Method for improving quality of whole wheat bread

Abstract

The invention provides a method for improving the quality of whole wheat bread, and belongs to the field of food processing. Transglutaminase is used for catalyzing cross-linking of casein and mucedin, a protein compound obtained after reaction can form a gluten network in the dough, the gluten network structure of the whole-wheat bread dough is improved, by means of the method, the specific volume of whole-wheat bread is increased, the texture is softer, and the sensory quality is improved. Meanwhile, the content of protein and calcium in the bread is increased, and the nutritional value of the whole-wheat bread is improved.

Description

Technical Field

[0001] The invention relates to the field of food processing, in particular to a method for improving the sensory quality and nutritional quality of whole wheat bread. Background Art

[0002] Whole wheat bread is made with whole wheat flour as the main ingredient. Whole wheat flour is processed from complete wheat grains (including germ, bran and endosperm), and is more nutritious than ordinary refined flour. Whole wheat bread retains the dietary fiber, vitamins, minerals and antioxidants in wheat, which can promote digestive health. In recent years, with people's concern and attention to health, and the significant increase in the number of obesity and diabetes patients worldwide, the market demand for whole wheat bread as a healthy food is growing.

[0003] However, due to the presence of bran and germ in whole wheat flour, its bread-making properties are usually poor. The dietary fiber in whole wheat flour will hinder the hydration of gluten protein and starch, inhibit the formation of gluten network in dough, resulting in low specific volume, high hardness and rough texture of whole wheat bread, which reduces consumer acceptance. Therefore, it is of great practical significance to improve the edible quality of whole wheat bread and increase its consumer acceptance in the food market.

[0004] Casein is the main protein in milk, accounting for about 80% of the total protein content of milk. It not only contains a variety of essential amino acids, but also increases the bioavailability of calcium, helps the human body absorb and utilize calcium more effectively, and promotes bone health. Casein exists in the form of aggregated micelles. Due to its special spatial conformation, it is difficult to form a gluten network in the dough, so it cannot be directly used as a protein ingredient in the production of whole wheat bread. Through modification, casein has the ability to form a gluten network in whole wheat dough, which can significantly improve the sensory and nutritional quality of whole wheat bread, and has important economic and social value.

[0005] Therefore, the present invention aims to solve the problems of low specific volume, high hardness and rough texture of whole wheat bread. We use transglutaminase (EC 2.3.2.13) to catalyze the combination of casein and gluten protein, so that the protein complex after the reaction can form a stable gluten network in the dough. The present invention enables the whole wheat bread to have a porous structure and a softer texture, thereby effectively improving the edible quality of the whole wheat bread. At the same time, the present invention increases the content of protein and calcium in the whole wheat bread, thereby improving the nutritional quality. Summary of the invention

[0006] The purpose of the present invention is to provide a method for improving the sensory quality and nutritional quality of whole wheat bread in view of the problems existing in whole wheat bread. The present invention utilizes transglutaminase to catalyze the cross-linking polymerization of gluten protein and casein, and the protein complex after the reaction can participate in the formation of a gluten network, so that the texture of the whole wheat bread is softer and more elastic, and the taste and nutritional quality of the food are improved.

[0007] A method for improving the quality of whole wheat bread, comprising the following steps:

[0008] (1) Mixing the protein ingredients: mixing casein and gluten protein, adding water and stirring to obtain a protein mixture;

[0009] (2) Enzymatic cross-linking reaction: adding transglutaminase to the protein mixture to carry out an enzymatic reaction to obtain an enzymatic reaction solution;

[0010] (3) Kneading: The raw materials include whole wheat flour, water, yeast, salt and enzymatic reaction liquid. Mix the raw materials and stir to knead the dough, control the temperature of the dough, and stir until the gluten network is formed;

[0011] (4) First fermentation (basic fermentation): the mixed dough is placed for the first fermentation;

[0012] (5) Dividing and shaping: Divide the dough after the first fermentation into small portions according to the required weight. Then shape each portion of dough;

[0013] (6) Second fermentation (proofing): The shaped dough is placed in a fermentation box for a second fermentation;

[0014] (7) Baking: Place the dough that has undergone the second fermentation into a preheated oven for baking.

