A crisp bakery product and a method for making the same

Abstract

The present application relates to the technical field of food processing, and discloses a crisp pastry and a preparation method thereof, which is prepared from low-gluten flour, L-cysteine, protease, glucono-delta-lactone, ammonium bicarbonate, sodium bicarbonate, soybean lecithin, a food-grade emulsifier composition and mixed sugar water according to weight parts; during preparation, the low-gluten flour is taken as a premix carrier, trace ingredients are added to obtain a premix powder, and then the premix powder is mixed with the remaining low-gluten flour; the sugar water and the emulsifier composition are added, stirred into an initial dough, and placed after film coating; the processed dough is divided, pressed into tablets, and sequentially sent into a tunnel oven for primary and secondary baking; and then the dough is forced to cool, air-dried, and packaged. The present application reduces the structural strength of the dough by using L-cysteine and protease, releases gas in stages by using multiple composite leavening agents, and locks moisture by establishing a water-oil interface, thereby solving the problems of using sodium pyrosulfite and aluminum-containing leavening agents in traditional pastry processing.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, specifically to a shortbread pastry and its preparation method. Background Technology

[0002] Shortbread pastries, represented by soft-serve ice cream, French pastries, and lotus seed cakes, are snack foods made primarily from flour, with the addition of specific flavoring ingredients, and processed through steps such as sugar boiling, dough kneading, resting or fermentation, shaping, and baking. The core requirement for these products is to achieve good puffing under high-temperature, rapid baking conditions, thereby creating a crisp and crumbly texture.

[0003] In traditional processing techniques, sodium metabisulfite is commonly used as a gluten improver. Due to its reducing properties, sodium metabisulfite can break the disulfide bonds in gluten proteins, reducing dough strength and improving extensibility. Simultaneously, it decomposes during baking to produce acidic substances, which react with sodium bicarbonate to replenish gas and synergistically promote leavening. However, sulfur-containing components pose a risk of triggering consumer allergies, residual sulfur dioxide can affect the flavor of pastries, and it is difficult to meet the stringent residue limits set by national food safety standards. Furthermore, traditional processes often add aluminum-containing additives as leavening agents or for sugar conversion during boiling. With the advancement of aluminum-free and clean labeling trends, these traditional additives inevitably face elimination.

[0004] In the search for alternatives, existing technologies often struggle to simultaneously address the issues of gluten weakening and gas production. When enzymes are used alone in the leavening process, their effects are slow and highly temperature-dependent, easily leading to excessive gluten weakening during processing. This reduces the dough's gas-holding capacity, causing the product to collapse or bubble on the surface. While conventional reducing agents can lower gluten strength, the lack of subsequent gas production often results in a hardened dough and a significantly less crumbly finished product.

[0005] In constructing puffing systems, existing formulas often use a single leavening agent. For example, relying solely on ammonium bicarbonate for thermal decomposition and gas production results in an overly concentrated gas production rate, with gas often being generated prematurely and dissipating into the air before the dough sets. The lack of a stepped gas production mechanism fails to effectively support the expansion of the dough, ultimately leading to uneven pore size inside the pastry and making it difficult to form an ideal loose structure.

[0006] Furthermore, existing technologies lack systematic control over dough volume and moisture content in industrial-scale production. On continuous production lines, dough gradually cools and loses moisture as exposure time increases, leading to changes in enzyme activity and decreased product consistency. Especially under high-temperature, rapid baking conditions, the internal moisture of the dough evaporates rapidly. If the dough itself has insufficient water-holding capacity, baked pastries are highly susceptible to starch retrogradation during storage, resulting in defects such as shrinkage, hardening, and cracking, thus reducing the product's shelf life. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a shortbread pastry and its preparation method, solving the problems of traditional shortbread pastries where the development of dough gluten is difficult to control precisely during processing, resulting in a hard texture; the gas production time of a single leavening agent is too concentrated, causing uneven size of the internal pores; and the pastry loses too much internal moisture during baking and storage, making the finished product prone to drying, aging, and breakage.

[0008] To achieve the above objectives, the present invention provides the following technical solution: A shortbread pastry made from ingredients comprising the following parts by weight: 100 portions of low-gluten flour; L-cysteine ​​0.10-0.14 parts; 0.04-0.06 parts of protease; 0.60-0.72 parts of gluconate-δ-lactone; 1.40-2.00 parts of ammonium bicarbonate; Sodium bicarbonate 0.44-0.56 parts; Soy lecithin 0.16-0.30 parts; 0.60-0.80 parts of food-grade emulsifier composition; Mixed sugar syrup 70.0-74.0 parts; The L-cysteine ​​and the protease work together to reduce the strength of the gluten structure inside the dough; the glucono-δ-lactone, the ammonium bicarbonate, and the sodium bicarbonate work together to release gas during heating, causing the dough to expand; and the soybean lecithin and the food-grade emulsifier composition work together to establish a water-oil interface and lock in internal moisture.

