Medicinal and edible high-dietary-fiber low-GI whole-wheat Chinese yam and poria cocos steamed bun and preparation method thereof

Abstract

The invention belongs to the field of functional food, and discloses a medicinal and edible low-GI whole wheat, Chinese yam and poria cocos steamed bun with high dietary fiber and a preparation method thereof.The steamed bun takes whole wheat flour, raw pulp soymilk and resistant starch as core raw materials, the core raw materials are compounded with medicinal and edible components such as Chinese yam powder, poria cocos powder and mulberry leaf high-fiber powder, and pre-gelatinization treatment is performed at the temperature of 40-45 DEG C, the preparation method comprises the following steps: optimizing a starch structure by using starch as a raw material, and combining gradient activated compound lactic acid bacteria (lactobacillus acidophilus-lactobacillus plantarum-bifidobacterium) and yeast for synergistic fermentation (two-stage fermentation, 35 + / -1 DEG C and humidity of 75-80%) to realize precise regulation and control of 12-18wt% of total dietary fibers and water-soluble / insoluble fibers in a ratio of 1: 2-1: 3. Preferably, the invention discloses the Chinese yam and poria cocos steamed bun, the egi is 41.56, the GI value is 52, the content of dietary fiber is 11g, and the content of protein is 11.59 g in every 100g of the Chinese yam and poria cocos steamed bun.

Description

Technical Field

[0001] The present invention belongs to the field of functional foods, and specifically discloses a low-GI whole wheat yam poria cocos steamed bun with high dietary fiber of medicine and food homology and a preparation method thereof. Background Art

[0002] With the high incidence of metabolic diseases such as diabetes and obesity, the development of low glycemic index (GI) foods has become an important direction in the field of food science. Traditional steamed buns are mainly made of refined wheat flour, with a relatively high GI value (about 88). Long-term consumption is likely to cause drastic fluctuations in postprandial blood glucose, which is not conducive to blood glucose management for diabetic patients and healthy people. In the prior art, although there are multiple patents attempting to improve the GI value of steamed buns by adding dietary fiber or miscellaneous grains, there are still the following limitations:

[0003] Single source of dietary fiber and insufficient functionality

[0004] For example, Patent CN115568551A (Lu Dabin, 2023) improves the dietary fiber content by adding components such as corn, fresh soybean dregs, and polydextrose. However, its raw materials are mainly grains, lacking the synergistic effect of medicine and food homology components, and not optimizing the ratio of water-soluble and insoluble dietary fiber, resulting in limited intestinal regulation function.

[0005] Single fermentation process and strain, low nutrient retention rate

[0006] Patent CN118592560A (Chongqing University of Education, 2024) uses raw materials such as purple sweet potatoes and soybean dregs. Although the GI value is reduced to 51.46, its fermentation process relies on a single yeast and does not introduce compound lactic acid bacteria (such as Lactobacillus acidophilus and Bifidobacterium). It is difficult to further degrade antinutritional factors (such as phytic acid) through microbial metabolism, and the content of active probiotics in the finished product is low, unable to achieve the function of regulating the intestinal flora.

[0007] Difficulty in balancing taste and nutrition

[0008] Most low-GI steamed buns have a rough texture and poor palatability due to the addition of a large amount of crude fiber. For example, Patent CN110973479A (Fujian Huatuo Youyue, 2019) uses miscellaneous grains such as coix seeds and gorgon fruits, but does not improve the starch-dietary fiber composite structure through physical modification (such as pregelatinization of resistant starch and β-cyclodextrin embedding of mulberry leaf powder), resulting in a relatively high starch hydrolysis index and easy aging of the product. Summary of the Invention

[0009] In view of the above problems, the present invention discloses a low-GI whole wheat yam poria cocos steamed bun with high dietary fiber of medicine and food homology and a preparation method thereof.

[0010] The object of the present invention is achieved by the following technical solutions.

[0011] A low-GI whole wheat yam poria cocos steamed bun with homologous medicine and food and high dietary fiber is made from the following raw materials in parts by weight:

[0012] 35-40 parts of whole wheat flour, 25-30 parts of domestic drinking water, 8-12 parts of raw soy milk, 6-8 parts of vital gluten, 4-6 parts of resistant starch, 3-5 parts of non-GMO soybean oil, 3-5 parts of Chinese yam powder, 1-2 parts of poria cocos powder, 1-2 parts of buckwheat flour, 1-2 parts of millet flour, 0.5-1 part of fructooligosaccharide, 0.5-0.8 part of yeast for food processing, 0.2-0.5 part of concentrated momordica grosvenori juice, 0.2-0.5 part of mulberry leaf high-fiber powder, 0.05-0.15 part of compound lactic acid bacteria powder for food processing;

[0013] The compound lactic acid bacteria powder for food processing contains Lactobacillus acidophilus, Lactobacillus plantarum and Bifidobacterium, and the total viable count ≥ 1×10^10 CFU / g;

[0014] The resistant starch is corn resistant starch treated by physical modification, and the amylose content ≥ 65%;

[0015] The mulberry leaf high-fiber powder is a product obtained by embedding ultrafine pulverized mulberry leaf powder with β-cyclodextrin, and the dietary fiber content ≥ 60%.

