Slow-sugar-increasing whole-grain fermented steamed bun and processing technology thereof

Abstract

The invention relates to the technical field of food processing, and particularly discloses slow-sugar-increasing whole-grain fermented steamed buns and a processing technology. The whole-grain fermented steamed buns are mainly prepared from the following raw materials in parts by weight: 50-60 parts of wheat flour, 15-25 parts of rice flour, 5-15 parts of millet flour, 5-10 parts of mung bean flour, 5-10 parts of soybean flour, 0.5-1.5 parts of yeast, 1-2 parts of table salt, 0.5-1.5 parts of vital gluten, 0.4-0.6 part of sodium alginate, 0.4-0.6 part of a silybum marianum extract, 0.01-0.03 part of a natural preservative and 45-55 parts of water. The whole-grain fermented steamed bun not only has the characteristics of low GI value, slow sugar increase and rich nutrition, but also has the advantages of high specific volume, low hardness, good elasticity and good chewiness, meanwhile, the whole-grain fermented steamed bun is uniform in internal air holes, soft in texture, good in bulkiness, fast in elastic recovery and strong in chewiness, the taste and quality of the whole-grain fermented steamed bun are improved, and market requirements are met.

Description

Technical Field

[0001] The present application relates to the field of food processing technology, and more specifically, to a slow-glycemic whole-grain fermented steamed bread and a processing technology thereof. Background Art

[0002] With the improvement of people's living standards and the enhancement of health awareness, low-sugar and low-calorie foods are gradually favored by consumers. Among them, whole-grain fermented steamed bread is rich in dietary fiber, vitamins and other nutrients, has excellent nutritional value, and can also improve satiety, has a low GI value, reduces the rate of blood sugar increase, is beneficial to human health, and has been widely used and developed in the market. Whole-grain fermented steamed bread is generally made by mixing wheat flour or several other staple foods and additives in a certain proportion, then kneading into dough, and fermenting and steaming to obtain whole-grain fermented steamed bread. Common additives are generally water, salt, and yeast to improve flavor and texture. However, the existing whole-grain fermented steamed bread has a small specific volume, insufficient elasticity, and poor taste. Summary of the invention

[0003] In order to improve the specific volume and elasticity of whole-grain fermented steamed bread, the present application provides a slow-glycemic whole-grain fermented steamed bread and a processing technology.

[0004] In a first aspect, the present application provides a slow-glycemic whole-grain fermented steamed bread, which adopts the following technical solution: A slow-glycemic whole-grain fermented steamed bread, which is mainly made of the following raw materials in parts by weight: 50-60 parts of wheat flour, 15-25 parts of rice flour, 5-15 parts of millet flour, 5-10 parts of mung bean flour, 5-10 parts of soybean flour, 0.5-1.5 parts of yeast, 1-2 parts of salt, 0.5-1.5 parts of gluten powder, 0.4-0.6 parts of sodium alginate, 0.4-0.6 parts of milk thistle extract, 0.01-0.03 parts of natural preservatives, and 45-55 parts of water.

[0005] The whole grain fermented steamed bread of the present application, through the mutual cooperation between the raw materials, not only has a low GI value, GI value <70, and has the effect of slowly raising blood sugar. It is also rich in nutrition and meets the body's needs for nutrients. At the same time, the specific volume is greater than 3.1mL / g, the hardness is less than 1400g, the elasticity is greater than 0.9, and the chewiness is less than 1100g, so that the whole grain fermented steamed bread shows uniform internal pore distribution, soft texture, good fluffiness, fast elastic recovery, strong chewiness, improve the taste and quality of the whole grain fermented steamed bread, and meet market demand.

