Rumex hanus bread and preparation method thereof

Abstract

According to the rumex hanus bread, a medium-planting fermentation method is adopted, rumex hanus seed leach liquor is added into medium-planting dough, and rumex hanus pulp is added into main dough. According to the rumex hanus bread, nutrition of the rumex hanus seeds and the fresh rumex hanus is utilized at the same time, the protein level and the nutrient abundance of the bread can be improved, the quality and the taste of the bread can be greatly improved, bioactive substances in the rumex hanus are utilized, and on the premise that no preservative or other additives are added, the rumex hanus bread has the advantages of being good in taste and good in taste. The functions of delaying spoilage and prolonging the shelf life are realized. Besides, the rumex hanus bread further has a good physiological regulation function, can improve physique and enhance immunity, and can meet the requirements of consumers in the aspects of food safety, food quality, food functionality and the like.

Description

Technical Field

[0001] The invention relates to the technical field of functional bread, in particular to leafy grass bread and preparation method of the leafy grass bread. Background Art

[0002] Bread is an important form of baked food and an indispensable component of residents' diet. Traditional bread lacks nutrients such as protein, dietary fiber, vitamins and minerals, and has a short shelf life. In order to improve nutrition and extend shelf life, people add a variety of additives to the ingredients to make up for the shortcomings of traditional bread. However, with the development of the concept of healthy nutrition in the food industry, bread products without additives are more popular with consumers. In recent years, functional raw materials of plant-derived ingredients such as fruits, vegetables, grains, and beans have been added to bread to develop "functional bread" with added value, so that bread can be used as a carrier rich in bioactive compounds and nutrients to make up for the nutritional shortcomings of traditional bread. In addition to increasing nutritional abundance and strengthening nutrition, functional bread also has a regulating and promoting effect on body health. However, the addition of foreign substances can easily destroy the gluten network structure, causing the quality of bread to deteriorate, such as increased hardness, reduced specific volume, and rough texture, which reduces consumer acceptance.

[0003] As a new food raw material, leaf grass not only has a high protein content, but also contains a variety of bioactive ingredients such as polysaccharides, flavonoids, polyphenols, tannins, etc. It is a plant raw material with significant nutritional advantages. The rich and diverse nutrients make leaf grass have good physiological regulation functions, but it is currently only added to food in the form of raw materials and auxiliary materials, which limits the nutritional and functional development of leaf grass. Therefore, if we can develop leaf grass functional bread with excellent quality, it will be favored by the market. Summary of the invention

[0004] The present invention has developed a leaf-eating grass bread, which not only helps to improve the protein level and nutritional richness of bread by utilizing the nutrients of leaf-eating grass seeds and fresh grass, but also greatly improves the quality and taste of bread. In addition, the bioactive substances in the leaf-eating grass are utilized to delay spoilage and extend the shelf life without adding preservatives and other additives. In addition, the leaf-eating grass bread also has good physiological regulation functions, can improve physical fitness and enhance immunity, and will be able to meet consumer needs in terms of food safety, food quality, and food functionality.

[0005] To achieve the above-mentioned purpose, the leafy grass bread provided by the present invention adopts a mid-seed fermentation method, wherein leafy grass seed extract is added to the mid-seed dough, and leafy grass slurry is added to the main dough.

[0006] Adding leaf grass seed extract to the middle dough can improve the fermentation power of the middle dough and improve its gas retention performance; adding leaf grass pulp to the main dough can make the nutrition of leaf grass seeds cooperate with the high polysaccharides, proteins and other bioactive ingredients in the leaf grass pulp, reduce the baking loss rate, improve the hardness, adhesion and elasticity of the bread, and improve the quality and taste of the bread. At the same time, the many bioactive substances of leaf grass can, on the one hand, play a good physiological regulation function, improve physical fitness and enhance immunity; on the other hand, they can also delay spoilage and extend the shelf life without adding preservatives and other additives. In addition, the synergy of leaf grass seed extract and leaf grass pulp can enrich volatile derivatives through the middle fermentation method, and can also enrich the flavor of bread, thereby comprehensively improving the quality of bread.

[0007] As a limitation of the above technical solution, the leaf-eating grass seed extract is a filtrate obtained by filtering the leaf-eating grass seeds after drying, crushing, and water extraction.

[0008] As a limitation of the above technical solution, the foliage grass seeds are first dried at 65-75°C and then dried at 280-320°C.

[0009] The leaf-eating grass seeds are dried at low temperature (65-75°C) and then at high temperature (280-320°C), which can balance the nutrient retention and drying effect. Low-temperature drying gently removes moisture, reduces the loss of heat-sensitive nutrients (such as vitamins and polyphenols), and maintains the physiological activity and dry matter content of the seeds; high-temperature drying quickly dehydrates, inactivates enzymes and microorganisms, prolongs the shelf life, and may promote the conversion of certain functional ingredients. It can ensure the stability and functionality of the seeds while retaining the active substances to the maximum extent.

