Black rice sugar-stabilizing health-preserving rice noodles and preparation method thereof

Abstract

The invention relates to black rice sugar-stabilizing health-preserving rice noodles and a preparation method thereof, and belongs to the technical field of rice noodle processing. The black rice sugar-stabilizing health-preserving rice noodles are prepared from the following raw materials in parts by weight: 40-75 parts of long-shaped rice flour, 10-18 parts of black rice flour, 4-12 parts of sugar-stabilizing rice flour, 8-15 parts of mung bean starch, 4-8 parts of vital gluten, 2-5 parts of black bean flour and 18-22 parts of water. By optimizing the preparation raw materials of the rice noodles, the novel low-GI rice noodles with the long-shaped rice as the main raw material are researched and developed, the low-GI rice noodles have the low GI value and the good texture and cooking characteristics, the requirements of consumers for the taste of traditional rice noodles can be met, healthier choices are provided, the development trend of current healthy diet is met, and the rice noodles have the good market prospects. And the application value is very high.

Description

Technical Field

[0001] The invention relates to the technical field of rice noodle processing, in particular to black rice sugar-stabilized health-preserving rice noodles and a preparation method thereof. Background Art

[0002] Blood sugar fluctuations caused by a high-carbohydrate diet have been shown to be an important cause of diabetes and cardiovascular disease.

[0003] Refined starch foods, such as traditional rice noodles, generally have a glycemic index (GI) higher than 70. Their rapid digestion characteristics lead to dramatic fluctuations in blood sugar after meals, exacerbating insulin resistance. Long-term intake of a high-GI diet can significantly increase the risk of diabetes and is highly correlated with chronic diseases such as obesity and metabolic syndrome. Traditional rice noodles are made mainly of refined white indica rice, with a protein content of only 3-5%, less than 0.5% dietary fiber, and a large amount of active ingredients such as B vitamins and γ-aminobutyric acid are lost during processing; their GI value is as high as 70-90, which is difficult to meet the sugar control needs of diabetic patients and healthy people. At the same time, rice noodles are a category with an annual market size of over 100 billion yuan, and the consumer group covers all age groups, but existing products are still mainly in a single form of high carbon water and low fiber. As consumers' demand for low-sugar, high-fiber foods grows, traditional rice noodles face an urgent need for nutritional upgrades.

[0004] Therefore, improving the formula and preparation method of traditional rice noodles and developing a new type of low GI rice noodles with indica rice as the main raw material can not only meet consumers' demand for the taste of traditional rice noodles, but also provide them with a healthier choice, which is in line with the current development trend of healthy diet and has high application value. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a black rice sugar-stabilized health-preserving rice noodle and a preparation method thereof. The black rice sugar-stabilized health-preserving rice noodle provided by the present invention has a low glycemic index, good elasticity and chewiness, and small cooking loss; its unique color and flavor provide consumers with a more nutritious and healthy choice.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] In a first aspect, the present invention provides a black rice healthy rice noodle with stable sugar content. The raw materials for preparing the black rice healthy rice noodle include the following components in parts by weight: 40-75 parts of indica rice flour, 10-18 parts of black rice flour, 4-12 parts of stable sugar rice flour, 8-15 parts of mung bean starch, 4-8 parts of gluten powder, 2-5 parts of black bean flour, and 18-22 parts of water.

[0008] The invention uses indica rice as a main raw material, adds black rice flour, sugar-stabilized rice flour, mung bean starch, gluten powder and black bean powder in appropriate weight proportions, and adopts a variety of coarse grains as raw materials to prepare low GI rice noodles.

[0009] Among them, indica rice is rich in resistant starch and γ-aminobutyric acid, which can regulate the intestinal flora and provide slow-release energy, helping to reduce the glycemic index of rice noodles. The selected sugar-stabilizing rice is high-resistant starch rice, which has a higher type RS2 resistant starch than ordinary indica rice, helping to reduce the GI value of rice noodles. Black rice is rich in dietary fiber, various vitamins and antioxidant components, has high nutritional value and a unique flavor, and has strong anti-digestibility due to its rich dietary fiber. Mung bean starch contains abundant resistant starch and soluble dietary fiber, delays gastric emptying by forming a gel, and can reduce the postprandial blood glucose peak. Wheat gluten can provide an essential amino acid balance and the nutritional value of rice noodles. Black beans have a high content of anthocyanins, and at the same time contain a large amount of high-quality plant protein and dietary fiber.