[0015] Preferably, in step (1), the mass ratio of casein to gluten is 1:1 to 4:1;

[0016] Preferably, in step (2), the amount of transglutaminase used is 0.5-4% of the total protein amount; the enzymatic reaction temperature is 35-50° C., and the enzymatic reaction time is 10-35 min;

[0017] Preferably, in step (3), the amount of the enzymatic reaction liquid added is calculated based on the total protein mass (on a dry basis), and the total protein mass is 10-20% of the mass of the whole wheat flour; the amount of the yeast added is 1-2% of the mass of the whole wheat flour; the amount of the salt added is 1.2-2% of the mass of the whole wheat flour; and the dough temperature is controlled to be lower than 28° C. during kneading.

[0018] Preferably, in step (4), the dough is fermented for the first time at a temperature of 26-32° C. and a humidity of 70-85% until the dough expands to 1.5-2.5 times.

[0019] Preferably, in step (5), shaping is performed according to the final product shape requirements, such as shaping into a round shape or a long strip shape.

[0020] Preferably, in step (6), the second fermentation temperature of the dough is 26-32° C., the humidity is 65-85%, and the time is 40-70 min.

[0021] Preferably, in step (7), the baking temperature is 160-200° C., and the baking time is 25-35 minutes, and the specific time is adjusted according to the size of the dough and the performance of the oven.

[0022] Beneficial effects of the present invention:

[0023] (1) Improved the texture of whole wheat bread: The protein after enzymatic reaction can participate in the formation of gluten network, increase the specific volume of whole wheat bread, make the texture softer, and improve the sensory quality of whole wheat bread.

[0024] (2) Improving nutritional value: By modifying casein to enable it to form a gluten network, the casein content in whole-wheat bread can be increased, thereby improving the overall nutritional value of the bread and providing more protein and more calcium. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Appearance of the whole wheat bread prepared in Example 1.

[0026] Figure 2 Specific volume of whole wheat bread prepared in Example 2.

[0027] Figure 3 Dynamic rheological diagram of the whole wheat bread dough prepared in Example 2.

[0028] Figure 4 The texture result diagram of the whole wheat bread prepared in Example 3.

[0029] Figure 5 Protein content in whole wheat bread prepared in Example 4.

[0030] Figure 6 Calcium content in whole wheat bread prepared in Example 4 DETAILED DESCRIPTION

[0031] (1) Determination of specific volume of bread

[0032] The baked whole wheat bread was left to stand at room temperature for 1 hour before mass and volume testing. The mass was directly measured using an electronic balance, and the volume was measured using the rapeseed volume displacement method (AACC Method 10-05.01). The specific volume of the bread is the ratio of volume to mass, expressed in mL / g. The test results are expressed as mean ± standard deviation (n = 3).

[0033] (2) Testing of rheological properties of whole wheat bread dough

[0034] The AR1000 rheometer of TA Company of the United States was used. The dough stirred until gluten was formed was placed on the test bottom plate, the upper plate diameter was 20mm, the distance between the plates was 2mm, the excess sample was removed with a scraper, and low-viscosity silicone oil was applied to the sample surface to prevent water evaporation. The sample was tested after standing for 5 minutes, the strain was set to 0.02%, the scanning frequency was 0.1-10Hz, and the test temperature was 25℃.

[0035] (3) Detection of the texture of whole wheat bread

[0036] The bread sample was cut into slices with a thickness of 2 cm and tested using a TA.XTPlus texture analyzer from SMS, UK. The test mode was TPA and a P / 25 probe was used. The probe descended at a speed of 1.00 mm / s before the test, the test speed was 1.00 mm / s, and the rise speed after the test was 3.00 mm / s. The probe compression ratio was 40%, and the interval between repeated compressions was 5 s. The test results were expressed as mean ± standard deviation (n = 3).

