Red kidney bean bread premixed flour as well as preparation method and application thereof

Abstract

The invention discloses red kidney bean bread premixed flour which comprises the following raw materials in parts by weight: 400-500 parts of pretreated red kidney bean powder, 370-500 parts of high gluten flour, 100-130 parts of vital gluten, 40-50 parts of milk powder, 80-90 parts of white granulated sugar and 8-10 parts of edible salt. When the red kidney bean powder is used for making red kidney bean bread, the protein content of the obtained bread is close to 30%, protein and amino acid are balanced, the bread has the characteristic of slowly increasing sugar, no additive component is added, and industrial large-scale production and family baking requirements can be met.

Description

Technical Field

[0001] The invention relates to the technical field of food, and in particular to a red kidney bean bread premix and a preparation method and application thereof. Background Art

[0002] Premix powder, also known as premixed powder, is a semi-finished product made by premixing some raw and auxiliary materials based on the physical and chemical properties of the raw materials. Its main consumer groups include home baking enthusiasts, small baking workshops and baking factories. Compared with the traditional baking production process, the use of baking premix powder simplifies the mixing steps and effectively reduces the complexity and failure rate of the production process.

[0003] Bread is one of the most widely consumed staple foods in the world, with an annual per capita consumption of between 59 and 70 kilograms. However, its main ingredient, refined wheat flour, is low in protein, fiber, minerals and bioactive compounds, and lacks the essential amino acid lysine, which limits the digestion and absorption of wheat flour protein. Surveys show that more than one-third of the world's population still faces malnutrition problems, and nearly 1 billion people are chronically deficient in protein. Therefore, it is particularly important to fortify wheat flour.

[0004] Legumes are favored by food manufacturers because of their rich nutrition (rich in protein, dietary fiber, minerals and phytochemicals), affordable price and easy access. Red kidney bean (Phaseolus vulgaris L.), as an under-exploited legume, has great potential to enhance the nutritional value of wheat products. It has a high protein content (22.06-32.63%), a starch content of 25.33-49.70%, and a considerable dietary fiber content (16.21-24.50%). In addition, the essential amino acid (EAA) composition of red kidney bean meets the guidelines of the World Health Organization, making it an ideal nutritional supplement for cereal protein.

[0005] At present, high-content bean flour substitution is only used in a few baked products, such as some pasta and cookie snacks, which have relatively low requirements for gluten network structure. However, in bread making, only a small amount (usually no more than 10%) of bean flour can be added to maintain the structure and sensory quality expected by consumers. Since bean protein lacks gliadin and glutenin that can form a gluten network, a high proportion of bean flour will weaken the structure and rheological properties of the dough, thereby affecting the overall quality of the bread. In addition to technical defects, the unpleasant bean smell associated with bean flour also greatly affects consumer acceptance. Summary of the invention

[0006] [Technical issues]

[0007] The invention aims to solve the problems of low protein content, lack of essential amino acid lysine, loss of dietary fiber, vitamins and minerals and other nutrients in the refining process, and high glycemic index of existing wheat bread. At the same time, it improves the defects of high proportion of high-gluten flour in nutritional supplement bread, small volume, poor texture and flavor, and excessive use of exogenous additives, aiming to provide a nutritionally balanced, healthy and delicious bread solution.

[0008] [Technical solution]

[0009] In view of the above problems existing in the prior art, the present invention provides a red kidney bean bread premix and a preparation method and application thereof. The red kidney bean powder in the bread premix of the present invention is added in an amount of up to 40-50%, the bread protein content is close to 30%, the protein amino acids are balanced, the sugar-raising property is slowed down, and zero ingredients are added, which can meet both industrial large-scale production and household baking needs.

[0010] The technical solution of the present invention is as follows:

[0011] The first object of the present invention is to provide a red kidney bean bread premix, comprising the following raw materials and the weight proportions of the raw materials:

[0012]

[0013] In one embodiment of the present invention, the preparation method of pretreated red kidney bean powder is:

[0014] (1) removing impurities and cleaning red kidney beans;

[0015] (2) Spread the washed red kidney beans on a stainless steel plate and steam them in a steamer at 100°C for 30-45 minutes;

[0016] (3) After steaming, air-dry in a 50°C air oven for 4-6 hours until the moisture content drops below 10%;

[0017] (4) The air-dried red kidney beans were crushed with a grinder and passed through an 80-mesh sieve.

[0018] In one embodiment of the present invention, the protein content of the high-gluten flour is 16.0-16.8 g / 100 g, and the total starch content is 70.0-72.0 g / 100 g.

[0019] In one embodiment of the present invention, the milk powder is cow's milk powder.

[0020] A second object of the present invention is to provide a method for preparing the above-mentioned red kidney bean bread premix, comprising the following steps:

[0021] (1) 400-500 parts of pretreated red kidney bean powder, 370-500 parts of high-gluten flour, and 100-130 parts of gluten powder were stirred at low speed for 3-5 minutes until they were evenly mixed;

[0022] (2) Continue to add 40-50 parts of milk powder, 80-90 parts of white sugar and 8-10 parts of edible salt, and stir at a low speed for 3-5 minutes until the mixture is evenly mixed to obtain the red kidney bean bread premix.

[0023] In an embodiment of the present invention, in steps (1) and (2), the rotation speed of the low-speed stirring is 50-100 rpm.

[0024] The third object of the present invention is to provide an application of the above-mentioned red kidney bean bread premix for making red kidney bean bread.