[0010] Using the above raw materials in appropriate proportions can make the rice noodles rich in dietary fiber, have good elasticity and chewiness, good cooking quality, and the appearance of the rice noodles is a unique dark red color. It is estimated that the GI value is relatively low, which can not only meet the needs of consumers for the taste of traditional rice noodles, but also provide them with a healthier and more novel flavor choice.

[0011] Preferably, the preparation raw materials of the black rice sugar-stabilizing and health-preserving rice noodles further include the following components in parts by weight: 1-5 parts of hulless barley flour, 1-5 parts of buckwheat flour, 1-5 parts of quinoa flour, 0-0.6 parts of mulberry leaf extract, 0-1.5 parts of arabinoxylan, and 0-0.1 parts of EGCG.

[0012] Epigallocatechin gallate (EGCG), mulberry leaf extract and arabinoxylan are all new food raw materials, with high food safety and strong functionality, and are suitable as supplements for functional foods.

[0013] As a preferred embodiment of the present invention, the addition amounts of the mulberry leaf extract, arabinoxylan and EGCG are all added based on the dry weight of the materials.

[0014] Preferably, the preparation raw materials of the black rice sugar-stabilizing and health-preserving rice noodles include the following components in parts by weight: 40-51 parts of indica rice flour, 15-18 parts of black rice flour, 6-12 parts of sugar-stabilizing rice flour, 8-14 parts of mung bean starch, 4-8 parts of wheat gluten, 2-5 parts of black bean flour, 3-5 parts of hulless barley flour, 1-4 parts of buckwheat flour, 2-3 parts of quinoa flour, 0.4-0.6 parts of mulberry leaf extract, 0.5-1.5 parts of arabinoxylan, 0.1 parts of EGCG, and 20 parts of water.

[0015] Under the conditions of the preferred parts by weight of the preparation raw materials of the black rice sugar-stabilizing and health-preserving rice noodles, the GI value of the rice noodles can be lower than 51, better reducing the increase in postprandial blood glucose; at the same time, the cooking breakage rate is lower, the cooking quality is good, and the elasticity and chewiness are better overall, providing a better eating experience.

[0016] Further preferably, the type of the black rice flour is black indica rice flour;

[0017] and / or, the type of the highland barley flour is black highland barley flour.

[0018] Black indica rice has the advantages of high amylose content, lower sugar and calorie content than ordinary black rice, and is suitable as a good raw material for rice noodle production. Compared with ordinary highland barley, black highland barley contains higher dietary fiber content and protein content, which helps to enhance the nutrition of rice noodles and improve the anti-digestibility of rice noodles.

[0019] In a second aspect, the present invention provides a method for preparing the above-mentioned black rice sugar-stabilizing health-preserving rice noodles, comprising the following steps:

[0020] (1) Screening and mixing the preparation raw materials, and extruding filaments with a single-screw extruder to obtain preliminarily formed rice noodles;

[0021] (2) Standing and aging the preliminarily formed rice noodles, and then passing hot steam for cooking treatment to obtain cooked rice noodles;

[0022] (3) Spraying and loosening the cooked rice noodles, and then drying and cutting them with gradient hot air to obtain the black rice sugar-stabilizing health-preserving rice noodles.

[0023] As a preferred technical solution of the present invention, the mulberry leaf extract, arabinoxylan and EGCG in the preparation raw materials are first dissolved in water and then mixed with other preparation raw materials to improve their dispersibility.

[0024] Preferably, in the preparation raw materials, the indica rice, black rice and sugar-stabilizing rice are respectively washed, dried and pulverized, and then ground into powder to obtain the indica rice flour, black rice flour and sugar-stabilizing rice flour.

[0025] Preferably, in the step (1), screening is carried out using an 80-mesh sieve.

[0026] Preferably, in the step (1), the temperature set by the single-screw extruder is 160-180 °C.

[0027] Preferably, in the step (1), mixing is to place the powder material in a mixer, add water and stir and mix at the same time.

[0028] Preferably, in the step (2), the temperature for standing and aging is 30-40 °C, and the time is 10-14 h.

[0029] Preferably, in the step (2), the conditions for cooking treatment are: steam cooking at a relative humidity of 99% and a temperature of 60-70 °C for 4.5-5.5 h.

