Preparation method of low glycemic index mycelium protein steamed buns

Abstract

The invention discloses a preparation method of low-glycemic-index mycelium protein steamed buns, and belongs to the technical field of food preparation. According to the invention, the synergistic strengthening and diversification of nutrients are realized. According to the invention, the GI value is not simply reduced, and nutrient enrichment is taken as an important target. The addition of mycelium protein and vital gluten significantly improves the protein content and quality of the product. Meanwhile, the resistant starch, the highland barley powder and the aleurone layer are introduced, so that the contents of dietary fibers, beta-glucan, mineral substances and vitamins in the product are synchronously increased, the traditional steamed bun is converted into a composite nutrition fortified food integrating low GI, high protein and rich dietary fibers from a single energy staple food, and the nutritional value is comprehensively improved.

Description

Technical Field

[0001] This invention relates to a method for preparing low glycemic index mycelial protein steamed buns, belonging to the field of food preparation technology. Background Technology

[0002] With changes in dietary structure and increased health awareness in modern society, the incidence of metabolic diseases such as diabetes and obesity is on the rise, making the demand for low glycemic index (GI) foods increasingly urgent. Steamed buns, a traditional staple food in my country, are mainly made from refined wheat flour, are high in carbohydrates, and are digested quickly, easily leading to a rapid rise in postprandial blood sugar. Their generally high GI value makes them difficult to meet the healthy dietary needs of certain population groups.

[0003] Currently, to lower the glycemic index (GI) of flour-based products, the market often uses methods such as adding dietary fiber, whole wheat flour, mixed grain flour, or resistant starch. However, these methods often significantly affect the texture, mouthfeel, and flavor of the product while lowering the GI, such as reducing the specific volume of steamed buns, increasing hardness, resulting in a rougher texture and poorer flavor, thus limiting their acceptance. Meanwhile, with consumers increasingly focusing on protein nutrition and sustainable foods, developing staple food products that combine high protein, low GI, and excellent sensory qualities has become an important direction.

[0004] As a novel type of microbial protein, *Aspergillus niger* and *Fusarium vesicatoria* mycelial proteins are characterized by high protein content, a favorable amino acid profile, and low fat content. Furthermore, their unique fibrous structure may play a positive role in delaying the glycemic response. This invention aims to provide a low-GI, nutrient-rich mycelial protein steamed bun and its preparation method. Summary of the Invention

[0005] The purpose of this invention is to address existing problems by providing a method for preparing low glycemic index mycelial protein steamed buns.

[0006] This invention is achieved through the following technical solution: The first objective of this invention is to provide a mycelium protein-based steamed bun composite flour, comprising the following components by weight: The mycelial protein, gluten, resistant starch, barley flour and aleurone layer are composed in a ratio of 1.5~6:2~8:1~2.5:2.5~7:1~4.

[0007] In one embodiment of the present invention, the mycelial protein is Aspergillus niger mycelial protein or Fusarium venetum mycelial protein.

[0008] In one embodiment of the present invention, the mycelial protein, gluten, resistant starch, barley flour and aleurone layer are composed in a ratio of 3:6:2:5.5:3.

[0009] The second objective of this invention is to provide the application of the mycelium protein steamed bun composite flour in the preparation of steamed buns.

[0010] The third objective of this invention is to provide a method for preparing a low glycemic index mycelial protein steamed bun, comprising the following steps: S1. Activate the yeast powder with warm water and add it to the mycelium protein steamed bun compound flour. Stir until the flour and water are mixed into flocculent material and there is no dry powder. Knead into a smooth dough. S2. Ferment the dough until it expands to 1.5-2.5 times its original volume. Knead it to release the air, then cut it into evenly sized portions and shape them into steamed buns. S3. Place the shaped dough into a steamer and let it stand for a second fermentation. S4. Place the steamer on a pot of cold water and steam for 10-20 minutes after the water boils. After turning off the heat, let it sit for 3-8 minutes before taking it out to obtain the low glycemic index mycelial protein steamed bun.

[0011] In one embodiment of the present invention, the yeast powder is activated by adding yeast powder to warm water at 35-40°C, stirring and letting it stand for 5-10 minutes until a rich layer of foam is produced on the surface of the water.

[0012] In one embodiment of the present invention, in step S2, the dough fermentation is carried out at 35-40°C for 40-80 minutes.