[0010] As a limitation of the above technical solution, the edible grass seeds are first soaked in water and then extracted with hot water at 70-80°C.

[0011] As a limitation of the above technical solution, the leaf-eating grass pulp is the filtrate obtained by squeezing the fresh leaf-eating grass after spraying it with a NaCO3 solution and filtering it; the preferred mass concentration of the NaCO3 solution is 4 to 6%.

[0012] The leafy grass pulp obtained after spraying with NaCO3 solution is in an acid-base environment that is conducive to the survival of yeast, which is conducive to the nutrients in the leafy grass pulp being used by the growth and reproduction of yeast.

[0013] As a limitation of the above technical solution, the raw materials of the middle dough include flour, yeast and leafy grass seed extract; the raw materials of the main dough include flour, leafy grass slurry, sugar, eggs, corn oil, milk powder and salt.

[0014] As a limitation of the above technical scheme, the raw materials of the middle dough are as follows: 15-25% special flour for bread, 3-5% fresh yeast, 5-15% edible grass seed extract; the raw materials of the main dough are as follows: 75-85% special flour for bread, 35-45% chilled edible grass slurry, 8-12% white sugar, 8-12% egg liquid, 2-6% corn oil, 2-6% milk powder, 0.5-1.5% salt; the percentage of each raw material usage is the mass percentage based on the total amount of special flour for bread required for the middle dough and the main dough.

[0015] Further improve the raw material components and proportions of the mid-seed dough and main dough, as well as the preparation conditions of edible grass seed extract and edible grass slurry, so as to give full play to the nutritional value of edible grass and optimize the quality of edible grass bread.

[0016] The present invention also provides a method for preparing the leafy grass bread as described above, comprising the following preparation steps:

[0017] 1) Preparation of medium-seed dough and fermentation: Mix and stir bread flour, yeast and edible grass seed extract to make the dough smooth and soft, and control the temperature of the preparation process and the temperature of the kneaded dough to be ≤27°C; ferment the kneaded medium-seed dough at a temperature of 25-28°C and a relative humidity of 70-80% for 1.5-2.5 hours.

[0018] 2) Modulating the main dough and secondary fermentation: mix sugar, corn oil, eggs, and edible grass pulp, stir to melt the sugar, add bread crumbs in the main dough ingredients, continue to stir at a low speed to mix into dough, add salt and fermented middle dough, knead at a high speed, let it stand, and knead at a high speed again, so that the surface of the dough is smooth and a uniform glove film can be pulled out, and the temperature of the modulation process and the temperature of the kneaded dough are controlled to be ≤27°C; ferment the kneaded main dough at a temperature of 35-38°C and a relative humidity of 82-88% for 0.8-1.2h; the kneaded main dough can also be fermented after being divided and shaped;

[0019] 3) Baking: After the secondary fermentation is completed, bake according to the requirements of the bread to obtain leafy grass bread.

[0020] As a limitation of the above technical scheme, the preparation conditions of the foliage grass seed extract are as follows: the foliage grass seeds are first dried at 65-75°C for 0.8-1.2h, then dried at 280-320°C for 25-35s, cooled to the recovery point of 150°C and then intermittently crushed for 1min, soaked in water at a material-liquid ratio of 1:(45-55), then extracted with hot water at 70-80°C, cooled to room temperature, and filtered to remove the residue.

[0021] As a limitation of the above technical solution, the baking conditions are as follows: the upper temperature of the oven is 170-190°C, the lower temperature is 150-170°C, and the baking time is 10-15 minutes.

[0022] The preparation of the leafy grass bread of the present invention can be carried out according to conventional fermentation operations. In order to ensure full utilization of the nutrients of the leafy grass, it is only necessary to control the temperature of the middle dough and the main dough during the preparation process. The preparation process is simple, convenient and easy to produce.

[0023] In summary, the leafy grass bread of the present invention, through the mid-seed fermentation method, adds leafy grass seed extract to the mid-seed dough and adds leafy grass slurry to the main dough, which synergistically promotes the nutrition, flavor, taste, functionality and safety of the bread, so that the nutritional advantages and bioactive ingredients of the leafy grass can be fully utilized in the bread, and will meet the needs of consumers in terms of food safety, food quality and food functionality. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 , the effects of different treatment groups on sensory evaluation of bread;

[0025] Figure 2 , the effect of different treatment groups on the hardness of bread during storage;

[0026] Figure 3 , Total bacterial counts of breads in different treatment groups after storage for 1 day (left) and 3 days (right);

[0027] Figure 4 , Total bacterial counts of breads in different treatment groups after 7-day storage;

[0028] Figure 5 , compound type count diagrams of different treatment groups;

[0029] Figure 6 , the influence of fermentation time on the fermentation ability of medium dough. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The experimental methods in the following examples and comparative examples are conventional methods unless otherwise specified; the raw materials or test materials used are typical products purchased from the market unless otherwise specified. The quantitative tests in the following examples and comparative examples were repeated three times, and the results were averaged.