[0030] Preferably, in the step (3), the conditions for gradient hot air drying are as follows: the temperature in zone I is 49-51°C, the relative humidity is 90-95%, and the time is 60-100 min; the temperature in zone II is 46-48°C, the relative humidity is 70-75%, and the time is 100-140 min; the temperature in zone III is 40-45°C, the relative humidity is 65-70%, and the time is 100-140 min; the temperature in zone IV is 30-32°C, the relative humidity is 65-70%, and the time is 30-60 min.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] By optimizing the preparation raw materials and adding a variety of coarse grains in specific proportions, the present invention provides a black rice blood sugar-stabilizing and health-preserving rice noodle. Compared with traditional rice noodles, it can significantly slow down the postprandial blood sugar response and has a special fragrance of black rice. It can further use highland barley, buckwheat and quinoa as auxiliary materials, and at the same time add different water-soluble dietary fibers, which can effectively reduce the GI value of the rice noodles, improve the texture characteristics and cooking quality, and endow the rice noodles with unique flavors; at the same time, the coarse grains are rich in a large amount of dietary fiber, which can promote intestinal peristalsis, is beneficial to intestinal health, and is also suitable for diabetics and people with blood sugar control to eat, providing consumers with a new staple food choice. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the preparation process of the black rice blood sugar-stabilizing and health-preserving rice noodle of the present invention;

[0034] Figure 2 It is a graph of the shear characteristics results of the rice noodles prepared from different preparation raw materials in the examples and comparative examples;

[0035] Figure 3 It is a graph of the digestion characteristics results of the rice noodles prepared from different preparation raw materials in the examples and comparative examples. DETAILED DESCRIPTION OF THE INVENTION

[0036] To better illustrate the purpose, technical solution and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments. The test methods used in the following embodiments are all conventional methods unless otherwise specified; the materials, reagents, etc. used are reagents and materials that can be obtained from commercial channels unless otherwise specified.

[0037] Example 1

[0038] An embodiment of the black rice blood sugar-stabilizing and health-preserving rice noodle of the present invention, the preparation raw materials of the black rice blood sugar-stabilizing and health-preserving rice noodle include the following components in parts by weight: 72.5 parts of indica rice flour, 15 parts of black rice flour, 6 parts of blood sugar-stabilizing rice, 15 parts of mung bean starch, 8 parts of gluten powder, 5 parts of black bean powder, and 20 parts of water.

[0039] The preparation method of the black rice blood sugar-stabilizing and health-preserving rice noodle in this embodiment is as follows:

[0040] (1) Wash the indica rice, black rice, and blood sugar-stabilizing rice respectively, dry them in the air, and then grind them into powder to obtain the indica rice powder, black rice powder, and blood sugar-stabilizing rice powder. Sieve all the powder materials, namely indica rice powder, black rice powder, blood sugar-stabilizing rice powder, mung bean starch, wheat gluten powder, and black bean powder, through an 80-mesh sieve to ensure the standard of raw materials. Then, accurately weigh the ingredients according to the preset weight ratio.

[0041] Pour the above powder materials into a mixer, slowly add water, and continuously stir to make the powder materials and water evenly mixed to obtain a mixed material. Transfer it into a single-screw extruder and extrude it into filaments at a high temperature of 170 °C to obtain preliminarily formed rice noodles.

[0042] (2) Transfer the preliminarily formed rice noodles to an aging room and let the rice noodles stand and age for 12 h in a stable environment at 30 °C.

[0043] After the aging of the rice noodles is completed, pass hot steam into them and steam-cook them at a temperature of 65 °C for 5 h, controlling the relative humidity to be 99%. Further carry out the cooking treatment on the rice noodles to obtain cooked rice noodles.

[0044] (3) Quickly put the cooked rice noodles into a spray cold water device and spray to loosen the rice noodles.

[0045] Send the loosened rice noodles into a drying room and adopt the gradient hot air drying technology to gradually remove the moisture in the rice noodles to make them reach an appropriate dryness. After the dried rice noodles are cut, they are bagged to obtain the above-mentioned black rice blood sugar-stabilizing health-preserving rice noodles.

[0046] The conditions for gradient hot air drying are as follows: the temperature in zone I is 50 °C, the relative humidity is 90 - 95%, and the time is 60 min; the temperature in zone II is 47 °C, the relative humidity is 70 - 75%, and the time is 120 min; the temperature in zone III is 45 °C, the relative humidity is 65 - 70%, and the time is 120 min; the temperature in zone IV is 30 °C, the relative humidity is 65 - 70%, and the time is 60 min, and the total duration is 6 h.

[0047] The schematic diagram of the preparation process of the above-mentioned black rice blood sugar-stabilizing health-preserving rice noodles is as Figure 1 .

