Medium GI tartary buckwheat bread and preparation method thereof

Abstract

The invention belongs to the technical field of food processing, and particularly relates to medium-GI tartary buckwheat bread and a preparation method thereof. The tartary buckwheat whole flour is obtained by pretreating the tartary buckwheat cortex layer, performing superfine grinding, then adding the crushed tartary buckwheat cortex layer into the tartary buckwheat core flour, the tartary buckwheat whole flour and the wheat flour are used as mixed raw materials, a small amount of specific modifier is supplemented, meanwhile, sugar substitutes in a specific proportion are added, dough is treated by using an ultrasonic stress technology, and sectional baking is used during baking, so that the tartary buckwheat whole flour is obtained. The raw materials and the technology are combined, the medium-GI tartary buckwheat bread is obtained, the nutritional value of the bread is guaranteed, meanwhile, the taste is improved, and the GI value of the bread is effectively reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of food processing, and particularly relates to medium GI tartary buckwheat bread and a preparation method thereof. Background Art

[0002] Bread is one of the most popular staple foods in the world and is mainly made from wheat flour. However, long-term consumption of wheat bread may lead to increased blood sugar and obesity. Therefore, people have begun to pay attention to multi-grain bread in recent years.

[0003] Buckwheat has become the main raw material for multi-grain bread because it contains flavonoids, resistant starch and dietary fiber. However, the multi-grain bread made from buckwheat on the market currently has the following problems: 1. The current multi-grain bread focuses more on low GI values, but low GI bread is more suitable for people who need blood sugar control and weight management, and cannot provide immediate energy to the body, so it is not suitable for long-term daily consumption by the public; 2. The nutrients and bioactive substances in buckwheat are more abundant in the buckwheat skin layer, but the buckwheat skin layer is hard and contains anti-nutritional factors such as phytic acid, which will affect the taste of the bread; the bread made from whole buckwheat flour on the market has higher nutritional value but poorer taste, while the bread without the buckwheat skin layer has better taste but lower nutritional value.

[0004] Therefore, how to provide a healthy bitter buckwheat bread that makes up for the nutritional and taste defects of existing breads on the market and is suitable for long-term daily consumption has become an urgent problem to be solved in the field. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a medium GI buckwheat bread and a preparation method thereof. The buckwheat cortex is pretreated and ultrafinely ground and then added back into the buckwheat core flour to obtain whole buckwheat flour, which is mixed with wheat flour and supplemented with a small amount of improver. At the same time, a specific proportion of sugar substitute is added, which ensures the nutritional value of the bread while improving the taste and effectively reduces the GI value of the bread.

[0006] The technical solution of the present invention is as follows:

[0007] In a first aspect of the present invention, a medium GI tartary buckwheat bread is provided, wherein the tartary buckwheat bread comprises the following components:

[0008] Buckwheat flour, high-gluten wheat flour, gluten powder, sugar, sugar substitute, milk powder, butter, yeast, fungal alpha-amylase, diacetyl tartaric acid diglyceride, edible salt and water.

[0009] Preferably, the sugar substitute is 99.5%-99.8% erythritol and 0.2%-0.5% steviol glycoside in terms of mass percentage.

[0010] Stevioside is a natural, high-sweetness sweetener. It is a white powder with a sweetness about 350 times that of sucrose. It can add sweetness to buckwheat bread without adding too many calories, and is suitable for diabetic patients. The sweetness of erythritol is about 70% of sucrose, but its calories are less than 5% of sugar. It is the sugar alcohol with the lowest energy. It can increase the sweetness of bread without having a significant impact on blood sugar, which helps to control blood sugar levels. A reasonable ratio of the two can reduce the GI value while ensuring the taste of buckwheat bread.