[0037] (4) Protein content detection

[0038] GB5009.5-2016 "National Food Safety Standard Determination of Protein in Food".

[0039] (5) Calcium content detection:

[0040] GB5009.92-2016 "National Food Safety Standard Determination of Calcium in Foods".

[0041] Comparative Example 1:

[0042] (1) Kneading: Mix whole wheat flour (300 g), yeast (3 g) and salt (4 g) and stir to knead the dough. Add ice water during the kneading process to control the dough temperature not exceeding 28° C. and stir until a gluten network is formed.

[0043] (2) First fermentation (basic fermentation): The mixed whole wheat dough is placed at 30°C and 70% humidity for the first fermentation. The fermentation is terminated when the dough expands to 2.0 times.

[0044] (3) Dividing and shaping: Cut the fermented dough into small portions (120g / portion), then shape each portion into a round shape, press to release air, and roll into a cylindrical shape.

[0045] (4) Second fermentation (proofing): The shaped dough is placed in a fermentation box for second fermentation. The temperature is controlled at 30°C and the humidity is 85%. The fermentation time is 50 minutes.

[0046] (5) Baking: Place the proofed dough into a preheated oven for baking at 180°C for approximately 25 minutes. The specific time will vary depending on the size of the dough and the performance of the oven.

[0047] Embodiment 1:

[0048] (1) Mixing the protein ingredients: Mix casein (40 g) and gluten protein (10 g), add 120 ml of water and stir to obtain a protein mixture;

[0049] (2) Enzymatic cross-linking reaction: 0.8 g of transglutaminase was added to the protein mixture, the temperature was maintained at 50° C., and the enzymatic reaction was carried out for 10 min to obtain an enzymatic reaction solution;

[0050] (3) Kneading: Mix whole wheat flour (300 g), yeast (3 g), salt (4 g) and the protein reaction solution of step 2 and stir to knead the dough. Add ice water during the stirring process to control the dough temperature not exceeding 28° C. and stir until a gluten network is formed.

[0051] (4) First fermentation (basic fermentation): The mixed dough is placed at 30°C and 70% humidity for the first fermentation. The fermentation is terminated when the dough expands to 2.0 times.

[0052] (5) Dividing and shaping: Cut the dough that has been fermented for the first time into small portions (120g / portion), then shape each portion of dough into a round shape, press to release air, and then roll it into a cylindrical shape.

[0053] (6) Second fermentation (proofing): The shaped dough is placed in a fermentation box for second fermentation with the temperature controlled at 30°C and the humidity at 85% for 50 min.

[0054] (7) Baking: The dough that has been fermented for the second time is placed in a preheated oven for baking at 180°C for approximately 25 minutes. The specific time may vary depending on the size of the dough and the performance of the oven.

[0055] The bread baked in this embodiment is as follows Figure 1 Compared with Comparative Example 1, the bread prepared in this embodiment exhibits a more porous structural feature.

[0056] Embodiment 2:

[0057] (1) Mixing the protein ingredients: Mix casein (40 g) and gluten protein (20 g), add 120 ml of water and stir to obtain a protein mixture;

[0058] (2) Enzymatic cross-linking reaction: add 0.3 g of transglutaminase to the protein mixture, maintain the temperature at 45° C., and perform the enzymatic reaction for 25 min to obtain an enzymatic reaction solution;

[0059] (3) Kneading: Mix whole wheat flour (300 g), yeast (3 g), salt (4 g) and the protein reaction solution of step 2 and stir to knead the dough. Add ice water during the stirring process to control the dough temperature not exceeding 28° C. and stir until a gluten network is formed.

[0060] (4) First fermentation (basic fermentation): The mixed dough is placed at 26°C and 80% humidity for the first fermentation. The fermentation is terminated when the dough expands to 1.5 times its original size.