[0025] The fourth object of the present invention is to provide a method for preparing red kidney bean bread using the above-mentioned red kidney bean bread premix, comprising the following steps: each raw material is measured in parts by weight;

[0026] (1) Add 20-25 parts of high-sugar yeast and 750-850 parts of water to 1150 parts of red kidney bean bread premix, first stir with a dough mixer at medium speed until the water is fully absorbed by the dough, then adjust to high speed and stir until the dough can be pulled into a thin film;

[0027] (2) Add 150-160 parts of butter to the dough, first beat at medium speed to allow the butter to be fully absorbed by the dough, then adjust to high speed and beat until a glove film appears on the dough;

[0028] (3) Leave the beaten dough to rise at room temperature for 30-40 minutes, and turn it over after 15-20 minutes to shape and exhaust the dough;

[0029] (4) Divide the proofed dough into 60-120 portions, shape them, and place them in a proofing box at a temperature of 37±2°C and a humidity of 85±5%rh to continue proofing for 60-90 minutes;

[0030] (5) putting the proofed dough into an oven and baking it to obtain the red kidney bean bread.

[0031] In one embodiment of the present invention, in steps (1) and (2), the rotation speed of medium-speed stirring is 100-150 rpm; the rotation speed of high-speed stirring is 200-300 rpm.

[0032] In step (1), the water temperature is changed according to the seasonal temperature to ensure that the center temperature of the dough after final beating is 25±1°C.

[0033] In step (1), a JOINT WTN YB-7LD mixer is used for stirring.

[0034] In one embodiment of the present invention, in step (5), the baking conditions are: the upper fire temperature is 190-200°C, the lower fire temperature is 180-190°C, and the baking time is 18-20 minutes. When there are 5 minutes left in the baking time, the baking tray is rotated 180° to ensure that the bread is heated evenly.

[0035] The beneficial technical effects of the present invention are:

[0036] (1) The amount of red kidney bean powder added in the present invention is 40-50%, which significantly increases the protein content of bread premix from 16% to 27-30%, effectively solving the problem of nutritional imbalance and lack of essential amino acid lysine in wheat bread, and achieving perfect complementarity between beans and cereals in lysine and sulfur-containing amino acids. In addition, the addition of bean powder also introduces a variety of functional ingredients into bread premix, such as flavonoids, tannins, phytosterols and dietary fiber, which not only enhance the antioxidant properties of the product, but also help reduce the risk of certain chronic diseases. By incorporating beans into bread premix, the total starch content can be reduced from 60% to 40%. At the same time, with the help of the glucose sustained-release properties of bean starch, the glycemic index of bread is successfully reduced by 13-15%, providing more abundant dietary options for people with special dietary needs such as diabetics.

[0037] (2) In modern food processing technology, the pretreatment method has an important impact on the final quality of the ingredients. Especially in pasta production, how to effectively integrate non-traditional raw materials such as bean powder while maintaining the integrity of the gluten network is a technical challenge. The normal pressure steaming adopted in the present invention is an effective pretreatment method, which can not only significantly optimize the gluten network structure that may be damaged by the large amount of bean powder added, but also effectively reduce the adverse effects of anti-nutritional factors in bean ingredients, while inhibiting the unique beany smell of bean bread; and the pretreatment process is relatively mild, which is conducive to retaining the beneficial ingredients in red kidney beans, and can promote the formation of resistant starch to a certain extent, thereby helping to reduce the glycemic index of bread; finally, the bread produced by the present invention is more in line with the contemporary people's pursuit of healthy diet.

[0038] (3) The red kidney bean bread premix of the present invention uses a scientific ratio and a unique pretreatment technology to make the red kidney bean bread have a similar taste and flavor to traditional bread while maintaining the characteristics of high protein and slow blood sugar rise. During the production process, since the premix has completed most of the preparation work, it is only necessary to follow simple steps to easily make delicious and healthy red kidney bean bread. Compared with traditional whole wheat bread, the bread made by the present invention has a fluffy texture and a delicate structure, and after pretreatment, the beany smell of red kidney beans is largely eliminated, and is replaced by a pleasant bean fragrance produced after the Maillard reaction; in addition, the present invention does not add any additives, and only improves the red kidney bean bread through pretreatment. It is a healthy zero-additive red kidney bean bread premix, which means that consumers can enjoy chemical additive-free, pure and natural food, which is very attractive to modern people who pursue a healthy lifestyle. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 The pore structure analysis of the breads obtained in Examples 1-6 and Comparative Examples 1-7;

[0040] Figure 2 The protein and total starch contents of the breads prepared in Examples 1-6 and Comparative Examples 1-7. DETAILED DESCRIPTION

[0041] The present invention is described in detail below in conjunction with the accompanying drawings and embodiments.

[0042] Example 1

[0043] A method for preparing red kidney bean bread premix comprises the following steps:

[0044] (1) removing impurities and cleaning red kidney beans;

[0045] (2) Spread the washed red kidney beans on a stainless steel plate and steam them in a steamer at 100°C for 15 min;

[0046] (3) After steaming, air-dry in a 50°C air oven for 6 h until the moisture content drops below 10%;

[0047] (4) crushing the air-dried red kidney beans with a grinder and passing through an 80-mesh powder sieve to obtain pretreated red kidney bean powder;

[0048] (5) 500 parts of pretreated red kidney bean powder, 370 parts of high-gluten flour, and 130 parts of gluten powder were stirred at 100 rpm for 3 min until they were uniformly mixed;

[0049] (6) Continue to add 40 parts of milk powder, 80 parts of white sugar and 8 parts of edible salt, and stir at 100 rpm for 3 minutes until the mixture is evenly mixed to obtain the red kidney bean bread premix.