[0032] Example

[0033] This embodiment relates to the preparation of the leafy grass bread of the present invention

[0034] 1. Raw material pretreatment

[0035] Chilled edible grass pulp: take fresh edible grass, wash and drain, spray with 5% (the concentration can be adjusted in the range of 4-6% in actual operation) NaCO3 solution, squeeze the juice with a juicer to remove the residue, and refrigerate the filtrate for later use.

[0036] Edible grass seed extract: take edible grass seeds, dry at 70℃ for 1h, hot air dry at 300℃ for 30s (in actual operation, it can be adjusted within the range of drying at 65-75℃ for 0.8-1.2h and drying at 280-320℃ for 25-35s), cool to the recovery point of 150℃, intermittently crush at 12000rpm for 1min, the material-liquid ratio, i.e. the mass ratio of edible grass seed crushed material to water is 1:50 (in actual operation, the material-liquid ratio can be adjusted within the range of 1:45-55), soak in water for 30min, extract with hot water at 70-80℃ for 30min, cool to room temperature, vacuum filter to remove residue, and use the filtrate for later use.

[0037] 2. Raw material formula

[0038] The middle seed fermentation method was adopted. The composition of the middle seed dough is shown in Table 1, and the composition of the main dough is shown in Table 2.

[0039] Table 1, medium dough formula

[0040]

[0041]

[0042] Table 2: Formula of other raw materials of main dough except middle dough

[0043]

[0044] 3. Bread making steps

[0045] 3.1. Weighing

[0046] According to the ingredient ratios in Table 1 and Table 2, weigh the ingredients for the middle dough and the main dough respectively.

[0047] 3.2. Preparation of medium dough

[0048] Pour bread flour, fresh yeast and edible grass seed extract into the bowl, start the mixer, and make the dough smooth and soft. The temperature of the kneaded dough should be ≤27℃ to prevent the dough temperature from being too high, which will affect the formation of the gluten network. It can be adjusted by changing the room temperature or the temperature of the edible grass seed extract.

[0049] 3.3. Fermentation of the middle dough

[0050] Take the kneaded dough out of the bowl, adjust the shape manually, place it in a fermentation bowl with a light oil coating on the surface, and put it into the fully automatic proofing room for 2 hours. The temperature of the fermentation box is 27°C (the temperature can be set at 25-28°C) and the relative humidity is 75% (the humidity can be set at 70-80%).

[0051] 3.4. Main dough preparation

[0052] Pour sugar, corn oil, egg liquid, milk powder, and chilled edible grass slurry into a bowl, stir to dissolve the sugar, add the bread flour of the main dough formula, start the mixer and stir at low speed for 2 minutes. After the materials are mixed into dough, add salt and fermented medium dough, start the mixer to mix at high speed to fully expand the gluten protein and form a strong gluten network structure. After mixing for 10 minutes, let it stand for 3 minutes to fully hydrate the flour, and continue to mix at high speed for 3 minutes. The surface of the mixed dough is smooth and a uniform glove film can be pulled out. The temperature of the mixed dough should be ≤27℃. It can be adjusted by changing the room temperature or the temperature control of the edible grass slurry.

[0053] 3.5 Segmentation and Reshaping

[0054] Take the kneaded main dough out of the bowl, weigh and divide it into 90g dough portions, gently knead each dough into a round shape, and shape it into a round bread shape.

[0055] 3.6. Secondary continued fermentation

[0056] Place the shaped bread on a baking tray with a light oil coating on the surface and put it into the fully automatic proofing room for 1 hour. The temperature of the fermentation box is 37°C (the temperature can be set at 35-39°C) and the relative humidity is 85% (the humidity can be set at 82-88%).

[0057] 3.7 Baking

[0058] Heat up the oven in advance, and bake in the oven immediately after the secondary fermentation is completed. The upper temperature of the oven is 180℃ (the temperature can be set at 170-190℃), and the lower temperature is 160℃ (the temperature can be set at 150-170℃). The baking time is 10min-15min. Pay attention to the state of the bread at any time during baking. If the oven temperature is too high, spray water to adjust the temperature in the oven.

