High-protein nutritional low-GI rice noodles and preparation method thereof

Abstract

The invention relates to high-protein nutritional low-GI rice noodles and a preparation method thereof, and belongs to the technical field of food processing. The high-protein nutritional low-GI rice noodles disclosed by the invention are prepared from the following raw materials: rice flour, soybean protein isolate, oat beta-glucan, buckwheat flour, mung bean starch, vital gluten and water. The rice noodles are prepared by combining the raw materials of soybean protein isolate, oat beta-glucan, buckwheat flour, mung bean starch, vital gluten and rice flour, so that the nutritional value of the rice noodles can be further enriched, the GI value of the rice noodles can be reduced, the sugar increasing rate in the digestion stage can be reduced, and meanwhile, the product can be endowed with better texture, cooking performance, color and luster; and the application value is very high.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, and in particular to a high-protein, nutritious, low-GI rice noodle and a preparation method thereof. Background Art

[0002] Rice noodles are a traditional food made with rice as the main raw material. They are widely popular in southern China and Southeast Asia. They are deeply loved by people for their refreshing and delicious taste and smooth texture. They have a history of more than 2,000 years in my country. Nowadays, rice noodles have a huge consumer group in the market, and the growing concept of food health has also made more requirements for rice noodles.

[0003] The main ingredient of rice noodles is rice starch, with a protein content of only 3-5%, which is lower than the 10-12% of wheat noodles. It lacks essential amino acids such as lysine, and the content of micronutrients such as B vitamins, calcium, and iron is significantly lower than that of whole grains and beans. Long-term single consumption may lead to insufficient protein intake, and it is necessary to supplement nutrition with meat, soy products, etc. The GI value of refined rice noodles can reach 70-90 (reference standard: glucose GI = 100), which is higher than coarse grains such as brown rice (GI ≈ 50). Its gelatinized starch is quickly converted into glucose during digestion, resulting in a rapid rise and drastic fluctuation in blood sugar levels after meals, posing a potential risk to diabetic patients and people with insulin resistance.

[0004] Therefore, developing a rice noodle with high protein nutrition, low glycemic index and good texture can better meet consumers' growing demand for healthy food 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 high-protein nutritious low-GI rice noodle and a preparation method thereof. The rice noodle provided by the present invention has a high protein content and rich nutritional ingredients, and at the same time, the rice noodle has good taste, texture and toughness, and can reduce the blood sugar production rate.

[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 high-protein, nutritious, low-GI rice noodle, wherein the raw materials for preparing the high-protein, nutritious, low-GI rice noodle include rice flour, soy protein isolate, oat β-glucan, buckwheat flour, mung bean starch, gluten powder, and water.

[0008] In order to better meet the growing demand of consumers for healthy food, the present invention provides a rice noodle with high protein nutrition, low glycemic index and good texture. Soy protein isolate is a complete protein containing all essential amino acids required by the human body; adding soy protein isolate can increase the overall protein content and promote the balance of nutritional components of rice noodles. Oat β-glucan is a soluble dietary fiber that can improve intestinal health, lower cholesterol and assist in controlling blood sugar levels. Buckwheat flour is rich in protein and dietary fiber, which can enrich the nutritional value and improve the flavor of rice noodles. Mung bean starch can improve the overall texture of rice noodles and reduce digestibility. Gluten is a high-quality source of plant protein and can also increase the protein content of rice noodles.

[0009] The high-protein nutritious low-GI rice noodles of the present invention are prepared using the above-mentioned several raw materials, which can give the product a good taste, toughness, texture, good cooking quality, good elasticity and chewiness, and yellow color, while helping to reduce the GI value. The added raw materials can significantly increase the protein content and reduce the rate of blood sugar production on the basis of maintaining the original flavor of the rice noodles, enriching the nutritional components of the rice noodles. Whether used as a staple food or paired with various dishes, the high-protein nutritious low-GI rice noodles of the present invention can add nutritional value and delicious experience to the daily diet.

[0010] Preferably, the raw materials for preparing the high-protein, nutritious, low-GI rice noodles include the following components in parts by weight: 66-72 parts of rice flour, 4-8 parts of soy protein isolate, 0.1-6.5 parts of oat β-glucan, 2-6 parts of buckwheat flour, 8-20 parts of mung bean starch, 2.5-5.5 parts of gluten powder, and 18-22 parts of water.

