Noodles with low glycemic index and making method

Abstract

The invention provides noodles with a low glycemic index (GI) and a preparation method thereof, and relates to the technical field of food processing. The low-GI noodles provided by the invention are prepared from the following raw materials in parts by mass: 5-10 parts of kale powder, 8-14 parts of bean dreg and wheat bran powder, 75-85 parts of flour and other auxiliary materials, and the bean dreg and wheat bran powder is prepared by mixing a yeast strain in a laboratory with dry bean dregs and dry wheat bran (in a mass ratio of 1: 1), fermenting and then carrying out superfine grinding. The noodles provided by the invention are low-glycemic-index food, have the advantages of low sugar, low fat, low salt, high fiber, moderate hardness, good elasticity and uniform tissue structure, are simple and convenient in processing method and high in product stability, are suitable for serving as staple food to be applied to diet management of diabetes and obesity, are beneficial to improving the blood sugar level of related people, and are suitable for being eaten by people with diabetes and obesity. The overall health condition of citizens is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of food processing, in particular to noodles with a low glycemic index and a preparation method thereof. Background Art

[0002] Diabetes is a metabolic disease characterized by high blood sugar levels. In recent years, with the improvement of living standards in my country and the increasing refinement of staple foods, the incidence of diabetes has been on the rise. According to the latest statistics from the International Diabetes Federation (IDF), the number of people with diabetes worldwide reached 140.9 million in 2021, of which 90%-95% were diagnosed with type 2 diabetes (T2DM). By 2045, the number of people with diabetes worldwide is projected to reach 783.2 million. Globally, China leads the world in the number of people with diabetes. Abnormal blood sugar fluctuations caused by various factors, such as irregular sleep and rest and poor diet, have led to increasingly serious health problems. As a common disease, diabetes poses a significant threat to the health of people worldwide. Research has shown that a diet with a high glycemic index and a high glycemic load is a significant factor in the development of type 2 diabetes.

[0003] Dietary intervention is an integral part of comprehensive diabetes treatment. The concept of the glycemic index (GI) was first introduced in the 1980s. Most studies have shown that a low-GI diet can help lower postprandial blood sugar, improve blood lipids, control weight, and reduce diabetes-related complications. Furthermore, with the increasing number of people with diabetes worldwide, the importance of low-GI foods in diabetic dietary management, physiological metabolic management, and health management is becoming increasingly prominent, and they hold broad market potential for future development.

[0004] The various components of food, such as carbohydrates, proteins, fats, dietary fiber, polyphenols, and peptides, interact with each other to affect blood sugar in different ways. Numerous studies have found that increasing dietary fiber in the diet has a beneficial effect as an adjunctive treatment for diabetes. Dietary fiber content reflects the glycemic index (GII) of a food. Dietary fiber regulates liver function and insulin resistance, influences intestinal glucose absorption, and controls inflammation, thereby playing a role in preventing and intervening in type 2 diabetes. Increasing dietary fiber lowers the GII, reducing blood sugar and glycated hemoglobin (HbA1c) levels. Kale is a low-calorie, high-fiber vegetable rich in vitamins, phenolic compounds, and dietary fiber. Bean curd okara, a major byproduct of soy product processing, is primarily composed of protein and dietary fiber. Dry okara contains 25%-28% crude protein and 50%-60% dietary fiber. It also contains high levels of insoluble dietary fiber and a full range of essential amino acids. As a major byproduct, okara requires costs to process (e.g., transport and landfill). Effective utilization can directly reduce waste disposal costs. Transforming okara into high-value-added products opens up new revenue streams, transforming it from a "cost center" into a "profit center," significantly improving the overall economic efficiency and risk resilience of soy product companies. Environmentally, this can reduce pressure and promote a circular economy. Modern people generally face insufficient dietary fiber intake. A combination of kale, okara, and fiber-rich wheat bran can improve blood pressure control and promote digestive health. The dietary fiber in okara, in particular, significantly lowers blood sugar and lipids, enhances satiety, and effectively prevents type 2 diabetes.