[0009] By adopting the above technical solution and the above formula combination, the following effects are achieved: Conventional formulas often struggle to balance crumbliness and dough elasticity. In this solution, L-cysteine ​​acts as a reducing agent, providing thiol groups to directly break the disulfide bonds in gluten proteins, reducing the cross-linking of protein macromolecules. Simultaneously, protease hydrolyzes peptide bonds within the flour, breaking long-chain proteins into short-chain peptides. These two components work synergistically during processing, reducing the structural strength of the dough from within and limiting excessive gluten network development, thus maintaining the crumbly texture of the finished pastry. Building upon this weakened gluten structure, glucono-δ-lactone slowly hydrolyzes into gluconic acid in the presence of moisture, subsequently neutralizing with sodium bicarbonate to slowly release carbon dioxide. During the high-temperature baking stage, ammonium bicarbonate decomposes, generating a large amount of carbon dioxide and ammonia. This combination of three components overcomes the limitations of concentrated gas production from a single leavening agent, achieving continuous, stepped foaming throughout the entire process from resting to baking, forming fine and uniformly sized micropores within the pastry. To address the issue of drying out during storage, the phospholipid groups provided by soybean lecithin synergistically work with a food-grade emulsifier composition to exert surface activity, effectively reducing the surface tension at the interface between free water and lipids. This mixed emulsifying component encapsulates moisture to form microcapsule structures, hindering the rapid evaporation and loss during high-temperature baking, thereby delaying starch aging and hardening of pastries during storage.

[0010] Preferably, the protease is selected from papain, bromelain, or fungal protease.

[0011] By employing the above technical solutions, the selection of protease directly affects the hydrolysis efficiency. The specific types of protease described above exhibit high hydrolytic activity within the set temperature range for batter preparation, thereby targeting and degrading gluten proteins.

[0012] Preferably, the method for preparing the mixed sugar water includes the following steps: Prepare the first pot of sugar water and the second pot of sugar water separately. Add granulated sugar, water and anhydrous citric acid to the first pot and mix well. Add granulated sugar, water and anhydrous citric acid to the second pot and mix well. The mass ratio of the white sugar to the water added to the first pot and the second pot is 2:1, and the mass ratio of the anhydrous citric acid to the white sugar is 0.012:100-0.0133:100. Heat the sugar water in the first pot and the sugar water in the second pot separately and boil them uncovered for 2-3 minutes. Do not cover the pot while boiling. After boiling, cool the sugar water in the first pot to room temperature for later use, and keep the sugar water in the second pot warm for later use. Take the cooled sugar water from the first pot and mix it with the warm sugar water from the second pot, and adjust the temperature to 85℃-95℃ to obtain the mixed sugar water.

[0013] The reason for using a two-pot mixing method in the preparation of the mixed sugar syrup is that anhydrous citric acid, under heating conditions, can catalyze the hydrolysis of granulated sugar, generating invert sugar syrup containing glucose and fructose, thus improving the moisturizing properties of the sugar syrup system. The open-boiling operation during this process removes excess water and promotes sugar concentration. By mixing the hot and cold sugar syrups, the overall temperature of the syrup can be adjusted to the target range in a short time, directly meeting the precise thermal requirements of the subsequent scalding process.

[0014] Preferably, the method for preparing the food-grade emulsifier composition includes the following steps: The food-grade emulsifier composition is prepared by mixing glyceryl monostearate with soybean lecithin, sucrose fatty acid ester or diacetyl tartaric acid mono- and diglycerides in a 1:1 mass ratio, heating and stirring at 50℃-60℃ until fully melted and composited, and then cooling.

[0015] By adopting the above technical solution, for the emulsifier composition, glyceryl monostearate and other emulsifiers undergo eutectic crystallization in the range of 50℃-60℃ to form a composite emulsion system with a wider hydrophilic-lipophilic balance value, which effectively enhances the ability to finely disperse the lipid components inside the raw materials.

[0016] Preferably, the raw materials further include additional ingredients selected from one of the following: 0.09 parts by weight of butter flavoring, 1.0 part by weight of sourdough starter, 3.6 parts by weight of cocoa powder, or 5.0 parts by weight of yam powder.

[0017] By adopting the above technical solutions and introducing these specific proportions of additional ingredients, it is possible to directionally impart specific flavors and nutrients to pastries without damaging the original rheological properties of the dough.