[0011] As an embodiment of the present invention, the raw materials for preparing the high-protein nutritious low-GI rice noodles include the following components in parts by weight: 66 parts of rice flour, 4 parts of soy protein isolate, 0.1 parts of oat β-glucan, 6 parts of buckwheat flour, 18.4 parts of mung bean starch, 5.5 parts of gluten powder, and 20 parts of water;

[0012] As an embodiment of the present invention, the raw materials for preparing the high-protein nutritious low-GI rice noodles include the following components in parts by weight: 66 parts of rice flour, 8 parts of soy protein isolate, 0.5 parts of oat β-glucan, 6 parts of buckwheat flour, 14 parts of mung bean starch, 5.5 parts of gluten powder, and 20 parts of water;

[0013] As an embodiment of the present invention, the raw materials for preparing the high-protein nutritious low-GI rice noodles include the following components in parts by weight: 66 parts of rice flour, 8 parts of soy protein isolate, 6.5 parts of oat β-glucan, 6 parts of buckwheat flour, 8 parts of mung bean starch, 5.5 parts of gluten powder, and 20 parts of water;

[0014] As an embodiment of the present invention, the raw materials for preparing the high-protein nutritious low-GI rice noodles include the following components in parts by weight: 70 parts of rice flour, 8 parts of soy protein isolate, 0.5 parts of oat β-glucan, 2 parts of buckwheat flour, 14 parts of mung bean starch, 5.5 parts of gluten powder, and 20 parts of water;

[0015] As an embodiment of the present invention, the raw materials for preparing the high-protein, nutritious, low-GI rice noodles include the following components in parts by weight: 69 parts of rice flour, 8 parts of soy protein isolate, 0.5 parts of oat β-glucan, 6 parts of buckwheat flour, 14 parts of mung bean starch, 2.5 parts of gluten powder, and 20 parts of water.

[0016] The weight proportion composition scheme of the raw materials for preparing the high-protein nutritional low-GI rice noodles of the present invention is not limited to the above-mentioned specific ones. Those skilled in the art can adopt other weight proportion composition within the scope defined by the present invention according to actual needs.

[0017] Further preferably, the raw materials for preparing the high-protein, nutritious, low-GI rice noodles include the following components in parts by weight: 66-68 parts of rice flour, 6-8 parts of soy protein isolate, 0.5-1 part of oat β-glucan, 4-6 parts of buckwheat flour, 10-14 parts of mung bean starch, 5-5.5 parts of gluten, and 18-22 parts of water.

[0018] Under the preferred raw material ratio, the high-protein nutritious low-GI rice noodles of the present invention have a low breaking rate and cooking loss, and have the highest chewiness and elasticity, good taste, and a GI value controlled below 53 to avoid excessive blood sugar increase after consumption; at the same time, the rice noodles appear yellow in appearance, which is easy to stimulate appetite.

[0019] Preferably, the GI value of the high-protein, nutritious, low-GI rice noodles is less than 53.

[0020] In a second aspect, the present invention provides a method for preparing the above-mentioned high-protein nutritional low-GI rice noodles, comprising the following steps:

[0021] (1) mixing and preparing raw materials, and then extruding by a single screw extruder to obtain preliminarily formed rice noodles;

[0022] (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;

[0023] (3) dividing the cooked rice noodles into strands, and then drying and cutting them with hot air to obtain the high-protein, nutritious, low-GI rice noodles.

[0024] Preferably, in step (1), the set temperature of the single screw extruder is 155-165°C.

[0025] Preferably, in step (1), the mixing and preparing of the raw materials is specifically as follows: placing rice flour, soy protein isolate, oat β-glucan, buckwheat flour, mung bean starch and gluten powder in a mixer, adding water and stirring and mixing.

[0026] Preferably, in step (2), the conditions for static aging are: standing at 30-40° C. for 10-12 hours.

[0027] Preferably, in step (2), the aging conditions are: aging temperature 60-70° C., aging time 10-14 h.

[0028] Preferably, in step (3), the separation is specifically: placing the cooked rice noodles in water at 20-30° C. and shaking them to separate the noodles.