[0006] The raw materials of the whole-grain fermented steamed bread of the present application are based on wheat flour, and rice flour, millet flour, mung bean flour, and red bean flour are added, and after reasonable proportioning, the whole-grain fermented steamed bread is ensured to have excellent protein, minerals, vitamins, etc., to improve the nutritional content of the whole-grain fermented steamed bread and meet the health needs of the body. Gluten, alginic acid, and milk thistle extract are added to the raw materials, and through the interaction between them, the gluten strength is improved, the water retention is improved, the elasticity and ductility are increased, the air holding power is improved, the gluten network is ensured to be stable, and the taste and quality of the whole-grain fermented steamed bread are increased.

[0007] Optionally, the milk thistle extract is prepared by the following method: T1. Washing, drying and crushing the milk thistle fruit to obtain milk thistle fruit powder; T2. Mixing milk thistle fruit powder and ethanol aqueous solution at a temperature of 60-70° C., soaking for 4-6 hours, filtering, and obtaining an alcohol extraction filtrate and an alcohol extraction residue; T3, hot pressing and filtering the alcohol extraction residue to obtain hot pressing filtrate and hot pressing residue; T4. Mix the hot-pressed filter residue and water at a temperature of 80-90° C., soak for 4-6 hours, and filter to obtain a water-extracted filtrate and a water-extracted filter residue; T5, mixing the water extraction filtrate, the alcohol extraction filtrate, and the hot pressing filtrate to obtain an extraction filtrate; T6. Concentrate and dry the extraction filtrate to obtain milk thistle extract.

[0008] By adopting the above technical scheme, first the milk thistle fruit is crushed to obtain the milk thistle fruit powder, at this time, the particle size is effectively reduced, which is convenient for the extraction of subsequent effective ingredients. Then ethanol water is used for soaking, and the ethanol and water in the ethanol aqueous solution can not only promote the dissolution of organic and inorganic effective ingredients in the milk thistle fruit powder, but also the cells in the milk thistle fruit powder can penetrate into a small amount of ethanol and water to expand the cell volume. Afterwards, hot pressing is carried out, and during the hot pressing process, mechanical damage can be effectively caused to the cell wall, and the cell is ruptured to promote the dissolution of effective ingredients. Then water is used for soaking, and the dissolution of effective ingredients in the cell is further promoted. Afterwards, the water extraction filtrate, the alcohol extraction filtrate, and the hot pressing filtrate are merged, and concentrated, dried, and the milk thistle fruit extract is obtained. The preparation method of the present application is adopted, which is not only convenient for the preparation of the milk thistle fruit extract, but also greatly improves the extraction efficiency and extraction rate through the mutual coordination between each step, and increases the content and type of active ingredients in the milk thistle fruit extract, and strengthens the use effect of the milk thistle fruit extract.

[0009] Optionally, the weight ratio of the milk thistle fruit powder, the ethanol aqueous solution and water is 1:(6-8):(6-8), and the mass concentration of ethanol in the ethanol aqueous solution is 70-80%.

[0010] By adopting the above technical scheme, the weight ratio of milk thistle fruit powder, ethanol aqueous solution and water is optimized, so as to control the addition amount of ethanol aqueous solution and water. The mass concentration of ethanol aqueous solution is also optimized to ensure the extraction rate of ethanol and water to milk thistle fruit powder, and also ensure the stability of the preparation of milk thistle fruit extract.

[0011] Optionally, in step T3, the pressure of the hot pressing treatment is 13-15 MPa, the temperature is 120-140° C., and the time is 15-20 min.

[0012] By adopting the above technical solution, the pressure, temperature and time of the hot pressing treatment are limited, which facilitates the hot pressing of the alcohol extraction residue.

[0013] Optionally, in step T6, the concentration treatment temperature is 60-80°C, and the concentration is to 1 / 10-1 / 5 of the volume of the extraction filtrate. In multiple embodiments, the concentration treatment temperature is 70°C, and the concentration is to 1 / 18 of the volume of the extraction filtrate. The temperature can also be set to 60°C, 65°C, 75°C, 80°C as needed, and it can also be concentrated to 1 / 10, 1 / 9, 1 / 7, 1 / 6, 1 / 5 of the volume of the extract as needed, but it is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0014] Optionally, in step T6, the end point of drying is drying to constant weight.