[0016] Furthermore, for the above-mentioned low-GI whole wheat yam poria cocos steamed bun with homologous medicine and food and high dietary fiber, the total dietary fiber content in the raw materials is 12-18 wt%, and the mass ratio of water-soluble dietary fiber to insoluble dietary fiber is 1:2-1:3.

[0017] Furthermore, for the above-mentioned low-GI whole wheat yam poria cocos steamed bun with homologous medicine and food and high dietary fiber, the preparation of the raw soy milk includes soaking non-GMO soybeans in hot water at 80-85°C, and then performing three-stage wet grinding with a colloid mill, with the grinding particle size ≤ 10 μm and without high-temperature sterilization treatment.

[0018] Furthermore, for the above-mentioned low-GI whole wheat yam poria cocos steamed bun with homologous medicine and food and high dietary fiber, the surface of the steamed bun is covered with an anti-aging film layer composed of mulberry leaf high-fiber powder and β-cyclodextrin in a mass ratio of 1:0.2-0.6, the film layer thickness is 50-100 μm, and the moisture migration rate ≤ 0.15 g / (m 2 ·h).

[0019] The present invention also discloses a preparation method of the above-mentioned steamed bun, including the following steps:

[0020] (1) Pretreatment: Pre-gelatinize whole wheat flour, vital gluten, and resistant starch at 40-45°C for 30-40 min;

[0021] (2) Kneading: Mix the pre-treated powder with potable water at 25 - 30°C, and sequentially add raw soy milk, non-genetically modified soybean oil, Chinese yam powder, Poria cocos powder, yellow rice flour, and millet flour, and stir at a speed of 60 - 80 r / min for 8 - 10 min to form a basic dough;

[0022] (3) Microflora activation: Mix food processing yeast and compound lactic acid bacteria powder at a mass ratio of 1:0.8 - 1.2, and activate them in stages at 28°C → 32°C → 36°C using the gradient heating method, with a total activation time of 45 - 60 min;

[0023] (4) Fermentation: Add the activated microflora, fructooligosaccharide, and concentrated Momordica grosvenori juice to the basic dough, and carry out two-stage fermentation in an environment at 35 ± 1°C and relative humidity of 75 - 80%. After the first-stage fermentation for 40 - 50 min, turn the dough over and continue the second-stage fermentation for 20 - 30 min;

[0024] (5) Molding and proofing: After dividing and molding the fermented dough, place it in an atomized environment containing mulberry leaf high-fiber powder for proofing, with a proofing temperature of 38 - 40°C and a time of 15 - 20 min;

[0025] (6) Steaming: Adopt segmented steam heating. First, steam at 100°C for 5 - 8 min, then cool down to 90 - 95°C and continue steaming for 12 - 15 min. After taking out of the steamer, quickly cool it to below 25°C.

[0026] Further, in the above method for preparing steamed buns, the atomized liquid in the atomized environment in step (5) is a suspension prepared by mixing mulberry leaf high-fiber powder and β-cyclodextrin at a mass ratio of 1:0.3 - 0.5, and the atomization particle size is controlled at 5 - 10 μm.

[0027] Further, in the above method for preparing steamed buns, the rapid cooling treatment in step (6) adopts three-stage gradient cooling. In the first stage, cool down to 60 - 65°C within 5 min, in the second stage, cool down to 40 - 45°C within 5 min, and in the third stage, naturally cool to room temperature.

[0028] Further, in the above method for preparing steamed buns, after the steaming in step (6) is completed, use pulsed intense light combined with ozone to carry out non-thermal sterilization treatment on the finished product, with a light intensity of 3 - 5 J / cm 2 , an ozone concentration of 8 - 12 mg / m 3 , and a treatment time of 30 - 60 s, so that the total number of colonies ≤ 100 CFU / g.

[0029] The present invention also discloses the application of the above-mentioned steamed buns in the preparation of foods for adjuvant treatment of diabetes. The daily substitution amount of the steamed buns as the staple food does not exceed 300 g, and in combination with insulin treatment, it can reduce the postprandial 2-hour blood glucose fluctuation range by 40 - 60%.

[0030] The present invention also discloses a quality detection method for the above-mentioned steamed buns, including:

[0031] (a) Measuring the eGI value using an in vitro digestion model, and controlling eGI ≤ 55;

[0032] (b) Observing the starch-dietary fiber composite structure through a laser confocal microscope, with the requirement that the composite index ≥ 85%;

[0033] (c) Detecting the viable count of lactic acid bacteria using the qPCR method, with the requirement that the viable count ≥ 1 × 10^6 CFU / g during the storage period.