[0029] Preferably, in step (3), the hot air drying time is 5-7 hours.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The high-protein nutritious low-GI rice noodles provided by the present invention select rice flour, soy protein isolate, oat beta-glucan, buckwheat flour, mung bean starch, gluten and water as preparation raw materials, so that the rice noodles have high protein nutritional value, while improving the digestion rate and taking into account the low glycemic index, which is conducive to the control of blood sugar fluctuation levels. By further optimizing the weight ratio of the components of each pigment prepared in the high-protein nutritious low-GI rice noodles, the elasticity and chewiness can be improved, so that the rice noodles have a better texture and taste, and the nutritional value and delicious experience are added. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The shear force result diagram of rice noodles prepared from different raw materials in the embodiments and comparative examples;

[0033] Figure 2 This is a diagram showing the digestibility characteristics of rice noodles made from different raw materials in the examples and comparative examples. DETAILED DESCRIPTION

[0034] In order to better illustrate the purpose, technical scheme and advantages of the present invention, the present invention will be further described below in conjunction with specific examples. The test methods used in the following examples are conventional methods unless otherwise specified; the materials and reagents used are reagents and materials that can be obtained from commercial channels unless otherwise specified.

[0035] Example 1

[0036] An embodiment of the high-protein nutritious low-GI rice noodles of the present invention, the raw materials for preparing the high-protein nutritious low-GI rice noodles in this embodiment are composed of the following components in parts by weight: 66 parts of rice flour, 4 parts of soy protein isolate, 0.1 parts of oat beta-glucan, 6 parts of buckwheat flour, 18.4 parts of mung bean starch, 5.5 parts of gluten powder, and 20 parts of water.

[0037] The preparation method of the high-protein nutrition low-GI rice noodles described in this embodiment is:

[0038] (1) accurately weighing the ingredients according to the set weight ratio, mixing rice flour, soy protein isolate, oat β-glucan, buckwheat flour, mung bean starch, and gluten powder into a mixer, adding water while stirring, uniformly mixing to obtain a mixture, transferring it to a single-screw extruder, and extruding it at a high temperature of 160° C. to obtain preliminarily formed rice noodles;

[0039] (2) Immediately transfer the initially formed rice noodles to an aging chamber and allow the rice noodles to age at 35°C for 12 h;

[0040] After the aging of the rice noodles is completed, hot steam is introduced into the rice noodles, and the rice noodles are further aged at 65° C. for 12 hours to obtain aged rice noodles;

[0041] (3) placing the cooked rice noodles in cold water (20-30°C) and shaking them to make the noodles spread out as much as possible;

[0042] The loose rice noodles after being separated are sent to a drying room for hot air drying, and the drying time is 6 hours; the dried rice noodles are cut by a cutting machine, and are packaged and bagged by an automatic packaging machine to obtain the high-protein nutrition low-GI rice noodles.

[0043] Example 2

[0044] An embodiment of the high-protein nutritious low-GI rice noodles of the present invention, the raw materials for preparing the high-protein nutritious low-GI rice noodles in this embodiment are composed of the following components in parts by weight: 66 parts of rice flour, 8 parts of soy protein isolate, 0.5 parts of oat beta-glucan, 6 parts of buckwheat flour, 14 parts of mung bean starch, 5.5 parts of gluten powder, and 20 parts of water.

[0045] The preparation method of the high-protein nutrition low GI rice noodles in this embodiment refers to the preparation method in Example 1.

[0046] Example 3

[0047] An embodiment of the high-protein nutritious low-GI rice noodles of the present invention, the raw materials for preparing the high-protein nutritious low-GI rice noodles in this embodiment are composed of the following components in parts by weight: 66 parts of rice flour, 8 parts of soy protein isolate, 6.5 parts of oat beta-glucan, 6 parts of buckwheat flour, 8 parts of mung bean starch, 5.5 parts of gluten powder, and 20 parts of water.

[0048] The preparation method of the high-protein nutrition low GI rice noodles in this embodiment refers to the preparation method in Example 1.

[0049] Example 4

[0050] An embodiment of the high-protein nutritious low-GI rice noodles of the present invention, the raw materials for preparing the high-protein nutritious low-GI rice noodles in this embodiment are composed of the following components in parts by weight: 70 parts of rice flour, 8 parts of soy protein isolate, 0.5 parts of oat beta-glucan, 2 parts of buckwheat flour, 14 parts of mung bean starch, 5.5 parts of gluten powder, and 20 parts of water.

[0051] The preparation method of the high-protein nutrition low GI rice noodles in this embodiment refers to the preparation method in Example 1.