[0018] Secondly, the present invention provides a method for preparing a shortbread pastry, comprising the following steps: Take 5%-15% of the total weight of the low-gluten flour as a premix carrier, add the L-cysteine, the protease, the glucono-δ-lactone, the ammonium bicarbonate, the sodium bicarbonate and the soybean lecithin, and stir thoroughly to obtain a premix powder. Mix the premix powder with the remaining low-gluten flour and stir thoroughly again to obtain a dry powder mixture. The dry powder mixture is put into a dough mixer, the mixed sugar water and the food-grade emulsifier composition are added, and the mixture is quickly stirred into a dough to obtain the initial dough. Take out the initial dough, cover it with a film to keep it warm, and place it for processing to obtain the dough to be processed; The dough to be processed is divided into multiple portions, which are then pressed into sheets and shaped to obtain shaped dough discs. The shaped dough is placed in a tunnel oven for a first baking to obtain a pre-baked dough; After the initial baked dough is cooled, it is baked a second time to obtain a rebaked dough. The re-baked dough is forced to cool down and exposed to air to dissipate gas, and finally packaged to obtain the shortbread pastry.

[0019] By adopting the above technical solution, the following effects are achieved: Trace functional substances are difficult to disperse evenly when directly added in large quantities. Therefore, this method first premixes L-cysteine, protease, and leavening agents with a small portion of low-gluten flour, and then mixes them into the bulk flour. This step-by-step mixing process ensures the uniform distribution of trace additives throughout the dry powder matrix, preventing excessive local gas production or uneven gluten degradation during subsequent processing. After the dry powder is mixed, a hot sugar solution is added to induce scalding, causing partial starch gelatinization, which increases the dough's water absorption and water retention. The specific temperature conditions at this point activate the reactivity of protease and L-cysteine, initiating the weakening process of the dough's network structure. Simultaneously, the food-grade emulsifier composition is evenly dispersed with the assistance of mechanical stirring, initially constructing the microstructure of the water-oil interface. For the post-forming heat treatment process, the first baking utilizes the initial high temperature to rapidly expand and set the dough. The second baking is carried out at a lower temperature, mainly to remove excess moisture from the surface of the pastry. Finally, by forcibly cooling down and exposing the product to air to dissipate the gas, the residual ammonia gas from the thermal decomposition of ammonium bicarbonate diffuses and escapes to the outside, eliminating the potential for off-flavors in the finished pastry.

[0020] Preferably, when adding the mixed sugar water, the temperature of the mixed sugar water is adjusted to 85℃-95℃ beforehand; the temperature of the obtained initial dough is controlled between 35℃-45℃; the placement treatment is to let it stand for 10min-12min or ferment for 2.5h at a temperature of 20℃-45℃.

[0021] By employing the above technical solution, the high-temperature sugar water introduced during the dough mixing process exchanges heat with the dry powder, precisely placing the overall temperature of the initial dough within the range of 35℃-45℃. This range is precisely the suitable condition for the catalytic hydrolysis reaction of enzymes such as papain. Relying on the static or fermentation process at this temperature, the protease and L-cysteine ​​work synergistically to break the disulfide bonds and peptide bonds within the gluten proteins, thoroughly completing the loosening of the internal structure of the dough.

[0022] Preferably, the time from the start of pressing to the completion of forming for each portion of the dough is limited to within 15 minutes, and the dough that has not been pressed into sheets is continuously covered with a film to keep it warm and moist.

[0023] By employing the above technical solution, prolonged exposure of the dough to air would lead to significant moisture loss. This method imposes strict time limits on the sheeting and forming process and physically isolates the unprocessed dough to prevent surface evaporation and crust formation over time. This operation maintains a constant internal temperature and humidity, ensuring that pastries formed at different times within the same batch maintain consistent physicochemical properties.

[0024] Preferably, the bottom heat temperature during the first baking is 280℃-295℃, the middle bottom heat temperature is 260℃-280℃, the rear bottom heat temperature is 260℃-280℃, the top heat temperature is 310℃-325℃, the middle top heat temperature is 295℃-310℃, the rear top heat temperature is 295℃-310℃, and the baking time is 1min28s-1min38s.

[0025] By employing the above-mentioned technical solution, precise heat transfer is required for the dough's maturation. A baking curve with a stepped decrease in bottom and top heat is used. The high temperature in the initial stage causes the dough surface to rapidly heat and deform, creating a closed vapor pressure inside. The temperature is appropriately lowered in the middle and later stages, allowing heat to continuously conduct inwards, promoting the complete decomposition of the internal chemical leavening agents. This short baking time not only ensures the dough's maturation but also avoids excessive dehydration and edge charring.

[0026] Preferably, the temperature of the secondary baking is 115℃-125℃ and the time is 10s-20s; the forced cooling lowers the temperature of the re-baked dough to below 40℃ and the time for gas dissipation is 15min-30min.