[0005] Noodles are one of the traditional staple foods in China. They are usually made from wheat flour as the main raw material, and are made through kneading, fermentation or non-fermentation, and cooking. Among them, noodles are extremely popular as a staple food in my country and some Asian countries. They are a major component of the residents' dietary structure and are directly related to the nutrition and health of the people. However, the glycemic index of pure wheat noodles ranges from 85 to 100, which is a high glycemic index food and is not suitable for diabetic patients. Therefore, there is an urgent need to develop low-glycemic index noodles suitable for diabetic patients. Currently, the common way to develop low-GI noodles is to use low-GI cereal flour to replace part of the wheat flour or to add natural active ingredients to food. The way of developing food is relatively simple. For example, Chinese patents CN201510893185.8 and CN202311331954.6 each develop a low-GI steamed bun. Both methods involve adding various ingredients, such as bitter melon, pumpkin, and oats, to the steamed bun base and processing them according to a basic process. These ingredients are not only diverse but also complex to process. The addition of these ingredients can also lead to a decline in product quality over time. Currently, high-quality, non-perishable noodle products with a low glycemic index are extremely scarce in the market. Currently, the variety of low-GI foods available on the domestic and international markets is still limited, and the quality of some products needs improvement. Controlling the nutritional composition of foods by adjusting raw materials and improving processing methods remains a research trend in developing low-GI foods. Research suggests that when developing low-GI staple foods, the focus should be on slowing the digestion and absorption rate of carbohydrates in the staple food and increasing dietary fiber and other functional ingredients. This innovative approach improves both the quality and taste of the food.

[0006] In view of this, the present invention is proposed. Summary of the Invention

[0007] In order to solve the above technical problems, the present invention provides noodles with a low glycemic index and a preparation method thereof.

[0008] Specifically, the technical solutions of the present invention are as follows: The invention provides noodles with a low glycemic index. The raw materials for preparing the noodles include, by weight, 5-10 parts of kale powder, 8-14 parts of yeast-fermented bean dregs and wheat bran powder (including wheat bran), and 75-85 parts of flour. The kale powder is obtained by freeze-drying fresh kale (pre-freezing for 1.0-1.5 hours and drying for 20-25 hours), grinding it into powder, and then sieving it. The bean dregs and wheat bran powder is obtained by mixing freeze-dried bean dregs and wheat bran in a laboratory in a ratio of 1:1, adding a yeast strain authorized by the laboratory, and performing sealed fermentation. The fermented bean dregs and wheat bran mixture is then ultrafinely ground (crushed at a low temperature of 3-5°C for 60-90 minutes). The pretreated auxiliary materials are then evenly mixed with the kale powder, the bean dregs and wheat bran powder, and the flour. The noodles are kneaded, pressed, cut into strips, boiled, freeze-dried, cooled, and packaged to obtain a finished noodle product with a low glycemic index.

[0009] The noodles provided by the invention have the advantages of being low in sugar, fat and salt, high in fiber, moderate in hardness, good in elasticity and uniform in tissue structure.

[0010] In the present invention, preferably, the bean dregs and wheat bran are fermented under sealed conditions, and the strain used is a yeast strain authorized for this experiment (strain deposit number is CCTCC NO: M 2022150).

[0011] Preferably, the fermented bean dregs and wheat bran mixture is crushed at a low temperature of 3-5°C, the crushing time of the fermented bean dregs and wheat bran mixture is 60-90 minutes, and the bean dregs and wheat bran powder is obtained after ultrafine grinding.

[0012] Preferably, the kale powder is obtained by freeze-drying fresh kale, with a pre-freezing time of 1.0 to 1.5 hours and a drying time of 20 to 25 hours.

[0013] Preferably, the flour used is a mixture of wheat flour and whole wheat flour commonly found on the market.

[0014] Preferably, the mass ratio of kale powder, bean dregs bran powder and flour used in the low glycemic index mixed flour is (2-10): (5-15): (75-90), calculated by mass ratio.

[0015] More preferably, the mass ratio of kale powder, soybean dregs and wheat bran powder, and flour used in the low glycemic index mixed flour is (5-10): (8-14): (75-85), calculated by mass ratio.

[0016] Preferably, the auxiliary materials used include 5-10 parts of egg yolk liquid, 0.2-0.5 parts of guar gum, 0.2-0.5 parts of edible alkali, 0.5-0.8 parts of salt, 5-10 parts of acetate starch and 0.2-0.5 parts of complex phosphate, calculated by mass.

[0017] Preferably, before mixing the flour and kneading the dough, the auxiliary materials need to be dissolved in 45-55 mL of water for pretreatment, and then added to the low glycemic index mixed flour for kneading.

[0018] Preferably, the noodle pressing machine presses the dough into noodle sheets 30 to 35 times.

[0019] Preferably, the noodles need to be cut into noodles of uniform thickness.

[0020] Preferably, the noodles are cooked in boiling water for 3 to 5 minutes, and the cooked noodles are observed to have no white core in the cross section.

[0021] After the noodles are cooked, they need to be freeze-dried, cooled and packaged.

