluten content is 12%, the following six groups of tests are carried out:

[0059] Experiment 1: Noodles were prepared with a mass ratio of high amylose wheat starch to glutinous wheat starch of 0:100.

[0060] Experiment 2: Noodles were prepared with a mass ratio of high-amylose wheat starch to glutinous wheat starch of 20:80.

[0061] Experiment 3: Noodles were prepared with a mass ratio of high amylose wheat starch to glutinous wheat starch of 40:60.

[0062] Experiment 4: Noodles were prepared with a mass ratio of high-amylose wheat starch to glutinous wheat starch of 60:40.

[0063] Experiment 5: Noodles were prepared with a mass ratio of high-amylose wheat starch to glutinous wheat starch of 80:20.

[0064] Experiment 6: Noodles were prepared with a mass ratio of high amylose wheat starch to glutinous wheat starch of 100:0.

[0065] When the gluten content was 16%, the following six groups of tests were conducted:

[0066] Experiment 7: Noodles were prepared with a mass ratio of high amylose wheat starch to glutinous wheat starch of 0:100.

[0067] Experiment 8: Noodles were prepared with a mass ratio of high-amylose wheat starch to glutinous wheat starch of 20:80.

[0068] Experiment 9: Noodles were prepared with a mass ratio of high-amylose wheat starch to glutinous wheat starch of 40:60.

[0069] Experiment 10: Noodles were prepared with a mass ratio of high amylose wheat starch to glutinous wheat starch of 60:40.

[0070] Experiment 11: Noodles were prepared with a mass ratio of high amylose wheat starch to glutinous wheat starch of 80:20.

[0071] Experiment 12: Noodles were prepared with a mass ratio of high amylose wheat starch to glutinous wheat starch of 100:0.

[0072] 3. Take the finished noodle samples obtained from the above 12 groups of tests, cook them and freeze-dry them, and take about 120 mg of the sample, divide it into 10 sections, and put it into a 50 mL centrifuge tube;

[0073] 4. Add 5 mL of distilled water and 5 mL of pepsin solution to the centrifuge tube and incubate at 37°C and 500 rpm for 30 min.

[0074] 5. Quickly add 5 mL of 0.02 M NaOH solution and 2 mL of distilled water to stop the reaction;

[0075] 6. Add 8 mL of pancreatin / amyloglucosidase mixed solution and shake at a constant temperature of 37°C and 500 rpm;

[0076] 7. After 1, 10, 20, 30, 60, 90, 120 and 240 min of reaction, take 100 μL of supernatant and add it to 900 μL of anhydrous ethanol;

[0077] 8. Determine the glucose content using the glucose oxidase method: take 100 μL of the diluted reaction solution and add it to 2 mL of glucose oxidase solution. Incubate it in a water bath at 50°C for 30 min. Measure the absorbance at 510 nm and calculate the amount of glucose released based on the standard sample.

[0078] 9. Taste evaluation:

[0079] Take the finished noodle samples obtained from the above 12 groups of tests, soak the cooked noodles in cold water for 20 seconds. Place 3 noodles in parallel on the stage of the texture analyzer, and use the A / LKB-F probe to extrude the noodles. The parameters are: extrusion rate of 70%, trigger force of 10g, compression time of 2s, and speeds before, during, and after the measurement of 2, 0.8, and 2mm / s;

[0080] The test results show that:

[0081] In the noodle samples prepared from experiments 1-6 or 7-12, the amount of starch hydrolyzed at the end of the in vitro digestion reaction decreased with the increase of the content of high-amylose wheat starch, while the resistant starch increased accordingly, indicating that increasing the proportion of amylose wheat starch in the starch composition (>40%) significantly reduced the digestion rate and digestibility (digestibility) of the noodles, thereby inhibiting the release of glucose.

[0082] In the noodle samples prepared from experiments 1-3 and 7-9, the noodle samples with 16% gluten content had a lower digestion rate and higher hardness and elasticity than the noodle samples with 12% gluten content under the same starch composition. However, this difference was not obvious in experiments 4-6 and 10-12. When the proportion of high-amylose wheat starch in the starch composition was >40%, the noodle samples with 16% gluten content had a lower digestion rate than the noodle samples with 12%, but there was no significant difference in noodle hardness.

[0083] Under the condition that starch is mixed with a specific amount of gluten, the inventors found unexpected effects on hardness and elasticity by changing the ratio of high amylose wheat starch and waxy wheat starch in the starch composition.

[0084] Among them, when the content of gluten starch is more than that of high-amylose wheat starch, the noodle hardness decreases with the increase of the proportion of high-amylose wheat starch, while when the content of high-amylose wheat starch is more than that of gluten starch, the noodle hardness increases with the increase of the proportion of high-amylose wheat starch. However, this effect was not seen in noodles without gluten. The appropriate gluten content may help maintain the cohesion of starch. At the same time, the change in the proportion of high-amylose wheat starch and gluten starch in the starch composition leads to a nonlinear U-shaped relationship between the hardness of noodles and the proportion of high-amylose wheat starch.