[0027] Even with the above-mentioned technical solution, pastries that have just undergone one baking process still have unstable internal components. The second baking process specifically evaporates the free water on the surface of the pastry, increasing the crispness of the surface layer without damaging the internal water-holding structure. Subsequently, the re-baked dough is rapidly cooled to below 40°C, utilizing the temperature difference between the inside and outside to accelerate the movement of gas molecules. Combined with the time for gas dissipation, this thoroughly removes residual ammonia and moisture from the pores, thereby reducing the product's water activity and extending its shelf life.

[0028] This invention provides a shortbread pastry and its preparation method. It has the following beneficial effects: 1. This invention utilizes the synergistic effect of L-cysteine ​​and protease to improve the processing performance of dough and enhance the crispness of pastries. The L-cysteine ​​in the formula provides thiol groups to break the disulfide bonds of gluten proteins, which, combined with the hydrolytic cleavage of long-chain protein peptide bonds by protease, reduces the structural strength inside the dough. This treatment method inhibits the excessive development of the gluten network, avoids the problem of poor product texture caused by dough hardening in traditional processing, and stabilizes the crispness of the finished pastries.

[0029] 2. This invention uses glucono-δ-lactone, sodium bicarbonate, and ammonium bicarbonate to construct a composite leavening system, which optimizes the pore structure inside the pastry. In the pre-processing stage, glucono-δ-lactone hydrolyzes and reacts with sodium bicarbonate to slowly release carbon dioxide. During the high-temperature baking stage, ammonium bicarbonate decomposes upon heating to generate gas in a concentrated manner, thereby overcoming the defect of excessively concentrated gas generation time of a single leavening agent. This allows the dough to achieve step-by-step continuous foaming during the resting and heating stages, resulting in finer and more uniform pores inside the final shaped pastry.

[0030] 3. This invention utilizes a combination of soybean lecithin and food-grade emulsifiers to enhance the product's water-holding capacity and delay storage aging. These two emulsifying components work together to exert surface activity, reducing the surface tension at the interface between free water and lipids, and encapsulating moisture internally. This state not only prevents the drastic evaporation and loss of moisture during the baking stage, preserving the essential moisture content of the pastry, but also effectively slows down the drying and hardening aging process of starch during subsequent storage, reducing the probability of product shrinkage and breakage. Attached Figure Description

[0031] Figure 1 This is a line graph showing the change in dough stretching resistance over time for embodiments and comparative examples of the present invention; Figure 2 This is a line graph showing the volume versus center height of the finished pastries in the embodiments and comparative examples of the present invention. Figure 3 Line graphs showing the absolute moisture content and hardness of the finished pastries in various embodiments and comparative examples of the present invention; Figure 4 This is a line graph showing the physicochemical safety indicators and ammonia residue of the finished products in the embodiments and comparative examples of the present invention; Figure 5 This is a line graph showing the distribution of color difference values ​​and pass rates of finished products in the embodiments and comparative examples of the present invention. Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Preparation Examples 1-6: Preparation Example 1: This preparation example provides a method for preparing a double-pot sugar solution of equal concentration, including the following steps: Prepare a first batch of sugar syrup and a second batch of sugar syrup separately. In the first batch, add 150 kg of granulated sugar, 75 kg of water (the mass ratio of granulated sugar to water is 2:1), and 19.0 g of anhydrous citric acid (the mass ratio of anhydrous citric acid to granulated sugar is approximately 0.0127:100) and mix well. In the second batch, add 150 kg of granulated sugar, 75 kg of water (the mass ratio of granulated sugar to water is 2:1), and 19.0 g of anhydrous citric acid (the mass ratio of anhydrous citric acid to granulated sugar is approximately...). Mix the 0.0127:100 sugar solution thoroughly; heat the first and second pots of sugar syrup to a boil for 2 to 3 minutes respectively, without covering during the boiling process; after boiling, cool the first pot of sugar syrup to room temperature for later use, and keep the second pot of sugar syrup warm for later use; when using, take the cooled sugar syrup from the first pot and mix it with the warm sugar syrup from the second pot, adjust the temperature to 85℃ to 90℃, weigh out 36.6kg of the mixed sugar syrup for later use, and according to the process calculation, the 36.6kg of mixed sugar syrup contains 3.0g of anhydrous citric acid.

