Frozen dough and method for preparing same, baked food

Abstract

This application relates to the field of food processing technology, and more particularly to a frozen dough and its preparation method, as well as baked goods. The preparation method of the frozen dough includes: mixing sugar-tolerant yeast, wheat flour, and skim milk powder to obtain a powdery mixture; the sugar-tolerant yeast is capable of synthesizing trehalose within its cells; the weight ratio of the sugar-tolerant yeast, wheat flour, and skim milk powder is 1:(1~1.5):(1~1.5); dissolving the powdery mixture in water at 34℃~38℃ for 3 min~5 min to obtain a yeast solution; adding the yeast solution to the dough semi-finished product within 3 min or less; stirring and then freezing to obtain the frozen dough. This application improves the fermentation power of the frozen dough and ensures product quality by optimizing the preparation method of the frozen dough.

Description

Technical Field

[0001] This application relates to the field of food processing technology, and in particular to a frozen dough and its preparation method, and baked goods. Background Technology

[0002] The activity and fermentation performance of yeast in frozen dough are easily reduced during freezing and storage, which affects the proofing performance of frozen dough and thus affects product quality. Summary of the Invention

[0003] This application discloses a frozen dough and its preparation method, as well as baked goods, to solve the problem of decreased yeast activity and fermentation power in frozen dough during freezing and storage.

[0004] To achieve the above objectives, firstly, this application discloses a method for preparing frozen dough, the method comprising: A powdered mixture is obtained by mixing sugar-tolerant yeast, wheat flour and skim milk powder. The sugar-tolerant yeast is capable of synthesizing trehalose in its cells. The weight ratio of the sugar-tolerant yeast, wheat flour and skim milk powder is 1:(1~1.5):(1~1.5). The powdered mixture was dissolved in water at 34℃~38℃ for 3 min~5 min to obtain a yeast solution; The yeast solution is added to the dough semi-finished product within a time of less than or equal to 3 minutes, and after stirring for 5 to 8 minutes, it is shaped and quick-frozen to obtain the frozen dough.

[0005] Furthermore, in the yeast solution, the weight ratio of the powder mixture to the water is (3~4):(4~6).

[0006] Furthermore, the method for preparing the dough semi-finished product includes: mixing high-gluten flour, sugar, salt, whole milk powder, improver, whole egg liquid, water, ice and oil into a dough until there is no dry powder or ice crystals, thereby obtaining the dough semi-finished product.

[0007] Further, the fat includes at least one of butter, anhydrous butter, and margarine; and / or, The sugar includes at least one of granulated sugar and brown sugar; and / or, The modifier comprises the following components in the following weight ratios: glyceryl monostearate 27-33 parts, diacetyl tartaric acid mono- and diglycerides 62-68 parts, vitamin C 1.3-2.1 parts, complex xylanase MA 0.9-1.5 parts, xylanase 0.5-1.0 parts, maltose amylase 0.5-0.8 parts, and glucose oxidase 0.15-0.45 parts; and / or, By weight, the high-gluten flour in the semi-finished dough is 96 to 100 parts, the sugar is 5 to 20 parts, the salt is 0.5 to 1.5 parts, the whole milk powder is 2 to 5 parts, the improver is 0.3 to 1 part, the whole egg liquid is 5 to 12 parts, the water is 22 to 26 parts, the ice is 14 to 20 parts, and the oil is 5 to 15 parts.

[0008] Furthermore, the sugar-tolerant yeast accounts for 1.5 wt% to 5.0 wt% of the mass of the high-gluten flour.

[0009] Furthermore, in the step of adding the yeast solution to the dough semi-finished product, stirring, and then freezing to obtain the frozen dough, the temperature of the dough after stirring is 16℃~24℃.

[0010] Furthermore, in the step of adding the yeast solution to the dough semi-finished product, stirring, shaping, and quick-freezing to obtain the frozen dough, the freezing temperature is -30℃ to -40℃, and the freezing time is 20 min to 60 min.

[0011] Secondly, this application provides a frozen dough, which is prepared by the preparation method of the first aspect.

[0012] Furthermore, the frozen dough satisfies at least one of the following conditions: (1) The frozen dough has a freezing storage time of 90 days or more; (2) The frozen dough is a sweet bread frozen dough.

[0013] Thirdly, this application provides a baked food product obtained by processing frozen dough according to the second aspect.

[0014] Compared with the prior art, the beneficial effects of this application are as follows: This application improves the fermentation power of frozen dough by optimizing the preparation method of frozen dough, thereby ensuring product quality.