[0011] Preferably, the buckwheat bread contains the following components by weight:

[0012] 30-35 parts of whole buckwheat flour, 70-65 parts of high-gluten wheat flour, 8-10 parts of gluten, 0.0003-0.0005 parts of fungal alpha-amylase, 0.04-0.07 parts of diacetyl tartaric acid diglyceride, 2-4 parts of white sugar, 6-8 parts of sugar substitute, 4-6 parts of milk powder, 6-8 parts of butter, 0.8-1 parts of salt, 1-2 parts of yeast and 55-57 parts of water.

[0013] In a second aspect of the present invention, a method for preparing the above-mentioned medium GI buckwheat bread is provided, comprising the following steps:

[0014] S1: Take buckwheat seeds and peel off the outer hard shell, grind the buckwheat core into powder and then sieve it, boil the buckwheat husk in water, dehydrate and dry it, and then grind it into ultrafine powder, and mix the obtained buckwheat husk powder with the buckwheat core powder to obtain the whole buckwheat powder for later use;

[0015] S2: putting the whole bitter buckwheat flour obtained in S1, high-gluten wheat flour, gluten powder, fungal α-amylase, diacetyl tartaric acid diglyceride, white sugar, sugar substitute, milk powder, yeast and salt into a dough mixer, mixing evenly, and then adding water to form a dough;

[0016] S3: Add butter to the dough obtained in S2 and continue kneading;

[0017] S4: taking out the dough obtained in S3 and subjecting it to ultrasonic stress proofing;

[0018] S5: dividing and shaping the dough obtained in S4 and placing it in a proofing box for fermentation;

[0019] S6: putting the fermented dough obtained in S5 into an oven for segmented baking, and obtaining medium GI buckwheat bread after cooling.

[0020] Preferably, in S1, the peeling of the outer shell is: after being peeled by a grain peeling machine for 6-10 minutes, the buckwheat shell retention is ≤5%; the sieving after grinding is: grinding into powder by a hammer cyclone mill, and the retention after passing through an 80-mesh sieve is ≤3%.

[0021] Preferably, in S1, the tartary buckwheat husk is placed in water with a material-water ratio of 1:10-15, boiled for 45-60 minutes, dehydrated and dried, and initially crushed to 80 meshes using a grinder and then ultrafinely crushed, and the ultrafinely crushing time is 50-60 minutes.

[0022] Preferably, in S2, the power of the dough mixer is 1.5 kW and the dough mixing time is 6 min.

[0023] Preferably, in S3, after adding butter, the power of the dough mixer is reduced to 1 kW, and the dough is kneaded for 6 minutes before switching to high speed.

[0024] Preferably, in S4, the ultrasonic stress-induced dough-proofing is specifically as follows: the sealed dough is directly placed in an ultrasonic working pool, 6L of distilled water is added to the working pool, and the initial temperature of the distilled water is 30°C; the ultrasonic frequency is set to 20-60kHz, and the power is 300W. The divergent ultrasonic single-frequency, synchronous triple-frequency and sequential triple-frequency working modes are used in sequence, that is, first the single-frequency working mode is used: the same frequency ultrasonic time is 5s, the interval time is 5s, and the ultrasonic treatment is 10-15min; then the synchronous triple-frequency working mode is used: 20, 40, and 60kHz are used for synchronous treatment for 10-15min; finally, the sequential triple-frequency working mode is used: in the order of 20kHz, 40kHz and 60kHz, each frequency works in turn for 10s, 30s is a cycle, and the ultrasonic treatment is 10-15min. The three working modes are used in sequence, and the dough is proofed for 30-45min.

[0025] Preferably, in S5, the dough weight after segmentation and shaping is 45-55 g; the dough fermentation temperature is 35° C., the fermentation humidity is 85-90%, and the fermentation time is 1 h.

[0026] Preferably, in S6, the segmented baking adopts a two-stage baking method, baking at 175-185° C. for 13 minutes, then switching to the upper heat at 200° C. for another 2-5 minutes.

[0027] Buckwheat bread is made by pre-treating the buckwheat husk by boiling water, ultrafinely grinding it and then adding it back into the husk. Compared with traditional wheat bread and buckwheat bread made from ordinary whole flour, it has richer nutritional value and a more delicate taste.