[0015] Optionally, the milk thistle fruit powder has an average particle size of 30-200 μm and a water content of 6-10 wt %.

[0016] By adopting the above technical solution, the average particle size and water content of milk thistle fruit powder are optimized to ensure the stability of milk thistle fruit powder, thereby ensuring the stability of the content of active ingredients in milk thistle extract and the use effect. In multiple embodiments, the average particle size of milk thistle fruit powder is 50 μm and the water content is 8 wt%. The average particle size can also be set to 30 μm, 40 μm, 80 μm, 100 μm, 120 μm, 150 μm, 180 μm, 200 μm as needed, and the water content can also be set to 6 wt%, 7 wt%, 9 wt%, 10 wt% as needed, but it is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0017] Optionally, the natural preservative is one or more of citric acid, tea polyphenols, and chitosan.

[0018] By adopting the above technical solution, natural preservatives are optimized, which facilitates the selection of natural preservatives. Moreover, natural preservatives can effectively increase the storage time and extend the shelf life without affecting the taste of whole grain fermented steamed bread.

[0019] Optionally, the water content of wheat flour, rice flour, millet flour, mung bean flour and soybean flour is ≤15wt%.

[0020] In a second aspect, the present application provides a processing technology for the slow-glycemic whole-grain fermented steamed bread, which adopts the following technical solution: A processing technology of the slow-glycemic whole-grain fermented steamed bread comprises the following steps: S1. Mixing yeast and part of water to obtain a yeast solution; S2, mixing wheat flour, rice flour, millet flour, mung bean flour and soybean flour to obtain a premix; S3, mixing the premix, salt, gluten, sodium alginate, milk thistle extract, and natural preservative, adding the remaining water and yeast solution, mixing, and kneading into dough to obtain raw dough; S4, fermenting the dough once, dividing it, rolling it into balls, shaping it, and then fermenting it twice to obtain fermented dough; S5. Steaming the fermented dough to obtain whole-grain fermented steamed bread.

[0021] By adopting the above technical scheme, not only is the preparation of whole-grain fermented steamed bread convenient, but also the yeast is dispersed in water in advance and the yeast solution is added, which effectively increases the uniformity of the mixture, ensures the uniformity of the yeast in the raw dough, and increases the uniformity of the internal pores, so that the texture of the whole-grain fermented steamed bread is uniform, and the taste and quality are improved.

[0022] Optionally, the weight ratio of the partial water and the remaining water is (3-5):(5-7).

[0023] By adopting the above technical solution, the weight ratio of part of the water and the remaining water is optimized, which not only facilitates the preparation of the yeast solution, but also ensures that the yeast is fully dispersed in the water, and also ensures the activity and use effect of the yeast. In multiple implementation schemes, the weight ratio of part of the water and the remaining water is 4:6, and the weight ratio can also be set to 3:7, 5:5 as needed, but it is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable.

[0024] Optionally, in step S4, the temperature of the first fermentation is 35-40°C, the humidity is 80-90%, and the time is 80-100 min, and the temperature of the second fermentation is 35-40°C, the humidity is 60-70%, and the time is 20-40 min.

[0025] By adopting the above technical scheme, the temperature, humidity and time of the first fermentation, as well as the temperature, humidity and time of the second fermentation are optimized, which not only facilitates the fermentation of the dough, but also effectively activates the yeast activity, fully converts the starch in the raw materials, and ensures the taste and quality of the whole grain fermented steamed buns.

[0026] In multiple embodiments, in step S4, the temperature of a fermentation is 37°C, the humidity is 85%, and the time is 90 min. The temperature can be set to 35°C, 36°C, 38°C, 39°C, or 40°C as needed. The humidity can also be set to 80%, 83%, 88%, or 90% as needed. The time can also be set to 80 min, 85 min, 95 min, or 100 min as needed, but it is not limited to the listed values, and other values ​​not listed within the numerical range are equally applicable.