[0052] Example 5

[0053] An embodiment of the high-protein nutritious low-GI rice noodles of the present invention, the raw materials for preparing the high-protein nutritious low-GI rice noodles in this embodiment are composed of the following components in parts by weight: 69 parts of rice flour, 8 parts of soy protein isolate, 0.5 parts of oat beta-glucan, 6 parts of buckwheat flour, 14 parts of mung bean starch, 2.5 parts of gluten powder, and 20 parts of water.

[0054] The preparation method of the high-protein nutrition low GI rice noodles in this embodiment refers to the preparation method in Example 1.

[0055] Comparative Example 1

[0056] The raw materials for preparing the rice noodles described in Comparative Example 1 are composed of the following components in parts by weight: 78.5 parts of rice flour, 8 parts of soy protein isolate, 8 parts of mung bean starch, 5.5 parts of gluten powder, and 20 parts of water.

[0057] The preparation method of rice noodles in Comparative Example 1 refers to the preparation method of Example 1.

[0058] Comparative Example 2

[0059] The raw materials for preparing the rice noodles described in Comparative Example 2 are composed of the following components in parts by weight: 72.5 parts of rice flour, 8 parts of soy protein isolate, 14 parts of mung bean starch, 5.5 parts of gluten powder, and 20 parts of water.

[0060] The preparation method of rice noodles in Comparative Example 2 refers to the preparation method of Example 1.

[0061] Comparative Example 3

[0062] The raw materials for preparing the rice noodles described in Comparative Example 3 are composed of the following components in parts by weight: 85.5 parts of rice flour, 8 parts of soy protein isolate, 0.5 parts of oat β-glucan, 6 parts of buckwheat flour, and 20 parts of water.

[0063] The preparation method of rice noodles in Comparative Example 3 refers to the preparation method of Example 1.

[0064] Comparative Example 4

[0065] The raw materials for preparing the rice noodles described in Comparative Example 4 are composed of the following components in parts by weight: 74 parts of rice flour, 0.5 parts of oat β-glucan, 6 parts of buckwheat flour, 14 parts of mung bean starch, 5.5 parts of gluten powder, and 20 parts of water.

[0066] The preparation method of the 4-meter noodle in the comparative example refers to the preparation method of Example 1.

[0067] The raw material components for preparing rice noodles in the above-mentioned embodiments and comparative examples are shown in Table 1.

[0068] Table 1: Composition of raw materials for preparing rice noodles in the examples and comparative examples

[0069]

[0070] Effect Example 1

[0071] In order to explore the cooking quality of the high-protein, nutritious, low-GI rice noodles provided by the present invention, the rice noodles of Examples 1-5 and Comparative Example 1 were tested as follows:

[0072] ① Sample soaking: Soak the sample in water at about 80℃ for 20 minutes before cooking.

[0073] ②Determination of cooking time: Take about 1000mL of boiling water in a beaker and heat it on an electric stove to keep the water slightly boiling. Randomly select 20 whole rice noodles and put them into the boiling water. Start timing with a timer. Start sampling from 3 minutes, and then use chopsticks to pick out one noodle every 1 minute and put it into a white porcelain bowl for tasting until it is soft and has no hard core. The time recorded is the cooking time.

[0074] ③Cooking loss rate and water absorption rate: Take 5 rice noodles in 250mL of water, cook until the optimal cooking time, then take them out, drain for 3 minutes and weigh them, dry the remaining soup to constant weight, and calculate the cooking loss rate according to the following formula:

[0075]

[0076] ④Breakage rate: Use a beaker to measure about 1000mL of boiling water, place it on an electric stove to heat, and keep the water slightly boiling. Randomly select 20 intact rice noodles, put them into boiling water, and start timing with a timer. After the above-measured steaming time is reached, use chopsticks to gently pick out the rice noodles and count the number of broken rice noodles (N). Calculate the breakage rate according to the following formula:

[0077]

[0078] ⑤Data processing: Microsoft Excel 2022 was used to organize data, Origin 2021 was used to draw graphs, and SPSS 26 was used to perform variance analysis on all data in this experiment. P>0.05 was considered to be insignificant, and P<0.05 was considered to be significant (the following other effect examples were all processed using this method).

[0079] The cooking quality test results of rice noodles prepared from different raw materials in the embodiments and comparative examples are shown in Table 2. Different letters in the same column indicate significant differences (p < 0.05) between the values.