[0034] Preparation Example 2: This preparation example provides a method for preparing a double-pot sugar solution of equal concentration, including the following steps: Prepare a first batch of sugar syrup and a second batch of sugar syrup separately. In the first batch, add 150 kg of white sugar, 75 kg of water (i.e., the mass ratio of white sugar to water is 2:1), and 18.0 g of anhydrous citric acid (i.e., the mass ratio of anhydrous citric acid to white sugar is 0.012:100) and mix well. In the second batch, add 150 kg of white sugar, 75 kg of water (i.e., the mass ratio of white sugar to water is 2:1), and 18.0 g of anhydrous citric acid (i.e., the mass ratio of anhydrous citric acid to white sugar is 0.012:100) and mix well. Heat the first and second pots of sugar water to a boil for 2 to 3 minutes each, without covering the pot during the boiling process. After boiling, cool the first batch of sugar water to room temperature for later use, and keep the second batch of sugar water warm for later use. When using, mix the cooled sugar water from the first pot with the warm sugar water from the second pot, adjust the temperature to 85℃ to 95℃, and weigh out 35.0kg of the mixed sugar water for later use. According to process calculations, this 35.0kg mixed sugar water contains 2.8g of anhydrous citric acid.

[0035] Preparation Example 3: This preparation example provides a method for preparing a double-pot sugar solution of equal concentration, including the following steps: Prepare a first batch of sugar syrup and a second batch of sugar syrup separately. In the first batch, add 150 kg of white sugar, 75 kg of water (i.e., the mass ratio of white sugar to water is 2:1), and 20.0 g of anhydrous citric acid (i.e., the mass ratio of anhydrous citric acid to white sugar is 0.0133:100) and mix well. In the second batch, add 150 kg of white sugar, 75 kg of water (i.e., the mass ratio of white sugar to water is 2:1), and 20.0 g of anhydrous citric acid (i.e., the mass ratio of anhydrous citric acid to white sugar is 0.0133:100) and mix well. Heat the first and second pots of sugar water to a boil for 2 to 3 minutes each, without covering the pot during the boiling process. After boiling, cool the first batch of sugar water to room temperature for later use, and keep the second batch of sugar water warm for later use. When using, mix the cooled sugar water from the first pot with the warm sugar water from the second pot, adjust the temperature to 85℃ to 95℃, and weigh out 37.0kg of the mixed sugar water for later use. According to process calculations, this 37.0kg mixed sugar water contains 3.3g of anhydrous citric acid.

[0036] Preparation Example 4: This preparation example provides a method for preparing a food-grade emulsifier composition, including the following steps: Glyceryl monostearate and soybean lecithin were mixed at a mass ratio of 1:1, heated and stirred at 50°C to 60°C until fully melted and compounded, and then cooled to obtain a food-grade emulsifier composition.

[0037] Preparation Example 5: This preparation example provides a method for preparing a food-grade emulsifier composition, including the following steps: Glyceryl monostearate and sucrose fatty acid ester were mixed in a mass ratio of 1:1, heated and stirred at 50°C to 60°C until fully melted and compounded, and then cooled to obtain a food-grade emulsifier composition.

[0038] Preparation Example 6: This preparation example provides a method for preparing a food-grade emulsifier composition, including the following steps: Glyceryl monostearate and diacetyl tartaric acid mono- and diglycerides were mixed in a mass ratio of 1:1, heated and stirred at 50°C to 60°C until fully melted and compounded, and then cooled to obtain a food-grade emulsifier composition.

[0039] Examples 1-6: Example 1: This embodiment provides a method for preparing shortbread, including the following steps: (1) Take 50 kg (i.e., 100 parts by weight) of low-gluten flour, and take 5 kg (i.e., 10 parts by weight, accounting for 10% of the total weight of low-gluten flour) of low-gluten flour as a premix carrier. Add 62 g (i.e., 0.124 parts by weight) of L-cysteine, 22 g (i.e., 0.044 parts by weight) of papain, 360 g (i.e., 0.72 parts by weight) of glucono-δ-lactone, 750 g (i.e., 1.50 parts by weight) of ammonium bicarbonate, 270 g (i.e., 0.54 parts by weight) of sodium bicarbonate, 120 g (i.e., 0.24 parts by weight) of soy lecithin and 45 g (i.e., 0.09 parts by weight) of butter flavoring. Stir thoroughly for 3 minutes until uniform. Mix the above premix powder with the remaining 45 kg (i.e., 90 parts by weight) of low-gluten flour and stir thoroughly again. (2) Add the mixed dry powder to the dough mixer, add 36.6 kg (i.e. 73.2 parts by weight) of the prepared mixed sugar water (temperature adjusted to 90°C) prepared in Example 1 and 380 g (i.e. 0.76 parts by weight) of the food-grade emulsifier composition prepared in Example 4, and stir quickly for 3 minutes until the dough forms a ball, and control the dough temperature at 42°C. (3) Take out the kneaded dough, cover it with plastic wrap to keep it warm, and let it stand at 30℃ for 11 minutes; (4) Divide the rested dough into two portions and use the soft rice cake mold to press and shape them in turn. Each portion of dough should be pressed and shaped within 15 minutes. The dough that is not used in the machine should be covered with a film to keep it warm and moist. (5) The shaped dough is placed into a tunnel oven for baking once. The oven temperature parameters are: bottom fire front section 290℃, middle section 275℃, back section 275℃, top fire front section 320℃, middle section 300℃, back section 300℃, baking time is 1 minute 34 seconds. (6) After cooling, bake the dough a second time at 125°C for 20 seconds. (7) After the second baking, the dough is forced to cool to below 40°C, exposed to air for 30 minutes to dissipate the gas, and then packaged to obtain the original flavor soft rice cracker product.