[0027] In multiple embodiments, in step S4, the temperature of the secondary fermentation is 37°C, the humidity is 65%, and the time is 30 min. The temperature can be set to 35°C, 36°C, 38°C, 39°C, or 40°C as needed. The humidity can also be set to 60%, 63%, 68%, or 70% as needed. The time can also be set to 20 min, 25 min, 35 min, or 40 min as needed, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are equally applicable.

[0028] Optionally, in step S5, the steaming temperature is 95-105° C. and the steaming time is 10-30 min.

[0029] By adopting the above technical solution, the steaming temperature and time are optimized to fully mature the fermented dough and ensure the taste and nutritional value of the whole grain fermented steamed bread. In multiple embodiments, the steaming temperature is 100°C and the time is 20 minutes. The temperature can also be set to 95°C, 98°C, 103°C, 105°C as needed. The time can also be set to 10 minutes, 15 minutes, 25 minutes, 30 minutes as needed, but it is not limited to the listed values. Other values ​​not listed in the numerical range are also applicable.

[0030] Optionally, the weight of each whole grain fermented steamed bun is 50-500 g. The weight of each whole grain fermented steamed bun can be set to 50 g, 100 g, 150 g, 200 g, 250 g, 300 g, 350 g, 400 g, 450 g, 500 g as needed, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0031] In summary, this application has at least the following beneficial effects: The slow-glycemic whole-grain fermented steamed bread of the present application, through the mutual cooperation between the raw materials, not only has a low GI value, GI value <70, and has the effect of slowing blood sugar rise. It is also rich in protein, minerals, vitamins, etc., which meets the body's needs for nutrients. It also has the advantages of high specific volume, low hardness, good elasticity, and good chewiness. At the same time, the internal pores are uniform, the texture is soft, the fluffiness is good, the elasticity recovery is fast, and the chewiness is strong, which improves the taste and quality of the whole-grain fermented steamed bread and meets market demand. DETAILED DESCRIPTION

[0032] In order to make the present application easier to understand, the present application will be further described in detail below in conjunction with the examples, which are merely illustrative and are not intended to limit the scope of application of the present application. The raw materials or components used in the present application can be obtained through commercial routes or conventional methods unless otherwise specified.

[0033] Preparation Example Preparation Example 1 A milk thistle extract is prepared by the following method: T1. Wash the milk thistle fruit, dry it in the sun, and crush it to obtain milk thistle fruit powder.

[0034] The milk thistle fruit powder has an average particle size of 50 μm and a water content of 8 wt %.

[0035] T2. Add 10 kg of milk thistle fruit powder to 70 kg of 75% ethanol aqueous solution at 65°C, and soak for 5 hours. Then filter to obtain alcohol extraction filtrate and alcohol extraction residue.

[0036] T3. The alcohol extraction residue was hot-pressed for 18 minutes at a pressure of 14 MPa and a temperature of 130° C. Then, the hot-pressed filtrate and hot-pressed residue were obtained by filtration.

[0037] T4. Add the hot-pressed filter residue into 70 kg of water at a temperature of 85°C and soak for 5 hours. Then filter to obtain a water-extracted filtrate and a water-extracted filter residue.

[0038] T5. Add the alcohol extraction filtrate and the hot-pressed filtrate to the water extraction filtrate, stir for 1 min, and obtain an extraction filtrate.

[0039] T6. The extraction filtrate was concentrated at 70°C to 1 / 8 of the volume of the extraction filtrate. Then, the filtrate was dried at 70°C to a constant weight to obtain a milk thistle extract.

[0040] Preparation Example 2 A milk thistle extract is prepared by the following method: T1. Wash the milk thistle fruit, dry it in the sun, and crush it to obtain milk thistle fruit powder.

[0041] The milk thistle fruit powder has an average particle size of 50 μm and a water content of 8 wt %.

[0042] T2. Add 10 kg of milk thistle fruit powder to 80 kg of 70% ethanol aqueous solution at 60°C, and soak for 6 hours. Then filter to obtain alcohol extraction filtrate and alcohol extraction residue.