[0059] Comparative Example 1

[0060] This comparative example uses the leafy grass pulp bread prepared by the medium seed fermentation method as a control, and the details are as follows:

[0061] The middle seed fermentation method is to mix the middle seed dough with 40% bread flour, 20% edible grass pulp and 4% fresh yeast (the amount of raw materials used is based on the total amount of bread flour, the same below) and knead it into a dough; ferment it for 2 hours at a temperature of 27°C and a relative humidity of 75%. Pour 10% white sugar, 4% corn oil, 10% egg liquid, 4% milk powder and 30% edible grass pulp into a bowl, stir and add 60% bread flour, stir at a low speed to mix into dough, add 1% salt and the fermented middle seed dough, stir at a high speed for 10 minutes, then let it stand for 3 minutes to hydrate, continue stirring for 3 minutes to obtain the main dough. After dividing and shaping, let it rise for 1 hour at a temperature of 38°C and a relative humidity of 85%, and then bake.

[0062] Comparative Example 2

[0063] This comparative example uses a mixed bread of seed extract prepared by the medium seed fermentation method and leafy grass pulp as a control, as follows:

[0064] The seed extract and the edible grass pulp are mixed in a mass ratio of 1:1, and the homogenized mixture is used as a standby. In the medium seed fermentation method, the medium seed dough is kneaded into a dough with 40% bread flour, 20% mixed liquid and 4% fresh yeast (the amount of raw materials is based on the total amount of bread flour, the same below); fermented for 2 hours at a temperature of 27°C and a relative humidity of 75%. Pour 10% white sugar, 4% corn oil, 10% egg liquid, 4% milk powder, and 30% mixed liquid into a bowl, stir and add 60% bread flour, stir at a low speed to mix into dough, add 1% salt and the fermented medium seed dough, stir at a high speed for 10 minutes, then let it stand for 3 minutes to hydrate, and continue stirring for 3 minutes to obtain the main dough. After splitting and shaping, it is baked after proofing for 1 hour at a temperature of 38°C and a relative humidity of 85%.

[0065] Comparative Example 3

[0066] This comparative example uses the seed extract bread prepared by the medium seed fermentation method as a control, and the details are as follows:

[0067] The middle seed fermentation method is to mix the middle seed dough with 40% bread flour, 20% edible grass seed extract and fresh yeast (the amount of raw materials is based on the total amount of bread flour, the same below) and knead it into a dough; ferment it for 2 hours at a temperature of 27°C and a relative humidity of 75%. Pour 10% white sugar, 4% corn oil, 10% egg liquid, 4% milk powder and 30% deionized water into a bowl, stir and add 60% bread flour, stir at a low speed to mix into dough, add 1% salt and the fermented middle seed dough, stir at a high speed for 10 minutes, then let it stand for 3 minutes to hydrate, continue stirring for 3 minutes to obtain the main dough. After dividing and shaping, let it rise for 1 hour at a temperature of 38°C and a relative humidity of 85%, and then bake.

[0068] Comparative Example 4

[0069] In this comparative example, the traditional bread prepared by the medium seed fermentation method is used as a blank control, and no leaf-eating grass-related ingredients are added to compare the performance differences of the leaf-eating grass bread of the present invention, as follows:

[0070] The middle seed fermentation method is to mix the middle seed dough with 40% bread flour, 20% deionized water and fresh yeast (the amount of raw materials is based on the total amount of bread flour, the same below) and knead it into a dough; ferment it for 2 hours at a temperature of 27°C and a relative humidity of 75%. Pour 10% white sugar, 4% corn oil, 10% egg liquid, 4% milk powder and 30% deionized water into a bowl, stir and add 60% bread flour, stir at a low speed to mix into dough, add 1% salt and the fermented middle seed dough, stir at a high speed for 10 minutes, then let it stand for 3 minutes to hydrate, continue stirring for 3 minutes to obtain the main dough. After dividing and shaping, let it rise for 1 hour at a temperature of 38°C and a relative humidity of 85%, and then bake.

[0071] Determination of dough and bread quality in the examples and comparative examples

[0072] (1) Dough quality determination

[0073] (1.1) Determination of specific volume of medium dough

[0074] After the fermentation of the middle dough is completed, the volume and mass are measured, and the specific volume of the middle dough is calculated according to the following formula.

[0075] v=V / m

[0076] Where: v is the specific volume, mL / g; V is the volume of the middle dough after fermentation, mL; m is the mass of the middle dough, g.

[0077] (1.2) Determination of dough texture

[0078] The texture parameters of bread were determined using the Multi Test 2.5-i texture analyzer. The fermented dough was placed on the sample table for testing. The TPA test was selected, and the probe was a PR / 36 cylindrical probe. The pre- and post-test and test speeds were set to 60.0 mm / min, the trigger force was 1.0 N, the deformation was 50%, and the hardness of the sample was recorded. The test was repeated three times and the average value was taken.