[0061] (5) Dividing and shaping: Cut the dough that has been fermented for the first time into small portions (about 120g / portion), then shape each portion of dough into a round shape, press to release air, and then roll it into a cylindrical shape.

[0062] (6) Second fermentation (proofing): The shaped dough is placed in a fermentation box for second fermentation. The temperature is controlled at 28°C, the humidity is 70%, and the fermentation time is 65 minutes.

[0063] (7) Baking: The dough that has been fermented for the second time is placed in a preheated oven for baking at 180°C for approximately 25 minutes. The specific time may vary depending on the size of the dough and the performance of the oven.

[0064] The specific volume test results of the baked bread in this embodiment are as follows: Figure 2 The specific volume of the bread prepared in this example is 2.97 mL / g, which is significantly higher than that of the bread in the comparative example, indicating that this example improves the rough and dense texture defect of whole wheat bread and is more in line with the taste of consumers.

[0065] The dynamic rheology of whole wheat dough in this embodiment is as follows Figure 3 The elastic modulus (G') and viscosity modulus (G") of the dough prepared in this example are higher than those in Comparative Example 1, indicating that the addition of the protein complex enhances the elasticity and viscosity of the whole wheat dough and improves the strength of the gluten network structure in the whole wheat dough.

[0066] Embodiment 3:

[0067] (1) Mixing the protein ingredients: Mix casein (15 g) and gluten protein (15 g), add 90 ml of water and stir to obtain a protein mixture;

[0068] (2) Enzymatic cross-linking reaction: add 0.6 g of transglutaminase to the protein mixture, maintain the temperature at 40° C., and perform the enzymatic reaction for 15 min to obtain an enzymatic reaction solution;

[0069] (3) Kneading: Mix whole wheat flour (300 g), yeast (3 g), salt (4 g) and the protein reaction solution of step 2 and stir to knead the dough. Add ice water during the stirring process to control the dough temperature not exceeding 28° C. and stir until a gluten network is formed.

[0070] (4) First fermentation (basic fermentation): The mixed dough is placed at 28°C and 80% humidity for the first fermentation. The fermentation is terminated when the dough expands to 2.5 times.

[0071] (5) Dividing and shaping: Cut the dough that has been fermented for the first time into small portions (120g / portion), then shape each portion of dough into a round shape, press to release air, and then roll it into a cylindrical shape.

[0072] (6) Second fermentation (proofing): The shaped dough is placed in a fermentation box for second fermentation. The temperature is controlled at 26°C, the humidity is 85%, and the fermentation time is 70 minutes.

[0073] (7) Baking: The dough that has been fermented for the second time is placed in a preheated oven for baking at 180°C for approximately 25 minutes. The specific time may vary depending on the size of the dough and the performance of the oven.

[0074] The texture test results of the bread baked in this embodiment are as follows: Figure 4 The hardness of the bread prepared in this embodiment is 9.04N, which is significantly lower than that of the comparative example. The texture results show that this embodiment reduces the hardness of the whole wheat bread, making it softer and more acceptable to consumers.

[0075] Embodiment 4:

[0076] (1) Mixing the protein ingredients: Mix casein (25 g) and gluten protein (15 g), add 120 ml of water and stir to obtain a protein mixture;

[0077] (2) Enzymatic cross-linking reaction: 1.6 g of transglutaminase was added to the protein mixture, the temperature was maintained at 35° C., and the enzymatic reaction was carried out for 35 min to obtain an enzymatic reaction solution;

[0078] (3) Kneading: Mix whole wheat flour (300 g), yeast (3 g), salt (4 g) and the protein reaction solution of step 2, and stir to knead the dough. Control the dough temperature not to exceed 28° C. and stir until a gluten network is formed.

[0079] (4) First fermentation (basic fermentation): The mixed dough is placed at 32°C and 85% humidity for the first fermentation. The fermentation is terminated when the dough expands to 2.0 times.