[0034] Compared with the existing technology, the present invention has the following advantages and beneficial effects:

[0035] Through the synergistic effect of the medicine-food homologous formula and the innovative process, the present invention achieves a multi-functional breakthrough for low-GI steamed buns. In terms of the formula: compounding Chinese yam powder (invigorating the spleen), Poria cocos powder (promoting diuresis) and β-cyclodextrin-embedded mulberry leaf high-fiber powder (dietary fiber ≥ 60%), combining resistant starch (amylose ≥ 65%) and fructooligosaccharide (prebiotic), forming a golden ratio of total dietary fiber of 12-18 wt% and water-soluble / insoluble fiber of 1:2-1:3, significantly delaying starch digestion (HI = 42.1%, eGI = 52.3). In terms of the process: gradient activation and compounding of lactic acid bacteria (viable count ≥ 1 × 10^10 CFU / g) and two-stage fermentation technology, enhancing the activity of probiotics (viable count ≥ 1 × 10^6 CFU / g after 14 days of storage), degrading anti-nutritional factors and improving the dough structure (specific volume increased by 25%); atomizing and proofing the mulberry leaf high-fiber powder to form an anti-aging film layer (water migration rate ≤ 0.15 g / (m 2 ·h)), combined with segmented steaming and rapid cooling processes, inhibiting starch retrogradation (hardness only increased by 15.2 N). Function verification: Clinical studies have shown that consuming 300 g per day can reduce the postprandial blood glucose fluctuation of diabetic patients by 54.3% (P < 0.01) and reduce insulin dependence; the non-thermal sterilization technology (total colony count ≤ 100 CFU / g) retains active ingredients while ensuring safety. The present invention has the advantages of precise blood sugar control, balanced nutrition, excellent taste, etc., providing a scientific staple food solution for the prevention and control of chronic diseases. Brief Description of the Drawings

[0036] Figure 1 Comparison chart of eGI values of steamed buns in the examples and comparative examples;

[0037] Figure 2 Comparison chart of the compliance index (%) of steamed buns in the examples and comparative examples;

[0038] Figure 3 Comparison of the water migration rate (m 2 ·h) of steamed buns in the examples and comparative examples. Detailed Description of the Invention

[0039] To make the objectives, technical solutions and advantages of the present invention clearer and more explicit, the present invention will be further described in detail below. However, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the scope of the present invention. In addition, in the following description, the descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention. All raw materials in the embodiments of the present invention can be obtained through commercial channels.

[0040] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0041] Table 1 and Table 2 disclose the raw materials and instruments and equipment of the present invention.

[0042] Table 1 Raw Material Table

[0043]

[0044]

[0045] Table 2 Instruments and Equipment Table

[0046]

[0047]

[0048] Example 1

[0049] Raw material formula:

[0050] 35 parts of whole wheat flour, 25 parts of domestic drinking water, 8 parts of raw soy milk, 6 parts of vital gluten, 4 parts of resistant starch (66% amylose), 3 parts of non-genetically modified soybean oil, 3 parts of Chinese yam powder, 1 part of Poria cocos powder, 1 part of buckwheat flour, 1 part of millet flour, 0.5 part of fructooligosaccharide, 0.5 part of yeast, 0.2 part of concentrated Momordica grosvenori juice, 0.2 part of mulberry high-fiber powder (61% dietary fiber), 0.05 part of compound lactic acid bacteria powder (viable count 1.0×10^10 CFU / g).

[0051] Preparation process:

[0052] (1) Pretreatment: Whole wheat flour, vital gluten, and resistant starch are pre-gelatinized at 40°C for 30 minutes;

[0053] (2) Dough making: The pre-treated powder is mixed with water at 25°C, and raw soy milk (wet-milled to a particle size of 10 μm through three stages), soybean oil, Chinese yam powder, etc. are added in sequence, and stirred at 60 r / min for 8 minutes;

[0054] (3) Flora activation: Yeast and compound lactic acid bacteria are mixed at a ratio of 1:0.8 and activated by gradient heating (maintained at 28°C for 15 min → maintained at 32°C for 20 min → maintained at 36°C for 10 min, total duration 45 min);

[0055] (4) Fermentation: In an environment of 35°C and relative humidity of 75%, turn over after the first-stage fermentation for 40 min, and the second-stage fermentation for 20 min;

[0056] (5) Proofing: The atomization environment uses a suspension of mulberry leaf high-fiber powder and β-cyclodextrin at a ratio of 1:0.3 (atomization particle size 10 μm), proofing temperature 38°C, time 15 min;

[0057] (6) Steaming and rapid cooling: Steam at 100°C for 5 min → cool down to 90°C and steam for 15 min, three-stage rapid cooling (cool down to 60°C within the first stage of 5 min, cool down to 40°C within the second stage of 5 min, and natural cooling in the third stage).

[0058] Finished product characteristics:

[0059] Total dietary fiber content 12.3 wt% (water-soluble: insoluble = 1:2);

[0060] Thickness of surface anti-aging film layer 50 μm (moisture migration rate 0.15 g / (m 2 ·h));

[0061] Viable count 1.2×10^6 CFU / g (stored for 7 days).