[0028] The beneficial effects of the present invention are:

[0029] (1) The present invention adjusts the buckwheat bread formula, adds a specific enzyme preparation and an emulsifier, and adopts a segmented baking technology to prepare a medium GI buckwheat bread, wherein a good network gluten is formed inside the bread, and the edible quality and appearance quality are improved. The prepared buckwheat bread has a uniform color, is soft and resilient, and has a good taste;

[0030] (2) The present invention uses a divergent ultrasonic dough-proofing technology and adopts multiple working modes such as single frequency, synchronous three-frequency and sequential three-frequency. Compared with the use of ordinary ultrasonic dough-proofing, the present invention significantly improves the microstructure and rheological properties of the dough, making the moisture state of the dough more uniform, which is beneficial to subsequent processing and molding; accelerates the dough proofing process, shortens the proofing time, improves production efficiency and helps to improve the stability of product quality;

[0031] (3) The present invention pre-treats and ultrafinely grinds the buckwheat husk layer and then adds it back into the bread, and uses a ratio of sucrose and sugar substitute to produce a medium GI buckwheat bread, which solves the problems of the current commercially available bread products having a single form and nutritional value, a rough taste, and a high glycemic index. The contents of rutin, quercetin, dietary fiber, etc. in the buckwheat bread of the present invention are increased, meeting the needs of modern people for hypoglycemic and healthy foods. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The internal structure diagram of buckwheat bread slices: A is prepared in Example 1 of the present invention, and B is prepared in Comparative Example 2;

[0033] Figure 2 1 is the microscopic morphology of the tartary buckwheat flour of the present invention, ab is the image after pretreatment and ultrafine grinding, and AB is the image after hammerstone cyclone grinding. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in conjunction with specific implementation methods.

[0035] Example 1

[0036] A medium GI tartary buckwheat bread, comprising the following components by weight:

[0037] 30 parts of bitter buckwheat flour, 70 parts of high-gluten wheat flour, 8 parts of gluten, 0.0003 parts of fungal α-amylase, 0.04 parts of diacetyl tartaric acid diglyceride, 2 parts of white sugar, 6 parts of sugar substitute, 4 parts of milk powder, 6 parts of butter, 0.8 parts of salt, 1 part of yeast. Among them, the sugar substitute is: 99.8% erythritol and 0.2% stevioside.

[0038] The above-mentioned buckwheat bread production method is as follows:

[0039] (1) Buckwheat seeds are peeled by a grain peeling machine for 6 minutes, and the buckwheat core retains 5% of the skin, and then ground into powder by a hammer cyclone mill and passed through an 80-mesh sieve to obtain a buckwheat core powder retaining 3%; the buckwheat husk layer is boiled for 60 minutes at a material-water ratio of 1:10, dehydrated and dried, and initially crushed to 80 mesh by a grinder, and then ultrafinely ground for 50 minutes to obtain buckwheat husk powder, and the obtained buckwheat husk powder is mixed with buckwheat core powder to obtain whole buckwheat powder;

[0040] (2) Put the whole bitter buckwheat flour, high-gluten wheat flour, gluten, fungal α-amylase, diacetyl tartaric acid diglyceride, white sugar, sugar substitute, milk powder, yeast, and salt into a dough mixer, mix them evenly, add water and knead them into dough, the amount of water added is 56 parts, the kneading time is 6 minutes, and the power of the dough mixer is 1.5 kW;

[0041] (3) After adding butter to the dough, the power of the dough mixer was reduced to 1 kW, and the dough mixer was switched to high speed after 6 min of kneading;