[0080] (5) Dividing and shaping: Cut the dough that has been fermented for the first time into small portions (120g / portion), then shape each portion of dough into a round shape, press to release air, and then roll it into a cylindrical shape.

[0081] (6) Second fermentation (proofing): The shaped dough is placed in a fermentation box for second fermentation. The temperature is controlled at about 32°C, the humidity is at 65%, and the fermentation time is 40 minutes.

[0082] (7) Baking: The dough that has been fermented for the second time is placed in a preheated oven for baking at 180°C for approximately 25 minutes. The specific time may vary depending on the size of the dough and the performance of the oven.

[0083] The content of protein and calcium in the whole wheat bread after baking in this embodiment is as follows: Figure 5 and Figure 6 The contents of protein and calcium in the baked whole wheat bread were 24.5 g / 100 g dry weight and 138 mg / 100 g dry weight, respectively, both higher than those in the comparative example. The results show that the present embodiment improves the nutritional quality of whole wheat bread.

[0084] Finally, it should be noted that the above embodiments are only for illustrating the features and technical ideas of the present invention. Obviously, the present invention is not limited to the above embodiments. Any variations and modifications made according to the spirit of the present invention should be considered as within the protection scope of the present invention.

Claims

1. A method for improving the quality of whole wheat bread, characterized in that: Here are the steps: (1) Mixing the protein ingredients: mixing casein and gluten protein, adding water and stirring to obtain a protein mixture; (2) Enzymatic cross-linking reaction: adding transglutaminase to the protein mixture to carry out an enzymatic reaction to obtain an enzymatic reaction solution; (3) Kneading: The raw materials include whole wheat flour, water, yeast, salt and enzymatic reaction liquid; the raw materials are mixed and stirred to knead the dough, the dough temperature is controlled, and the dough is stirred until a gluten network is formed; (4) First fermentation: The mixed dough is placed for the first fermentation; (5) Dividing and shaping: The dough that has been fermented for the first time is divided and cut into small portions according to the required weight; each portion of dough is then shaped; (6) Second fermentation: The shaped dough is placed in a fermentation box for second fermentation; (7) Baking: Place the dough that has undergone the second fermentation into a preheated oven for baking.

2. A method for improving the quality of whole wheat bread according to claim 1, characterized in that: In step (1), the mass ratio of casein to gluten protein is 1:1 to 4:

1.

3. A method for improving the quality of whole wheat bread according to claim 1, characterized in that: In step (2), the amount of transglutaminase used is 0.5-4% of the total protein amount; the enzymatic reaction temperature is 35-50° C., and the enzymatic reaction time is 10-35 min.

4. A method for improving the quality of whole wheat bread according to claim 1, characterized in that: In step (3), the amount of enzymatic reaction liquid added is calculated based on the total protein mass, which is 10-20% of the mass of whole wheat flour; the amount of yeast added is 1-2% of the mass of whole wheat flour; the amount of salt added is 1.2-2% of the mass of whole wheat flour; and the dough temperature is controlled to be lower than 28° C. during kneading.

5. A method for improving the quality of whole wheat bread according to claim 1, characterized in that: In step (4), the dough is fermented for the first time at a temperature of 26 to 32° C. and a humidity of 70 to 85% until the dough expands to 1.5 to 2.5 times its original size.

6. A method for improving the quality of whole wheat bread according to claim 1, characterized in that: In step (5), shaping is performed according to the final product shape requirements, such as shaping into a round shape or a long strip shape.

7. A method for improving the quality of whole wheat bread according to claim 1, characterized in that: In step (6), the second fermentation of the dough is carried out at a temperature of 26 to 32° C. and a humidity of 65 to 85% for 40 to 70 minutes.

8. The method for improving the quality of whole wheat bread according to claim 1, characterized in that: In step (7), the baking temperature is 160-200° C. and the baking time is 25-35 minutes. The specific time is adjusted according to the size of the dough and the performance of the oven.

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