[0048] Example 2

[0049] An example of the black rice blood sugar-stabilizing health-preserving rice noodles of the present invention, the preparation raw materials of the black rice blood sugar-stabilizing health-preserving rice noodles include the following components in parts by weight: 61.5 parts of indica rice powder, 15 parts of black rice powder, 6 parts of blood sugar-stabilizing rice, 15 parts of mung bean starch, 8 parts of wheat gluten powder, 5 parts of black bean powder, 4 parts of buckwheat flour, 4 parts of hulless barley flour, 3 parts of quinoa flour, and 20 parts of water.

[0050] The preparation method of the black rice steady - sugar health - preserving rice noodles in this embodiment refers to the preparation method of Embodiment 1.

[0051] Embodiment 3

[0052] An embodiment of the black rice steady - sugar health - preserving rice noodles of the present invention, the preparation raw materials of the black rice steady - sugar health - preserving rice noodles include the following components in parts by weight: indica rice flour 51 parts, black rice flour 18 parts, steady - sugar rice 8 parts, mung bean starch 8 parts, wheat gluten 4 parts, black bean flour 3 parts, buckwheat flour 3 parts, hulless barley flour 3 parts, quinoa flour 2 parts, mulberry leaf extract 0.6 part, arabinoxylan 0.5 part, EGCG 0.1 part, water 20 parts.

[0053] The preparation method of the black rice steady - sugar health - preserving rice noodles in this embodiment refers to the preparation method of Embodiment 1.

[0054] Embodiment 4

[0055] An embodiment of the black rice steady - sugar health - preserving rice noodles of the present invention, the preparation raw materials of the black rice steady - sugar health - preserving rice noodles include the following components in parts by weight: indica rice flour 40 parts, black rice flour 15 parts, steady - sugar rice 6 parts, mung bean starch 15 parts, wheat gluten 8 parts, black bean flour 5 parts, buckwheat flour 4 parts, hulless barley flour 4 parts, quinoa flour 3 parts, mulberry leaf extract 0.4 part, arabinoxylan 1 part, EGCG 0.1 part, water 20 parts.

[0056] The preparation method of the black rice steady - sugar health - preserving rice noodles in this embodiment refers to the preparation method of Embodiment 1.

[0057] Embodiment 5

[0058] An embodiment of the black rice steady - sugar health - preserving rice noodles of the present invention, the preparation raw materials of the black rice steady - sugar health - preserving rice noodles include the following components in parts by weight: indica rice flour 40 parts, black rice flour 18 parts, steady - sugar rice 12 parts, mung bean starch 14 parts, wheat gluten 6 parts, black bean flour 2 parts, buckwheat flour 1 part, hulless barley flour 5 parts, quinoa flour 2 parts, mulberry leaf extract 0.5 part, arabinoxylan 1.5 parts, EGCG 0.1 part, water 20 parts.

[0059] The preparation method of the black rice steady - sugar health - preserving rice noodles in this embodiment refers to the preparation method of Embodiment 1.

[0060] Comparative Example 1

[0061] A kind of black rice rice noodles, including the following components in parts by weight: indica rice flour 83.5 parts, black rice flour 15 parts, mung bean starch 15 parts, wheat gluten 8 parts, water 20 parts.

[0062] The preparation method of the black rice rice noodles in this embodiment refers to the preparation method of Embodiment 1.

[0063] The preparation raw material components of the black rice rice noodles in the embodiments and comparative examples are shown in Table 1 below.

[0064] Table 1 Composition of raw materials for the preparation of black rice rice noodles in examples and comparative examples

[0065]

[0066]

[0067] Effect Example 1

[0068] To explore the texture properties of the black rice sugar-stabilizing and health-preserving rice noodles provided by the present invention, the following TPA tests were conducted on the rice noodles of the examples and comparative examples:

[0069] The rice noodles cooked for the optimal steaming time were immediately placed on the sample plate of the texture analyzer for testing. The P36 / R probe was selected, the pre-test speed was 2 mm / s, the test speed was 1 mm / s, the post-test speed was 2 mm / s, the compression ratio was 60%, the trigger force was 0.04905 N, the interval between two compressions was 5 s, and each sample was tested 3 times. The texture property results of the rice noodles with different preparation raw materials in the examples and comparative examples are shown in Table 2. Different letters in the same column indicate significant differences between the values (p < 0.05).