[0050] The method for preparing red kidney bean bread using the red kidney bean bread premix comprises the following steps:

[0051] (1) Add 20 parts of high-sugar yeast and 750 parts of water to 1150 parts of red kidney bean bread premix, first stir with a dough mixer at 100 rpm until the water is fully absorbed by the dough, then adjust the speed to 200 rpm and stir until the dough can be pulled into a thin film;

[0052] (2) adding 160 parts of butter to the dough, first beating at 100 rpm so that the butter is fully absorbed by the dough, and then adjusting the speed to 200 rpm and beating until a glove film appears on the dough;

[0053] (3) Place the beaten dough at room temperature (25±1°C) to rise for 40 minutes, and turn it over after 20 minutes to shape and exhaust the dough;

[0054] (4) Divide the proofed dough into 120 portions, shape them and place them in a proofing box at a temperature of 37±2°C and a humidity of 85±5%rh to continue proofing for 60 minutes;

[0055] (5) The proofed dough is placed in an oven at 190° C. on the upper side and 180° C. on the lower side and baked for 20 min to obtain the red kidney bean bread.

[0056] Example 2

[0057] A method for preparing red kidney bean bread premix comprises the following steps:

[0058] Same as Example 1, except that in step (2), the steaming time is 30 min.

[0059] Example 3

[0060] A method for preparing red kidney bean bread premix comprises the following steps:

[0061] Same as Example 1, except that in step (2), the steaming time is 45 minutes.

[0062] Example 4

[0063] A method for preparing red kidney bean bread premix comprises the following steps:

[0064] Same as Example 1, except that in step (2), the steaming time is 60 min.

[0065] Example 5

[0066] A method for preparing red kidney bean bread premix comprises the following steps:

[0067] (1) removing impurities and cleaning red kidney beans;

[0068] (2) Spread the washed red kidney beans on a stainless steel plate and steam them in a steamer at 100°C for 45 minutes;

[0069] (3) After steaming, air-dry in a 50°C air oven for 4 h until the moisture content drops below 10%;

[0070] (4) crushing the air-dried red kidney beans with a grinder and passing through an 80-mesh powder sieve to obtain pretreated red kidney bean powder;

[0071] (5) 450 parts of pretreated red kidney bean powder, 435 parts of high-gluten flour, and 115 parts of gluten powder were stirred at 50 rpm for 5 min until they were uniformly mixed;

[0072] (6) Continue to add 40 parts of milk powder, 80 parts of white sugar and 8 parts of edible salt, and stir at 50 rpm for 5 minutes until the mixture is evenly mixed to obtain the red kidney bean bread premix.

[0073] The method for preparing red kidney bean bread using the red kidney bean bread premix comprises the following steps:

[0074] (1) Add 20 parts of high-sugar yeast and 850 parts of water to 1150 parts of red kidney bean bread premix, first stir with a dough mixer at 150 rpm until the water is fully absorbed by the dough, then adjust the speed to 300 rpm and stir until the dough can be pulled into a thin film;

[0075] (2) adding 160 parts of butter to the dough, first beating at 150 rpm so that the butter is fully absorbed by the dough, and then adjusting the speed to 300 rpm and beating until a glove film appears on the dough;

[0076] (3) Place the beaten dough at room temperature (25±1°C) to rise for 40 minutes, and turn it over after 20 minutes to shape and exhaust the dough;

[0077] (4) Divide the proofed dough into 120 portions, shape them and place them in a proofing box at a temperature of 37±2°C and a humidity of 85±5%rh to continue proofing for 60 minutes;

[0078] (5) The proofed dough is placed in an oven at 190° C. on the upper side and 180° C. on the lower side and baked for 20 min to obtain the red kidney bean bread.

[0079] Example 6

[0080] A method for preparing red kidney bean bread premix comprises the following steps:

[0081] (1) removing impurities and cleaning red kidney beans;

[0082] (2) Spread the washed red kidney beans on a stainless steel plate and steam them in a steamer at 100°C for 45 minutes;

[0083] (3) After steaming, air-dry in a 50°C air oven for 5 h until the moisture content drops below 10%;

[0084] (4) crushing the air-dried red kidney beans with a grinder and passing through an 80-mesh powder sieve to obtain pretreated red kidney bean powder;

[0085] (5) 400 parts of pretreated red kidney bean powder, 500 parts of high-gluten flour, and 100 parts of gluten powder were stirred at 100 rpm for 3 min until they were uniformly mixed;

[0086] (6) Continue to add 40 parts of milk powder, 80 parts of white sugar and 8 parts of edible salt, and stir at 100 rpm for 3 minutes until the mixture is evenly mixed to obtain the red kidney bean bread premix.

[0087] The method for preparing red kidney bean bread using the red kidney bean bread premix comprises the following steps:

[0088] (1) Add 20 parts of high-sugar yeast and 850 parts of water to 1150 parts of red kidney bean bread premix, first stir with a dough mixer at 150 rpm until the water is fully absorbed by the dough, then adjust the speed to 300 rpm and stir until the dough can be pulled into a thin film;

[0089] (2) adding 160 parts of butter to the dough, first beating at 150 rpm so that the butter is fully absorbed by the dough, and then adjusting the speed to 300 rpm and beating until a glove film appears on the dough;

[0090] (3) Place the beaten dough at room temperature (25±1°C) to rise for 40 minutes, and turn it over after 20 minutes to shape and exhaust the dough;

[0091] (4) Divide the proofed dough into 120 portions, shape them and place them in a proofing box at a temperature of 37±2°C and a humidity of 85±5%rh to continue proofing for 60 minutes;

[0092] (5) The proofed dough is placed in an oven at 190° C. on the upper side and 180° C. on the lower side and baked for 20 min to obtain the red kidney bean bread.