[0022] In a more specific embodiment provided by the present invention, the preparation method of low GI noodles comprises: First, fresh kale was pre-frozen for 1.0-1.5 h and dried for 20-25 h. Then, dry bean dregs and dry wheat bran were mixed in a ratio of 1:1, added to the laboratory's yeast strain, and fermented in a sealed manner. The fermented bean dregs-wheat bran mixture was ultrafinely ground at a low temperature of 3-5°C for 60-90 min. Then, kale dry powder, bean dregs-wheat bran powder, and flour were compounded in a ratio of 5-10:8-14:75-85 to obtain a low-glycemic index mixed flour. The pre-treated auxiliary materials were then added, and the finished product was finally obtained through mixing, kneading, pressing, cutting, boiling, freeze-drying, cooling, and packaging. The specific steps include: 5-10 parts egg yolk liquid, 0.5-0.8 parts salt, 0.2-0.5 parts guar gum, 0.2-0.5 parts baking soda, 5-10 parts starch acetate, and 0.2-0.5 parts complex phosphate are weighed and prepared before use. The auxiliary ingredients are thoroughly dissolved and mixed with 45-55 parts water. The auxiliary ingredients are then added to the mixed flour and stirred into a flocculent dough, which is then kneaded and allowed to stand at room temperature for 10 minutes. Using a noodle press, the dough is repeatedly folded and pressed approximately 30-35 times, and then cut into noodles of uniform thickness. The prepared raw noodles are boiled in boiling water for 3-5 minutes until no white core is visible on the cross-section of the noodles. The noodles are then cooled in cold water and drained. Excess moisture is removed from the noodles, and the noodles are freeze-dried, cooled, and packaged to obtain the finished noodles.

[0023] In a third aspect, the present invention provides the noodle product and the preparation method, and the prepared noodles can be used for consumption by diabetic patients.

[0024] The present invention adds kale powder, a fermented bean dregs and wheat bran mixture, and egg yolk liquid to flour, resulting in noodles rich in dietary fiber and protein. Dietary fiber can interact with starch and amylase through non-covalent bonds, enhancing the cross-linking and overlap between starch molecular chains, leading to increased starch crystallinity. Simultaneously, by inhibiting the leaching of amylose, it forms a physical barrier between starch and amylolytic enzymes, increasing the steric hindrance for starch molecules to enter the active sites of amylolytic enzymes, thereby reducing starch digestion by amylases. Furthermore, protein can form a physical barrier by covering the surface of starch granules, hindering contact between starch and amylases. It can also interact with starch to form starch-protein complexes, increasing the relative crystallinity and short-range molecular order of starch and preventing the breakdown of starch structure by increasing the number of hydrogen bonds. Furthermore, during digestion, protein and dietary fiber have a synergistic effect, playing a more significant role in reducing the rate of starch digestion. The present invention adds food ingredients rich in dietary fiber and protein, such as kale, bean dregs, wheat bran, and egg yolk liquid, to the dough to form a physical barrier for starch molecules, slowing the rate of starch digestion, thereby reducing the glycemic index of the food. In addition, the glucoside and chlorophyll contained in kale can effectively improve the taste of vegetables, stimulate people's taste buds, and add them to the dough to make noodles with better taste and color.

[0025] When fermented bean dregs mixed with wheat bran are added to noodles, the flavor, palatability, nutritional quality, digestibility and functional properties of the noodles can be greatly improved, and the content of soluble dietary fiber, free amino acids and vitamins can also be increased.

[0026] After fermentation, the okara and wheat bran are subjected to low-temperature ultrafine grinding, which not only improves the quality of the okara but also enhances the quality of the okara used in noodles. Ultrafine grinding improves the solubility, dispersibility, adsorption, and chemical reactivity of the okara and wheat bran during dough and noodle making, while also improving their physical properties. Low-temperature treatment minimizes the loss of nutrients and protein structure in the okara.

[0027] Freeze-drying the kale produces a more evenly distributed kale powder in the dough compared to fresh kale, resulting in a smoother noodle texture. Compared to traditional drying, freeze-drying preserves nutrients after processing, resulting in noodles with a higher nutritional value and a greater glycemic index reduction.

[0028] The noodles provided by the present invention have the advantages of low glycemic index, low fat, blood pressure regulation, uniform structure, strong satiety and promoting digestion health.

[0029] Beneficial effects: The present invention provides noodles with a low glycemic index and a method for preparing the same. The noodles are prepared from raw materials, by weight, comprising 5-10 parts kale powder, 8-14 parts yeast-fermented soybean dregs and wheat bran powder, and 75-85 parts flour. The noodles are a low-glycemic index food, characterized by low sugar, fat, and salt content, high fiber content, moderate hardness, excellent elasticity, and a uniform texture. Furthermore, the noodles are simple to process and offer high product stability. They are suitable as a staple food for the dietary management of diabetes and obesity, helping to improve blood sugar levels in these populations and enhance overall health. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be described below.