[0043] T3. The alcohol extraction residue was subjected to hot pressing treatment at a pressure of 15 MPa and a temperature of 120° C. for 20 minutes, and then filtered to obtain hot pressing filtrate and hot pressing residue.

[0044] T4. Add the hot-pressed filter residue into 80 kg of water at a temperature of 80°C and soak for 6 hours. Then filter to obtain a water-extracted filtrate and a water-extracted filter residue.

[0045] T5. Add the alcohol extraction filtrate and the hot-pressed filtrate to the water extraction filtrate, stir for 1 min, and obtain an extraction filtrate.

[0046] T6. The extraction filtrate was concentrated at 70°C to 1 / 8 of the volume of the extraction filtrate. Then, the filtrate was dried at 70°C to a constant weight to obtain a milk thistle extract.

[0047] Preparation Example 3 A milk thistle extract is prepared by the following method: T1. Wash the milk thistle fruit, dry it in the sun, and crush it to obtain milk thistle fruit powder.

[0048] The milk thistle fruit powder has an average particle size of 50 μm and a water content of 8 wt %.

[0049] T2. Add 10 kg of milk thistle fruit powder to 60 kg of 80% ethanol aqueous solution at 70°C, and soak for 4 hours. Then filter to obtain alcohol extraction filtrate and alcohol extraction residue.

[0050] T3. The alcohol extraction residue was hot-pressed for 15 minutes at a pressure of 13 MPa and a temperature of 140° C. Then, the hot-pressed filtrate and hot-pressed residue were obtained by filtration.

[0051] T4. Add the hot-pressed filter residue into 60 kg of water at a temperature of 90°C and soak for 4 hours. Then filter to obtain a water-extracted filtrate and a water-extracted filter residue.

[0052] T5. Add the alcohol extraction filtrate and the hot-pressed filtrate to the water extraction filtrate, stir for 1 min, and obtain an extraction filtrate.

[0053] T6. The extraction filtrate was concentrated at 70°C to 1 / 8 of the volume of the extraction filtrate. Then, the filtrate was dried at 70°C to a constant weight to obtain a milk thistle extract.

[0054] Preparation Example 4 A milk thistle extract, which is different from Preparation Example 1 in that steps T3 and T4 are different.

[0055] Steps T3 and T4 are as follows: adding alcohol extraction residue into 70 kg of water at a temperature of 85° C. and soaking for 5 hours, and then filtering to obtain water extraction filtrate and water extraction residue. Example

[0056] Table 1 Amount of each raw material for whole grain fermented steamed bread (unit: kg) Example 1 A slow-glycemic whole-grain fermented steamed bread, the raw materials and raw material ratios of which are shown in Table 1.

[0057] Among them, the water content of wheat flour, rice flour, millet flour, mung bean flour and soybean flour is 13wt%; the yeast is selected from Angel Yeast Co., Ltd.; gluten powder and sodium alginate are both selected from Hebei Runbu Biotechnology Co., Ltd.; the natural preservative is citric acid; and the milk thistle extract is prepared by the method of Preparation Example 1.

[0058] A processing technology for slow-glycemic whole-grain fermented steamed bread comprises the following steps: Divide the water into two parts, namely, partial water and remaining water, and the weight ratio of partial water to remaining water is 4:6.

[0059] S1. Add yeast to part of the water and stir for 2 minutes to obtain a yeast solution.

[0060] S2. Add rice flour, millet flour, mung bean flour and soybean flour to wheat flour, stir for 2 minutes, and obtain a premix.

[0061] S3. Add salt, gluten, sodium alginate, milk thistle extract, and natural preservative to the premix, and stir for 2 minutes. Then add the remaining water and yeast solution, stir for 5 minutes, and knead into dough to obtain raw dough.