[0093] Comparative Example 1

[0094] A method for preparing red kidney bean bread premix comprises the following steps:

[0095] (1) removing impurities and cleaning red kidney beans;

[0096] (2) After cleaning, air-dry in a 50°C air oven for 3 h until the moisture content drops below 10%;

[0097] (3) crushing the air-dried red kidney beans with a grinder and passing through an 80-mesh sieve to obtain red kidney bean powder;

[0098] (4) 500 parts of red kidney bean powder, 370 parts of high-gluten flour, and 130 parts of gluten powder were stirred at 100 rpm for 3 min until they were uniformly mixed;

[0099] (5) Continue to add 40 parts of milk powder, 80 parts of white sugar and 8 parts of edible salt, and stir at 100 rpm for 3 minutes until the mixture is evenly mixed to obtain the red kidney bean bread premix.

[0100] The method for preparing red kidney bean bread using the red kidney bean bread premix comprises the following steps:

[0101] (1) Add 20 parts of high-sugar yeast and 800 parts of water to 1150 parts of red kidney bean bread premix, first stir with a dough mixer at 100 rpm until the water is fully absorbed by the dough, then adjust the speed to 200 rpm and stir until the dough can be pulled into a thin film;

[0102] (2) adding 160 parts of butter to the dough, first beating at 100 rpm so that the butter is fully absorbed by the dough, and then adjusting the speed to 200 rpm and beating until a glove film appears on the dough;

[0103] (3) Place the beaten dough at room temperature (25±1°C) to rise for 40 minutes, and turn it over after 20 minutes to shape and exhaust the dough;

[0104] (4) Divide the proofed dough into 120 portions, shape them and place them in a proofing box at a temperature of 37±2°C and a humidity of 85±5%rh to continue proofing for 60 minutes;

[0105] (5) The proofed dough is placed in an oven at 190° C. on the upper side and 180° C. on the lower side and baked for 20 min to obtain the red kidney bean bread.

[0106] Comparative Example 2

[0107] A method for preparing red kidney bean bread premix comprises the following steps:

[0108] (1) removing impurities and cleaning red kidney beans;

[0109] (2) Soak the red kidney beans in 4°C water overnight and peel them;

[0110] (3) After peeling, the red kidney beans were air-dried in a 50° C. air oven for 3 h until the moisture content dropped below 10%;

[0111] (4) crushing the air-dried red kidney beans with a grinder and passing through an 80-mesh sieve to obtain red kidney bean powder;

[0112] (5) 500 parts of red kidney bean powder, 370 parts of high-gluten flour, and 130 parts of gluten powder were stirred at 100 rpm for 3 min until they were uniformly mixed;

[0113] (6) Continue to add 40 parts of milk powder, 80 parts of white sugar and 8 parts of edible salt, and stir at 100 rpm for 3 minutes until the mixture is evenly mixed to obtain the red kidney bean bread premix.

[0114] The method for preparing red kidney bean bread using the red kidney bean bread premix comprises the following steps:

[0115] (1) Add 20 parts of high-sugar yeast and 750 parts of water to 1150 parts of red kidney bean bread premix, first stir with a dough mixer at 150 rpm until the water is fully absorbed by the dough, then adjust the speed to 300 rpm and stir until the dough can be pulled into a thin film;

[0116] (2) adding 160 parts of butter to the dough, first beating at 150 rpm so that the butter is fully absorbed by the dough, and then adjusting the speed to 300 rpm and beating until a glove film appears on the dough;

[0117] (3) Place the beaten dough at room temperature (25±1°C) to rise for 40 minutes, and turn it over after 20 minutes to shape and exhaust the dough;

[0118] (4) Divide the proofed dough into 120 portions, shape them and place them in a proofing box at a temperature of 37±2°C and a humidity of 85±5%rh to continue proofing for 60 minutes;

[0119] (5) The proofed dough is placed in an oven at 190° C. on the upper side and 180° C. on the lower side and baked for 20 min to obtain the red kidney bean bread.

[0120] Comparative Example 3

[0121] A method for preparing red kidney bean bread premix comprises the following steps:

[0122] (1) removing impurities and cleaning red kidney beans;

[0123] (2) The red kidney beans were baked in an oven at 160°C for 20 min;

[0124] (3) After baking, air-dry in a 50°C air oven for 2 h until the moisture content drops below 10%;

[0125] (4) crushing the air-dried red kidney beans with a grinder and passing through an 80-mesh sieve to obtain red kidney bean powder;

[0126] (5) 500 parts of red kidney bean powder, 370 parts of high-gluten flour, and 130 parts of gluten powder were stirred at 50 rpm for 5 min until they were uniformly mixed;

[0127] (6) Continue to add 40 parts of milk powder, 80 parts of white sugar and 8 parts of edible salt, and stir at 50 rpm for 5 minutes until the mixture is evenly mixed to obtain the red kidney bean bread premix.