[0080] Table 2 Cooking quality test results of rice noodles prepared in Examples and Comparative Examples

[0081] sample Cooking loss rate (%) Water absorption (%) Strip breaking rate (%) Example 1 <![CDATA[9.71±0.22 b ]]> <![CDATA[176.79±0.75 b ]]> <![CDATA[4.33±0.00 c ]]> Example 2 <![CDATA[6.33±0.35 d ]]> <![CDATA[178.33±1.54 ab ]]> <![CDATA[3.66±0.33 d ]]> Example 3 <![CDATA[6.36±0.17 d ]]> <![CDATA[181.49±0.09 a ]]> <![CDATA[5.11±0.36 b ]]> Example 4 <![CDATA[10.19±0.30 b ]]> <![CDATA[155.10±1.22 d ]]> <![CDATA[4.19±0.33 cd ]]> Example 5 <![CDATA[7.88±0.18 c ]]> <![CDATA[172.45±0.35 c ]]> <![CDATA[5.33±0.66 b ]]> Comparative Example 1 <![CDATA[18.23±0.32 a ]]> <![CDATA[145.03±1.75 e ]]> <![CDATA[7.89±0.70 a ]]>

[0082] From Table 2, we can see that:

[0083] The raw materials for the preparation of comparative example 1 only use rice flour, soy protein isolate, mung bean starch, gluten and water, with a cooking loss rate of 18.23%, a water absorption rate of 145.03%, and a breaking rate of 7.89%; and each embodiment adopts the raw material composition of the high-protein nutrition low GI rice noodles defined by the present invention, and compared with comparative example 1, it presents different characteristics in various indicators: the cooking loss rate of embodiment 3 is lower, which is 6.36%, the water absorption rate is the highest, reaching 181.49%, and the breaking rate is 5.11%, indicating that embodiment 3 is outstanding in reducing the loss of cooking materials and improving water absorption, but the breaking rate needs to be further optimized; the breaking rate of embodiment 2 is the lowest, reaching 3.66%, the cooking loss rate is 6.33%, and the water absorption rate is 178.33%. Its raw material formula has a great advantage in maintaining the structural integrity of rice noodles and reducing losses. Overall, the embodiment of the present invention has a significant effect on improving the cooking quality of rice noodles compared with comparative example 1, among which the raw material strategy of embodiment 2 has the best effect on improving the cooking quality of rice noodles.

[0084] Effect Example 2

[0085] In order to explore the color of the high-protein, nutritious, low-GI rice noodles provided by the present invention, the rice noodles of Examples 1-5 and Comparative Example 1 were subjected to the following color difference test:

[0086] Spread the rice noodles flat on the table and measure them with a colorimeter. * Represents brightness, a * represents the red and green values, b * represents the yellow-blue value, W represents whiteness, and ΔE represents the color difference from the control group. W and ΔE are calculated by the following formula:

[0087]

[0088] The color difference test results of 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 (p < 0.05) between the values.

[0089] Table 3 Color difference test results of rice noodles in the embodiments and comparative examples

[0090] sample <![CDATA[L * ]]> <![CDATA[a * ]]> <![CDATA[b * ]]> W ΔE Example 1 <![CDATA[43.77±0.51 c ]]> <![CDATA[1.56±0.02 c ]]> <![CDATA[15.59±0.25 b ]]> <![CDATA[46.49±0.57 b ]]> <![CDATA[4.08±0.05 c ]]> Example 2 <![CDATA[38.43±0.35 d ]]> <![CDATA[2.15±0.25 a ]]> <![CDATA[16.66±0.33 a ]]> <![CDATA[41.94±0.35 e ]]> <![CDATA[8.93±0.14 a ]]> Example 3 <![CDATA[39.46±0.69 d ]]> <![CDATA[2.09±0.12 a ]]> <![CDATA[14.96±0.22 c ]]> <![CDATA[42.25±0.69 d ]]> <![CDATA[7.27±0.09 b ]]> Example 4 <![CDATA[44.73±0.21 b ]]> <![CDATA[1.32±0.09 d ]]> <![CDATA[13.11±0.62 d ]]> <![CDATA[46.63±0.22 b ]]> <![CDATA[1.65±0.4 d ]]> Example 5 <![CDATA[43.11±0.23 c ]]> <![CDATA[1.76±0.17 b ]]> <![CDATA[15.03±0.17 bc ]]> <![CDATA[45.68±0.24 c ]]> <![CDATA[4.13±0.05 c ]]> Comparative Example 1 <![CDATA[46.15±0.21 a ]]> <![CDATA[1.03±0.15 e ]]> <![CDATA[12.32±0.27 e ]]> <![CDATA[47.77±0.23 a ]]> -