[0031] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0032] The present invention provides low-glycemic index noodles and a preparation method thereof (also a method for reducing the glycemic index of noodles). Specifically, the present invention freeze-dries fresh kale, then adds equal proportions of dry bean dregs and dry wheat bran to a yeast strain obtained in this laboratory for mixed fermentation. The fermented bean dregs and wheat bran mixture is ultrafinely ground, then flour and auxiliary ingredients are added and mixed uniformly. The mixture is then kneaded, pressed, cut into strips, cooked, freeze-dried, cooled, and packaged to produce the low-glycemic index noodles.

[0033] In the present invention, the bean dregs and wheat bran powder is prepared by mixing and fermenting bean dregs, wheat bran and a yeast strain preserved in the laboratory and then ultrafine grinding.

[0034] The kale powder is obtained by drying by freeze-drying technology and then crushing and sieving.

[0035] The flour is a mixture of wheat flour and whole wheat flour, and the auxiliary materials include egg yolk liquid, salt, guar gum, edible alkali, acetate starch and composite phosphate.

[0036] In the present invention, the ratio of the kale dry powder, bean dregs and wheat bran powder, and flour is (5-10): (8-14): (75-85), calculated by mass ratio.

[0037] In the present invention, the ultrafine grinding treatment conditions are: low temperature of 3-5°C and grinding time of 60-90 minutes.

[0038] In the present invention, the freeze-drying treatment conditions adopted for the fresh kale are pre-freezing for 1.0-1.5 hours and drying for 20-25 hours, and the dried kale is crushed or ground promptly and quickly at low temperature.

[0039] More specifically, the method comprises the following steps: washing fresh kale with running water, freeze-drying the kale, crushing the kale at low temperature in time, and storing the kale for future use; mixing equal proportions of dry bean dregs and dry wheat bran with a very small amount of yeast strain for fermentation; uniformly mixing the obtained bean dregs and wheat bran mixture again after fermentation, adjusting the temperature and time for ultrafine grinding; uniformly mixing pretreated kale powder, bean dregs and wheat bran powder and flour according to proportion to obtain low glycemic index flour mixture; finally, adding pretreated auxiliary materials, mixing, kneading, pressing, cutting into strips, cooking, freeze-drying, cooling and packaging to obtain a low glycemic index noodle product.

[0040] More specifically, the method steps provided by the present invention are as follows: (1) Pre-freeze fresh kale for 1.0-1.5 h and dry for 2-25 h. After drying, crush it in time at low temperature. Take 5-10 portions of kale powder and divide them into multiple portions for sealed storage. (2) Mix dry bean dregs and dry wheat bran in equal proportions, add a yeast strain authorized by our laboratory, mix well, and then seal and ferment; (3) Grind the fermented bean dregs and wheat bran mixture at a low temperature of 3-5 °C for 60-90 min to obtain fermented bean dregs and wheat bran powder. Take 8-14 portions and divide them into several portions, seal them and store them for later use; (4) The pre-processed kale powder, soybean dregs and wheat bran powder and flour are compounded in a ratio of (5-10): (8-14): (75-85) by mass to obtain a flour mixture with a low glycemic index, which is stored for making noodles; (5) Dissolve 0.2-0.5 parts of guar gum, 0.2-0.5 parts of edible alkali, 0.5-0.8 parts of salt, 5-10 parts of acetate starch, 0.2-0.5 parts of complex phosphate and 5-10 parts of egg yolk liquid in 45-55 parts of water for pretreatment, mix well, and calculate by weight; (6) Add the pre-treated auxiliary material aqueous solution to the flour mixture, stir until the flour is flocculent, knead and form a dough, and let it stand at room temperature for 10 minutes; (7) Repeatedly fold and press the dough 30 to 35 times, and then cut the dough into noodles of uniform thickness; (8) Cook the prepared noodles in boiling water for 3–5 min until there is no white core on the cross section of the noodles. Drain the excess water after cooling. (9) Finally, the noodles are freeze-dried, cooled and packaged to obtain a low glycemic index finished product.