[0128] The method for preparing red kidney bean bread using the red kidney bean bread premix comprises the following steps:

[0129] (1) Add 20 parts of high-sugar yeast and 860 parts of water to 1150 parts of red kidney bean bread premix, first stir with a dough mixer at 100 rpm until the water is fully absorbed by the dough, then adjust the speed to 250 rpm and stir until the dough can be pulled into a thin film;

[0130] (2) adding 160 parts of butter to the dough, first beating at 100 rpm to allow the butter to be fully absorbed by the dough, and then adjusting the speed to 250 rpm and beating until a glove film appears on the dough;

[0131] (3) Place the beaten dough at room temperature (25±1°C) to rise for 40 minutes, and turn it over after 20 minutes to shape and exhaust the dough;

[0132] (4) Divide the proofed dough into 120 portions, shape them and place them in a proofing box at a temperature of 37±2°C and a humidity of 85±5%rh to continue proofing for 60 minutes;

[0133] (5) The proofed dough is placed in an oven at 190° C. on the upper side and 180° C. on the lower side and baked for 20 min to obtain the red kidney bean bread.

[0134] Comparative Example 4

[0135] A method for preparing red kidney bean bread premix comprises the following steps:

[0136] (1) removing impurities and cleaning red kidney beans;

[0137] (2) Red kidney beans were sterilized in an autoclave at 121°C for 15 min;

[0138] (3) After high pressure steaming, air-dry in a 50°C air oven for 4 h until the moisture content drops below 10%;

[0139] (4) crushing the air-dried red kidney beans with a grinder and passing through an 80-mesh sieve to obtain red kidney bean powder;

[0140] (5) 500 parts of red kidney bean powder, 370 parts of high-gluten flour, and 130 parts of gluten powder were stirred at 80 rpm for 4 min until they were uniformly mixed;

[0141] (6) Continue to add 40 parts of milk powder, 80 parts of white sugar and 8 parts of edible salt, and stir at 80 rpm for 4 minutes until the mixture is evenly mixed to obtain the red kidney bean bread premix.

[0142] The method for preparing red kidney bean bread using the red kidney bean bread premix comprises the following steps:

[0143] (1) Add 20 parts of high-sugar yeast and 880 parts of water to 1150 parts of red kidney bean bread premix, first stir with a dough mixer at 150 rpm until the water is fully absorbed by the dough, then adjust the speed to 250 rpm and stir until the dough can be pulled into a thin film;

[0144] (2) adding 160 parts of butter to the dough, first beating at 150 rpm so that the butter is fully absorbed by the dough, and then adjusting the speed to 250 rpm and beating until a glove film appears on the dough;

[0145] (3) Place the beaten dough at room temperature (25±1°C) to rise for 40 minutes, and turn it over after 20 minutes to shape and exhaust the dough;

[0146] (4) Divide the proofed dough into 120 portions, shape them and place them in a proofing box at a temperature of 37±2°C and a humidity of 85±5%rh to continue proofing for 60 minutes;

[0147] (5) The proofed dough is placed in an oven at 190° C. on the upper side and 180° C. on the lower side and baked for 20 min to obtain the red kidney bean bread.

[0148] Comparative Example 5

[0149] A method for preparing red kidney bean bread premix comprises the following steps:

[0150] (1) removing impurities and cleaning red kidney beans;

[0151] (2) placing the red kidney beans in a constant temperature incubator at 37±2°C and 80±5% humidity for three days for germination;

[0152] (3) picking out the sprouted red kidney beans and air-drying them in a 50°C air oven for 4 h until the moisture content drops below 10%;

[0153] (4) crushing the air-dried red kidney beans with a grinder and passing through an 80-mesh sieve to obtain red kidney bean powder;

[0154] (5) 500 parts of red kidney bean powder, 370 parts of high-gluten flour, and 130 parts of gluten powder were stirred at 100 rpm for 5 min until they were uniformly mixed;

[0155] (6) Continue to add 40 parts of milk powder, 80 parts of white sugar and 8 parts of edible salt, and stir at 100 rpm for 5 minutes until the mixture is evenly mixed to obtain the red kidney bean bread premix.

[0156] The method for preparing red kidney bean bread using the red kidney bean bread premix comprises the following steps:

[0157] (1) Add 20 parts of high-sugar yeast and 800 parts of water to 1150 parts of red kidney bean bread premix, first stir with a dough mixer at 100 rpm until the water is fully absorbed by the dough, then adjust the speed to 300 rpm and stir until the dough can be pulled into a thin film;

[0158] (2) adding 160 parts of butter to the dough, first beating at 100 rpm so that the butter is fully absorbed by the dough, and then adjusting the speed to 300 rpm and beating until a glove film appears on the dough;

[0159] (3) Place the beaten dough at room temperature (25±1°C) to rise for 40 minutes, and turn it over after 20 minutes to shape and exhaust the dough;

[0160] (4) Divide the proofed dough into 120 portions, shape them and place them in a proofing box at a temperature of 37±2°C and a humidity of 85±5%rh to continue proofing for 60 minutes;

[0161] (5) The proofed dough is placed in an oven at 190° C. on the upper side and 180° C. on the lower side and baked for 20 min to obtain the red kidney bean bread.

[0162] Comparative Example 6

[0163] A method for preparing red kidney bean bread premix comprises the following steps:

[0164] (1) removing impurities and cleaning red kidney beans;

[0165] (2) Red kidney beans were microwaved at rated power (800 W) for 2 min;

[0166] (3) After microwave treatment, air-dry in a 50°C air oven for 4 h until the moisture content drops below 10%;

[0167] (4) crushing the air-dried red kidney beans with a grinder and passing through an 80-mesh sieve to obtain red kidney bean powder;

[0168] (5) 500 parts of red kidney bean powder, 370 parts of high-gluten flour, and 130 parts of gluten powder were stirred at 100 rpm for 5 min until they were uniformly mixed;

[0169] (6) Continue to add 40 parts of milk powder, 80 parts of white sugar and 8 parts of edible salt, and stir at 100 rpm for 5 minutes until the mixture is evenly mixed to obtain the red kidney bean bread premix.