[0040] Example 2: This embodiment provides a method for preparing shortbread, including the following steps: (1) Take 50 kg (i.e. 100 parts by weight) of low-gluten flour, and take 2.5 kg (i.e. 5 parts by weight, accounting for 5% of the total weight of low-gluten flour) of low-gluten flour as a premix carrier. Add 50 g (i.e. 0.10 parts by weight) of L-cysteine, 20 g (i.e. 0.04 parts by weight) of bromelain, 300 g (i.e. 0.60 parts by weight) of glucono-δ-lactone, 700 g (i.e. 1.40 parts by weight) of ammonium bicarbonate, 220 g of sodium bicarbonate (i.e. 0.44 parts by weight) and 80 g (i.e. 0.16 parts by weight) of soybean lecithin. Stir thoroughly for 3 minutes until uniform. Mix the above premix powder with the remaining 47.5 kg (i.e. 95 parts by weight) of low-gluten flour and stir thoroughly again. (2) Add the mixed dry powder to the dough mixer, add 35.0 kg (i.e. 70.0 parts by weight) of the prepared mixed sugar water (temperature adjusted to 85°C) prepared in Example 2 and 300 g (i.e. 0.60 parts by weight) of the food-grade emulsifier composition prepared in Example 5, and stir quickly for 2 minutes until the dough forms a ball, and control the dough temperature at 35°C. (3) Take out the kneaded dough, cover it with plastic wrap to keep it warm, and let it stand at 20℃ for 10 minutes; (4) Divide the rested dough into two portions and use the soft rice cake mold to press and shape them in turn. Each portion of dough should be pressed and shaped within 15 minutes. The dough that is not used in the machine should be covered with a film to keep it warm and moist. (5) The shaped dough is placed into a tunnel oven for baking once. The oven temperature parameters are: bottom fire front section 280℃, middle section 260℃, back section 260℃, top fire front section 310℃, middle section 295℃, back section 295℃, baking time is 1 minute 28 seconds. (6) After cooling, bake the dough a second time at 115°C for 10 seconds. (7) After the second baking, the dough is forced to cool to below 40°C, exposed to air for 15 minutes to dissipate the gas, and then packaged to obtain the original flavor soft rice cracker product.

[0041] Example 3: This embodiment provides a method for preparing shortbread, including the following steps: (1) Take 50 kg (i.e. 100 parts by weight) of low-gluten flour, and take 7.5 kg (i.e. 15 parts by weight, which is 15% of the total weight of low-gluten flour) of low-gluten flour as a premix carrier. Add 70 g (i.e. 0.14 parts by weight) of L-cysteine, 30 g (i.e. 0.06 parts by weight) of fungal protease, 360 g (i.e. 0.72 parts by weight) of gluconate-δ-lactone, 1000 g (i.e. 2.00 parts by weight) of ammonium bicarbonate, 280 g (i.e. 0.56 parts by weight) of sodium bicarbonate and 150 g (i.e. 0.30 parts by weight) of soybean lecithin. Stir thoroughly for 5 minutes until uniform. Mix the above premix powder with the remaining 42.5 kg (i.e. 85 parts by weight) of low-gluten flour and stir thoroughly again. (2) Add the mixed dry powder to the dough mixer, add 37.0 kg (i.e. 74.0 parts by weight) of the prepared mixed sugar water (temperature adjusted to 95°C) prepared in Example 3 and 400 g (i.e. 0.80 parts by weight) of the food-grade emulsifier composition prepared in Example 6, and stir quickly for 3 minutes until the dough forms a ball, and control the dough temperature at 45°C. (3) Take out the kneaded dough, cover it with plastic wrap to keep it warm, and let it stand at 45℃ for 12 minutes; (4) Divide the rested dough into two portions and use the French pastry mold to press and shape them in turn. Each portion of dough should be pressed and shaped within 15 minutes. The dough that is not used in the machine should be covered with a film to keep it warm and moist. (5) The shaped dough is placed into a tunnel oven for baking. The oven temperature parameters are: bottom fire front section 295℃, middle section 280℃, back section 280℃, top fire front section 325℃, middle section 310℃, back section 310℃, baking time is 1 minute 38 seconds. (6) After cooling, bake the dough a second time at 125°C for 20 seconds. (7) After the second baking, the dough is forced to cool to below 40°C, exposed to air for 30 minutes to dissipate the gas, and then packaged to obtain the original flavor French pastry.