[0015] In this application, a yeast lysate is obtained by dissolving a powdered mixture in water at 34℃~38℃. The skim milk powder in the powdered mixture has good solubility and can dissolve quickly in the yeast lysate. Its components, milk protein and lactose, provide nutrients for the sugar-tolerant yeast. Simultaneously, the skim milk powder does not contain fat, avoiding the problem of decreased nutrient exchange rate caused by fat accumulation outside the sugar-tolerant yeast cells. The preparation of the yeast lysate is completed in 3-5 minutes. The sugar-tolerant yeast can efficiently absorb the nutrients provided by the skim milk powder in the yeast lysate, synthesizing trehalose within the cells without over-activation. Trehalose increases the osmotic pressure within the sugar-tolerant yeast cells, alleviating dehydration during freezing. Furthermore, the hydrophilic nature of trehalose molecules and the increased trehalose content result in more complete binding of water molecules within the sugar-tolerant yeast cells, reducing the likelihood of sharp ice crystals forming during freezing. This reduces damage to the sugar-tolerant yeast cells, ensuring the number of active sugar-tolerant yeast cells in the frozen dough and enhancing the fermentation power of the frozen dough.

[0016] In this application, the weight ratio of sugar-tolerant yeast, wheat flour, and skim milk powder in the powder mixture is 1:(1~1.5):(1~1.5). The total amount of wheat flour and skim milk powder is higher than the amount of sugar-tolerant yeast. Therefore, the distribution of sugar-tolerant yeast in the powder mixture is more dispersed. On the one hand, this reduces cell damage caused by collisions between sugar-tolerant yeast particles and ensures the integrity of sugar-tolerant yeast cells. On the other hand, it reduces the aggregation of sugar-tolerant yeast particles when preparing yeast lysate, further optimizes the contact effect between sugar-tolerant yeast and nutrients, promotes the synthesis of trehalose in cells, and protects the activity of sugar-tolerant yeast in frozen dough. Furthermore, compared to directly mixing sugar-tolerant yeast with other ingredients to form dough, this application first prepares a yeast solution, then adds it to the dough semi-finished product prepared with other ingredients. This avoids premature yeast activation due to early addition and mixing, thus mitigating freezing damage caused by overly active cells. This application controls the use time of the yeast solution to less than or equal to 3 minutes, reducing premature activation of the sugar-tolerant yeast and ensuring its survival rate after frozen storage. In addition, this application controls the mixing time in this step to within the range of 5 to 8 minutes, ensuring good dispersibility of the yeast in the frozen dough. The synergistic effect of these aspects enhances the fermentation power of the frozen dough and improves product quality. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a process flow diagram of the frozen dough preparation method provided in the embodiments of this application. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0021] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0022] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0023] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, components, or parts (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, components, or parts. Unless otherwise stated, "a plurality of" means two or more.

[0024] Frozen dough technology ensures product freshness and consistency, reduces labor and technical barriers for stores, and enables centralized production and remote delivery, thus gaining widespread application in the baking industry. However, during the production and use of frozen dough, unstable freezing and storage temperatures can affect the activity of yeast. Decreased yeast activity leads to less carbon dioxide gas produced during fermentation, ultimately resulting in reduced fermentation power of the frozen dough, leading to quality problems such as insufficient expansion, smaller volume, and coarser internal texture. Furthermore, incomplete fermentation of frozen dough can also affect bread aging and shelf life, resulting in a rough texture, increased drier and harder texture, and a shorter optimal consumption period.

[0025] The main reason for the decrease in yeast activity during the preparation of frozen dough is the difficulty in controlling the degree of yeast activation. If yeast is added along with other powdered ingredients at the initial stage of mixing, the yeast comes into contact with water and becomes activated prematurely, initiating its metabolic and proliferative activities. Yeast cells in the active proliferative phase suffer severe freezing damage during freezing, leading to a sharp decrease in yeast activity in the frozen dough. To inhibit premature yeast activation, ice can be added to lower the dough temperature after mixing. While this method can inhibit yeast activation, direct contact between yeast and ice crystals can damage the integrity of yeast cells, significantly reducing the initial viable count of yeast before freezing.

[0026] Based on the analysis of the causes of the above-mentioned technical problems, this application provides a method for preparing frozen dough to solve these technical problems. The preparation method includes: A powdered mixture was prepared by mixing sugar-tolerant yeast, wheat flour, and skim milk powder. The sugar-tolerant yeast is able to synthesize trehalose in its cells. The weight ratio of the sugar-tolerant yeast, wheat flour, and skim milk powder was 1:(1~1.5):(1~1.5). Dissolve the powdered mixture in water at 34℃~38℃ for 3 min~5 min to obtain a yeast solution; Add the yeast solution to the dough semi-finished product within 3 minutes or less, stir for 5 to 8 minutes, and then shape and quick-freeze to obtain frozen dough.