[0170] The method for preparing red kidney bean bread using the red kidney bean bread premix comprises the following steps:

[0171] (1) Add 20 parts of high-sugar yeast and 850 parts of water to 1150 parts of red kidney bean bread premix, first stir with a dough mixer at 150 rpm until the water is fully absorbed by the dough, then adjust the speed to 300 rpm and stir until the dough can be pulled into a thin film;

[0172] (2) adding 160 parts of butter to the dough, first beating at 200 rpm so that the butter is fully absorbed by the dough, and then adjusting the speed to 500 rpm and beating until a glove film appears on the dough;

[0173] (3) Place the beaten dough at room temperature (25±1°C) to rise for 40 minutes, and turn it over after 20 minutes to shape and exhaust the dough;

[0174] (4) Divide the proofed dough into 120 portions, shape them and place them in a proofing box at a temperature of 37±2°C and a humidity of 85±5%rh to continue proofing for 60 minutes;

[0175] (5) The proofed dough is placed in an oven at 190° C. on the upper side and 180° C. on the lower side and baked for 20 min to obtain the red kidney bean bread.

[0176] Comparative Example 7

[0177] A method for making bread without red kidney bean powder comprises the following steps:

[0178] (1) 1000 parts of high-gluten flour, 40 parts of milk powder, 80 parts of white sugar and 8 parts of edible salt were stirred at 100 rpm for 3 min until they were uniformly mixed to prepare a bread premix;

[0179] (2) adding 20 parts of high-sugar yeast and 680 parts of water to 1150 parts of bread premix, first stirring with a dough mixer at 150 rpm until the water is fully absorbed by the dough, then adjusting the speed to 300 rpm and stirring until the dough can be pulled into a thin film;

[0180] (2) adding 160 parts of butter to the dough, first beating at 150 rpm so that the butter is fully absorbed by the dough, and then adjusting the speed to 300 rpm and beating until a glove film appears on the dough;

[0181] (3) Place the beaten dough at room temperature (25±1°C) to rise for 40 minutes, and turn it over after 20 minutes to shape and exhaust the dough;

[0182] (4) Divide the proofed dough into 120 portions, shape them and place them in a proofing box at a temperature of 37±2°C and a humidity of 85±5%rh to continue proofing for 60 minutes;

[0183] (5) The proofed dough is placed in an oven at 190° C. on the upper side and 180° C. on the lower side and baked for 20 minutes to obtain the bread.

[0184] Experiment 1 Bread quality evaluation

[0185] Bread was prepared using Examples 1-6 and Comparative Examples 1-7, respectively. The specific volume of bread is defined as the ratio of the volume of bread to its mass, and the volume was measured using the millet substitution method. A colorimeter was used to determine the L*, a*, and b* values ​​of the bread crust. The total texture determination (TPA) of bread was based on the AACC74-09 test method with slight modifications. After the bread was cooled for 2 hours, it was cut into uniform slices (15 mm), and three slices were taken for TPA testing in a texture analyzer. The probe used was P36R, and the measurement parameters were: the measurement speed was 1.5 mm / s throughout the entire process, the strain force was 5 g, the deformation degree was 50%, and the interval between two compressions was 1 s. A scanner (Cano Scan LiDE110) was used to scan the bread cross section, and the ImageJ software was used to analyze the pore properties of the bread cross section. Each group of samples was measured 6 times. The specific volume and texture analysis of the bread are shown in Table 1; the colorimetric analysis of the bread is shown in Table 2.

[0186] Table 1

[0187]

[0188]

[0189] The specific volume and texture of bread are key indicators for evaluating bread quality. Generally, elasticity, cohesion and resilience are directly proportional to bread quality, while hardness and chewiness are inversely proportional. As shown in Table 1, the specific volume of wheat bread in Comparative Example 7 is the largest, at 4.45 g / cm 3 After adding 50% red kidney bean powder, the specific volume of comparative example 1 dropped to 3.37 g / cm 3 . At the same time, six pretreatment experiments were carried out on red kidney bean bread. Except for the normal pressure steaming treatment, the pretreatments of Comparative Examples 2 to 6 did not show a good improvement in the bread structure. In Examples 1-4, the specific volume of the red kidney bean bread was improved to varying degrees after 30-60 minutes of normal pressure steaming treatment. Among them, the 45-minute normal pressure steaming treatment in Example 3 had the best improvement effect. The hardness of the red kidney bean bread was reduced by 39%, the elasticity was increased by 3%, the cohesion was increased by 22%, and the recovery was increased by 43%. As the bean flour content gradually decreased from 50% to 45% and then to 40%, the specific volume of the bread also increased accordingly, and the texture became softer.

[0190] Table 2

[0191]

[0192] The color of bread is one of the key factors that determine consumers' willingness to buy. After adding red kidney bean flour, the L* value of both the crust and the crumbs generally showed a downward trend compared with the wheat bread in Comparative Example 7, while the a* value showed an upward trend. This phenomenon is partly attributed to the inherent deep red hue of red kidney beans, but also because red kidney bean flour is rich in protein, which promotes the Maillard reaction and caramelization reaction on the surface of the bread. This trend of deepening color becomes more obvious as the normal pressure steaming time increases. Although the deep red color of red kidney bean bread is different from traditional light-colored bread, this dark color can be seen as a sign of pure naturalness and high protein, which helps to attract consumers' attention.