[0079] (2) Bread quality measurement

[0080] (2.1) Determination of baking loss rate and specific volume

[0081] The bread quality was measured after the bread was left to stand at room temperature for 1 hour after being taken out of the oven, and the bread baking loss rate was calculated according to the following formula.

[0082] L=(m1-m2) / m2×100%

[0083] Where: L is the baking loss rate, %; m1 is the mass of the dough (i.e. the mass of the dough after fermentation and before baking), g; m2 is the mass of the bread left at room temperature for 1 hour after being taken out of the oven, g.

[0084] The volume of bread left at room temperature for 1 hour after being baked was determined by the millet replacement method, and the specific volume of the bread was calculated according to the following formula.

[0085] v=V / m2

[0086] Where: v is the specific volume, mL / g; V is the volume of the bread, mL; m2 is the mass of the bread left at room temperature for 1 hour after being taken out of the oven, g.

[0087] (2.2) Determination of texture characteristics

[0088] The texture parameters of bread were determined using the Multi Test 2.5-i texture analyzer. The bread crumbs were cut into 20 mm thick slices after standing at room temperature for 1 hour after being baked and placed on the sample table for testing. The TPA test was selected, and the probe was a PR / 36 cylindrical probe. The pre- and post-test and test speeds were set to 60.0 mm / min, the trigger force was 1.0 N, the deformation was 50%, and the hardness of the sample was recorded. The test was repeated three times and the average value was taken.

[0089] (2.3) Sensory characteristics determination

[0090] The prepared bread was placed at room temperature for 1 hour, and then evaluated by 6 trained sensory evaluators in terms of the shape, color, smell, taste and texture of the bread. The evaluation criteria are shown in Table 3.

[0091] Table 3. Bread sensory evaluation table

[0092]

[0093]

[0094] (2.4) Determination of bread storage characteristics

[0095] (2.4.1) Determination of changes in moisture content of bread crumbs during storage

[0096] In a refrigerated environment at 4°C, bread from the same batch was sliced ​​after being placed for 1 day and 7 days respectively. 3 g of bread core was selected and the moisture content was determined according to GB 5009.3-2016.

[0097] (2.4.2) Determination of hardness change of bread samples during storage

[0098] The samples are the same as those in 4.4.1. The bread crumb is cut into 20 mm thick slices. The rest is tested for hardness according to 5.2.

[0099] (2.4.3) Microbiological indicators of bread during storage

[0100] The determination shall be carried out in accordance with the method in GB 4789.2-2022 "National Food Safety Standard for Microbiological Examination of Foods - Determination of Total Colony Count". The determination of coliform bacteria shall be carried out in accordance with the method in GB 4789.3-2016 "National Food Safety Standard for Microbiological Examination of Foods - Coliform Count".

[0101] (2.4) Determination of volatile flavor substances

[0102] Headspace solid phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) was used to detect the aroma volatiles in bread crumbs. The compounds were quantified by peak area normalization method.

[0103] The SPME fiber was aged at 270 °C for 10 min at the gas chromatograph inlet. 2 g of bread was weighed, 2 μL of 1,2-dichlorobenzene was added, and the sample was sealed and incubated at 60 °C for 30 min. The fiber was then placed 5 mm from the top of the sample. After headspace extraction for 30 min, the sample was immediately inserted into the gas chromatography-mass spectrometry (GC-MS) inlet for GC-MS detection.

[0104] Chromatographic conditions: The column temperature was set at 40°C for 2 minutes, then raised to 180°C at 5°C / min, and then raised to 250°C for 10 minutes. The carrier gas was helium, the carrier gas flow rate was 1 mL / min, the injection port temperature was 250°C, and the run time was 30 minutes.

[0105] Mass spectrometry conditions: electron bombardment ionization source, electron energy 70 eV, interface temperature 280 °C, ion source temperature 230 °C, quadrupole temperature 150 °C, scanning mass range 35-450 amu.

[0106] Results Analysis

[0107] (I) Specific volume and texture characteristics of medium dough

[0108] The specific volume and texture parameters of the medium dough are shown in Table 4 below. Due to the long fermentation period, the hydration of the dough is more sufficient, the fermentation of the yeast is more complete, and the maturity of the dough is more perfect. The specific volume of the medium dough reflects the degree of volume expansion and fermentation power, which directly affects the fermentation of the subsequent main dough. The specific volume of the embodiment is significantly higher than that of comparative examples 1 to 4, and the embodiment performs best in terms of dough volume expansion and gas retention capacity. The level of specific volume is mainly related to the fermentation performance of the dough and the stability of the gluten network. The edible grass seed extract added in the embodiment promotes the activity of the yeast, and the edible grass pulp enhances the elasticity of the gluten network, thereby increasing the specific volume of the dough. In terms of dough texture characteristics, the embodiment has the lowest hardness and the highest elasticity, indicating that its dough is easier to stretch and shape during processing, and can better maintain its shape during processing. It may be because the polysaccharides and proteins in the edible grass pulp improve the flexibility of the gluten network, enhance the elasticity of the gluten network, and make it have better processing performance, providing strong technical support for the production of high-quality bread.