[0042] (4) The dough was taken out and ultrasonically proofed. The ultrasonic frequency of the dough was set to 20-60 kHz, the power was 300 W, and the single-frequency, synchronous three-frequency and sequential three-frequency working modes were used in sequence: single-frequency working mode: the same frequency ultrasonic time was 5 s, the interval time was 5 s, and the ultrasonic treatment was 10 min; synchronous three-frequency working mode: 20, 40, and 60 kHz were used for synchronous treatment for 10 min; sequential three-frequency working mode: 20 kHz, 40 kHz and 60 kHz were used in sequence, each frequency worked for 10 s in turn, 30 s as a cycle, and the ultrasonic treatment was 10 min;

[0043] (5) Divide and shape the dough into 50 g each, roll into balls and place the resulting dough into a proofing box for fermentation at a temperature of 35° C., a humidity of 85%, and a fermentation time of 1 h;

[0044] (6) Put the dough into the oven and bake it at a temperature of 180°C for 13 minutes, then turn it to 200°C and bake it for another 2 minutes. The cooling time is 3 hours, and after cooling, the finished buckwheat bread is obtained.

[0045] Example 2

[0046] The difference from Example 1 is that in step (1), after the buckwheat grains are peeled by a grain peeling machine for 8 minutes, the buckwheat core retains 3% of the skin, and the other steps and parameters are the same as those in Example 1.

[0047] Example 3

[0048] The difference from Example 1 is that the amount of whole buckwheat flour is adjusted to 35 parts, and the other steps and parameters are the same as those in Example 1.

[0049] Comparative Example 1

[0050] The difference from Example 1 is that no gluten is added to the raw materials of buckwheat bread.

[0051] Comparative Example 2

[0052] The difference from Example 1 is that the fungal α-amylase in the raw material is replaced by amylase, and the diacetyl tartaric acid diglyceride is replaced by sodium stearoyl lactylate. The other steps and parameters are the same as those in Example 1.

[0053] Comparative Example 3

[0054] The difference from Example 1 is that the amount of gluten added is 20 parts, and the other steps and parameters are the same as those in Example 1.

[0055] Comparative Example 4

[0056] The difference from Example 1 is that the diacetyl tartaric acid diglyceride in the raw material is replaced by calcium stearoyl lactylate, and the other steps and parameters are the same as those in Example 1.

[0057] Comparative Example 5

[0058] The difference from Example 1 is that the diacetyl tartaric acid diglyceride in the raw material is replaced by a compound of calcium stearoyl lactylate and glyceryl monostearate, the mass ratio of calcium stearoyl lactylate to glyceryl monostearate is 3:1, and the other steps and parameters are the same as those in Example 1.

[0059] Comparative Example 6

[0060] The difference from Example 1 is that the fungal α-amylase in the raw material is replaced by saccharifying enzyme, and the other steps and parameters are the same as those in Example 1.

[0061] Comparative Example 7

[0062] The difference from Example 1 is that the fungal α-amylase in the raw material is replaced by a compound of fungal α-amylase and saccharifying enzyme in a mass ratio of 1:1, and the other steps and parameters are the same as those in Example 1.

[0063] Comparative Example 8

[0064] The difference from Example 1 is that the fungal α-amylase in the raw material is replaced by a compound of fungal α-amylase and saccharifying enzyme (mass ratio is 1:1), and diacetyl tartaric acid diglyceride is replaced by a compound of calcium stearoyl lactylate and monostearate glyceryl (mass ratio is 3:1), and the other steps and parameters are the same as in Example 1.

[0065] Comparative Example 9

[0066] The difference from Example 1 is that in step (1), the tartary buckwheat husk layer is not boiled, and after being peeled by a grain peeling machine, the tartary buckwheat husk is directly ultrafinely ground and then added back to the tartary buckwheat core powder to obtain the whole tartary buckwheat flour. The other steps and parameters are the same as those in Example 1.

[0067] Comparative Example 10

[0068] The difference from Example 1 is that in step (4), ordinary ultrasound is used to treat the dough: the ultrasonic working frequency is 20 kHz, the power is 300 W, the working time is 4 s, the interval time is 3 s, and the ultrasonic time is 30 min.