[0091] From Table 3, we can see that:

[0092] Chroma can reflect the appearance quality of rice noodles. Compared with the comparative example, the brightness value L of the rice noodles in Examples 1-5 is * Reduce, yellow-green value b * Increased. This shows that the formulas of the embodiments all reduce the brightness of the rice noodles to varying degrees, making the color more yellowish. The combination of the raw material components in the specific ratios in the embodiments of the present invention has a great influence on the appearance quality of the rice noodles. Among them, the brightness values ​​of Examples 2 and 3 are the lowest, showing a darker appearance, while the yellow-green value of Example 2 is the highest, and the color of the rice noodles under this formula is the most yellow.

[0093] Effect Example 3

[0094] In order to explore the texture characteristics of the high-protein, nutritious, low-GI rice noodles provided by the present invention, the rice noodles of Examples 1-5 and Comparative Example 1 were tested as follows:

[0095] ①TPA: Place the rice noodles cooked for the best cooking time (according to the time in effect example 1) on the sample plate of the texture analyzer within 15 minutes for testing. Use the P36 / R probe, the pre-test speed is 2mm / s, the test speed is 1mm / s, the post-test speed is 2mm / s, the compression ratio is 50%, the trigger force is 0.04905N, the interval between two compressions is 5s, and each sample is tested 7 times.

[0096] ① Shear characteristics: Select rice noodles with the best cooking time, use a texture analyzer with HDP / LKBF probe, and set the shear characteristics parameters as 2mm / s before test, 0.17mm / s after test, 2mm / s after test, 15g trigger force, and 80% deformation. Each time, select rice noodles with uniform thickness (3-5 pieces) for testing, and calculate the average value after at least 3 measurements.

[0097] The texture test results of rice noodles prepared with different raw materials in the embodiments and comparative examples are shown in Table 4; the shear force test results are shown in Table Figure 1 .

[0098] Table 4 Texture test results of rice noodles in the examples and comparative examples

[0099] sample Hardness(g) Viscosity (g.sec) elasticity(%) Chewing degree Example 1 <![CDATA[927±25 a ]]> <![CDATA[-40.06±1.22 f ]]> <![CDATA[96.40±0.00 d ]]> <![CDATA[747±6 a ]]> Example 2 <![CDATA[890±32 b ]]> <![CDATA[-35.78±0.16 e ]]> <![CDATA[97.40±0.20 a ]]> <![CDATA[738±10 a ]]> Example 3 <![CDATA[479±19 e ]]> <![CDATA[-25.26±0.56 b ]]> <![CDATA[97.00±0.01 b ]]> <![CDATA[383±12 d ]]> Example 4 <![CDATA[723±1 c ]]> <![CDATA[-27.78±0.16 c ]]> <![CDATA[96.40±0.10 d ]]> <![CDATA[571±8 c ]]> Example 5 <![CDATA[842±16 b ]]> <![CDATA[-28.52±0.12 d ]]> <![CDATA[96.80±0.10 c ]]> <![CDATA[676±5 b ]]> Comparative Example 1 <![CDATA[679±13 d ]]> <![CDATA[-20.76±0.14 a ]]> <![CDATA[96.40±0.30 d ]]> <![CDATA[543±8 c ]]>

[0100] From Table 4, we can see that:

[0101] The rice noodles made with different raw materials in Examples 1-5 and Comparative Example 1 have significant differences in texture. In terms of hardness, the rice noodles in Example 1 have the highest hardness and are significantly higher than the comparative example, while the rice noodles in Example 3 have the lowest hardness, which may be due to the different weight portions of mung bean starch that affect the rigidity of the rice noodles; the rice noodles in Example 1 have the highest viscosity and the lowest elasticity, and the viscosity and elasticity of all examples are higher than the comparative example; at the same time, the chewiness of Examples 1 and 2 is the highest, and the elasticity of Example 2 is the highest. Overall, the rice noodles prepared with the raw material weight portion formula of Example 2 have the best edible taste and are more chewy.

[0102] according to Figure 1 The results show that the shear properties of rice noodles are basically consistent with the texture properties. Example 1 has the highest hardness and also has the highest shear force; Example 3 has the lowest hardness and the corresponding shear force is relatively low.