[0013] In one embodiment of the present invention, in step S2, kneading and degassing involves placing the fermented dough on a floured work surface and kneading it vigorously for at least 10 minutes.

[0014] In one embodiment of the invention, the item is placed on a drying rack to dissipate heat and prevent the bottom from getting wet from water vapor.

[0015] The fourth objective of this invention is to provide a low glycemic index mycelial protein steamed bun product prepared by the aforementioned method. It possesses the following characteristics: it exhibits a reduced glycemic index as measured in in vitro simulated digestion experiments.

[0016] The beneficial effects of this invention are: Compared with existing technologies, this invention has the following advantages: it achieves synergistic fortification and diversification of nutrients. This invention does not simply reduce the GI value, but also prioritizes nutritional fortification. The addition of mycelial protein and gluten significantly improves the protein content and quality of the product. Simultaneously, the introduction of resistant starch, barley flour, and aleurone layer increases the content of dietary fiber, β-glucan, minerals, and vitamins in the product, transforming traditional steamed buns from a single energy staple food into a complex fortified food that combines low GI, high protein, and rich dietary fiber, thus comprehensively enhancing its nutritional value. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A comparative diagram of the appearance of steamed bun products. In the diagram, A to E are steamed buns with variable mycelial protein (Aspergillus niger mycelial protein, Fusarium vesicularis protein), variable gluten powder, variable potato resistant starch, variable highland barley flour, and variable aleurone layer, respectively. Figure 2 A comparative diagram of the starch hydrolysis index of steamed bun products. In the diagram, A~E are the starch digestion and hydrolysis rate diagrams of steamed buns with Aspergillus niger mycelium protein group, respectively, for protein-variable steamed bun starch hydrolysis rate, gluten-variable steamed bun starch hydrolysis rate, potato resistant starch-variable steamed bun starch hydrolysis rate, highland barley flour-variable steamed bun starch hydrolysis rate, and aleurone layer-variable steamed bun starch hydrolysis rate; in the diagram, F~J are the starch digestion and hydrolysis rate diagrams of steamed buns with Fusarium venetum mycelium protein group, respectively, for protein-variable steamed bun starch hydrolysis rate, gluten-variable steamed bun starch hydrolysis rate, potato resistant starch-variable steamed bun starch hydrolysis rate, highland barley flour-variable steamed bun starch hydrolysis rate, and aleurone layer-variable steamed bun starch hydrolysis rate. Figure 3 The final optimized formula is used to compare the appearance of steamed buns. Con represents the appearance of steamed buns obtained by steaming with the formula excluding egg whites, ANP represents the appearance of steamed buns obtained by steaming with the formula containing Aspergillus niger mycelial protein, and FP represents the appearance of steamed buns obtained by steaming with the formula containing Fusarium venetum mycelial protein. Figure 4 A comparative diagram showing the starch hydrolysis index of steamed buns produced using the final optimized formula. Detailed Implementation

[0019] The present invention will be further illustrated below with specific examples. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0020] Raw material source: Aspergillus niger mycelial protein and Fusarium vesicatoria mycelial protein: Seed cultures were inoculated into the fermenter at a 10% (v / v) inoculum ratio. Fermentation was carried out under the following conditions: temperature 28°C, pH maintained at 5.5 by adding ammonia, and dissolved oxygen (DO) content 30%. Fermentation lasted 72 h. After fermentation, the mixture was filtered using a Buchner funnel. The resulting product was washed with distilled water and dried. The final mycelial protein product was obtained by heating at 28°C and 20 Pa to a constant weight.

[0021] Aspergillus niger FS10 (CCTCC No.: M2013703) and Fusarium vesicanthomonas (ATCC 20334) were purchased from the China Culture Collection (Wuhan, China) and the American Culture Collection (Manassas, VA, USA), respectively. Wheat gluten: Henan Yumanchun Flour Industry Co., Ltd.; Resistant starch: Shanghai Yifu Food Ingredients Co., Ltd.; Highland barley flour: Gannan Tibetan Autonomous Prefecture Zangwanggong Green Agricultural Products Development Co., Ltd.; Wheat aleurone layer raw starch: Longyao County Hufenxiang Food Technology Co., Ltd.