[0109] Table 4. Effects of different treatment groups on dough quality

[0110]

[0111] (II) Bread baking loss rate and specific volume

[0112] The baking loss rate and specific volume of bread are shown in Table 5 below. The effects of different treatment groups on bread quality show significant differences in baking loss rate and specific volume indicators (P<0.05). Specific volume can reflect the degree of dough volume expansion and retention capacity, and directly affect the appearance, taste and texture of the finished bread. The specific volume of the embodiment is significantly higher than that of comparative examples 1, 3, and 4, and has advantages in dough gas retention and fluffiness. Although there is no significant difference in the specific volume of comparative example 2, it is also lower than that of the embodiment. This may be due to the inappropriate ratio and process of edible grass pulp and seed extract, which in turn produces some dilution effects and mechanical shearing effects that hinder gluten protein cross-linking, weaken the gluten network structure, and reduce the retention efficiency of carbon dioxide gas, resulting in insufficient expansion during baking, which is ultimately manifested as a specific volume lower than that of the embodiment. Baking loss is mainly the evaporation of water during bread baking and the volatilization of substances such as ethanol, organic acids and carbon dioxide. Too high or too low will have a certain impact on bread. The baking loss rate of the embodiment is significantly lower than that of other comparative examples, and the loss of water and quality during the baking process is less. This may be because some hydrophilic polysaccharides in the extract of the foliar grass seeds in the bread of the embodiment bind free water by forming a colloidal network, assist gluten cross-linking, and enhance the stability of the air chamber; in addition, the high water-holding fiber in the foliar grass pulp can absorb and bind water, and dynamically regulate the release of water during baking. It can effectively reduce the loss of water or volatile substances during baking and improve processing efficiency.

[0113] Table 5 Effect of different treatment groups on bread quality

[0114]

[0115] (III) Bread texture characteristics

[0116] The texture of bread is an important carrier of pleasure, typical and representative, and an important objective indicator, mainly including hardness, adhesion and elasticity. These indicators are affected by the moisture content, protein content, gluten content and other components in the dough, and determine the quality and taste of the bread. The texture parameters of bread in different treatment groups are shown in Table 6 below. The embodiment performs best in hardness, adhesion and elasticity. The bread in the embodiment is the softest and has the best taste. The inside of the bread is delicate and moist, and has good toughness. The synergistic effect of the foliage grass seed extract and the foliage grass pulp graded significantly improves the texture characteristics. It may be that the two synergistically enhance the ductility of gluten, optimize the uniform distribution of water, and thus reduce local hardening; or the gluten protein and additives form a composite network to enhance the resilience of the air chamber wall. In addition, it may be that the extract plays a role in delaying starch aging and maintaining structural flexibility.

[0117] Table 6 Effects of different treatment groups on bread texture characteristics

[0118]

[0119] (IV) Sensory evaluation of bread

[0120] Food sensory evaluation is a comprehensive food quality indicator that can reflect consumers' real experience as a whole. The shape, color, taste, smell and texture of bread reflect people's subjective feelings and preferences for the product. The sensory evaluation of bread in different treatment groups can be seen in Figure 1 . As can be seen from the figure, the embodiment is significantly better than the control group in terms of total score and each sub-index. Its advantages come from the multi-dimensional optimization of sensory characteristics by the synergistic treatment of foliage grass components. In terms of morphology and organization, the uniformity of the air chambers of the composite network formed by gluten protein and additives is improved, and the low hardness and high elasticity in the texture parameters are combined to give the bread a fluffy and full macroscopic structure; in terms of color and smell: the natural pigments and volatile flavor substances in the seed extract enhance the baking aroma through the Maillard reaction, while delaying excessive surface browning; in terms of taste, lower adhesion can reduce the stickiness in the mouth, and the uniform moisture distribution and starch retardation aging jointly maintain the moist and soft texture of the bread of the embodiment. In general, the functional synergistic treatment of different components of foliage grass can comprehensively improve the sensory acceptance of bread, and its mechanism is highly correlated with the improvement of physical and chemical properties.