[0069] Comparative Example 11

[0070] The difference from Example 1 is that in step (6), two-stage baking is not used, and ordinary baking mode is used: the baking temperature is 180° C., the baking time is 15 minutes, the cooling time is 3 hours, and the finished buckwheat bread is obtained after cooling.

[0071] Test Example 1

[0072] The eGI values ​​of the embodiments and comparative examples were theoretically calculated, and the eGI value calculation process was as follows:

[0073] (1) Calculation of the area under the starch hydrolysis curve (AUC)

[0074]

[0075] Where, C∞ is the equilibrium value (%) of starch hydrolysis rate after 180 min of hydrolysis; t f is the final time (180 min); t0 is the starting time (0 min); k is the first-order reaction kinetic constant.

[0076] (2) Calculation of starch hydrolysis index (HI)

[0077]

[0078] (3) Calculation of eGI

[0079] eGI=39.71+(0.549×HI)

[0080] The results are shown in Table 1:

[0081] Table 1 eGI values ​​and specific volumes of different samples

[0082]

[0083]

[0084] As can be seen from Table 1, the eGI values ​​of Examples 1-3 are lower than those of Comparative Examples 1-3, and there is a great relationship between the eGI values ​​and the raw material ratios thereof. As the gluten content increases, the eGI value decreases regularly. However, from the perspective of specific volume, the greater the amount of whole buckwheat flour added, the lower the quality of the bread. This is because as the amount of whole buckwheat flour increases, the gluten protein content in the flour decreases, and the consequence is that the bread does not form a mass and the bread does not rise well. This shows that the more whole buckwheat flour is added, the better. Compared with ordinary ultrasonic treatment (Comparative Example 10), the divergent ultrasonic stress dough-proofing makes the moisture state of the dough more uniform, which is beneficial to subsequent processing and molding; it accelerates the dough proofing process, thereby shortening the proofing time and improving the dough proofing effect. The production efficiency is improved and the product quality stability is improved, the internal network of the dough is homogenized, and the specific volume of the bread is improved; compared with changing the enzyme preparation and the emulsifier (Comparative Examples 4-8), the bread prepared by compounding fungal alpha-amylase and diacetyl tartaric acid diglyceride in the present invention is larger in volume, can also make the bread softer, enhance the extensibility and gas retention ability, and the bread feels better after being baked; and compared with not pre-treating the bitter buckwheat skin layer by boiling (Comparative Example 9), the bread prepared by the pre-treatment of the present invention has better taste and texture, is easier to absorb nutrients, and has more fully exerted functional characteristics; the present invention uses a two-stage baking mode, and compared with the ordinary baking mode (Comparative Example 11), the finished bread prepared by the present invention has more uniform color and better flavor.

[0085] Test Example 2

[0086] 10 tasters were selected to conduct sensory evaluation on the breads prepared in each embodiment and comparative example, and sensory scores were given based on the shape, color, smell, taste and texture of the breads. The scoring criteria and scores are shown in Table 2:

[0087] Table 2 Bread sensory scoring standards

[0088]

[0089]

[0090] The scores of each bread are shown in Table 3:

[0091] Table 3 Sensory scores of bread samples

[0092] Case form Color odor Taste organize Total score Example 1 18 19 20 20 18 95 Example 2 18 18 19 19 17 91 Example 3 18 18 18 19 19 92 Comparative Example 1 15 18 17 13 15 78 Comparative Example 2 17 17 16 15 11 76 Comparative Example 3 16 14 18 10 9 66 Comparative Example 4 16 15 11 14 12 68 Comparative Example 5 15 12 14 11 15 67 Comparative Example 6 16 16 12 15 10 69 Comparative Example 7 16 11 13 15 14 69 Comparative Example 8 16 14 17 13 13 73 Comparative Example 9 16 11 17 10 11 65 Comparative Example 10 16 14 16 12 10 68 Comparative Example 11 14 10 12 15 16 67

[0093] It can be seen from the data in Table 3 that the sensory scores of the embodiments are relatively high, all reaching above 90 points, while the sensory scores of the comparative examples are all below 90 points, and the score of comparative example 3 is only 66 points, and the score of comparative example 9 is only 65 points, indicating that the bread produced using the specific raw materials and raw material ratios of the present invention has good shape, color, aroma and good eating taste.