[0070] Table 2 Texture property results of different black rice rice noodles in examples and comparative examples

[0071] Sample Hardness (g) Elasticity (%) Viscosity (g.sec) Chewiness Example 1 <![CDATA[504.85±28.42 c > <![CDATA[91.03±1.17 b > <![CDATA[-47.48±2.22 bc > <![CDATA[452.85±10.37 cd > Example 2 <![CDATA[501.78±15.91 cd > <![CDATA[94.37±2.09 a > <![CDATA[-32.19±2.09 a > <![CDATA[489.93±12.30 c > Example 3 <![CDATA[482.46±28.51 cd > <![CDATA[95.67±1.47 a > <![CDATA[-34.46±6.06 ab > <![CDATA[403.42±23.78 de > Example 4 <![CDATA[877.20±81.08 a > <![CDATA[95.60±0.36 a > <![CDATA[-49.05±3.87 c > <![CDATA[784.03±61.31 a > Example 5 <![CDATA[713.15±58.91 b > <![CDATA[95.50±0.54 a > <![CDATA[-36.92±2.57 abc > <![CDATA[691.27±52.75 b > Comparative Example 1 <![CDATA[434.43±29.29 d > <![CDATA[91.37±0.59 b > <![CDATA[-41.69±3.47 abc > <![CDATA[355.06±18.34 e >

[0072] As can be seen from Table 2:

[0073] As the content of indica rice flour decreases and the content of raw materials such as mung bean starch increases, the hardness and chewiness of the rice noodles generally show an upward trend, and the amylose content significantly affects the texture properties of the rice noodles. The amylose content of the mung bean starch used in the present invention is 30 - 40%. Adding a certain proportion of mung bean starch can increase the overall amylose content of the material, making the rice noodles have better gel properties. Comparing Comparative Example 1 and Example 4, the hardness increased from 434.43 g to 877.20 g, an increase of 101.92%. The elasticity is less affected by the formula and is above 90% in all cases. The elasticity is the highest in Examples 3 - 5, and the chewiness is the highest under the preparation raw material formula of Example 4. Generally speaking, different formulas have a significant impact on the hardness and chewiness of the rice noodles, have a relatively small impact on the elasticity, and the viscosity has a slight change.

[0074] Effect Example 2

[0075] To explore the shear properties of the black rice sugar-stabilizing and health-preserving rice noodles provided by the present invention, the following shear tests were conducted on the rice noodles of the examples and comparative examples:

[0076] The rice noodles with the optimal cooking time were tested using a texture analyzer equipped with an HDP / LKBF probe. The parameter settings for the shear properties were as follows: pre-test speed of 2 mm / s, test speed of 0.10 mm / s, post-test speed of 2 mm / s, trigger force of 15 g, and deformation measurement reaching 80%. Each time, 3 rice noodle samples with uniform thickness were selected for testing, and the average value was calculated after measuring 3 times.

[0077] The shear property results of the rice noodles with different preparation raw materials in the examples and comparative examples are as Figure 2 shown, and different letters indicate significant differences between the values (p < 0.05).

[0078] From Figure 2 it can be seen that, combined with the results of Effect Example 1, the shear property of black rice noodles has a high correlation with hardness. Rice noodle samples with higher hardness may have higher shear resistance. The shear force of Comparative Example 1 was the lowest, only 26 g, and the shear force of Example 4 was the highest, reaching 39 g. Generally speaking, the shear force of the examples was generally higher than that of the comparative examples. The physical properties of starch-based foods are greatly affected by the starch content of different components. During the retrogradation process of amylose, they will entangle with each other to form a dense gel network. In addition, since wheat gluten contains more than 80% gluten protein and black bean powder contains a certain proportion of protein, regulating wheat gluten and black bean powder can also improve the gel properties of rice noodles.

[0079] Effect Example 3

[0080] To explore the cooking quality of the black rice steady-sugar and health-care rice noodles provided by the present invention, the rice noodles of the examples and comparative examples were tested as follows:

[0081] ① Sample soaking:

[0082] Before cooking, the rice noodle samples were soaked in water at 80°C for 20 min.

[0083] ② Cooking time determination:

[0084] Measure about 1000 mL of boiling water with a beaker, place it on an electric stove to heat, and keep the water in a slightly boiling state. Randomly select 20 intact rice noodles, put them into the boiling water, and start timing with a timer. Sampling starts from 3 min, and then every 1 min, pick out 1 rice noodle with chopsticks and put it into a white porcelain bowl for tasting until the taste is soft and there is no hard core. Record this time as the cooking time.

[0085] ③ Broken strip rate determination:

[0086] Measure about 1000 mL of boiling water with a beaker, place it on an electric stove to heat, and keep the water in a slightly boiling state. Randomly select 20 intact rice noodles, put them into the boiling water, and start timing with a timer. After reaching the cooking time measured in the previous step, gently pick out the rice noodles with chopsticks and count the number of broken rice noodles.