[0121] (V) Bread storage characteristics

[0122] a. Effects of different treatment groups on the moisture content of bread during storage

[0123] The moisture content and water retention rate of bread in different treatment groups are shown in Table 7. The moisture content of bread in different groups showed a downward trend during storage for 1 to 7 days. After storage for 1 day and 7 days, the moisture content of the embodiment was significantly higher than that of the comparative examples 1 to 4; the hydrophilic groups in the foliage grass seed extract and the substances in the foliage grass pulp synergistically formed a network structure, which not only improved the initial moisture adsorption, but also achieved the effect of delaying moisture migration through the dense network structure. Although the water retention rate of bread in the embodiment was also higher than that of the comparative example group, there was no significant difference.

[0124] Table 7. Moisture content and water retention rate of bread in different treatment groups

[0125]

[0126] b. Effects of different treatment groups on bread hardness during storage

[0127] Figure 2 The hardness changes of bread in different treatment groups after being stored at room temperature for one week. After research, it was found that the hardness of bread showed a negative correlation with the quality of bread. The larger the index, the worse the taste and quality of the bread. During the storage period, bread will experience water migration and evaporation, starch recrystallization, and reduced softness of gluten protein. These phenomena are called bread aging. The change in the hardness of bread during the storage period can be used to directly reflect the overall freshness of the bread. Figure 2 It can be concluded that, with the extension of storage time, the hardness of the five types of bread increases continuously, but the hardness of the examples is significantly lower than that of the four comparative examples.

[0128] c. Effects of different treatment groups on the microbial indicators of bread during storage

[0129] According to the National Food Safety Standard for Cakes and Breads (GB 7099-2015), the total number of colonies in bread stored at room temperature for 5 days should not exceed 3×10 4 CFU / g. Controlling the total colony count is one of the important measures to ensure food safety, which aims to ensure the safety and sanitary quality of food. If the total colony count of food seriously exceeds the standard, it will destroy the nutritional components of the food, making the food lose its edible value, and will accelerate the spoilage of food, endangering human health. The samples measured in the experiment of the present invention did not use any preservatives, and the finished products were not treated with the surface spraying of edible alcohol commonly used in industry. The microbial content of bread in different treatment groups for a storage period of 7 days is shown in Table 8. As the storage time increases, the total colony count of bread in different treatment groups shows an upward trend. The embodiment still meets the national standard conditions after 7 days of storage, while the total colony count of the bread in Comparative Examples 3 and 4 exceeded the standard on the fourth day of storage. Figure 3It is the ratio of the total number of bacterial colonies in the breads of different treatment groups stored for one day and three days. As shown in the figure, the total number of bacterial colonies in comparative example 4 (blank control) increases significantly with the extension of storage time. Figure 4 The total bacterial counts of the breads in different treatment groups after 7 days of storage also showed the same situation. There were significant differences in the microbial control effects of the different treatment groups during storage, and the bread in the example had a better preservation effect.

[0130] Table 8. Total bacterial counts of bread in different treatment groups during storage

[0131]

[0132] (VI) Analysis of volatile flavor substances in bread

[0133] The headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) method (which can collect, extract, concentrate and inject samples) is used to separate and identify the volatile components of the samples, thereby achieving qualitative and quantitative analysis of flavor substances.

[0134] Figure 5 is the number of compound types in the examples and comparative examples 1 to 4. According to the results, the examples have the most compound types, while the types and contents of various compounds in comparative example 4 are relatively low. Table 9 shows the volatile component contents of different treatment groups.

[0135] Table 9. Volatile component content in different treatment groups

[0136]

[0137]

[0138] As can be seen from the results in the table above, the esters, aldehydes and alcohol compounds in the bread are rich in variety and high in content. Ethyl octanoate, n-hexanal, ethanol, 1-hexanol, 3-hydroxy-2-butanone, ethyl maltol, acetic acid and propionic acid are the main volatile components that play an important role in the unique flavor of the bread in the example.

[0139] Fermentation is an indispensable part of bread making. During this process, yeast will continuously produce CO2, which diffuses from the liquid phase into the bubbles. Gas cells continue to grow on the gluten network. Due to the pressure generated by the expansion, the gluten network will continue to expand, making the dough expand as a whole and elastic. The middle fermentation can form a better network structure of the dough due to its longer fermentation time, produce a unique bread fermentation aroma, and make the effect and characteristics of the dough more mature. Further study the effect of different fermentation times on the fermentation power of the middle dough.

[0140] (VII) Dough fermentation characteristics

[0141] Make a medium dough, and then divide the kneaded medium dough into 30g each. Then measure the dough fermentation power by the measuring cylinder method. Put the divided dough into a 100mL measuring cylinder, and make sure that the gap in the measuring cylinder is fully compacted. Place the entire measuring cylinder in a proofing room (temperature 27°C, relative humidity 75%) for fermentation, and record the increased fermentation volume of the dough at the same time. Figure 6 .