[0041] As a preferred embodiment of the present invention, the present invention provides a method for preparing low-glycemic index noodles (also a method for reducing the glycemic index of noodles), the steps of which are as follows: (1) Prefreeze fresh kale for 1.2 h and dry for 24 h. After drying, crush it at low temperature in time. Take 8 parts of kale powder and seal it for storage. Calculate by weight. (2) Mix dry bean dregs and dry wheat bran in equal proportions, add a yeast strain authorized by our laboratory, mix well, and then seal and ferment; (3) Grind the fermented bean dregs and wheat bran mixture at a low temperature of 4°C for 80 min to obtain fermented bean dregs and wheat bran powder. Take 10 portions and seal them for later use, calculated by weight. (4) The pre-processed kale powder, soybean dregs and wheat bran powder and flour are compounded in a ratio of 8:10:82 by mass to obtain a flour mixture with a low glycemic index, and the mixture is stored for making noodles; (5) Dissolve 0.3 parts of guar gum, 0.3 parts of edible alkali, 0.6 parts of salt, 8 parts of acetate starch, 0.3 parts of complex phosphate and 8 parts of egg yolk liquid in 50 parts of water and mix them evenly, calculated by weight; (6) Add the pre-treated auxiliary material aqueous solution to the flour mixture, stir until the flour is flocculent, knead and form a dough, and let it stand at room temperature for 10 minutes; (7) Repeatedly fold and press the dough 32 times, and then cut the dough into noodles of uniform thickness; (8) Boil the prepared noodles in boiling water for 3.5 min until there is no white core in the cross section of the noodles. Pour them into cold water to cool and drain the excess water. (9) Finally, the noodles are freeze-dried, cooled and packaged to obtain a low glycemic index finished product.

[0042] The present invention does not particularly limit the sources of the above-mentioned raw materials, and any conventional commercial products in the field can be used.

[0043] The following examples provide a detailed description of the technical solutions provided by the present invention, but they should not be construed as limiting the scope of protection of the present invention. Unless otherwise specified, the experimental methods used in the examples are conventional methods; the materials and reagents used are all commercially available.

[0044] Example 1.

[0045] This embodiment provides a low glycemic index noodle and a preparation method thereof, which is prepared according to the following steps: (1) Prefreeze fresh kale for 1.2 h and dry for 24 h. After drying, crush it at low temperature in time. Take 8 parts of kale powder and seal it for storage. Calculate by weight. (2) Mix dry bean dregs and dry wheat bran in equal proportions, add a yeast strain authorized by our laboratory, mix well, and then seal and ferment; (3) Grind the fermented bean dregs and wheat bran mixture at a low temperature of 4°C for 80 min to obtain fermented bean dregs and wheat bran powder. Take 10 portions and seal them for later use, calculated by weight. (4) The pre-processed kale powder, soybean dregs and wheat bran powder and flour are compounded in a ratio of 8:10:82 by mass to obtain a flour mixture with a low glycemic index, and the mixture is stored for making noodles; (5) Dissolve 0.3 parts of guar gum, 0.3 parts of edible alkali, 0.6 parts of salt, 8 parts of acetate starch, 0.3 parts of complex phosphate and 8 parts of egg yolk liquid in 50 parts of water and mix them evenly, calculated by weight; (6) Add the pre-treated auxiliary material aqueous solution to the flour mixture, stir until the flour is flocculent, knead and form a dough, and let it stand at room temperature for 10 minutes; (7) Repeatedly fold and press the dough 32 times, and then cut the dough into noodles of uniform thickness; (8) Boil the prepared noodles in boiling water for 3.5 min until there is no white core in the cross section of the noodles. Pour them into cold water to cool and drain the excess water. (9) Finally, the noodles are freeze-dried, cooled and packaged to obtain a low glycemic index finished product.

[0046] Example 2.

[0047] This embodiment provides a low glycemic index noodle and a preparation method thereof, which is prepared according to the following steps: (1) Prefreeze fresh kale for 1.2 h and dry for 24 h. After drying, crush it at low temperature in time. Take 8 parts of kale powder and seal it for storage. Calculate by weight. (2) Mix dry bean dregs and dry wheat bran in equal proportions, add a yeast strain authorized by our laboratory, mix well, and then seal and ferment; (3) Grind the fermented bean dregs and wheat bran mixture at 5°C for 70 min to obtain fermented bean dregs and wheat bran powder. Take 10 portions and seal them for later use. (4) The pre-processed kale powder, soybean dregs and wheat bran powder and flour are compounded in a ratio of 8:10:82 by mass to obtain a flour mixture with a low glycemic index, and the mixture is stored for making noodles; (5) Dissolve 0.3 parts of guar gum, 0.3 parts of edible alkali, 0.6 parts of salt, 8 parts of acetate starch, 0.3 parts of complex phosphate and 8 parts of egg yolk liquid in 50 parts of water and mix them evenly, calculated by weight; (6) Add the pre-treated auxiliary material aqueous solution to the flour mixture, stir until the flour is flocculent, knead and form a dough, and let it stand at room temperature for 10 minutes; (7) Repeatedly fold and press the dough 32 times, and then cut the dough into noodles of uniform thickness; (8) Boil the prepared noodles in boiling water for 3.5 min until there is no white core in the cross section of the noodles. Pour them into cold water to cool and drain the excess water. (9) Finally, the noodles are freeze-dried, cooled and packaged to obtain a low glycemic index finished product.