[0042] Example 4: This embodiment provides a method for preparing shortbread, including the following steps: (1) Take 50 kg (i.e. 100 parts by weight) of low-gluten flour, take 5 kg (i.e. 10 parts by weight, which is 10% of the total weight of low-gluten flour) of low-gluten flour as a premix carrier, add 62 g (i.e. 0.124 parts by weight) of L-cysteine, 22 g (i.e. 0.044 parts by weight) of papain, 360 g (i.e. 0.72 parts by weight) of glucono-δ-lactone, 750 g (i.e. 1.50 parts by weight) of ammonium bicarbonate, 270 g (i.e. 0.54 parts by weight) of sodium bicarbonate, 120 g (i.e. 0.24 parts by weight) of soybean lecithin and 500 g (i.e. 1.0 part by weight) of old dough fermentation material, stir thoroughly for 3 minutes until uniform, mix the above premix powder with the remaining 45 kg (i.e. 90 parts by weight) of low-gluten flour, and stir thoroughly again; (2) Add the mixed dry powder to the dough mixer, add 36.6 kg (i.e. 73.2 parts by weight) of the prepared mixed sugar water (temperature adjusted to 90°C) prepared in Example 1 and 380 g (i.e. 0.76 parts by weight) of the food-grade emulsifier composition prepared in Example 4, and stir quickly for 3 minutes until the dough forms a ball, and control the dough temperature at 42°C. (3) Take out the kneaded dough, cover it with a plastic film to keep it warm and moist, and ferment it at 30℃ for 2.5 hours; (4) Divide the fermented dough into two portions and use the French pastry mold to press and shape them in turn. Each portion of dough should be pressed and shaped within 15 minutes. The dough that is not used in the machine should be covered with a film to keep it warm and moist. (5) The shaped dough is placed into a tunnel oven for baking once. The oven temperature parameters are: bottom fire front section 290℃, middle section 275℃, back section 275℃, top fire front section 320℃, middle section 300℃, back section 300℃, baking time is 1 minute 34 seconds. (6) After cooling, bake the dough a second time at 125°C for 20 seconds. (7) After the second baking, the dough is forced to cool to below 40°C, exposed to air for 30 minutes to dissipate the gas, and then packaged to obtain the finished old dough cake.

[0043] Example 5: This embodiment provides a method for preparing shortbread, including the following steps: (1) Take 50 kg (i.e. 100 parts by weight) of low-gluten flour, and take 5 kg (i.e. 10 parts by weight, which is 10% of the total weight of low-gluten flour) of low-gluten flour as a premix carrier. Add 62 g (i.e. 0.124 parts by weight) of L-cysteine, 22 g (i.e. 0.044 parts by weight) of papain, 360 g (i.e. 0.72 parts by weight) of glucono-δ-lactone, 750 g (i.e. 1.50 parts by weight) of ammonium bicarbonate, 270 g (i.e. 0.54 parts by weight) of sodium bicarbonate, 120 g (i.e. 0.24 parts by weight) of soybean lecithin and 1.8 kg (i.e. 3.6 parts by weight) of sifted cocoa powder. Stir thoroughly for 3 minutes until uniform. Mix the above premix powder with the remaining 45 kg (i.e. 90 parts by weight) of low-gluten flour and stir thoroughly again. (2) Add the mixed dry powder to the dough mixer, add 37.0 kg (i.e. 74.0 parts by weight) of the prepared mixed sugar water (temperature adjusted to 90°C) prepared in Example 3 and 380 g (i.e. 0.76 parts by weight) of the food-grade emulsifier composition prepared in Example 4, and stir quickly for 3 minutes until the dough forms a ball, and control the dough temperature at 42°C. (3) Take out the kneaded dough, cover it with plastic wrap to keep it warm, and let it stand at 30℃ for 11 minutes; (4) Divide the rested dough into two portions and use the soft rice cake mold to press and shape them in turn. Each portion of dough should be pressed and shaped within 15 minutes. The dough that is not used in the machine should be covered with a film to keep it warm and moist. (5) The shaped dough is placed into a tunnel oven for baking once. The oven temperature parameters are: bottom fire front section 290℃, middle section 275℃, back section 275℃, top fire front section 320℃, middle section 300℃, back section 300℃, baking time is 1 minute 34 seconds. (6) After cooling, bake the dough a second time at 125°C for 20 seconds. (7) After the second baking, the dough is forced to cool to below 40°C, exposed to air for 30 minutes to dissipate the gas, and then packaged to obtain the finished cocoa-flavored soft rice cracker.