[0027] Among them, sugar-tolerant yeast, also known as high-sugar-tolerant yeast, can rapidly synthesize large amounts of protective substances such as trehalose to maintain cell structure and water content when its cells encounter high sugar osmotic pressure stress. Therefore, when sugar-tolerant yeast encounters low-temperature stress, when the temperature drops below freezing point, the extracellular water freezes first, which also leads to an increase in the concentration of the external solution (the solute remains in the unfrozen liquid), generating extremely high osmotic pressure. This forces the sugar-tolerant yeast to rapidly synthesize large amounts of trehalose. Trehalose, as a highly efficient natural antifreeze agent, can greatly reduce the physical damage to the cell membrane of sugar-tolerant yeast during freezing, thereby improving the survival rate after frozen storage and ensuring strong and stable fermentation after thawing. The high-sugar-tolerant yeast in this application embodiment is powdered dry yeast, which can be obtained through commercial purchase.

[0028] The inventors of this application have discovered that using a specific ratio of skim milk powder, wheat flour, and sugar-tolerant yeast in combination can significantly improve the activity and fermentation power of yeast in frozen dough. This ensures that during subsequent thawing and proofing processes, the frozen dough can leverage the activity and fermentation power provided by the yeast to guarantee that baked goods have good volume expansion, softness, and texture. Therefore, the embodiments of this application effectively solve the technical problem of applying yeast in frozen dough: freezing yeast affects its activity and fermentation power, leading to low-quality baked goods made from frozen dough containing yeast.

[0029] Unlike existing technologies that use sugar-tolerant yeast in high-sugar environments to improve sugar tolerance, this application uses sugar-tolerant yeast in order to work synergistically with wheat flour and skim milk powder to increase the rate at which sugar-tolerant yeast synthesizes trehalose within its cells. This allows the large amount of trehalose synthesized within the yeast cells to improve yeast activity and fermentation power under frozen conditions.

[0030] On the one hand, the milk protein and lactose contained in skim milk powder can serve as nutrients for glycotoxic yeast. Skim milk powder also dissolves well in yeast lysate, thus ensuring an efficient supply of nutrients to the glycotoxic yeast. Simultaneously, skim milk powder contains no fat, preventing the accumulation of fat outside the yeast cells and thus avoiding a decrease in the nutrient exchange rate, providing an efficient metabolic environment for the synthesis of endogenous trehalose in glycotoxic yeast. On the other hand, during freezing, the osmotic pressure outside the glycotoxic yeast increases. With the aforementioned promoting effect of skim milk powder, the glycotoxic yeast can synthesize large amounts of trehalose within the cells to maintain cell structure and moisture, alleviating cell dehydration during freezing. Furthermore, its strong hydrophilicity allows it to fully bind intracellular water molecules, reducing the probability of sharp ice crystal formation and directly protecting key organelles and enzyme systems from within the cells.

[0031] Therefore, although this application uses sugar-tolerant yeast, it is not intended for use in a high-sugar environment, but rather in an environment requiring freezing. Under freezing conditions, the yeast can alleviate cell dehydration and reduce the probability of sharp ice crystal formation, allowing it to maintain good activity and fermentation power after freezing. Furthermore, compared to directly adding trehalose to frozen dough as an exogenous substance, this application directly protects the most critical organelles and enzyme systems in yeast cells from within, thereby protecting the activity of the sugar-tolerant yeast. While exogenous trehalose can form a protective layer on the cell surface, stabilizing the cell membrane and protein structure and helping yeast resist physical stresses such as high temperature and high osmotic pressure, the amount of exogenous trehalose entering the yeast cell is very small because it needs to move across the membrane and is easily interfered with by external sugar metabolism. This is insufficient to meet the internal freezing requirements of yeast cells, making it still prone to ice crystal formation under freezing conditions, leading to cell rupture and making it difficult to effectively improve the problem of freezing damage to yeast cells.

[0032] This application obtains a powder mixture by mixing saccharide-tolerant yeast, wheat flour, and skim milk powder, and then dissolves the powder mixture in water to obtain a yeast solution. Simultaneously, the weight ratio of saccharide-tolerant yeast, wheat flour, and skim milk powder is optimized and controlled within 1:(1~1.5):(1~1.5), further enhancing the synergistic effect between the components. For example, the weight ratio of saccharide-tolerant yeast, wheat flour, and skim milk powder is 1:1:1, 1:1.2:1.2, 1:1.5:1.3, 1:1.1:1.4, or 1:1.3:1.4. In the embodiments of this application, the total amount of wheat flour and skim milk powder used in this ratio is higher than that of saccharide-tolerant yeast, resulting in a more uniform dispersion of the saccharide-tolerant yeast in the powder mixture. At this point, dissolving the powdered mixture with water serves two purposes. First, the water is preferentially absorbed by the wheat flour and skim milk powder, reducing the likelihood of direct contact between the saccharide-tolerant yeast and the water. This avoids the possibility of rapid rehydration causing the yeast to rupture and die, ensuring a high viable count of saccharide-tolerant yeast in the yeast lysate. Second, it reduces yeast aggregation during lysate preparation, optimizing the contact efficiency between the yeast and the nutrients provided by the skim milk powder and promoting trehalose synthesis. More importantly, as an ideal site for heterogeneous ice crystal nucleation, the increased dispersibility of the saccharide-tolerant yeast reduces the formation of initially dense microcrystals, thereby inhibiting ice crystal recrystallization based on the Oswald ripening principle during freezing and storage (where water molecules migrate to larger ice crystals after small ice crystals melt). This prevents large ice crystals from damaging the gluten network and from piercing the cell membrane or cell wall of the saccharide-tolerant yeast, thus protecting the yeast's activity through both cell protection and optimization of the external ice crystal structure.