[0087] The broken strip rate is calculated according to the following formula:

[0088]

[0089] Wherein,

[0090] N - the number of broken strip rice noodles;

[0091] ④ Determination of cooking loss:

[0092] Take 5 rice noodles and put them into 250 mL of water. After cooking until the optimal cooking time, take them out, drain for 3 min and then weigh. Dry the remaining soup to constant weight, and calculate the cooking loss rate according to the following formula:

[0093]

[0094] The test results of the cooking quality of the rice noodles prepared from different raw materials in the examples and comparative examples are shown in Table 3. Different letters in the same column indicate significant differences between the values (p < 0.05).

[0095] Table 3 Test results of the cooking quality of black rice noodles in the examples and comparative examples

[0096]

[0097]

[0098] As can be seen from Table 3:

[0099] In the examples, the cooking broken strip rate of the black rice stable blood sugar and health - preserving rice noodles of the present invention is all lower than 10%. Among them, adopting the raw material preparation strategy of Example 4 has the smallest cooking loss rate and broken strip rate, as well as the highest re - hydration rate. Its gel properties are relatively good, and the broken strip rate is only 0.71%. The cooking loss rates of other examples are all about 10%.

[0100] Effect Example 4

[0101] To explore the color of the black rice stable blood sugar and health - preserving rice noodles provided by the present invention, the following tests were carried out on the rice noodles of the examples and comparative examples:

[0102] Lay the rice noodles flat on the table and measure them with a color difference meter. L * represents brightness, a * represents the red - green value, b * represents the yellow - blue value, and ΔE represents the color difference from the white board. ΔE is calculated by the following formula:

[0103]

[0104] The results of the color difference values of black rice rice noodles under different preparation raw materials in the examples and comparative examples are shown in Table 4. Different letters in the same column indicate significant differences between the values (p < 0.05).

[0105] Table 4 Results of the color difference values of black rice rice noodles in the examples and comparative examples

[0106] Sample L* a* b* ΔE Example 1 <![CDATA[20.45±0.13 bcd > <![CDATA[3.56±0.05 ab > <![CDATA[2.40±0.06 bc > <![CDATA[69.71±0.13 c > Example 2 <![CDATA[21.39±0.08 ab > <![CDATA[3.45±0.03 b > <![CDATA[2.48±0.15 b > <![CDATA[72.80±0.01 b > Example 3 <![CDATA[19.93±1.43 cd > <![CDATA[3.72±0.09 a > <![CDATA[2.62±0.17 ab > <![CDATA[74.97±1.42 a > Example 4 <![CDATA[21.65±0.32 a > <![CDATA[3.55±0.13 ab > <![CDATA[2.76±0.14 a > <![CDATA[73.24±0.33 b > Example 5 <![CDATA[20.95±0.35 abc > <![CDATA[3.41±0.17 b > <![CDATA[2.10±0.08 d > <![CDATA[73.95±0.35 ab > Comparative Example 1 <![CDATA[19.57±0.28 d > <![CDATA[3.22±0.08 c > <![CDATA[2.19±0.08 cd > <![CDATA[70.56±0.28 c >

[0107] From Table 4:

[0108] Among them, L represents lightness, a* represents the red-green index, and b* represents the yellow-blue index. It can be seen that all samples showed relatively small L values, indicating that the rice noodles had a relatively low lightness. This was because black rice contains more anthocyanins, which made the rice noodles show a dark red color during the extrusion molding process and changed with the change of the black rice addition amount. Moreover, the addition of black rice not only gave the rice noodles a unique appearance but also made the rice noodles have a special aroma.

[0109] Effect Example 5

[0110] To explore the digestion characteristics and GI value of the black rice blood sugar-stabilizing and health-care rice noodles provided by the present invention, the following tests were carried out on the rice noodles in the examples and comparative examples:

[0111] 1. Digestion characteristics: Refer to the method of Englyst and make slight modifications. Take 0.5 g of cooked rice noodles and place them in a 250 ml conical flask, add 5 glass beads, add 15 mL of 0.5 mol / L acetic acid buffer solution with pH = 5.2 and 10 mL of a mixed enzyme solution containing glucoamylase (100 U / mL) and α-amylase (290 U / mL). Place the conical flask in a water bath at 37 °C and shake it in a water bath at a rotation speed of 170 rpm to carry out the enzymatic hydrolysis reaction and start timing. At 0, 20 min, and 120 min time periods, accurately pipette 1 mL of the enzymatic hydrolysis solution, place it in a centrifuge tube, add 4 mL of absolute ethanol to inactivate it, centrifuge at 4000 rpm for 10 min, and use the glucose oxidase method to measure the absorbance of the supernatant at 505 nm using an enzyme-labeling instrument, and calculate the contents of rapidly digestible starch, slowly digestible starch, and resistant starch according to the following formula.