[0062] S4. The dough is fermented for 90 minutes at a temperature of 37° C. and a humidity of 85%. The dough is then divided, rolled into balls, and shaped. The dough is then fermented for 30 minutes at a temperature of 37° C. and a humidity of 65% to obtain a fermented dough.

[0063] S5. Steaming the fermented dough at 100° C. for 20 minutes to obtain whole-grain fermented steamed bread.

[0064] Example 2 A slow-rising glycemic whole-grain fermented steamed bread, which is different from Example 1 in that the raw material ratio of the whole-grain fermented steamed bread is different, and the raw material ratio is shown in Table 1.

[0065] Example 3 A slow-rising glycemic whole-grain fermented steamed bread, which is different from Example 1 in that the raw material ratio of the whole-grain fermented steamed bread is different, and the raw material ratio is shown in Table 1.

[0066] Example 4 A slow-glycemic whole-grain fermented steamed bread, which is different from Example 1 in that the source of the milk thistle extract in the raw materials of the whole-grain fermented steamed bread is different, and the milk thistle extract is prepared by the method of Preparation Example 2.

[0067] Example 5 A slow-glycemic whole-grain fermented steamed bread, which is different from Example 1 in that the source of the milk thistle extract in the raw materials of the whole-grain fermented steamed bread is different, and the milk thistle extract is prepared by the method of Preparation Example 3.

[0068] Example 6 A slow-glycemic whole-grain fermented steamed bread, which is different from Example 1 in that the source of the milk thistle extract in the raw materials of the whole-grain fermented steamed bread is different, and the milk thistle extract is prepared by the method of Preparation Example 4.

[0069] Comparative Example Comparative Example 1 A slow-glycemic whole-grain fermented steamed bread, which is different from Example 1 in that gluten, sodium alginate and milk thistle extract are not added to the raw materials of the whole-grain fermented steamed bread.

[0070] Comparative Example 2 A slow-glycemic whole-grain fermented steamed bread, which is different from Example 1 in that an equal amount of gluten powder is used to replace sodium alginate and milk thistle extract in the raw materials of the whole-grain fermented steamed bread.

[0071] Comparative Example 3 A slow-glycemic whole-grain fermented steamed bread, which is different from Example 1 in that, in the raw materials of the whole-grain fermented steamed bread, equal amounts of sodium alginate are used to replace gluten powder and milk thistle extract.

[0072] Comparative Example 4 A slow-glycemic whole-grain fermented steamed bread, which is different from Example 1 in that, in the raw materials of the whole-grain fermented steamed bread, gluten powder and sodium alginate are replaced with equal amounts of milk thistle extract.

[0073] Comparative Example 5 A slow-glycemic whole-grain fermented steamed bread, which is different from Example 1 in that, in the raw materials of the whole-grain fermented steamed bread, the milk thistle extract is replaced by equal amounts of gluten and sodium alginate, and the weight ratio of gluten to sodium alginate is 2:1.

[0074] Comparative Example 6 A slow-glycemic whole-grain fermented steamed bread, which is different from Example 1 in that, in the raw materials of the whole-grain fermented steamed bread, equal amounts of gluten and milk thistle extract are used to replace sodium alginate, and the weight ratio of gluten to milk thistle extract is 2:1.

[0075] Comparative Example 7 A slow-glycemic whole-grain fermented steamed bread, which is different from Example 1 in that, in the raw materials of the whole-grain fermented steamed bread, equal amounts of sodium alginate and milk thistle extract are used to replace gluten, and the weight ratio of sodium alginate to milk thistle extract is 1:1.

[0076] Comparative Example 8 A slow-glycemic whole-grain fermented steamed bread, which is different from Example 1 in that an equal amount of inulin is used to replace the milk thistle extract in the raw materials of the whole-grain fermented steamed bread, and the inulin is selected from Hebei Runbu Biotechnology Co., Ltd.