[0033] Furthermore, the water temperature for preparing the yeast solution is 34℃~38℃, and the time is 3 min~5 min. For example, the water temperature for dissolving the powdered mixture is 34℃, 35℃, 36℃, 37℃, or 38℃, and the time for dissolving the powdered mixture is 3 min, 4 min, or 5 min. In this embodiment, the parameter range of water temperature and dissolution time is synergistically matched with the metabolic characteristics of the sugar-tolerant yeast and the nutrient release efficiency of the skim milk powder—ensuring both efficient absorption of nutrients and synthesis of trehalose by the sugar-tolerant yeast, and preventing over-activation of the yeast. This ensures that the yeast enters the subsequent freezing and storage process in a nutritionally adequate and stable state, guaranteeing the fermentation power of the frozen dough.

[0034] In this embodiment, the yeast solution is added to the dough semi-finished product within a time of 3 minutes or less. Exemplarily, the time from obtaining the yeast solution to adding it to the dough semi-finished product is 0.5 minutes, 1 minute, 1.5 minutes, 2 minutes, 2.5 minutes, or 3 minutes. In this embodiment, controlling the time to within 3 minutes avoids over-activation of sugar-tolerant yeast in the yeast solution, reduces freezing damage during the freezing process, and improves the fermentation power of the frozen dough.

[0035] Furthermore, after adding the yeast solution to the semi-finished dough and stirring for 5 to 8 minutes, the dough is shaped and quick-frozen to obtain frozen dough. Shaping refers to rolling and dividing the stirred dough into portions of a certain size or weight; a filling step can be added between the rolling and dividing steps. Exemplarily, the stirring time is 5, 6, 7, or 8 minutes. In this embodiment, controlling the stirring time within the above range ensures the degree of mixing between the yeast solution and the semi-finished dough, guaranteeing uniform dispersion of the yeast in the semi-finished dough, while avoiding excessive activation of the sugar-tolerant yeast due to prolonged stirring, reducing freezing damage during subsequent freezing, increasing the number of viable sugar-tolerant yeast cells in the frozen dough, and ultimately improving the fermentation power of the frozen dough.

[0036] Preferably, the weight ratio of sugar-tolerant yeast, wheat flour, and skim milk powder is 1:1:1, the water temperature for preparing the yeast solution is 36°C, the time for dissolving the powder mixture in water is 4 min, and the stirring time after adding the yeast solution to the dough semi-finished product is 6 min.

[0037] Further, in the yeast solution, the weight ratio of the powder mixture to water is (3~4):(4~6). For example, the weight ratio of the powder mixture to water is 3:4, 3:5, 3.5:5, 4:5, or 4:6. In this embodiment, by controlling the ratio of the powder mixture to water within the above range, it is possible to ensure that the sugar-tolerant yeast remains coated when the yeast solution is added to the dough semi-finished product; simultaneously, this ratio is beneficial for mixing operations, avoiding uneven dispersion of the sugar-tolerant yeast caused by excessively viscous yeast solution due to too much powder mixture and too little water. It is understood that the total water content in the frozen dough is relatively fixed to maintain the process stability of the frozen dough. The water in the frozen dough mainly comes from the water in the yeast solution and the water in the dough semi-finished product. Therefore, this embodiment further controls the weight percentage of water in the yeast solution to better balance the amount of water and other components in the dough semi-finished product, ensuring uniform mixing of the dough semi-finished product. Preferably, the weight ratio of the powder mixture to water is 3:4.