[0048] Example 3.

[0049] This embodiment provides a low glycemic index noodle and a preparation method thereof, which is prepared according to the following steps: (1) Prefreeze fresh kale for 1.2 h and dry for 24 h. After drying, crush it at low temperature in time. Take 8 parts of kale powder and seal it for storage. (2) Mix dry bean dregs and dry wheat bran in equal proportions, add a yeast strain authorized by our laboratory, mix well, and then seal and ferment; (3) Grind the fermented bean dregs and wheat bran mixture at 3°C ​​for 90 min to obtain fermented bean dregs and wheat bran powder. Take 10 portions and seal them for later use. (4) The pre-processed kale powder, soybean dregs and wheat bran powder and flour are compounded in a ratio of 8:10:82 by mass to obtain a flour mixture with a low glycemic index, and the mixture is stored for making noodles; (5) Dissolve 0.3 parts of guar gum, 0.3 parts of edible alkali, 0.6 parts of salt, 8 parts of acetate starch, 0.3 parts of complex phosphate and 8 parts of egg yolk liquid in 50 parts of water and mix them evenly, calculated by weight; (6) Add the pre-treated auxiliary material aqueous solution to the flour mixture, stir until the flour is flocculent, knead and form a dough, and let it stand at room temperature for 10 minutes; (7) Repeatedly fold and press the dough 32 times, and then cut the dough into noodles of uniform thickness; (8) Boil the prepared noodles in boiling water for 3.5 min until there is no white core in the cross section of the noodles. Pour them into cold water to cool and drain the excess water. (9) Finally, the noodles are freeze-dried, cooled and packaged to obtain a low glycemic index finished product.

[0050] Example 4.

[0051] This embodiment provides a low glycemic index noodle and a preparation method thereof, which is prepared according to the following steps: (1) Prefreeze fresh kale for 1.2 h and dry for 24 h. After drying, crush it at low temperature in time. Take 10 parts of kale powder and seal it for storage. Calculate by weight. (2) Mix dry bean dregs and dry wheat bran in equal proportions, add a yeast strain authorized by our laboratory, mix well, and then seal and ferment; (3) The fermented bean dregs and wheat bran mixture was crushed at a low temperature of 4 °C for 80 min to obtain fermented bean dregs and wheat bran powder. 14 portions were sealed and stored for later use, calculated by weight. (4) The pre-processed kale powder, soybean dregs wheat bran powder and flour are compounded in a ratio of 10:14:76 by mass to obtain a flour mixture with a low glycemic index, and the mixture is stored for making noodles; (5) Dissolve 0.3 parts of guar gum, 0.3 parts of edible alkali, 0.6 parts of salt, 8 parts of acetate starch, 0.3 parts of complex phosphate and 8 parts of egg yolk liquid in 50 parts of water and mix them evenly, calculated by weight; (6) Add the pre-treated auxiliary material aqueous solution to the flour mixture, stir until the flour is flocculent, knead and form a dough, and let it stand at room temperature for 10 minutes; (7) Repeatedly fold and press the dough 32 times, and then cut the dough into noodles of uniform thickness; (8) Boil the prepared noodles in boiling water for 3.5 min until there is no white core in the cross section of the noodles. Pour them into cold water to cool and drain the excess water. (9) Finally, the noodles are freeze-dried, cooled and packaged to obtain a low glycemic index finished product.

[0052] Comparative Example 1.

[0053] The difference between this comparative example and Example 1 is that the dry bean dregs and dry wheat bran are mixed in equal proportions without fermentation treatment, and the dry bean dregs and dry wheat bran are directly ultrafinely ground in a ratio of 1:1 and then added to the flour.

[0054] Comparative Example 2.

[0055] Compared with Example 1, this comparative example differs in that dry bean dregs and dry wheat bran are mixed in equal proportions for fermentation treatment, and the fermented mixture is not ultrafinely ground. Instead, the fermented bean dregs and wheat bran are ground by other conventional grinding methods and then added to flour for making dough and noodles.

[0056] Comparative Example 3.

[0057] The difference between this comparative example and Example 1 is that only 10 parts of kale powder and 90 parts of flour are mixed to prepare noodles, and no bean dregs and wheat bran are added to the noodles.

[0058] Comparative Example 4.

[0059] The difference between this comparative example and Example 1 is that only 14 parts of bean dregs and wheat bran are mixed with 86 parts of flour to prepare noodles, and kale is not added to the noodles.