[0077] Performance Testing The whole grain fermented steamed bread obtained in Examples 1-6 and Comparative Examples 1-8 were taken respectively, and the rapeseed weight displacement method was used to detect the specific volume of the whole grain fermented steamed bread. The hardness, elasticity and chewiness of the whole grain fermented steamed bread were detected using an ST-Z16 texture analyzer. The test results are shown in Table 2.

[0078] Table 2 Test results Test items Specific volume / (mL / g) Hardness / (g) elasticity Chewing degree / (g) Example 1 3.45 1120 0.947 864 Example 2 3.32 1243 0.941 964 Example 3 3.26 1305 0.936 1012 Example 4 3.35 1217 0.942 943 Example 5 3.31 1254 0.936 975 Example 6 3.17 1392 0.928 1082 Comparative Example 1 2.13 2421 0.861 1885 Comparative Example 2 2.31 2246 0.872 1746 Comparative Example 3 2.55 2005 0.886 1563 Comparative Example 4 2.42 2137 0.881 1662 Comparative Example 5 2.87 1695 0.911 1314 Comparative Example 6 2.73 1831 0.901 1422 Comparative Example 7 2.97 1593 0.914 1235 Comparative Example 8 3.05 1516 0.922 1172 As can be seen from Table 2, the whole grain fermented steamed bread of the present application has a higher specific volume of 3.17-3.45 mL / g, and it also has lower hardness and chewiness, with a hardness of 1120-1392 g and a chewiness of 864-1082 g. At the same time, it also has higher elasticity, with an elasticity of 0.928-0.947, which makes the whole grain fermented steamed bread have the advantages of high specific volume, low hardness, good elasticity and good chewiness. The whole grain fermented steamed bread also has uniform internal pore distribution, soft texture, good fluffiness, fast elastic recovery and strong chewiness, thereby improving the taste and quality of the whole grain fermented steamed bread and meeting market demand.

[0079] Comparative Examples 1-4 are compared. In Comparative Example 1, gluten, sodium alginate, and milk thistle extract are not added to the raw materials of whole-grain fermented steamed bread; in Comparative Example 2, gluten is added to the raw materials of whole-grain fermented steamed bread; in Comparative Example 3, sodium alginate is added to the raw materials of whole-grain fermented steamed bread; in Comparative Example 4, milk thistle extract is added to the raw materials of whole-grain fermented steamed bread. It can be seen that adding gluten, sodium alginate, or milk thistle extract to the raw materials alone can increase the specific volume and elasticity, and reduce the hardness and chewiness.

[0080] Example 1 is compared with Comparative Examples 5-7. Comparative Example 5: gluten and sodium alginate are added to the raw materials of whole-grain fermented steamed bread; Comparative Example 6: gluten and milk thistle extract are added to the raw materials of whole-grain fermented steamed bread; Comparative Example 7: sodium alginate and milk thistle extract are added to the raw materials of whole-grain fermented steamed bread; Example 1: gluten, sodium alginate and milk thistle extract are added to the raw materials of whole-grain fermented steamed bread. It can be seen from this that by adding gluten, sodium alginate and milk thistle extract to the raw materials at the same time, and utilizing the synergistic effect between the three, the specific volume can be significantly increased, the hardness and chewiness can be significantly reduced, and the elasticity can be improved, so that the whole-grain fermented steamed bread exhibits a better taste and quality.

[0081] Example 1 is compared with Comparative Example 8. Inulin is added to the raw materials of whole-grain fermented steamed bread in Comparative Example 8; and milk thistle extract is added to the raw materials of whole-grain fermented steamed bread in Example 1. It can be seen that, compared with adding inulin to the raw materials, adding milk thistle extract to the raw materials can enhance the interaction between inulin and gluten and sodium alginate, and improve the taste of whole-grain fermented bread.

[0082] It should be noted that the embodiments described above are only used to explain the present application and do not constitute any limitation to the present application. The present application is described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present application may be modified as specified within the scope of the claims of the present application, and the present invention may be revised without departing from the scope and spirit of the present application. Although the present application described therein relates to specific methods, materials and embodiments, it does not mean that the present application is limited to the specific examples disclosed therein. On the contrary, the present application can be extended to all other methods and applications with the same functions.