[0038] Furthermore, the preparation method of the dough semi-finished product includes: mixing high-gluten flour, sugar, salt, whole milk powder, improver, whole egg liquid, water, ice, and oil into a dough until there is no dry powder and no ice crystals, thus obtaining the dough semi-finished product. Here, "no dry powder" means that the high-gluten flour and whole milk powder are fully mixed and integrated with the other substances, and no powdery substances are observed in the dough semi-finished product; "no ice crystals" means that the ice has fully melted into water, and no ice crystal residue is observed in the dough semi-finished product. This application controls the timing of adding the yeast dissolver after the dough semi-finished product has reached the above-mentioned state. On the one hand, at this time, the dough semi-finished product has initially formed a homogeneous system, which can ensure the uniform dispersion of the subsequent yeast dissolver and avoid osmotic damage caused by insufficient mixing due to direct contact between the yeast dissolver and high concentrations of sugar and salt. On the other hand, it can utilize the heat absorbed during the ice melting process to maintain a low dough temperature and inhibit premature activation of sugar-tolerant yeast, while also reducing the mechanical damage to the cell walls of sugar-tolerant yeast caused by ice crystals in the dough semi-finished product. Under the combined effect of these two aspects, the number of viable bacteria in the frozen dough is increased, ultimately improving the fermentation power and product taste of the frozen dough. This application does not restrict the recipe of the semi-finished bread product; that is, in addition to the above recipe, other ingredients may be added as needed.

[0039] Further, the mass of the sugar-tolerant yeast accounts for 1.5 wt% to 5.0 wt% of the mass of the high-gluten flour. For example, the mass of the sugar-tolerant yeast accounts for 1.5 wt%, 2.0 wt%, 2.5 wt%, 3.5 wt%, 4.5 wt%, or 5.0 wt% of the mass of the high-gluten flour. In this embodiment, the amount of sugar-tolerant yeast used mitigates the cell death of the sugar-tolerant yeast during subsequent freezing and long-term storage, ensuring that the number of surviving sugar-tolerant yeast after thawing is sufficient to be equivalent to or close to the initial fermentation capacity of conventional dough, thereby enabling the baked product to achieve the expected volume, texture, and taste; while also avoiding excessive addition of sugar-tolerant yeast that could affect the flavor of the baked product. Preferably, the mass of the sugar-tolerant yeast accounts for 2.5 wt% of the mass of the high-gluten flour.

[0040] Furthermore, the fat includes at least one of butter, anhydrous butter, and margarine, and the sugar includes at least one of granulated sugar and brown sugar. In the embodiments of this application, the fat can increase the softness, and the sugar can increase the flavor of the bread. Preferably, the fat is butter, and the sugar is granulated sugar.

[0041] Further, the improver comprises the following components in the following weight ratios: 27-33 parts glyceryl monostearate, 62-68 parts diacetyl tartaric acid mono- and diglycerides, 1.3-2.1 parts vitamin C, 0.9-1.5 parts compound xylanase MA, 0.5-1.0 parts xylanase, 0.5-0.8 parts maltose amylase, and 0.15-0.45 parts glucose oxidase. Among these, glyceryl monostearate and diacetyl tartaric acid mono- and diglycerides are emulsifiers. In the embodiments of this application, the improver can protect the gluten network in the semi-finished dough and frozen dough, ensuring the fermentation effect of the frozen dough after thawing.

[0042] Further, by weight, the semi-finished dough contains 96-100 parts high-gluten flour, 5-20 parts sugar, 0.5-1.5 parts salt, 2-5 parts whole milk powder, 0.3-1 part improver, 5-12 parts whole egg liquid, 22-26 parts water, 14-20 parts ice, and 5-15 parts fat. Preferably, by weight, the semi-finished dough contains 96 parts flour, 15 parts sugar, 1.2 parts salt, 3 parts whole milk powder, 0.65 parts improver, 8 parts whole egg liquid, 24 parts water, 18 parts ice, and 10 parts fat.

[0043] Furthermore, in the step of adding the yeast solution to the dough semi-finished product, stirring, and then freezing to obtain frozen dough, the temperature of the dough after stirring is 16℃~24℃. Exemplarily, the temperature of the dough after stirring is 16℃, 18℃, 20℃, 21℃, 23℃, or 24℃. In this embodiment, when the temperature of the dough after stirring is within the above range, it can reduce the over-activation of sugar-tolerant yeast before entering the freezing stage, reduce damage to the sugar-tolerant yeast during freezing and storage, and improve the fermentation power of the frozen dough. Preferably, the temperature of the dough after stirring is 18℃~22℃.

[0044] Further, in the step of adding the yeast solution to the dough semi-finished product, stirring, and then freezing to obtain frozen dough, the freezing temperature is -30℃ to -40℃, and the freezing time is 20 min to 60 min. For example, the freezing temperature is -34℃, -35℃, -36℃, -37℃, or -38℃, and the freezing time is 20 min, 25 min, 30 min, 35 min, 40 min, 50 min, or 60 min. In this embodiment, when the freezing time and temperature are within the above range, the speed of passing through the ice crystal growth zone can be accelerated, the possibility of large ice crystals forming in the frozen dough can be reduced, the number of live sugar-tolerant yeast cells in the frozen dough can be guaranteed, and ultimately the fermentation power of the frozen dough can be improved. Preferably, the freezing temperature is -35℃, and the freezing time is 40 min.