[0062] Example 2

[0063] Raw material formula:

[0064] Whole wheat flour 40 parts, domestic drinking water 30 parts, raw soy milk 12 parts, vital wheat gluten 8 parts, resistant starch 6 parts (amylose 70%), non-genetically modified soybean oil 5 parts, Chinese yam powder 5 parts, Poria cocos powder 2 parts, yellow rice flour 2 parts, millet flour 2 parts, fructooligosaccharide 1 part, yeast 0.8 part, concentrated Momordica grosvenori juice 0.5 part, mulberry leaf high-fiber powder 0.5 part (dietary fiber 65%), compound lactic acid bacteria powder 0.15 part (viable count 1.5×10^10 CFU / g).

[0065] Preparation process:

[0066] (1) Pretreatment: Whole wheat flour, vital wheat gluten, and resistant starch are pre-gelatinized at 45°C for 40 min;

[0067] (2) Dough mixing: The pretreated powder is mixed with water at 30°C, and raw soy milk (grinding particle size 6 μm), soybean oil, Chinese yam powder, etc. are added in sequence, and stirred at 80 r / min for 10 min;

[0068] (3) Flora activation: Yeast and compound lactic acid bacteria are mixed at a ratio of 1:1.2 and activated by gradient heating (maintained at 28°C for 20 min → maintained at 32°C for 25 min → maintained at 36°C for 15 min, total duration 60 min);

[0069] (4) Fermentation: In an environment of 36°C and relative humidity of 80%, turn over after the first-stage fermentation for 50 min, and the second-stage fermentation for 30 min;

[0070] (5) Proofing: Atomized liquid mulberry leaf high-fiber powder: β-cyclodextrin = 1:0.5 (atomization particle size 5 μm), proofing temperature 40°C, time 20 min;

[0071] (6) Steaming and rapid cooling: Steam at 100°C for 8 min → steam at 95°C for 12 min, three-stage rapid cooling (5 min → 65°C → 5 min → 45°C → natural cooling).

[0072] Finished product characteristics:

[0073] Total dietary fiber content 17.8 wt% (water-soluble: insoluble = 1:3);

[0074] Surface anti-aging film layer thickness 100 μm (water migration rate 0.10 g / (m 2 ·h));

[0075] Viable count 2.0×10^6 CFU / g (stored for 7 days).

[0076] Example 3

[0077] Raw material formula:

[0078] Whole wheat flour 38 parts, domestic drinking water 28 parts, raw soy milk 10 parts, vital gluten 7 parts, resistant starch 5 parts (amylose 68%), non-genetically modified soybean oil 4 parts, Chinese yam powder 4 parts, Poria cocos powder 1.5 parts, yellow rice flour 1.5 parts, millet flour 1.5 parts, fructooligosaccharide 0.8 part, yeast 0.6 part, concentrated Momordica grosvenori juice 0.3 part, mulberry leaf high-fiber powder 0.4 part (dietary fiber 63%), compound lactic acid bacteria powder 0.1 part (viable count 1.2×10^10 CFU / g).

[0079] Preparation process: The same as Example 1, only adjusting the fermentation humidity to 78% and the proofing time to 18 min.

[0080] Finished product characteristics:

[0081] Total dietary fiber content 15.1 wt% (water-soluble: insoluble = 1:2.5);

[0082] Film layer thickness 75 μm (water migration rate 0.12 g / (m 2 ·h));

[0083] The eGI value is 52.3 (determined by in vitro digestion method).

[0084] Example 4

[0085] Verification of the proportion of the anti-aging film layer

[0086] Adjustment items:

[0087] The atomized liquid is prepared with mulberry leaf high-fiber powder and β-cyclodextrin at a ratio of 1:0.2 (lower limit) and 1:0.6 (upper limit), and the film layer thicknesses are 50 μm and 100 μm respectively.

[0088] Results:

[0089] The moisture migration rate of the 1:0.2 group is 0.14 g / (m 2 ·h);

[0090] The moisture migration rate of the 1:0.6 group is 0.09 g / (m 2 ·h);

[0091] Film layer uniformity: The surface of the 1:0.6 group has no cracks, and the 1:0.2 group has slight granularity.

[0092] Example 5

[0093] Verification of non-thermal sterilization parameters

[0094] Post-treatment process:

[0095] Treatment with pulsed intense light combined with ozone, parameter combination:

[0096] Lower limit: Light intensity 3 J / cm 2 、Ozone 8 mg / m 3 、Time 30 s;

[0097] Upper limit: Light intensity 5 J / cm 2 、Ozone 12 mg / m 3 、Time 60 s.

[0098] Results:

[0099] The total number of colonies is 95 CFU / g (lower limit) and 75 CFU / g (upper limit) respectively;

[0100] The viable count of lactic acid bacteria is ≥1×10^6 CFU / g.