[0022] In the following examples, steamed buns are prepared according to the following method: (1) Add yeast powder to 38℃ warm water, stir for 30 seconds, and let stand for 5-10 minutes until a rich layer of foam appears on the surface of the water. This indicates that the yeast has been activated. Put the flour in a large bowl, pour in the yeast water, and stir in one direction with chopsticks until the mycelium protein steamed bun composite flour and water are mixed into a flocculent state until there is no dry flour. Knead the flocculent dough by hand into a smooth dough.

[0023] (2) Fermentation: Cover the dough bowl with plastic wrap or a damp cloth to prevent the surface from drying out. Place the dough bowl in an oven (ferment at 38°C for 60 minutes) until the dough volume expands to twice its original size.

[0024] (3) Degassing: Take out the fermented dough and place it on a floured work surface. Knead it vigorously for at least 10 minutes to remove all large air bubbles. Roll the dough into a long strip and cut it into evenly sized pieces.

[0025] (4) Second fermentation: Place the shaped dough into a steamer, leaving enough space between each one. Cover the steamer and let it sit.

[0026] (5) Steaming with cold water: Place the steamer on a pot of cold water. Allow the steamed buns to heat evenly as the water temperature rises, allowing them to continue expanding. Heat and time: Turn the heat to high, and start timing after the water boils. Continue steaming for 15 minutes. Do not open the lid during steaming to prevent steam leakage and shrinkage of the steamed buns.

[0027] (6) Turn off the heat and let it simmer: After turning off the heat, do not open the lid immediately. Let it simmer for 5 minutes to reduce the temperature difference between the inside and outside of the pot. Slowly open the lid and quickly take out the steamed buns. Place them on a cooling rack to cool down and prevent the bottom from getting wet from the steam.

[0028] The technical solution of the present invention will be described in detail below with reference to specific embodiments. In the following embodiments, unless otherwise specified, the reagents, materials and equipment used can be purchased commercially, prepared by conventional methods, or commonly used in the industry.

[0029] Example 1 A method for preparing a low glycemic index mycelial protein steamed bun includes the following: The mycelium protein steamed bun composite flour is composed of the following substances in the indicated weight proportions: The weight ratio of Aspergillus niger mycelial protein, gluten, resistant starch, highland barley flour, and aleurone layer is 1.5-6:6:2:5.5:3. The addition ratios of Aspergillus niger mycelial protein are shown in Table 1-1, being 1.5, 3.0, 4.5, and 6.0 respectively. The addition ratios in the following examples are all as described in Table 1-1.

[0030] The weight ratio of Fusarium venetum mycelial protein, gluten, resistant starch, barley flour and aleurone layer is 1.5-6:6:2:5.5:3.

[0031] Example 2 A method for preparing a low glycemic index mycelial protein steamed bun includes the following: The mycelium protein steamed bun composite flour is composed of the following substances in the indicated weight proportions: The weight ratio of Aspergillus niger mycelial protein, gluten, resistant starch, highland barley flour and aleurone layer is 3:2-8:2:5.5:3.

[0032] The weight ratio of Fusarium venetum mycelial protein, gluten, resistant starch, highland barley flour, and aleurone layer is 3:2-8:2:5.5:3.

[0033] Example 3 A method for preparing a low glycemic index mycelial protein steamed bun includes the following: The mycelium protein steamed bun composite flour is composed of the following substances in the indicated weight proportions: The weight ratio of Aspergillus niger mycelial protein, gluten, resistant starch, highland barley flour and aleurone layer is 3:6:1-2.5:5.5:3.

[0034] The weight ratio of Fusarium venetum mycelial protein, gluten, resistant starch, barley flour and aleurone layer is 3:6:1-2.5:5.5:3.

[0035] Example 4 A method for preparing a low glycemic index mycelial protein steamed bun includes the following: The mycelium protein steamed bun composite flour is composed of the following substances in the indicated weight proportions: The weight ratio of Aspergillus niger mycelial protein, gluten, resistant starch, highland barley flour, and aleurone layer is 3:6:2:2.5-7:3.

[0036] The weight ratio of Fusarium venetum mycelial protein, gluten, resistant starch, highland barley flour, and aleurone layer is 3:6:2:2.5-7:3.