[0103] Effect Example 4

[0104] In order to explore the digestion characteristics and GI value of the high-protein nutrition low-GI rice noodles provided by the present invention, the rice noodles of all embodiments and comparative examples were tested as follows:

[0105] 1. Digestion characteristics: refer to the method of Englyst and make slight modifications. Take 0.5g of cooked rice noodles and place them in a 250ml conical flask and add 5 glass beads, add 15mL of 0.5mol / L pH=5.2 acetic acid buffer solution and 10mL of mixed enzyme solution containing saccharifying enzyme (100U / mL) and α-amylase (290U / mL). Place the conical flask in a water bath and shake it at 37℃ with a speed of 170rpm, perform enzymatic reaction and start timing. Accurately draw 1mL of enzymatic solution at 0, 20min, and 120min time periods, place it in a centrifuge tube, add 4mL of anhydrous ethanol to inactivate, centrifuge at 4000rpm for 10min, use the glucose oxidase method, use an enzyme marker to measure the absorbance of the supernatant at 505nm, and calculate the content of fast-digestible starch, slow-digestible starch, and resistant starch according to the following formula.

[0106]

[0107] Among them G 20 :Glucose content in digestive juice at 20min (mg)

[0108] F G :Free glucose content in digestive juice (mg)

[0109] G 120: Glucose content in digestive juice at 120 minutes (mg)

[0110] TS: Total starch content (mg)

[0111] 2. Estimated GI value:

[0112] ① Sample preparation: soak the rice noodle sample in 80℃ water for 20 minutes, then put it in boiling water to reach the optimal cooking time and remove it for later use;

[0113] ② Oral chewing simulation: refer to the method of Gawlik-Dziki et al. and make appropriate adjustments. Take 1g of the treated rice noodle sample in a conical flask, add 10mL of pH 6.5 phosphate buffer solution containing salivary amylase, tap gently with a mortar for 15s, add 5 glass beads, and shake in a 37℃ water bath for 10min.

[0114] ③ Gastric digestion simulation: adjust the pH to 1.2 with 5M HCL, then add 10mL of 0.03M NaCl solution (pH=1.2) containing pepsin, and shake in a 37°C water bath for 30min.

[0115] ④ Intestinal digestion simulation: Use 1M NaOH to adjust the pH to 7.0, add 10mL of intestinal fluid (add 0.05g of pancreatic enzyme, 0.3g of porcine bile salt, and 0.3g of saccharifying enzyme to 100mL of phosphate buffer solution), 5mL of 120mM NaCl solution and 5mL of 120mM KCl, and shake in a 37℃ water bath for 180min. Accurately aspirate 1mL of sample at 10, 20, 30, 45, 60, 90, 120, 150, and 180min respectively, and put it into a centrifuge tube containing 4mL of anhydrous ethanol, and centrifuge at 5000rpm for 10min.

[0116] ⑤ Glucose determination: Take the supernatant after centrifugation and use a glucose determination kit to measure the absorbance at 505nm to calculate the glucose content in different time periods.

[0117] ⑥Calculation method: Calculate the hydrolysis rate of starch according to the amount of glucose released, draw a curve of the change of starch hydrolysis rate over time, and calculate the digestion curve of all rice noodle samples according to the equation First-order kinetic fitting was performed, model fitting and mapping were performed using origin software, and the hydrolysis equilibrium constant k was calculated.

[0118] The area under the digestion curve (AUC) was calculated by the following formula:

[0119] AUC=C∞(t f -t 0 )-(C∞ / k)[1-e -k(tf-t0) ]

[0120] Where Ct: starch hydrolysis rate at time t; C∞: final starch hydrolysis rate; t f : Total digestion reaction time (180 min); t 0 : digestion start time (0min); k: kinetic constant;

[0121] The hydrolysis index (HI) is calculated by the following formula:

[0122]

[0123] Choose white bread as a reference and calculate the GI of rice noodles using the following formula:

[0124] GI=0.862HI+8.819

[0125] The estimated glycemic index results of rice noodles prepared from different raw materials in the examples and comparative examples are shown in Table 5; the digestive characteristics results are shown in Table 5. Figure 2 ; RDS is rapidly digestible starch, which can be digested and absorbed in the small intestine within 20 minutes; SDS is slowly digestible starch, which can be digested and absorbed in the small intestine within 20-120 minutes; RS is resistant starch, which cannot be digested and absorbed in the small intestine; There are significant differences between the values ​​indicated by different letters (p < 0.05).