[0101] Example 6

[0102] Verification of the three-stage rapid cooling gradient

[0103] Adjustment of rapid cooling parameters:

[0104] The first stage cools down to 60 °C (Example 1) vs 65 °C (Example 2);

[0105] The second-stage temperature is reduced to 40 °C (Example 1) vs 45 °C (Example 2).

[0106] Results:

[0107] For the 60 °C → 40 °C group: the shrinkage rate of the bun center is 2.1%;

[0108] For the 65 °C → 45 °C group: the shrinkage rate is 1.8% and the texture is more uniform.

[0109] Comparative Example 1

[0110] Missing compound lactic acid bacteria

[0111] Adjustment item: Only 0.6 parts of yeast are used, and compound lactic acid bacteria powder is not added.

[0112] Results:

[0113] The viable count ≤ 1 × 10^4 CFU / g;

[0114] The dough fermentation volume is reduced by 18%;

[0115] The eGI value is 61.4 (compared with 52.3 in Example 3)

[0116] Comparative Example 2

[0117] No pre-gelatinization treatment

[0118] Adjustment item: Skip step (1) pre-gelatinization treatment.

[0119] Results:

[0120] The starch hydrolysis index increases to 61.3% (42.1% in Example 3);

[0121] The specific volume of the bun is reduced by 22% and the taste is hard.

[0122] Comparative Example 3

[0123] Replaced with ordinary mulberry leaf powder

[0124] Adjustment item: Use unembedded mulberry leaf powder (dietary fiber 50%).

[0125] Results:

[0126] The starch-dietary fiber composite index is 71.5% (89.2% in Example 3).

[0127] The moisture migration rate is 0.28 g / (m 2 ·h) (compared with 0.12 in Example 3).

[0128] Comparative Example 4

[0129] Adjustment item: Cancel two-stage fermentation and only perform single fermentation for 70 min.

[0130] Result:

[0131] The pore distribution inside the dough is uneven, and the specific volume difference reaches 25%;

[0132] eGI value is 56.9 (52.3 for Example 3)

[0133] Test Example 1

[0134] In vitro digestion and eGI determination

[0135] Method:

[0136] Simulate oral-stomach-small intestine digestion according to the Englyst method, using pancreatic enzyme (Sigma-Aldrich, 8×USP) and amyloglucosidase;

[0137] Take samples every 20 min to measure the reducing sugar content and calculate the hydrolysis rate (%);

[0138] According to the empirical formula eGI = 29.2 + 0.549×HI (HI is the hydrolysis index at 120 min).

[0139] The results are shown in Table 3.

[0140] Table 3 In vitro digestion and eGI determination

[0141] Group HI(%) eGI Example 3 42.1 52.3 Comparative Example 1 58.7 61.4 Comparative Example 2 61.3 62.8

[0142] It can be seen from the data in Table 3 that the starch hydrolysis index (HI) of Example 3 is 42.1%, significantly lower than that of Comparative Example 1 (58.7%) and Comparative Example 2 (61.3%), indicating that the compound lactic acid bacteria (degrading phytic acid and promoting slow release of starch) and pregelatinization treatment (forming resistant structure) synergistically reduce the starch digestion rate. Through independent sample t-test analysis, the differences in HI between Example 3 and Comparative Examples 1 and 2 are all statistically significant (t = 6.24, P < 0.01; t = 7.18, P < 0.01). The eGI value of 52.3 meets the low-GI food standard (≤55), while Comparative Example 1 (61.4) still belongs to medium-GI food (55 - 70). The data prove the key role of the compound microbial community and pregelatinization process in blood sugar control effect.

[0143] Test Example 2

[0144] Starch-dietary fiber composite structure

[0145] Method:

[0146] Stain the sample sections using a laser confocal microscope (Leica TCS SP8):

[0147] Starch: FITC-labeled (green);

[0148] Dietary fiber: Rhodamine B-labeled (red);

[0149] Calculate the composite index = area of the overlapping region / total starch area × 100%.

[0150] The results are shown in Table 4.

[0151] Table 4 Starch-dietary fiber composite structure

[0152] Group Composite Index(%) Example 3 89.2 Comparative Example 3 71.5

[0153] As can be seen from the data in Table 4, the composite index of Example 3 is 89.2%, significantly higher than 71.5% of Comparative Example 3 (F = 42.6, P < 0.001). After β-cyclodextrin encapsulation of mulberry leaf high-fiber powder, its dietary fiber and starch form a dense network structure, effectively hindering the contact of amylase (the enzyme activity is reduced by 38%), while the composite index of ordinary mulberry leaf powder is only 71.5% due to uneven fiber dispersion. For every 10% increase in the composite index, the starch hydrolysis rate can be reduced by about 15% (linear regression R 2 = 0.89).

[0154] Test Example 3

[0155] Viable cell count stability

[0156] Method:

[0157] The qPCR method (primers: Lactobacillus spp. 16S rRNA gene) was used to detect the viable cell count during storage;

[0158] Storage conditions: 25°C, humidity 60%, and the data on days 0, 7, and 14 were detected.

[0159] The results are shown in Table 5.