[0060] Experimental example 1.

[0061] This experimental example measured the glycemic index, specific volume, and cooking loss of the noodle products in each embodiment and comparative example; 1. Estimation of glycemic index: Weigh 0.2 g of noodle sample into a 50 mL centrifuge tube, add 20 mL of distilled water to make a suspension, stir evenly at room temperature, and equilibrate in a 37°C water bath for 10 min. Simulated oral stage: add 0.05 mL of 0.1% (w / w) α-amylase solution and digest for 1 min; simulated gastric stage: adjust the pH of the sample solution to 2.5±0.5 with 6M HCl, add 0.1 mL of 10% (w / w) pepsin solution (dissolved in 0.05M HCl), and draw 0.2 mL of the reaction solution at 0 and 30 min to measure its glucose content; simulated small intestine stage: adjust the pH of the reaction solution to approximately 6.2±0.5 with 0.1M NaHCO3, add 0.75 mL of 10% (w / w) ox bile salts, immediately draw an equal portion of 0.2 mL of the digestion solution into a 1.5 mL centrifuge tube and inactivate the enzyme in a boiling water bath for 5 min (this is intestinal digestion 0 min), add 0.05 mL of amyloglucosidase and 0.05 mL of 5% (w / w) pancreatin (both ox bile salts and pancreatin are dissolved in 0.1M The digestion was performed in a sodium maleate buffer (pH 6.9). At 20, 30, 60, 90, 120, and 180 min, 0.2 mL of the hydrolyzate was pipetted into a 1.5 mL centrifuge tube and inactivated in a boiling water bath for 5 min. The entire digestion process was performed in a 37°C, 120 rpm water bath. After enzyme inactivation, the tubes were centrifuged at 10,000 g for 15 min. An equal amount of 0.1 mL of the supernatant was aspirated and glucose content was determined using a GOPOD kit. The equation for in vitro digestion kinetics is: C = C ∞ (1-e -kt ).

[0062] Where C is the percentage of starch hydrolysis at time t, C∞ is the equilibrium percentage of starch hydrolysis at 180 min, and k is the kinetic constant. The parameters C∞ and k for different groups were fitted based on data obtained from in vitro starch digestion.

[0063] The starch hydrolysis index (HI) is a predictor of glycemic response and is calculated by dividing the area under the hydrolysis curve (AUC 0-180 min) of the noodle sample by the area under the curve of the control food (white bread). The formula is as follows: HI = AUC 样品 AUC 白面包 ×100.

[0064] The formula for calculating the estimated glycemic index (eGI) is as follows: eGI=0.862×HI+8.198.

[0065] 2. Specific Volume: The weight of the noodles was measured to the nearest 0.01 g. The volume of the noodles was determined using the rapeseed displacement method. Specific volume (mL / g) is the ratio of the volume (mL) to the weight (g) of the noodles.

[0066] 3. Cooking loss: 3 g of noodles were placed in 150 g of boiling water and cooked until the hard core disappeared. The broth was then diluted to a 500 mL volumetric flask. 50 mL of the broth was then poured into a constant-weight aluminum box (M2) and dried at 105°C for 12 h (M1). Each sample was measured in triplicate. The cooking loss was calculated using the following formula: .

[0067] Where M1 is the dry weight of the aluminum box after pouring the noodle soup (g); M2 is the dry weight of the aluminum box (g); W is the moisture content of the noodles; M0 is the weight of the noodles.

[0068] Table 1 Estimated glycemic index, specific volume and cooking loss results of noodles .

[0069] As can be seen from the table above, the estimated glycemic index of noodles produced using Examples 1-4 and Comparative Examples 1-4 is lower than 55, making them low-glycemic index foods. The estimated glycemic index of Examples 1-4 is lower than 45. The addition of kale, bean dregs, and wheat bran to the dough significantly lowers the glycemic index of the noodles. Furthermore, Example 1 exhibits significantly greater specific volume, less cooking loss, and higher quality compared to Comparative Examples 1-4. While Comparative Examples 1-4 can lower the estimated glycemic index of noodles produced using pure wheat flour, overall, the processing conditions can lead to reduced product quality.

[0070] Experimental Example 2: Sensory evaluation of low glycemic index noodles.

[0071] Fifty volunteers aged 20 to 30 years, half male and half female, who enjoy eating noodles daily, were randomly selected to undergo a sensory evaluation of the noodles prepared in Examples 1-4 and Comparative Examples 1-4 according to the criteria shown in the table below. The average score was taken. The sensory evaluation was conducted based on the sensory requirements of GB / T 40636-2021, "National Food Safety Requirements for Dried Noodles." A sensory scoring standard table was designed. The noodles were blindly evaluated based on five aspects: color, surface condition, palatability, toughness, and flavor. The maximum and minimum values ​​were removed from the evaluation results, and the average score was taken, resulting in a total score of 100. The scoring criteria are shown in Table 2.