Claims

1. Slow-glycemic whole-grain fermented steamed bread, characterized by: The whole-grain fermented steamed bread is mainly made of the following raw materials in parts by weight: 50-60 parts of wheat flour, 15-25 parts of rice flour, 5-15 parts of millet flour, 5-10 parts of mung bean flour, 5-10 parts of soybean flour, 0.5-1.5 parts of yeast, 1-2 parts of salt, 0.5-1.5 parts of gluten powder, 0.4-0.6 parts of sodium alginate, 0.4-0.6 parts of milk thistle extract, 0.01-0.03 parts of natural preservatives, and 45-55 parts of water.

2. The slow-sugar-rising whole-grain fermented steamed bread according to claim 1, characterized in that: The milk thistle extract is prepared by the following method: T1. Washing, drying and crushing the milk thistle fruit to obtain milk thistle fruit powder; T2. Mixing milk thistle fruit powder and ethanol aqueous solution at a temperature of 60-70° C., soaking for 4-6 hours, filtering, and obtaining an alcohol extraction filtrate and an alcohol extraction residue; T3, hot pressing and filtering the alcohol extraction residue to obtain hot pressing filtrate and hot pressing residue; T4. Mix the hot-pressed filter residue and water at a temperature of 80-90° C., soak for 4-6 hours, and filter to obtain a water-extracted filtrate and a water-extracted filter residue; T5, mixing the water extraction filtrate, the alcohol extraction filtrate, and the hot pressing filtrate to obtain an extraction filtrate; T6. Concentrate and dry the extraction filtrate to obtain milk thistle extract.

3. The slow-glycemic whole-grain fermented steamed bread according to claim 2, characterized in that: The weight ratio of the milk thistle fruit powder, the ethanol aqueous solution and water is 1:(6-8):(6-8), and the mass concentration of ethanol in the ethanol aqueous solution is 70-80%.

4. The slow-glycemic whole-grain fermented steamed bread according to claim 2, characterized in that: In step T3, the pressure of the hot pressing treatment is 13-15 MPa, the temperature is 120-140° C., and the time is 15-20 min.

5. The slow-glycemic whole-grain fermented steamed bread according to claim 2, characterized in that: The milk thistle fruit powder has an average particle size of 30-200 μm and a water content of 6-10 wt %.

6. The slow-glycemic whole-grain fermented steamed bread according to claim 1, characterized in that: The natural preservative is one or more of citric acid, tea polyphenols and chitosan.

7. The processing technology of the slow-glycemic whole-grain fermented steamed bread according to any one of claims 1 to 6, characterized in that: The steps include: S1. Mixing yeast and part of water to obtain a yeast solution; S2, mixing wheat flour, rice flour, millet flour, mung bean flour and soybean flour to obtain a premix; S3, mixing the premix, salt, gluten, sodium alginate, milk thistle extract, and natural preservative, adding the remaining water and yeast solution, mixing, and kneading into dough to obtain raw dough; S4, fermenting the dough once, dividing it, rolling it into balls, shaping it, and then fermenting it twice to obtain fermented dough; S5. Steaming the fermented dough to obtain whole-grain fermented steamed bread.

8. The processing technology of the slow-glycemic whole-grain fermented steamed bread according to claim 7, characterized in that: The weight ratio of the partial water and the remaining water is (3-5):(5-7).

9. The processing technology of the slow-glycemic whole-grain fermented steamed bread according to claim 7, characterized in that: In step S4, the temperature of the first fermentation is 35-40°C, the humidity is 80-90%, and the time is 80-100 min, and the temperature of the second fermentation is 35-40°C, the humidity is 60-70%, and the time is 20-40 min.

10. The processing technology of the slow-glycemic whole-grain fermented steamed bread according to claim 7, characterized in that: In step S5, the steaming temperature is 95-105° C. and the steaming time is 10-30 min.

Images