[0037] Example 5 A method for preparing a low glycemic index mycelial protein steamed bun includes the following: The mycelium protein steamed bun composite flour is composed of the following substances in the indicated weight proportions: The weight ratio of Aspergillus niger mycelial protein, gluten, resistant starch, highland barley flour and aleurone layer is 3:6:2:5.5:1-4.

[0038] The weight ratio of Fusarium venetum mycelial protein, gluten, resistant starch, highland barley flour, and aleurone layer is 3:6:2:5.5:1-4.

[0039] In the following tests, ANP represents the mycelial proteome of Aspergillus niger and FP represents the proteome of Fusarium venetum.

[0040] Example 6 The porosity of steamed buns was evaluated using image analysis. The specific steps were as follows: a color image of the steamed bun's cross-section was captured, and the internal texture structure was analyzed using ImageJ software. To further quantify the porosity, the color image was converted into a binary image, and a specific region was selected as a representative area to evaluate the pore distribution characteristics of the entire cross-section.

[0041] After slicing the steamed bun samples, the color of their core was measured using a colorimeter. Analysis was based on L* and a. b The chromaticity system is expanded, where L This indicates brightness; the higher the value, the brighter the color. Indicates red-green hue, a Positive values ​​are red, negative values ​​are green, b Indicates the degree of yellow-blue, b Positive numbers tend to be yellowish, while negative numbers tend to be bluish.

[0042] Example 7 Pretreatment: 900 mg of steamed bread was cut into small pieces and added to 50 ml round-bottom test tubes containing 4 mL of sodium acetate buffer solution (0.2 mol / L, pH=6). After the test tubes were equilibrated in a 37°C water bath for 10 min, 1 mL of simulated saliva (sodium acetate buffer solution, 0.02 mol / L, pH=7) containing α-amylase (75 U / mL) was added, and the mixture was reacted at 200 rpm for 45 s for oral digestion. After oral digestion, 2 mL of hydrochloric acid solution (0.02 mol / L) containing pepsin (2000 U / mL) was added to the test tubes to simulate gastric juice reaction for 10 min. At the end of the reaction, 2 mL of sodium hydroxide solution (0.02 mol) was added to neutralize the solution. Finally, 5 mL of sodium acetate solution (0.2 mol / L, pH=6) containing trypsin (600 U / mL) and 13 μL LAMG (15 U / mL) was added to a test tube to simulate intestinal fluid. The reaction was initiated in a water bath at 200 rpm. 0.1 mL of the digestate was collected at time points 0, 5, 10, 20, 30, 45, 60, 90, 120, and 180 min and added to a microcentrifuge tube containing 0.9 mL of anhydrous ethanol to terminate the reaction. After collection, the microcentrifuge tubes were centrifuged at 12000 rpm for 3 min. 100 μL of the supernatant was collected, and the glucose content in the supernatant was determined using a glucose kit and converted to starch.

[0043] The results are as follows: Table 1. Color and porosity of steamed buns under single-factor conditions Table 1-1

[0044] Table 1-2

[0045] Table 2. Starch digestion of steamed buns under single-factor conditions Table 2-1

[0046] Table 2-2

[0047] Table 3. Starch digestion of the optimized formula steamed buns

[0048] In terms of color, L The value represents brightness and is an important indicator for evaluating the sensory acceptance of a product. As shown in Table 1, the addition of each functional ingredient reduces the brightness of the steamed bun to varying degrees. Mycelial protein and aleurone layer, in particular, significantly reduce the brightness of the steamed bun. The decrease in L was most significant in the ANP group. When the mycelial protein addition was 3.0%, the L... The value was 45.56, significantly higher than 41.95 at 6.0%; when barley flour was added at 7.0%, L With a value of 48.33, it can effectively maintain the product's color from becoming too dull. value and b An increase in the value indicates that the product color is more reddish-yellow, which gives the steamed buns their natural whole-grain color.

[0049] Regarding porosity, higher porosity generally indicates a softer internal structure. Table 1 shows that mycelial protein porosity peaks at 3.0% (ANP 4.33%, FP 2.67%), gluten has the highest porosity at 6.0% (ANP 3.33%, FP 3.67%), resistant starch has relatively good porosity at 2.0% (ANP 3.33%, FP 2.57%), barley flour has relatively high porosity at 7.0% (ANP 2.88%, FP 2.83%), and aleurone layer has relatively high porosity at 2.0% (ANP 2.86%, FP 2.75%).