Claims

1. A medium GI buckwheat bread, characterized in that: Contains the following ingredients: Buckwheat flour, high-gluten wheat flour, gluten powder, sugar, sugar substitute, milk powder, butter, yeast, fungal alpha-amylase, diacetyl tartaric acid diglyceride, edible salt and water.

2. The bread according to claim 1, characterized in that Calculated by mass percentage, the sugar substitute comprises 99.5%-99.8% erythritol and 0.2%-0.5% stevioside.

3. The bread according to claim 1, characterized in that By weight, it contains the following components: 30-35 parts of whole buckwheat flour, 70-65 parts of high-gluten wheat flour, 8-10 parts of gluten, 0.0003-0.0005 parts of fungal alpha-amylase, 0.04-0.07 parts of diacetyl tartaric acid diglyceride, 2-4 parts of white sugar, 6-8 parts of sugar substitute, 4-6 parts of milk powder, 6-8 parts of butter, 0.8-1 parts of salt, 1-2 parts of yeast and 55-57 parts of water.

4. The method for preparing bread according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1: Take buckwheat seeds and peel off the outer hard shell, grind the buckwheat core into powder and then sieve it, boil the buckwheat husk in water, dehydrate and dry it, and then grind it into ultrafine powder, and mix the obtained buckwheat husk powder with the buckwheat core powder to obtain the whole buckwheat powder for later use; S2: putting the whole bitter buckwheat flour obtained in S1, high-gluten wheat flour, gluten powder, fungal α-amylase, diacetyl tartaric acid diglyceride, white sugar, sugar substitute, milk powder, yeast and salt into a dough mixer, mixing evenly, and then adding water to form a dough; S3: Add butter to the dough obtained in S2 and continue kneading; S4: taking out the dough obtained in S3 and subjecting it to ultrasonic stress proofing; S5: dividing and shaping the dough obtained in S4 and placing it in a proofing box for fermentation; S6: putting the fermented dough obtained in S5 into an oven for segmented baking, and obtaining medium GI buckwheat bread after cooling.

5. The preparation method according to claim 4, characterized in that: In S1, the peeling of the outer shell is: after being peeled by a grain peeling machine for 6-10 minutes, the buckwheat shell retention is ≤5%; the sieving after grinding is: after being ground into powder by a hammer cyclone mill and passed through an 80-mesh sieve, the retention amount is ≤3%.

6. The preparation method according to claim 4, characterized in that: In S1, the tartary buckwheat husk is placed in water with a material-water ratio of 1:10-15, boiled for 45-60 minutes, dehydrated and dried, and crushed to 80 meshes by a grinder and then ultrafinely crushed, and the ultrafinely crushing time is 50-60 minutes.

7. The preparation method according to claim 4, characterized in that: In S2, the power of the dough mixer is 1.5 kW, and the dough mixing time is 6 min.

8. The preparation method according to claim 4, characterized in that: In S4, the ultrasonic resting method is a divergent ultrasonic resting method, the ultrasonic frequency is set to 20-60kHz, the power is 300W, and the resting time is 30-45min.

9. The preparation method according to claim 4, characterized in that: In S5, the dough weight after division and shaping is 45-55g; the dough fermentation temperature is 35°C, the fermentation humidity is 85-90%, and the fermentation time is 1h.

10. The preparation method according to claim 4, characterized in that: In S6, the segmented baking adopts a two-stage baking method, baking at 175-185° C. for 13 minutes, then switching to an upper fire of 200° C. for another 2-5 minutes.

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