[0193] Figure 1 The bread pore analysis diagrams of the examples and comparative examples are shown, af is examples 1 to 6, and gm is comparative examples 1 to 7; it can be observed from the figure that the pore structure of the blank bread of comparative example 7 is evenly distributed and fine, reflecting good pore characteristics. However, after adding 50% red kidney bean powder, larger holes appeared in the pores of the bread of comparative example 1. After various pretreatment attempts, normal pressure steaming is a pretreatment method with relatively good improvement effect. As the pretreatment time increases from 15min to 60min, the pore structure of the bread gradually tends to be uniform and delicate, among which the pore structure of the bread pretreated for 30min and 45min is relatively prominent.

[0194] Experiment 2: Sensory evaluation of bread

[0195] 10 people were selected to form a sensory evaluation panel to conduct sensory evaluation on the prepared red kidney bean bread. The sensory evaluation criteria and scores of bread are shown in Tables 3 and 4, respectively.

[0196] Table 3

[0197]

[0198] Table 4

[0199]

[0200]

[0201] The sensory evaluation of red kidney bean bread was conducted in three aspects: bread color and texture, internal morphology and structure, and flavor and taste. The results showed that the sensory score of red kidney bean bread made directly without pretreatment was low, which was manifested as small bread volume, hard texture and rough structure, accompanied by obvious beany smell. In the embodiment, the sensory evaluation score of bread was significantly improved after 30-45 minutes of normal pressure steaming, and the sensory attributes such as specific volume, texture and beany smell were effectively improved.

[0202] Experiment 3 Determination of protein content and amino acid composition

[0203] The protein content was determined by the Kjeldahl method in the national standard GB 5009.5-2016. The amino acid composition was quantified by high performance liquid chromatography, and acid hydrolysis and alkaline hydrolysis were used at the same time. For acid hydrolysis, 8 mL of 6 mol / L HCl was first added to 100 mg of freeze-dried bread sample, and then the mixture was fully hydrolyzed at 120 ° C after nitrogen sealing (22 h). Then it was cooled to room temperature, and the hydrolyzate was completely transferred to a stoppered test tube, neutralized with 10 mol / L NaOH (about 4.8 mL), and made up to 25 mL with distilled water. For alkaline hydrolysis, 8 mL of 5 M NaOH was first added for hydrolysis, and then 6 mol / L HCl was added for neutralization, and finally made up to 25 mL with distilled water. After acid hydrolysis and alkaline hydrolysis were made up to volume, they were filtered using double-layer filter paper, and the filtrate was centrifuged (10000 r / min, 10 min) and passed through a membrane (0.22 μm water filter membrane) and placed in a liquid phase vial for determination. Chromatographic conditions included a Hypersil ODS C18 column (4.6 mm × 150 mm, 5 μm), operated at 40°C, and detection wavelengths of 338 nm and 262 nm. The mobile phases were 20 mmol / L sodium acetate aqueous solution (A) and sodium acetate aqueous solution (20 mmol / L): methanol: acetonitrile = 1:2:2 (v / v) (B), with a flow rate of 1.0 mL / min. Bread protein content as Figure 2 The essential amino acid (mg / g) analysis results of bread are shown in Table 5.

[0204] Table 5

[0205]

[0206]

[0207] Compared with the wheat bread of Comparative Example 7 (16.85%), the protein content of red kidney bean bread (26.85-30.96%) is significantly higher. As the amount of soy flour added increases from 40% to 50%, the protein content of bread also shows an upward trend. According to the regulations of the European Commission, when 20% of the energy in a product is provided by protein, it can be identified as a "high-protein" food. Therefore, the red kidney bean bread in this experiment clearly meets the standards of high-protein food.

[0208] The composition and proportion of amino acids are key factors in determining the nutritional quality of protein. By determining the eight essential amino acids in each sample, the distribution of amino acid components can be comprehensively analyzed. Lysine is the primary limiting amino acid in white bread, while sulfur-containing amino acids are the primary limiting amino acids in beans. As can be seen from Table 5, the lysine content in Comparative Example 7 is only 19.44 mg / g, which is far from the 48 mg / g standard recommended by FAO / WHO. However, after adding 50% red kidney bean powder for nutritional fortification, the lysine content is significantly increased to 32.71 mg / g in Comparative Example 1. In addition, the content of sulfur-containing amino acids in Comparative Example 7 is 13.09 mg / g, which is very close to 13.21 mg / g in white bread, thereby achieving amino acid complementarity between lysine and sulfur-containing amino acids. Among various pretreatments, the 15-45 min atmospheric pressure steaming process is relatively mild and has the least negative impact on the amino acid composition. Although Examples 5 and 6 are relatively excellent in terms of specific volume and texture, the content of protein and amino acids is also reduced due to the reduction of bean powder.

[0209] Experiment 4: In vitro starch digestion assay

[0210] The total starch content of bread was determined using the enzymatic hydrolysis method in the national standard GB 5009.9-85; the in vitro starch digestion experiment was determined using the following method: weigh 0.1g of freeze-dried bread sample (the experimental group weighed the weight of equal carbohydrates) and put it into 5mL of sodium acetate buffer solution (pH 5.2, 0.5M), add 5mL of mixed enzyme (α-amylase 200U / mL, amyloglucosidase 200U / mL), add 2-3 glass beads, digest for 0, 5, 10, 20, 30, 45, 60, 90, 120, 150, 180min, and then take 0.1mL of the digestion solution and transfer it to a 2mL centrifuge tube pre-added with 0.9mL of anhydrous ethanol to stop digestion. The amount of glucose released in the supernatant was determined using the Megazyme d-glucose kit. The starch digestibility (%) was calculated as the ratio of the weight of digested starch to the weight of total starch in the bread. The total starch content of bread is as follows: Figure 2 The results of in vitro starch digestion analysis of bread are shown in Table 6.