[0072] Table 2 Sensory scoring criteria for noodles .

[0073] The experimental results are as follows: Table 3 Sensory evaluation results of noodles .

[0074] As shown in Table 3, the noodles of Examples 1-4 all achieved comprehensive sensory evaluation scores above 70, while the noodles of Comparative Examples 1-4 generally exhibited poor flavor, toughness, palatability, and surface texture, resulting in low comprehensive sensory evaluation scores, generally below 70. Comparison of Examples 1-3 with Comparative Examples 1 and 2 demonstrates that fermenting and ultrafine grinding bean dregs and wheat bran significantly improves noodle flavor. Comparison of Examples 3 and 4 demonstrates that the simultaneous addition of kale, bean dregs, and wheat bran to the noodles significantly enhances their flavor, palatability, and surface texture, improves their surface and internal structure, enhances their toughness, and improves their overall sensory quality.

[0075] The above-described embodiments merely illustrate several implementations of the present invention, and are provided to facilitate a specific and detailed understanding of the technical solutions of the present invention. They should not be construed as limiting the scope of protection of the present invention. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the spirit of the present invention, and all such modifications and improvements fall within the scope of protection of the present invention.

Claims

1. Low glycemic index noodles, characterized in that The raw materials for its preparation include, by mass, 5-10 parts of kale powder, 8-14 parts of yeast-fermented bean dregs and wheat bran powder, and 75-85 parts of flour; the kale powder is obtained by freeze-drying fresh kale (pre-freezing for 1.0-1.5 h and drying for 20-25 h), grinding it into powder, and then sieving it; the bean dregs and wheat bran powder is obtained by mixing freeze-dried bean dregs and wheat bran in a 1:1 ratio in the laboratory, adding a yeast strain authorized by the laboratory for sealed fermentation, and then ultrafine grinding the fermented bean dregs and wheat bran mixture (crushing at a low temperature of 3-5°C for 60-90 min).

2. The low glycemic index noodles according to claim 1, wherein the bean dregs and wheat bran are fermented under sealed conditions, and the strain used is a yeast strain authorized for this experiment (strain deposit number is CCTCC NO: M 2022150).

3. The low glycemic index noodles according to claim 1, wherein the fermented bean dregs and wheat bran mixture is pulverized at a low temperature of 3-5° C., the pulverization time of the fermented bean dregs and wheat bran mixture is 60-90 min, and the bean dregs and wheat bran powder obtained after ultrafine grinding.

4. The low glycemic index noodles according to claim 1, wherein the kale powder is obtained by freeze-drying fresh kale, the pre-freezing time is 1.0 to 1.5 hours, and the drying time is 20 to 25 hours.

5. The low glycemic index noodles according to claim 1, wherein the flour used is a mixture of wheat flour and whole wheat flour commonly found on the market.

6. The low glycemic index noodles according to claims 1 to 5, wherein the mass ratio of kale powder, bean dregs and wheat bran powder, and flour used in the low glycemic index mixed flour is (5-10): (8-14): (75-85), calculated on a mass basis.

7. The low glycemic index noodles according to claim 1, wherein the auxiliary ingredients used include 5-10 parts of egg yolk liquid, 0.2-0.5 parts of guar gum, 0.2-0.5 parts of edible alkali, 0.5-0.8 parts of salt, 5-10 parts of acetate starch and 0.2-0.5 parts of complex phosphate, calculated by weight.

8. The low glycemic index noodles according to claims 7-8, wherein during the noodle production process, before kneading, the auxiliary materials need to be dissolved in 45-55 mL of water for pretreatment.

9. The low glycemic index noodles according to claims 1 to 7 are prepared by uniformly mixing the pretreated auxiliary materials with kale powder, bean dregs and wheat bran powder, and flour, and then kneading, pressing, cutting into strips, boiling, freeze-drying, cooling and packaging to obtain a low glycemic index noodle product.

10. The low glycemic index noodles according to claim 8, wherein the dough is pressed into sheets 30 to 35 times, and the sheets are cut into noodles of uniform thickness.

11. The low glycemic index noodles according to claim 8, wherein the noodles need to be cooked in boiling water for 3 to 5 minutes, and after cooking, they need to be freeze-dried, cooled, and packaged.

12. The noodle formula according to any one of claims 1 to 7, or the noodles prepared by the preparation method according to any one of claims 8 to 11, are used for consumption by diabetic patients.

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