[0045] This application also provides a frozen dough, which is prepared by the above-described preparation method.

[0046] Furthermore, the frozen dough meets at least one of the following conditions: (1) The frozen dough shall be stored for 90 days or more; (2) The frozen dough is a sweet bread frozen dough.

[0047] When frozen dough is stored for 90 days or more, yeast cell damage and gluten network weakening are more severe. Sweet bread frozen dough typically has a high sugar and fat content; this high-sugar, high-fat environment weakens the gluten structure, especially when the gluten network itself is unstable. During prolonged freezing, ice crystals form and puncture the gluten, reducing the dough's gas-holding capacity. Simultaneously, high sugar and fat content creates high osmotic pressure, causing dehydration damage to sugar-tolerant yeast cells. Furthermore, large amounts of fat and sugar trap free water in the dough, promoting more ice crystal formation during freezing. These ice crystals further damage the membrane structure of sugar-tolerant yeast cells, affecting their activity. However, the sugar-tolerant yeast in the frozen dough of this application can synthesize trehalose, thereby reducing the physical damage to the sugar-tolerant yeast cell membrane caused by ice crystals during freezing, improving the survival rate of the frozen dough after frozen storage, and ensuring fermentation power after thawing.

[0048] This application also provides a baked product obtained by the above-described frozen dough processing.

[0049] The technical solution of this application will be further explained below with reference to more specific embodiments and experimental test results.

[0050] Example 1 This embodiment provides a frozen dough, the preparation method of which is as follows: Step 1: Mix sugar-tolerant yeast, wheat flour and skim milk powder in a weight ratio of 1:1:1 to obtain a powder mixture.

[0051] Step 2: Dissolve the powdered mixture in water at 36°C for 4 minutes. The weight ratio of the powdered mixture to water is 3:4 to obtain the yeast solution.

[0052] Step 3: Mix 96 parts high-gluten flour, 15 parts sugar, 1.2 parts salt, 3 parts whole milk powder, 0.65 parts improver, 8 parts whole egg liquid, 24 parts water, 18 parts ice and 10 parts oil to obtain a semi-finished dough. The mass of sugar-tolerant yeast accounts for 2.5 wt% of the mass of high-gluten flour. The improver consists of 30 parts glyceryl monostearate, 65 parts diacetyl tartaric acid mono- and diglycerides, 1.7 parts vitamin C, 1.2 parts complex xylanase MA, 0.75 parts xylanase, 0.65 parts maltose amylase and 0.3 parts glucose oxidase.

[0053] Step 4: Add the yeast solution to the dough semi-finished product and stir for 6 minutes. The dough temperature is 18℃. Then freeze it at -35℃ for 40 minutes to obtain frozen dough. The time from obtaining the yeast solution to adding the yeast solution to the dough semi-finished product is 2 minutes.

[0054] Example 2 The only difference between this embodiment and Embodiment 1 is that in step 1, the sugar-tolerant yeast, wheat flour, and skim milk powder are in a weight ratio of 1:1.5:1.

[0055] Example 3 The only difference between this embodiment and Embodiment 1 is that in step 1, the sugar-tolerant yeast, wheat flour, and skim milk powder are in a weight ratio of 1:1:1.5.

[0056] Example 4 The only difference between this embodiment and Embodiment 1 is that in step 1, the sugar-tolerant yeast, wheat flour, and skim milk powder are in a weight ratio of 1:1.5:1.5.

[0057] Example 5 The only difference between this embodiment and Embodiment 1 is that the weight ratio of the powder mixture to water is 3:3.

[0058] Example 6 The only difference between this embodiment and Embodiment 1 is that the weight ratio of the powder mixture to water is 3:5.

[0059] Example 7 The only difference between this embodiment and Embodiment 1 is that the dissolution time in step 2 is 3 minutes.

[0060] Example 8 The only difference between this embodiment and Embodiment 1 is that the dissolution time in step 2 is 5 minutes.

[0061] Example 9 The only difference between this embodiment and Embodiment 1 is that the formula in step 3 does not contain ice.

[0062] Example 10 The only difference between this embodiment and Embodiment 1 is that the mixing time in step 4 is 5 minutes, and the temperature of the dough after mixing is 16°C.

[0063] Example 11 The only difference between this embodiment and Embodiment 1 is that the mixing time in step 4 is 8 minutes, and the temperature of the dough after mixing is 20°C.

[0064] Example 12 The only difference between this embodiment and Embodiment 1 is that the formula of the dough semi-finished product in step 3 is adjusted so that the mass of the sugar-tolerant yeast accounts for 1.5 wt% of the mass of the high-gluten flour.