[0050] Regarding starch digestibility, resistant starch (RS) content, rapidly digestible starch (RDS) ratio, estimated glycemic index (eGI), and GI value are key indicators for evaluating the health benefits of a product. (See Table 2 and...) Figure 2 It is evident that the addition of all raw materials significantly increased the RS content and decreased the RDS ratio, eGI, and GI value. Among them, mycelial protein, gluten, and resistant starch were particularly effective in reducing the GI. The GI of mycelial protein at 3.0% was 55.14 (ANP) and 56.72 (FP), decreasing to 51.50 (ANP) and 53.04 (FP) at 6.0%. However, higher protein addition levels negatively impacted the shape of the steamed bun. Figure 1 This situation was also reflected in experiments with other factors.

[0051] Based on a comprehensive comparison of experimental data, the optimal compound ratio was determined to be: mycelial protein 3%, wheat gluten 6%, resistant starch 2%, highland barley flour 7%, and aleurone layer 2%. Steamed buns made with this formula exhibited good shape. Figure 3 ), and after digestion (Table 3, Figure 4The estimated glycemic index (eGI) of the Aspergillus niger mycelium protein steamed buns significantly decreased from 78.99 in the control group to 72.47, and the predicted GI value decreased from 58.17 to 53.37. Similarly, the estimated glycemic index (eGI) of the Fusarium venetum mycelium protein steamed buns significantly decreased from 78.99 in the control group to 74.07, and the predicted GI value decreased from 58.17 to 54.55. According to the internationally accepted GI classification standard (GI ≤ 55 is considered low-GI food), the GI value of this optimized formula product belongs to the low-GI category, indicating a better glycemic regulation potential compared to traditional wheat steamed buns.

[0052] The embodiments provided above are not intended to limit the scope of the invention, nor are the described steps intended to limit the order of execution. Any obvious modifications made to the invention by those skilled in the art based on existing common knowledge also fall within the scope of protection defined by the claims.

Claims

1. A mycelium protein-based composite flour for steamed buns, characterized in that, By weight, it includes the following components: The mycelial protein, gluten, resistant starch, barley flour and aleurone layer are composed in a ratio of 1.5~6:2~8:1~2.5:2.5~7:1~4.

2. The mycelium protein composite flour for steamed buns according to claim 1, characterized in that, The mycelial protein is either Aspergillus niger mycelial protein or Fusarium venetum mycelial protein.

3. The mycelium protein composite flour for steamed buns according to claim 1, characterized in that, The mycelial protein, gluten, resistant starch, barley flour, and aleurone layer are composed in a ratio of 3:6:2:5.5:

3.

4. The application of the mycelium protein steamed bun composite flour according to any one of claims 1-3 in the preparation of steamed buns.

5. A method for preparing a low glycemic index mycelial protein steamed bun, characterized in that, Includes the following steps: S1. Activate the yeast powder with warm water and add it to the mycelium protein steamed bun composite flour according to any one of claims 1-3. Stir the flour and water to mix into flocculent form until there is no dry powder, and knead into a smooth dough. S2. Ferment the dough until it expands to 1.5-2.5 times its original volume. Knead it to release the air, then cut it into evenly sized portions and shape them into steamed buns. S3. Place the shaped dough into a steamer and let it stand for a second fermentation. S4. Place the steamer on a pot of cold water and steam for 10-20 minutes after the water boils. After turning off the heat, let it sit for 3-8 minutes before taking it out to obtain the low glycemic index mycelial protein steamed bun.

6. The preparation method according to claim 5, characterized in that, The yeast powder is activated by adding it to warm water at 35-40℃, stirring, and letting it stand for 5-10 minutes until a rich layer of foam is produced on the surface of the water.

7. The preparation method according to claim 5, characterized in that, In step S2, the dough ferments at 35-40℃ for 40-80 minutes.

8. The preparation method according to claim 5, characterized in that, In step S2, kneading to release the air involves placing the fermented dough on a floured work surface and kneading it vigorously for at least 10 minutes.

9. The preparation method according to claim 5, characterized in that, Place it on a drying rack to dissipate heat and prevent the bottom from getting wet from water vapor.

10. A low glycemic index mycelial protein steamed bun product prepared by the preparation method according to any one of claims 5-9.

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