[0160] Table 5 Viable cell count stability test

[0161]

[0162] As can be seen from the data in Table 5, the viable cell count of Example 3 remained at 1.1×10^6 CFU / g after 14 days of storage, while the viable cell count of Comparative Example 1 (without compounded lactic acid bacteria) dropped sharply from 1.0×10^4 CFU / g to ≤1×10^2 CFU / g (ANOVA, F = 35.2, P < 0.05). The compounded lactic acid bacteria (Lactobacillus acidophilus + Bifidobacterium) inhibit the growth of miscellaneous bacteria by producing acid, and β-cyclodextrin encapsulation protects the activity of the bacteria, and the viable cell survival rate is increased by 200 times compared with single yeast fermentation.

[0163] Test Example 4

[0164] Postprandial blood glucose in diabetic patients

[0165] Method:

[0166] Double-blind randomized controlled trial: 60 patients with type II diabetes were divided into an experimental group (300 g of the steamed bun of Example 3 per day) and a control group (ordinary steamed bun);

[0167] Continuous intervention for 4 weeks, and the postprandial 2-h blood glucose fluctuation amplitude (ΔBG = peak - baseline) was monitored.

[0168] The results are shown in Table 6.

[0169] Table 6 Postprandial blood glucose in diabetic patients

[0170] Group ΔBG(mmol / L) Decrease Rate(%) Experimental Group 2.1±0.3 54.3％ Control Group 4.6±0.5 -

[0171] As can be seen from Table 6, the postprandial 2-h blood glucose fluctuation amplitude ΔBG of the experimental group (the steamed bun of Example 3) was 2.1 ± 0.3 mmol / L, which was 54.3% lower than that of the control group (ordinary steamed bun, ΔBG = 4.6 ± 0.5) (t = 9.87, P < 0.01). According to the linear regression model, for every 10-unit decrease in eGI, the decrease in ΔBG increased by about 12%

[0172] (R 2 = 0.76). In addition, the insulin dosage of the patients in the experimental group decreased by 18% (P < 0.05), indicating that long-term consumption can improve insulin sensitivity.

[0173] Test Example 5

[0174] Performance of the anti-aging film layer

[0175] Method:

[0176] Use a water migration rate detector (TOLEDO MX5) to detect the water migration rate of the film layer;

[0177] Accelerated aging test: Store at 40 °C and 75% humidity for 24 h, and measure the change in hardness (TA.XT Plus texture analyzer).

[0178] The results are shown in Table 7.

[0179] Table 7 Performance of the anti-aging film layer

[0180] Group <![CDATA[Water migration rate (g / (m 2 ·h))]]> Increase in Hardness(N) Example 3 0.12 15.2 Comparative Example 3 0.28 32.7

[0181] As can be seen from the data in Table 7, the water migration rate of Example 3 was 0.12 g / (m 2 ·h), which was significantly lower than 0.28 g / (m 2·h) (F = 58.3, P < 0.001). β-cyclodextrin locks moisture through its hydrophobic cavity, and the increase in film hardness is only 15.2 N (32.7 N for Comparative Example 3). The moisture migration rate is strongly positively correlated with the change in hardness (Pearson r = 0.92, P < 0.001), proving that the film can effectively inhibit starch recrystallization and delay aging.

[0182] Summary of Test Examples

[0183] Table 8 Summary of Test Examples

[0184] Test Index Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 eGI Value 52.3 61.4 62.8 55.6 56.9 Composite Index(%) 89.2 84.1 76.3 71.5 80.4 Number of Viable Bacteria(CFU / g) <![CDATA[1.8×10 6 > <![CDATA[1.0×10 4 > <![CDATA[1.2×10 6 > <![CDATA[1.5×10 6 > <![CDATA[1.6×10 6 > <![CDATA[Water migration rate (g / (m 2 ·h))]]> 0.12 0.18 0.22 0.28 0.20

[0185] From Figures 1 - 3 , and from the data of the above test examples, it can be seen that the present invention has the following advantages:

[0186] 1. The compound formula of medicine and food homologous ingredients works synergistically to achieve dual breakthroughs in nutrition and function

[0187] (1) Precise compatibility improves blood sugar control effect: Through the compounding of Chinese yam powder (invigorating the spleen), Poria cocos powder (promoting diuresis), and mulberry leaf high-fiber powder (lowering blood sugar), combined with Siraitia grosvenorii concentrated juice (natural sweetener) and fructooligosaccharide (prebiotic), a multi-target blood sugar regulation system is formed. After the mulberry leaf high-fiber powder is embedded with β-cyclodextrin, the dietary fiber content is ≥ 60%, and it synergistically delays starch digestion with resistant starch (amylose ≥ 65%). The in vitro digestion test of Example 3 shows that the starch hydrolysis index is only 42%, and the eGI value is 52.3, which is significantly lower than that of ordinary steamed buns (eGI = 88) and Comparative Example 1 (eGI = 61.4).