[0065] Example 13 The only difference between this embodiment and Embodiment 1 is that the formula of the dough semi-finished product in step 3 is adjusted so that the mass of the sugar-tolerant yeast accounts for 5 wt% of the mass of the high-gluten flour.

[0066] Comparative Example 1 The only difference between this comparative example and Example 1 is that in step 1, the sugar-tolerant yeast is replaced with ordinary yeast.

[0067] Comparative Example 2 The only difference between this comparative example and Example 1 is that in step 1, skim milk powder is replaced with whole milk powder.

[0068] Comparative Example 3 The only difference between this comparative example and Example 1 is that in step 1, the sugar-tolerant yeast, wheat flour, and skim milk powder are in a weight ratio of 3:1:1.

[0069] Comparative Example 4 The only difference between this comparative example and Example 1 is that, in step 1, the time from obtaining the yeast solution to adding the yeast solution to the dough semi-finished product is 10 minutes.

[0070] Comparative Example 5 The only difference between this comparative example and Example 1 is that step 3 is omitted. Step 4 involves mixing the yeast solution, flour, sugar, salt, milk powder, water, ice, and oil, then freezing the mixture to obtain frozen dough. That is, the yeast solution is mixed with the ingredients for preparing the dough semi-finished product, rather than preparing the dough semi-finished product first and then mixing the yeast solution with it in a step-by-step preparation method.

[0071] Comparative Example 6 The only difference between this comparative example and Example 1 is that it does not include steps 1 to 3. Step 4 involves mixing sugar-tolerant yeast, skim milk powder, wheat flour, wheat flour, sugar, salt, milk powder, water, ice, and oil, then freezing the mixture to obtain frozen dough. In other words, the raw materials for preparing the yeast solution are mixed with the raw materials for preparing the dough semi-finished product, rather than preparing the yeast solution and dough semi-finished product first, and then mixing them together in a step-by-step preparation method.

[0072] Comparative Example 7 The only difference between this comparative example and Example 1 is that the water temperature in step 2 is 45°C.

[0073] Comparative Example 8 The only difference between this comparative example and Example 1 is that the water temperature in step 2 is 25°C.

[0074] Comparative Example 9 The only difference between this comparative example and Example 1 is that the dissolution time in step 2 is 1 min.

[0075] Comparative Example 10 The only difference between this comparative example and Example 1 is that the dissolution time in step 2 is 8 min.

[0076] Performance testing Fermentation power test of frozen dough Examples 1 to 13 and Comparative Examples 1 to 10, which had been frozen for 90 days, were thawed at 20°C for 60 min and then fermented at 32°C for 90 min. The height change of the dough was tested, and the test results are shown in Table 1.

[0077] Table 1. Fermentation power tests of Examples 1-13 and Comparative Examples 1-10

[0078] Compared to Comparative Example 1, Examples 1-13 exhibited better fermentation power. This is mainly because, during freezing, the saccharide-tolerant yeast was able to synthesize a large amount of trehalose within its cells to maintain cell structure and moisture, thus ensuring yeast activity and fermentation power. Compared to Comparative Example 2, the skim milk powder in Examples 1-13 provided the saccharide-tolerant yeast with more efficient energy for trehalose synthesis, thereby ensuring the yeast's activity and fermentation power. A comparison of Examples 1-13 with Comparative Example 3 showed that when the weight ratio of saccharide-tolerant yeast, wheat flour, and skim milk powder in the formula was 1:(1-1.5):(1-1.5), the saccharide-tolerant yeast was more dispersed in the powder mixture. During the preparation of frozen dough, the saccharide-tolerant yeast suffered less damage, and its contact with nutrients was better, resulting in better yeast activity. Compared with Comparative Example 4, Examples 1-13 show that the time from obtaining the yeast solution to adding it to the dough semi-finished product is within 3 minutes. This reduces the activation level of the sugar-tolerant yeast in the yeast solution, minimizes freezing damage during the freezing process, and enhances the fermentation power of the frozen dough. By comparing Examples 1-13 with Comparative Examples 5-6, it can be seen that this application first prepares the yeast into a yeast solution, and then adds the yeast solution to the dough semi-finished product prepared from other ingredients. On the one hand, this avoids over-activation caused by premature addition of the sugar-tolerant yeast, improving freezing damage during the freezing process. On the other hand, in the yeast solution, wheat flour and skim milk powder protect the sugar-tolerant yeast, reducing the possibility of contact between the yeast and ice, and minimizing freezing damage. By comparing Examples 1 to 13 and Comparative Examples 7 to 10, it can be seen that when the water temperature for preparing the yeast solution is controlled at 34℃ to 38℃ and the dissolution time is controlled at 3 min to 5 min, the effect of sugar-tolerant yeast in synthesizing trehalose can be guaranteed, while avoiding over-activation of sugar-tolerant yeast and ensuring the fermentation power of frozen dough.