[0211] Table 6

[0212]

[0213] Bread usually releases high levels of glucose after being digested, and excessive intake can easily lead to obesity. As people's pursuit of healthy diet continues to increase, bread with low glucose release will have a broad market prospect. Figure 2 It can be observed that the total starch content of the wheat bread in Comparative Example 7 is as high as 60%. After adding 40-50% red kidney bean powder, the total starch content dropped to 40-44%, which reduced the carbohydrate content in the bread by about 1 / 3. In Table 6, compared with 11.76% in Comparative Example 7, the addition of different pretreated red kidney bean powders increased the resistant starch content of the red kidney bean bread, among which Example 3 had the highest resistant starch content of 26.43%. In terms of rapidly digestible starch, except for the germination treatment in Comparative Example 5, Examples 2-7 all increased the RDS content to varying degrees. In terms of eGI value, the eGI value of Comparative Example 7 is 94.4. After adding red kidney bean powder, the eGI values ​​of Examples 1-7 are reduced to 13-15%, among which the eGI value of Example 2-3 treated with normal pressure steaming for 15-30 min is relatively the lowest, mainly due to the increase of resistant starch during the normal pressure steaming process.

[0214] In summary, different pretreatment methods have certain nutritional strengthening effects on wheat bread, but the effect of normal pressure steaming treatment is better, which can significantly improve the specific volume and color of high-protein, slow-rising sugar red kidney bean bread, while reducing the hardness and chewiness of the bread, giving the red kidney bean bread a softer texture while strengthening the nutrition, which is a more suitable pretreatment method. An in-depth study of normal pressure steaming treatment showed that there was no significant change in the red kidney bean bread after 15 minutes of treatment. After 30-45 minutes of treatment, the quality attributes of the red kidney bean bread were improved, and this trend weakened after 60 minutes. Although reducing the bean powder content in Example 5-6 can also improve the structural characteristics of the red kidney bean bread to a certain extent, its nutritional attributes are correspondingly weakened.

[0215] The embodiments provided above are not intended to limit the scope of the present invention, and the steps described are not intended to limit the execution order thereof. Those skilled in the art may make obvious improvements to the present invention in combination with existing common knowledge, which also fall within the scope of protection defined by the claims of the present invention.

Claims

1. A red kidney bean bread premix, characterized in that: The raw materials and the weight proportions of each raw material are as follows:

2. The red kidney bean bread premix according to claim 1, characterized in that The preparation method of pretreated red kidney bean powder is: (1) removing impurities and cleaning red kidney beans; (2) Spread the washed red kidney beans on a stainless steel plate and steam them in a steamer at 100°C for 30-45 minutes; (3) After steaming, air-dry in a 50°C air oven for 4-6 hours until the moisture content drops below 10%; (4) The air-dried red kidney beans were crushed with a grinder and passed through an 80-mesh sieve.

3. The red kidney bean bread premix according to claim 1, characterized in that The protein content of high-gluten flour is 16.0-16.8g / 100g, and the total starch content is 70.0-72.0g / 100g.

4. The red kidney bean bread premix according to claim 1, characterized in that Milk powder is cow's milk powder.

5. A method for preparing the red kidney bean bread premix according to claim 1, characterized in that: The steps include: (1) 400-500 parts of pretreated red kidney bean powder, 370-500 parts of high-gluten flour, and 100-130 parts of gluten powder were stirred at low speed for 3-5 minutes until they were evenly mixed; (2) Continue to add 40-50 parts of milk powder, 80-90 parts of white sugar and 8-10 parts of edible salt, and stir at a low speed for 3-5 minutes until the mixture is evenly mixed to obtain the red kidney bean bread premix.

6. An application of the red kidney bean bread premix according to claim 1, characterized in that: Used to make red kidney bean bread.

7. A method for making red kidney bean bread using the red kidney bean bread premix according to claim 1, characterized in that: The method comprises the following steps: each raw material is measured in parts by weight; (1) Add 20-25 parts of high-sugar yeast and 750-850 parts of water to 1150 parts of red kidney bean bread premix, first stir with a dough mixer at medium speed until the water is fully absorbed by the dough, then adjust to high speed and stir until the dough can be pulled into a thin film; (2) Add 150-160 parts of butter to the dough, first beat at medium speed to allow the butter to be fully absorbed by the dough, then adjust to high speed and beat until a glove film appears on the dough; (3) Leave the beaten dough to rise at room temperature for 30-40 minutes, and turn it over after 15-20 minutes to shape and exhaust the dough; (4) Divide the proofed dough into 60-120 portions as needed, shape the dough, and place it in a proofing box at a temperature of 37±2° C. and a humidity of 85±5% rh to continue proofing for 60-90 minutes; (5) putting the proofed dough into an oven and baking it to obtain the red kidney bean bread.

8. The method according to claim 7, characterized in that In steps (1) and (2), the speed of medium-speed stirring is 100-150 rpm; the speed of high-speed stirring is 200-300 rpm.

9. The method according to claim 7, characterized in that: In step (1), the water temperature is changed according to the seasonal temperature to ensure that the center temperature of the dough after the final beating is 25±1°C.

10. The method according to claim 7, characterized in that In step (5), the baking conditions are: the upper fire temperature is 190-200°C, the lower fire temperature is 180-190°C, and the baking time is 18-20 minutes. When there are 5 minutes left in the baking time, the baking tray is rotated 180° to ensure that the bread is heated evenly.

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