[0188] (2) Scientific optimization of the dietary fiber ratio: The water-soluble dietary fiber (such as fructooligosaccharide, β-glucan) and insoluble fiber (such as cellulose, lignin) in the raw materials are compounded in a ratio of 1:2 - 1:3, which not only promotes intestinal peristalsis but also delays the absorption of glucose by adsorbing it with water-soluble fiber. The total dietary fiber content in Examples 1 - 3 is 12.3 - 17.8 wt%, and the clinical test (Test Example 4) shows that the reduction in postprandial blood sugar fluctuation of patients reaches 54.3%

[0189] (P < 0.01).

[0190] 2. The innovative fermentation process improves nutrient utilization rate and probiotic activity

[0191] (1) Co-fermentation of compound microbial communities: Lactobacillus acidophilus, Lactobacillus plantarum and Bifidobacterium (total viable count ≥ 1×10^10 CFU / g) are co-fermented with yeast, and are activated in a stepwise gradient manner (28°C → 32°C → 36°C), significantly enhancing the metabolic activity of the microbial communities. In Example 3, the viable count reaches 1.8×10^6 CFU / g (after storage for 14 days), while in Comparative Example 1 (single yeast), the viable count is only 1×10^4 CFU / g. The metabolism of the microbial communities can degrade anti-nutritional factors such as phytic acid, release minerals (such as iron and zinc), and improve the nutrient absorption rate.

[0192] (2) Two-stage fermentation to regulate the dough structure: In the first stage of fermentation (40 - 50 min), uniform pores are formed, and in the second stage of fermentation (20 - 30 min) after turning over, the gluten network is strengthened. Compared with Comparative Example 4 (single fermentation for 70 min), the specific volume of the steamed buns in Example 3 is increased by 25%, the texture is soft, and the resilience is increased by 18%.

[0193] 3. Physical modification technology to improve product texture and stability

[0194] (1) Pre-gelatinization treatment of resistant starch: Pre-gelatinization at 40 - 45°C partially crystallizes the starch, forming an anti-digestible structure. The starch hydrolysis index of Comparative Example 2 (without pre-gelatinization) reaches 61%, which is significantly higher than 42% of Example 3 (P < 0.01).

[0195] (2) Atomized embedding of anti-aging film layer: Mulberry leaf high-fiber powder and β-cyclodextrin (1:0.2 - 0.6) are atomized and proofed to form a 50 - 100 μm film layer, inhibiting water migration (the water migration rate in Example 3 is 0.12 g / (m 2 ·h) vs 0.28 of Comparative Example 3). Laser confocal microscopy analysis (Test Example 2) shows that the composite index reaches 89.2%, effectively delaying starch recrystallization, and the increase in hardness at room temperature is only 15.2 N (32.7 N for Comparative Example 3).

[0196] 4. Non-thermal sterilization process to ensure safety and retain active ingredients

[0197] Pulsed intense light (3 - 5 J / cm 2 ) combined with ozone (8 - 12 mg / m 3 ) are used to treat for 30 - 60 s, making the total colony count ≤ 100 CFU / g, and at the same time maintaining the viable count of lactic acid bacteria ≥ 1×10^6 CFU / g (Example 5). Traditional high-temperature sterilization will destroy the activity of probiotics, while the process of the present invention retains the functional ingredients on the premise of ensuring hygienic safety.

[0198] 5. Define clinical value and quality control standards

[0199] (1) Application in adjuvant treatment of diabetes: Through the double-blind test of 60 patients (Test Example 4), it is confirmed that eating 300 g per day can reduce the postprandial blood glucose fluctuation by 52.7% and reduce the insulin dosage by 18% (P<0.05).

[0200] (2) Strict quality inspection system: Adopt triple standards of in vitro digestion model (eGI≤55), laser confocal microscopy analysis (composite index≥85%), and qPCR viable bacteria detection (≥1×10^6CFU / g) to ensure product consistency.

[0201] In summary, through formula design, process innovation and function verification, the present invention solves the problems of single function, poor taste and short shelf life of traditional low-GI steamed buns, and provides a scientific and reliable staple food choice for chronic disease patients and healthy people.

[0202] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. Therefore, based on the innovative concept of the present invention, any changes and modifications made to the embodiments described herein, or equivalent structural or equivalent process transformations made using the content of the specification of the present invention, and directly or indirectly applying the above technical solutions to other related technical fields, are all included in the protection scope of the present invention patent.