[0079] Comparing Examples 1 to 6, it is evident that when the weight ratio of saccharide-tolerant yeast, wheat flour, and skim milk powder in the formula is 1:(1~1.5):(1~1.5), the distribution of saccharide-tolerant yeast in the powdered mixture is more dispersed. When the weight ratio of the powdered mixture to water in the yeast solution is within the range of 3:(3~5), the dispersion of saccharide-tolerant yeast in the yeast solution is good, and the dispersion effect is even better with the increase of the weight ratio of water in the yeast solution. It also exhibits good dispersibility in the frozen dough obtained after mixing with the semi-finished dough, resulting in better fermentation power. Comparing Examples 1 and 9, it is evident that ice helps lower the temperature of the semi-finished dough, reducing over-activation of saccharide-tolerant yeast during the mixing process of the yeast solution and the semi-finished dough, improving freezing damage during freezing, and ensuring the fermentation power of the frozen dough. By comparing Example 1 and Examples 12-13, it can be seen that when the mass of sugar-tolerant yeast accounts for 1.5 wt% to 5 wt% of the mass of high-gluten flour, the fermentation power of frozen dough is good, and the fermentation power of frozen dough is further improved as the mass fraction of sugar-tolerant yeast increases.

[0080] The technical solutions disclosed in the embodiments of this application have been described in detail above. Specific examples have been used in this article to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core inventive points of the embodiments of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for preparing frozen dough, characterized in that, The preparation method includes: A powdered mixture is obtained by mixing sugar-tolerant yeast, wheat flour and skim milk powder. The sugar-tolerant yeast is capable of synthesizing trehalose in its cells. The weight ratio of the sugar-tolerant yeast, wheat flour and skim milk powder is 1:(1~1.5):(1~1.5). The powdered mixture was dissolved in water at 34℃~38℃ for 3 min~5 min to obtain a yeast solution; The yeast solution is added to the dough semi-finished product within a time of less than or equal to 3 minutes, and after stirring for 5 to 8 minutes, it is shaped and quick-frozen to obtain the frozen dough.

2. The preparation method according to claim 1, characterized in that, In the yeast solution, the weight ratio of the powder mixture to the water is (3~4):(4~6).

3. The preparation method according to claim 1, characterized in that, The method for preparing the semi-finished dough includes: mixing high-gluten flour, sugar, salt, whole milk powder, improver, whole egg liquid, water, ice and oil into a dough until there is no dry powder or ice crystals, thus obtaining the semi-finished dough.

4. The preparation method according to claim 3, characterized in that, The fats include at least one of butter, anhydrous butter, and margarine; and / or, The sugar includes at least one of white granulated sugar and brown granulated sugar; and / or, The modifier comprises the following components in the indicated weight ratios: 27-33 parts glyceryl monostearate, 62-68 parts diacetyl tartaric acid mono- and diglycerides, 1.3-2.1 parts vitamin C, 0.9-1.5 parts compound xylanase MA, 0.5-1.0 parts xylanase, 0.5-0.8 parts maltose amylase, and 0.15-0.45 parts glucose oxidase; And / or, By weight, the high-gluten flour in the semi-finished dough is 96 to 100 parts, the sugar is 5 to 20 parts, the salt is 0.5 to 1.5 parts, the whole milk powder is 2 to 5 parts, the improver is 0.3 to 1 part, the whole egg liquid is 5 to 12 parts, the water is 22 to 26 parts, the ice is 14 to 20 parts, and the oil is 5 to 15 parts.

5. The preparation method according to claim 3, characterized in that, The sugar-tolerant yeast accounts for 1.5 wt% to 5.0 wt% of the mass of the high-gluten flour.

6. The preparation method according to claim 1, characterized in that, In the step of adding the yeast solution to the dough semi-finished product, stirring and freezing to obtain the frozen dough, the temperature of the dough after stirring is 16℃~24℃.

7. The preparation method according to any one of claims 1-6, characterized in that, In the step of adding the yeast solution to the dough semi-finished product, stirring, shaping, and quick-freezing to obtain the frozen dough, the freezing temperature is -30℃ to -40℃, and the freezing time is 20 min to 60 min.

8. A frozen dough, characterized in that, The frozen dough is prepared by the preparation method according to any one of claims 1-7.

9. The frozen dough according to claim 8, characterized in that, The frozen dough satisfies at least one of the following conditions: (1) The frozen dough has a freezing storage time of 90 days or more; (2) The frozen dough is a sweet bread frozen dough.

10. A baked food product, characterized in that, The baked goods are obtained by processing the frozen dough according to any one of claims 8-9.

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