[0085] TPA can be used to evaluate the texture properties of noodles, such as hardness, elasticity, adhesion, cohesion and chewiness. The hardness of noodles shows a nonlinear U-shaped relationship with the proportion of high-amylose wheat starch, which may be due to the fact that the gluten content may help maintain the cohesion of starch on the one hand, and the starch granule structure unique to wheat starch on the other hand. It is generally believed in the art that noodles will become harder and harder with the proportion of high-amylose wheat starch (using the same scheme, using corn starch to replace wheat starch, the noodles will become harder and harder with the increase in the proportion of high-amylose corn starch, and no U-shaped relationship is shown under the same gluten content conditions). RN16-00 high-amylose wheat starch has the highest hardness, and RN12-40 has the lowest hardness (reconstituted noodles (RN) or RF samples are designated according to the principles of the example: RN16-40, indicating that the flour is composed of 16% gluten and 84% starch and the starch is 40% high-amylose wheat starch and 60% waxy wheat starch). The elasticity of reconstituted noodles increased with increasing proportion of high amylose wheat starch, reaching a peak at 80% high amylose wheat starch and then sharply decreasing at 100% high amylose wheat starch. The cohesiveness of noodles reached a peak at 40% high amylose wheat starch addition and then decreased significantly as the addition of high amylose wheat starch increased to 80% and 100%. The cohesiveness of noodles was the lowest at 100% high amylose wheat starch, indicating that a high proportion of amylose may lead to a looser noodle structure. In addition, increasing gluten content resulted in higher cohesion. This suggests that gluten content may help maintain cohesion, especially at higher high amylose wheat starch ratios. The adhesiveness of noodles was consistent between different high amylose wheat starch ratios and gluten contents, and the adhesiveness of noodles increased significantly when the high amylose wheat starch ratio exceeded 40%.

[0086] Table 1

[0087]

[0088] The more high-amylose wheat starch there was, the lower the eGI values ​​in the noodles. Specifically, for noodles containing 12% gluten, the eGI dropped from 89.48 at 0% high-amylose wheat starch to 63.34 at 100% high-amylose wheat starch. A similar pattern was observed in noodles with 16% protein, where the eGI dropped from 85.37 to 65.43 when the high-amylose wheat starch content increased to 100%. The lower the gluten content, the greater the variation.

[0089] At the same high-amylose wheat starch ratio, noodles with higher protein content generally showed slightly higher eGI values. In addition, the effect of protein became more obvious at high HAWS levels. When the high-amylose wheat starch ratio was below 60%, noodles with higher gluten content tended to show lower eGI values. However, in samples containing 80% or 100% high-amylose wheat starch, this trend was reversed, with higher gluten content corresponding to higher eGI values.

[0090] Although noodles made from high-amylose corn starch have a lower digestion rate and a final digestibility that is significantly lower than that of waxy and ordinary corn starch noodles, noodles with high amylose content show the highest hardness and their dough formability is not satisfactory, which limits their adaptability in industrial production and affects the sensory quality of the final product.

[0091] Table 2 Texture characteristics of noodles made from different corn starches

[0092]

[0093] Table 3 Digestion rate of noodles made from different corn starches

[0094]

[0095] The texture analyzer used in this application is not of the same model, and the experimental results have a slight systematic deviation, which does not affect the experimental conclusions.

[0096] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined as herein.

[0097] It should be understood that the detailed description of the technical solutions of the present invention by means of the preferred embodiments is illustrative rather than restrictive. A person skilled in the art may modify the technical solutions described in the embodiments, or replace some of the technical features by equivalents, based on reading the specification of the present invention; and these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing noodles with low hardness and low digestibility, characterized in that: The noodle raw materials include: gluten and starch; the starch includes high-amylose wheat starch and glutinous wheat starch; The preparation method comprises: S1. Weigh high amylose wheat starch, gluten starch and gluten powder according to weight; S2, uniformly mixing high amylose wheat starch, gluten starch and gluten to obtain reconstituted flour; S3, kneading the reconstituted flour, sodium chloride and water to obtain dough; S4, using a dough pressing machine to roll the dough for multiple times to obtain dough sheets; S5. Use a strip cutter to cut the dough into noodles.

2. The method according to claim 1, characterized in that: The ratio of gluten to starch is 10-20:90-80.

3. The method according to claim 1, characterized in that: The ratio of gluten to starch is 12-16:88-84.

4. The method according to claim 1, characterized in that: The ratio of high amylose wheat starch to waxy wheat starch is 40-80:60-20.

5. The method according to claim 1, characterized in that: The ratio of high amylose wheat starch to waxy wheat starch is 40-60:60-40.

6. The method according to claim 1, characterized in that: S5 performs proofing operation before cutting into strips.

7. A noodle with low hardness and low digestibility, characterized in that: The noodle raw materials include: gluten and starch; the starch includes high-amylose wheat starch and glutinous wheat starch.

8. The noodles according to claim 7, characterized in that: The ratio of gluten to starch is 10-20:90-80.

9. The noodles according to claim 7, characterized in that: The ratio of high amylose wheat starch to waxy wheat starch is 40-80:60-20.

10. The noodles according to claim 7, characterized in that: The noodles are dry noodles or wet noodles; the moisture content of dry noodles is 5-14.5%; the moisture content of wet noodles is 50-75%.

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