[0112]

[0113] Among them, G 20 : Glucose content (mg) in the digestive juice at 20 min

[0114] F G : Free glucose content (mg) in the digestive juice

[0115] G 120 : Glucose content (mg) in the digestive juice at 120 min

[0116] TS: Total starch content (mg)

[0117] 2. Estimate the GI value:

[0118] ① Sample preparation: Take the rice noodle sample and soak it in water at 80 °C for 20 min, then take it out and set aside after reaching the optimal cooking time in boiling water;

[0119] ② Oral chewing simulation: Refer to the method of Gawlik-Dziki et al. and make appropriate adjustments. Take 1 g of the treated rice noodle sample in a conical flask, add 10 mL of phosphate buffer solution with pH = 6.5 containing salivary amylase, gently tap it with a mortar for 15 s and add 5 glass beads, and shake it in a water bath at 37 °C for 10 min.

[0120] ③ Gastric digestion simulation: Adjust the pH to 1.2 with 5M HCl, then add 10 mL of NaCl solution with 0.03M pH = 1.2 containing pepsin, and shake it in a water bath at 37 °C for 30 min.

[0121] ④ Intestinal digestion simulation: Use 1M NaOH to adjust the pH to 7.0, add 10 mL of intestinal fluid (add 0.05 g of pancreatin, 0.3 g of porcine bile salt, and 0.3 g of glucoamylase to 100 mL of phosphate buffer solution), 5 mL of 120 mM NaCl solution and 5 mL of 120 mM KCl, shake it in a water bath at 37 °C for 180 min. Accurately absorb 1 mL of the sample at 10, 20, 30, 45, 60, 90, 120, 150, and 180 min and put it into a centrifuge tube containing 4 mL of absolute ethanol, and centrifuge it at 5000 rpm for 10 min.

[0122] ⑤ Glucose determination: Take the supernatant after centrifugation, use a glucose determination kit to measure the absorbance at 505 nm, and thus calculate the glucose content at different time periods.

[0123] ⑥ Calculation method: According to the glucose release amount, calculate the hydrolysis rate of starch, draw a curve of the hydrolysis rate of starch changing with time, perform first-order kinetic fitting on the digestion curves of all rice noodle samples according to the equation and use origin software for model fitting and charting to calculate the hydrolysis equilibrium constant k.

[0124] The area under the digestion curve (AUC) is calculated by the following formula:

[0125] AUC = C∞(t f - t 0 ) - (C∞ / k)[1 - e -k(tf-t0)

[0126] where Ct: the hydrolysis rate of starch at time t; C∞: the final hydrolysis rate of starch; t f ​: Total digestion reaction duration (180 min); t 0 : Digestion start time (0 min); k: kinetic constant

[0127] The hydrolysis index (HI) is calculated by the following formula:

[0128]

[0129] White bread was selected as the reference, and the GI of rice noodles was calculated by the following formula:

[0130] GI = 0.862HI + 8.819

[0131] The digestion characteristics results of black rice noodles prepared from different raw materials in the examples and comparative examples are as follows Figure 3 ; The estimated glycemic index results are shown in Table 5 below

[0132] Table 5 Estimated glycemic index of black rice noodles in examples and comparative examples

[0133]

[0134]

[0135] From Table 5 and Figure 3 it can be seen that:

[0136] RDS (rapidly digestible starch) can be digested and absorbed within 20 minutes in the small intestine; SDS (slowly digestible starch) can be digested and absorbed within 20 - 120 minutes in the small intestine; RS (resistant starch) cannot be digested and absorbed in the small intestine. The eGI values of the black rice stable blood sugar and health - promoting rice noodles obtained by using the raw material strategies of Examples 2 - 5 of the present invention are all lower than 55, belonging to low - glycemic foods, which can reduce the sharp rise in blood sugar after eating staple foods

[0137] In Examples 3 - 5 of the present invention, the added stable - blood - sugar rice contains more endogenous resistant starch, thus delaying the digestion and decomposition of starch and reducing the eGI value of rice noodles; mung bean starch has a high amylose content and forms RS3 - type resistant starch during the aging process, hindering the decomposition of starch by amylase; hulless barley flour, buckwheat flour and quinoa contain more dietary fiber, which cannot be decomposed and absorbed by digestive enzymes in the human gastrointestinal tract, delaying the digestion and absorption rate of starch; EGCG is a polyphenol substance, which can form a V - type complex with starch, weakening the decomposition of amylase. By regulating the ratio of each component, the rice noodles prepared under the raw material strategy of Example 5 have the lowest eGI value