[0126] Table 5 Estimated glycemic index of rice noodles in the examples and comparative examples

[0127]

[0128]

[0129] From Table 5 and Figure 2 It can be seen that:

[0130] The size of the eGI value reflects the estimated glycemic index of rice noodles after they are eaten. The larger the eGI value, the greater the blood glucose production rate within 180 minutes after the rice noodles are eaten. Compared with the rice noodles in the comparative example, the rice noodles prepared by using specific raw materials in the embodiments of the present invention can reduce the blood glucose production rate of rice noodles; among them, the eGI value of Example 2 is the lowest, corresponding to Figure 1 The results show that the RS content in the rice noodles of Example 2 is the highest and the SDS content is the lowest. It can be inferred that the rate of blood sugar generation during its digestion is the slowest, and it has the best effect in regulating postprandial blood sugar. The eGI value of the rice noodles in Examples 1, 2, 3, and 5 is lower than 55, reaching the level of low GI rice noodles (GI < 55), which helps to reduce the risk of excessive blood sugar generation and is suitable for the dietary needs of people with high blood sugar. At the same time, by comparing the various examples, it can be seen that the different weight ratios of the components such as soy protein isolate, oat β-glucan, and buckwheat flour also significantly affect the final GI value.

[0131] In summary, the present invention enriches the nutritional value of rice noodles by limiting the specific raw material formula for preparing high-protein nutritious low-GI rice noodles and optimizing the weight ratio of soy protein isolate, oat β-glucan, buckwheat flour, mung bean starch and gluten powder, while reducing the GI value of rice noodles, reducing the blood sugar rise rate in the digestion stage, and reducing blood sugar fluctuations; it also gives the rice noodle products better cooking performance and texture, and the elasticity, chewing shape and color are suitable, which can better meet the growing demand of consumers for healthy food.

[0132] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A high-protein, nutritious, low-GI rice noodle, characterized in that: The raw materials for preparing the high-protein nutritious low-GI rice noodles include rice flour, soy protein isolate, oat beta-glucan, buckwheat flour, mung bean starch, gluten powder and water.

2. The high-protein nutrition low GI rice noodle according to claim 1, characterized in that The raw materials for preparing the high-protein nutritious low-GI rice noodles include the following components in parts by weight: 66-72 parts of rice flour, 4-8 parts of isolated soy protein, 0.1-6.5 parts of oat beta-glucan, 2-6 parts of buckwheat flour, 8-20 parts of mung bean starch, 2.5-5.5 parts of gluten powder and 18-22 parts of water.

3. The high-protein nutrition low GI rice noodle according to claim 2, characterized in that: The raw materials for preparing the high-protein nutritious low-GI rice noodles include the following components in parts by weight: 66-68 parts of rice flour, 6-8 parts of isolated soy protein, 0.5-1 parts of oat beta-glucan, 4-6 parts of buckwheat flour, 10-14 parts of mung bean starch, 5-5.5 parts of gluten powder and 18-22 parts of water.

4. The high-protein nutrition low GI rice noodle according to claim 2, characterized in that The GI value of the high-protein nutritious low-GI rice noodles is less than 53.

5. The method for preparing high-protein nutrition low GI rice noodles according to any one of claims 1 to 4, characterized in that: The following steps are involved: (1) mixing and preparing raw materials, and then extruding 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) dividing the cooked rice noodles into strands, and then drying and cutting them with hot air to obtain the high-protein, nutritious, low-GI rice noodles.

6. The method for preparing high-protein nutrition low GI rice noodles as claimed in claim 5, characterized in that: In the step (1), the set temperature of the single screw extruder is 155-165°C.

7. The method for preparing high-protein nutrition low GI rice noodles as claimed in claim 5, characterized in that: In the step (2), the conditions for static aging are: standing at 30-40° C. for 10-12 hours.

8. The method for preparing high-protein nutrition low GI rice noodles as claimed in claim 5, characterized in that: In the step (2), the aging conditions are: aging temperature 60-70° C., aging time 10-14 h.

9. The method for preparing high-protein nutrition low GI rice noodles as claimed in claim 5, characterized in that: In the step (3), the separation is specifically: placing the cooked rice noodles in water at 20-30° C. and shaking them to separate the noodles.

10. The method for preparing high-protein nutrition low GI rice noodles as claimed in claim 5, characterized in that: In the step (3), the hot air drying time is 5-7 hours.

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