Claims

1. A low-GI whole wheat yam poria cocos bun with homologous medicine and food and high dietary fiber and its preparation method, characterized in that It is made from the following raw materials in parts by weight: 35 - 40 parts of whole wheat flour, 25 - 30 parts of domestic drinking water, 8 - 12 parts of raw soy milk, 6 - 8 parts of wheat gluten, 4 - 6 parts of resistant starch, 3 - 5 parts of non - genetically modified soybean oil, 3 - 5 parts of Chinese yam powder, 1 - 2 parts of Poria cocos powder, 1 - 2 parts of yellow millet flour, 0.5 - 1 part of fructooligosaccharide, 0.5 - 0.8 part of yeast for food processing, 0.2 - 0.5 part of concentrated Momordica grosvenori juice, 0.2 - 0.5 part of high - fiber mulberry leaf powder, 0.05 - 0.15 part of compound lactic acid bacteria powder for food processing; The compound lactic acid bacteria powder for food processing contains Lactobacillus acidophilus, Lactobacillus plantarum and Bifidobacterium, and the total viable count ≥ 1×10^10 CFU / g; The resistant starch is corn resistant starch treated by physical modification, and the amylose content ≥ 65%; The high - fiber mulberry leaf powder is a product obtained by embedding ultrafine - ground mulberry leaf powder with β - cyclodextrin, and the dietary fiber content ≥ 60%.

2. The steamed bun according to claim 1, characterized in that: The total dietary fiber content in the raw materials is 12 - 18 wt%, and the mass ratio of water - soluble dietary fiber to insoluble dietary fiber is 1:2 - 1:

3.

3. The steamed bun according to claim 1, characterized in that: The preparation of the raw soy milk includes soaking non - genetically modified soybeans in hot water at 80 - 85°C, and then performing three - stage wet grinding with a colloid mill, with the grinding particle size ≤ 10 μm and without high - temperature sterilization treatment.

4. The steamed bun according to claim 1, characterized in that: The surface of the steamed bun is covered with an anti-aging film layer composed of mulberry leaf high-fiber powder and β-cyclodextrin in a mass ratio of 1:0.2-0.6, the thickness of the film layer is 50-100 μm, and the moisture migration rate ≤ 0.15 g / (m 2 ·h).

5. A method for preparing a steamed bun according to any one of claims 1-3, characterized in that It includes the following steps: (1) Pretreatment: Pre - gelatinize the whole wheat flour, wheat gluten and resistant starch at 40 - 45°C for 30 - 40 min; (2) Dough - making: Mix the pretreated powder with domestic drinking water at 25 - 30°C, and sequentially add raw soy milk, non - genetically modified soybean oil, Chinese yam powder, Poria cocos powder, yellow millet flour, and stir at a speed of 60 - 80 r / min for 8 - 10 min to form a basic dough; (3) Microbial activation: Mix the yeast for food processing and the compound lactic acid bacteria powder according to a mass ratio of 1:0.8 - 1.2, and activate them in stages at 28°C → 32°C → 36°C using the gradient temperature - rising method, with the total activation time of 45 - 60 min; (4) Fermentation: Add the activated microbial population, fructooligosaccharide and concentrated Momordica grosvenori juice to the basic dough, and perform two - stage fermentation in an environment at 35 ± 1°C and relative humidity of 75 - 80%. After the first - stage fermentation for 40 - 50 min, turn it over and continue the second - stage fermentation for 20 - 30 min; (5) Molding and proofing: After dividing and molding the fermented dough, place it in an atomized environment containing high - fiber mulberry leaf powder for proofing, with the proofing temperature of 38 - 40°C and time of 15 - 20 min; (6) Steaming: Use segmented steam heating. First, steam at 100°C for 5 - 8 min, then cool down to 90 - 95°C and continue steaming for 12 - 15 min. After taking it out of the cage, quickly cool it to below 25°C.

6. The preparation method according to claim 5, characterized in that: The atomized liquid in the atomized environment in step (5) is a suspension prepared by mixing high - fiber mulberry leaf powder and β - cyclodextrin according to a mass ratio of 1:0.3 - 0.5, and the atomized particle size is controlled at 5 - 10 μm.

7. The preparation method according to claim 5, characterized in that: The rapid cooling treatment described in step (6) adopts a three-stage gradient cooling. In the first stage, the temperature is cooled to 60 - 65 °C within 5 minutes. In the second stage, the temperature is cooled to 40 - 45 °C within 5 minutes. In the third stage, it is naturally cooled to room temperature.

8. The preparation method according to claim 5, characterized in that: After the steaming in step (6) is completed, pulsed intense light combined with ozone is used for non-thermal sterilization treatment of the finished product, with the light intensity of 3 - 5 J / cm 2 , the ozone concentration of 8 - 12 mg / m 3 , and the treatment time of 30 - 60 s, so that the total number of colonies ≤ 100 CFU / g.

9. Use of the steamed bun according to any one of claims 1-4 in the preparation of a food for adjuvant treatment of diabetes, characterized in that: The daily substitution amount of the steamed buns as the staple food does not exceed 300 g, and combined with insulin treatment, it can reduce the blood glucose fluctuation range by 40 - 60% two hours after meals.

10. The quality inspection method for the steamed bun according to any one of claims 1-4, characterized in that, It includes the following steps: (a) Use an in vitro digestion model to measure the eGI value, and control eGI ≤ 55; (b) Observe the starch-dietary fiber composite structure through a laser confocal microscope, and require the composite index ≥ 85%; (c) Use the qPCR method to detect the viable count of lactic acid bacteria, and require the viable count ≥ 1×10^6 CFU / g during the storage period.

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