[0138] In summary, by optimizing the raw material formula for preparing rice noodles, the present invention prepares black rice steady-sugar health-preserving rice noodles from specific parts by weight of indica rice flour, black rice flour, steady-sugar rice flour, mung bean starch, vital wheat gluten, and black bean powder. It has a low glycemic index, good elasticity and chewiness, and low cooking loss. Its unique color and flavor provide consumers with a more nutritious and healthy choice.

[0139] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A black rice sugar-stabilized health-preserving rice noodle, characterized in that: The raw materials for preparing the black rice sugar-stabilized health-preserving rice noodles include the following components in parts by weight: 40-75 parts of indica rice flour, 10-18 parts of black rice flour, 4-12 parts of sugar-stabilized rice flour, 8-15 parts of mung bean starch, 4-8 parts of gluten powder, 2-5 parts of black bean flour, and 18-22 parts of water.

2. The black rice sugar-stabilizing health-preserving rice noodle according to claim 1, characterized in that: The raw materials for preparing the black rice sugar-stable health-preserving rice noodles also include the following components in parts by weight: 1-5 parts of highland barley flour, 1-5 parts of buckwheat flour, 1-5 parts of quinoa flour, 0-0.6 parts of mulberry leaf extract, 0-1.5 parts of arabinoxylan, and 0-0.1 parts of EGCG.

3. The black rice sugar-stabilizing health-preserving rice noodle according to claim 2, characterized in that: The raw materials for preparing the black rice sugar-stable health-preserving rice noodles include the following components in parts by weight: 40-51 parts of indica rice flour, 15-18 parts of black rice flour, 6-12 parts of sugar-stable rice flour, 8-14 parts of mung bean starch, 4-8 parts of gluten powder, 2-5 parts of black bean flour, 3-5 parts of highland barley flour, 1-4 parts of buckwheat flour, 2-3 parts of quinoa flour, 0.4-0.6 parts of mulberry leaf extract, 0.5-1.5 parts of arabinoxylan, 0.1 parts of EGCG, and 20 parts of water.

4. The black rice sugar-stabilizing health-preserving rice noodle according to claim 2, characterized in that: The type of the black rice flour is black indica rice flour; And / or, the type of highland barley flour is black highland barley flour.

5. The method for preparing the black rice sugar-stabilizing health-preserving rice noodles according to any one of claims 1 to 4, characterized in that: The steps include: (1) screening and mixing the prepared raw materials, and extruding the noodles by a single screw extruder to obtain preliminarily formed rice noodles; (2) allowing the preliminarily formed rice noodles to stand for aging, and then introducing hot steam to perform a aging process to obtain aging rice noodles; (3) The cooked rice noodles are sprayed to make them shredded, and then dried and cut with gradient hot air to obtain the black rice sugar-stabilized health-preserving rice noodles.

6. The method for preparing the black rice sugar-stabilizing health-preserving rice noodles according to claim 5, characterized in that: In the step (1), the sieving is performed using an 80-mesh sieve.

7. The method for preparing the black rice sugar-stabilized health-preserving rice noodles according to claim 5, characterized in that: In the step (1), the temperature of the single screw extruder is set at 160-180°C.

8. The method for preparing the black rice sugar-stabilized health-preserving rice noodles according to claim 5, characterized in that: In the step (2), the temperature of the static aging is 30-40° C. and the time is 10-14 hours.

9. The method for preparing the black rice sugar-stabilized health-preserving rice noodles according to claim 5, characterized in that: In the step (2), the aging treatment conditions are: steam aging at a relative humidity of 99% and a temperature of 60-70° C. for 4.5-5.5 hours.

10. The method for preparing the black rice sugar-stabilized health-preserving rice noodles according to claim 5, characterized in that: In the step (3), the conditions for gradient hot air drying are: the temperature of zone I is 49-51°C, the relative humidity is 90-95%, and the time is 60-100 min; the temperature of zone II is 46-48°C, the relative humidity is 70-75%, and the time is 100-140 min; the temperature of zone III is 40-45°C, the relative humidity is 65-70%, and the time is 100-140 min; the temperature of zone IV is 30-32°C, the relative humidity is 65-70%, and the time is 30-60 min.

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