[0142] like Figure 6 As shown, the dough growth volume of different kinds of dough in the embodiment and the comparative example at different fermentation times was measured. It can be seen that the fermentation volume of the dough increases with the extension of the fermentation time, and the embodiment has a higher fermentation power due to the addition of the edible grass seed extract. It may be due to the promotion of the gas production capacity of the yeast, which in turn promotes the fermentation process of the dough. It may also be that the edible grass slurry cross-links with the gluten protein molecules during fermentation, strengthening the gluten network structure, allowing it to withstand more dough gravity, allowing the dough to reach a higher fermentation height.

[0143] In summary, the leaf-eating grass bread of the present invention, by synergistically utilizing the nutrients of leaf-eating grass seeds and fresh grass, not only helps to improve the protein level and nutritional richness of bread, but also can greatly improve the quality of bread, and utilizes the bioactive substances in the leaf-eating grass to achieve the function of delaying spoilage and extending the shelf life without adding preservatives and other additives. In addition, this leaf-eating grass bread also has good physiological regulation function, can improve physical fitness and enhance immunity, and will be able to meet consumer needs in terms of food safety, food quality, and food functionality.

Claims

1. A leafy grass bread, characterized in that: The leafy grass bread adopts a middle seed fermentation method, wherein leafy grass seed extract is added to the middle seed dough, and leafy grass slurry is added to the main dough.

2. The leafy grass bread according to claim 1, characterized in that: The leaf-eating grass seed extract is a filtrate obtained by drying, crushing, water-extracting and filtering the leaf-eating grass seeds.

3. The leafy grass bread according to claim 2, characterized in that: The foliage grass seeds are first dried at 65-75°C and then at 280-320°C.

4. The leafy grass bread according to claim 2, characterized in that: The seeds of foliage grass are first soaked in water and then extracted with hot water at 70-80℃.

5. The leafy grass bread according to claim 1, characterized in that: The leaf-eating grass pulp is a filtrate obtained by squeezing the fresh leaf-eating grass after spraying it with a NaCO3 solution and filtering it; the preferred mass concentration of the NaCO3 solution is 4-6%.

6. The leafy grass bread according to claim 1, characterized in that: The raw materials of the middle dough include flour, yeast and edible grass seed extract; the raw materials of the main dough include flour, edible grass slurry, sugar, eggs, corn oil, milk powder and salt.

7. The leafy grass bread according to claim 6, characterized in that: The raw materials of the medium dough are as follows: 15-25% of special flour for bread, 3-5% of fresh yeast, and 5-15% of edible grass seed extract; the raw materials of the main dough are as follows: 75-85% of special flour for bread, 35-45% of chilled edible grass slurry, 8-12% of white sugar, 8-12% of egg liquid, 2-6% of corn oil, 2-6% of milk powder, and 0.5-1.5% of salt; the percentage of each raw material usage is the mass percentage based on the total amount of special flour for bread required for the medium dough and the main dough.

8. A method for preparing leafy grass bread as claimed in any one of claims 1 to 7, characterized in that: The method comprises the following preparation steps: 1) Preparation of medium-seed dough and fermentation: Mix and stir bread flour, yeast and edible grass seed extract to make the dough smooth and soft, and control the temperature of the preparation process and the temperature of the kneaded dough to be ≤27°C; ferment the kneaded medium-seed dough at a temperature of 25-28°C and a relative humidity of 70-80% for 1.5-2.5 hours. 2) Preparing the main dough and secondary fermentation: mix sugar, corn oil, eggs and edible grass pulp, stir to melt the sugar, add bread crumbs in the main dough ingredients, stir and mix to form dough, add salt and fermented middle dough, knead to make the dough surface smooth and able to pull out a uniform glove film, control the temperature of the preparation process and the temperature of the kneaded dough to be ≤27°C; ferment the kneaded main dough at a temperature of 35-38°C and a relative humidity of 82-88% for 0.8-1.2h; 3) Baking: After the secondary fermentation is completed, bake according to the requirements of the bread to obtain leafy grass bread.

9. The method for preparing leafy grass bread according to claim 8, characterized in that: The preparation conditions of the foliage grass seed extract are as follows: the foliage grass seeds are first dried at 65-75°C for 0.8-1.2h, then dried at 280-320°C for 25-35s, cooled to a recovery point of 150°C and then intermittently crushed for 1min, soaked in water at a material-liquid ratio of 1:45-55, and then extracted with hot water at 70-80°C, cooled to room temperature, and filtered to remove residue.

10. The method for preparing leafy grass bread according to claim 8, characterized in that: The baking conditions are as follows: the upper temperature of the oven is 170-190°C, the lower temperature is 150-170°C, and the baking time is 10-15 minutes.

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