[0044] Example 6: This embodiment provides a method for preparing shortbread, including the following steps: (1) Take 50 kg (i.e., 100 parts by weight) of low-gluten flour, and take 5 kg (i.e., 10 parts by weight, accounting for 10% of the total weight of low-gluten flour) of low-gluten flour as a premix carrier. Add 62 g (i.e., 0.124 parts by weight) of L-cysteine, 22 g (i.e., 0.044 parts by weight) of papain, 360 g (i.e., 0.72 parts by weight) of glucono-δ-lactone, 750 g (i.e., 1.50 parts by weight) of ammonium bicarbonate, 270 g (i.e., 0.54 parts by weight) of sodium bicarbonate, 120 g (i.e., 0.24 parts by weight) of soybean lecithin and 2.5 kg (i.e., 5.0 parts by weight) of yam powder. Stir thoroughly for 3 minutes until uniform. Mix the above premix powder with the remaining 45 kg (i.e., 90 parts by weight) of low-gluten flour and stir thoroughly again. (2) Add the mixed dry powder to the dough mixer, add 37.0 kg (i.e. 74.0 parts by weight) of the prepared mixed sugar water (temperature adjusted to 90°C) prepared in Example 3 and 380 g (i.e. 0.76 parts by weight) of the food-grade emulsifier composition prepared in Example 4, and stir quickly for 3 minutes until the dough forms a ball, and control the dough temperature at 42°C. (3) Take out the kneaded dough, cover it with plastic wrap to keep it warm, and let it stand at 30℃ for 11 minutes; (4) Divide the rested dough into two portions and use the soft rice cake mold to press and shape them in turn. Each portion of dough should be pressed and shaped within 15 minutes. The dough that is not used in the machine should be covered with a film to keep it warm and moist. (5) The shaped dough is placed into a tunnel oven for baking once. The oven temperature parameters are: bottom fire front section 290℃, middle section 275℃, back section 275℃, top fire front section 320℃, middle section 300℃, back section 300℃, baking time is 1 minute 34 seconds. (6) After cooling, bake the dough a second time at 125°C for 20 seconds. (7) After the second baking, the dough is forced to cool to below 40°C, exposed to air for 30 minutes to dissipate the gas, and then packaged to obtain the finished yam-flavored soft snow cake.

[0045] Comparative Examples 1-8: Comparative Example 1: Compared with Example 1, the difference is that L-cysteine, papain, glucono-δ-lactone and sodium bicarbonate were not added in step (1), but 20g sodium metabisulfite and 200g ammonium alum (containing aluminum leavening agent) were used instead, and the rest were the same.

[0046] Comparative Example 2: Compared with Example 1, the difference is that the segmented forming operation in step (4) is omitted. The dough after resting is not divided equally, and all of it is put into the machine for continuous pressing and forming at one time, so that the total waiting and processing time of the dough at room temperature reaches 45 minutes. The rest are the same.

[0047] Comparative Example 3: Compared with Example 1, the difference is that L-cysteine ​​and papain were not added in step (1), but all other steps are the same.

[0048] Comparative Example 4: The difference from Example 1 is that gluconate-δ-lactone was not added in step (1), but all other steps are the same.

[0049] Comparative Example 5: Compared with Example 1, the difference is that soybean lecithin was not added in step (1) and food-grade emulsifier composition was not added in step (2), while the rest are the same.

[0050] Comparative Example 6: Compared with Example 1, the difference is that the mixed sugar water added in step (2) is replaced with an equal amount of 36.6 kg of mixed sugar water containing 4.5 g of anhydrous citric acid, and the rest are the same.

[0051] Comparative Example 7: Compared with Example 1, the difference is that the mixed sugar water added in step (2) is replaced with an equal amount of 36.6 kg of mixed sugar water containing 1.5 g of anhydrous citric acid, and the rest are the same.

[0052] Comparative Example 8: Compared with Example 1, the difference is that the secondary baking operation in step (6) and the operation of exposing to air in step (7) are omitted. That is, after the first baking is completed, it is directly cooled to room temperature and sealed for packaging. The rest are the same.

[0053] Test Examples 1-5: Test Example 1: This test case aims to verify the actual effect of the chemical-biological dual-effect gluten reduction system of the present invention, and the influence of the limited segmented forming processing time window on the rheological properties of dough.

[0054] Experimental steps: The doughs from Example 1, Comparative Example 2, and Comparative Example 3 that had just formed into a ball at the end of the kneading process were taken as test samples, and the moment of dough formation was recorded as the starting point of 0 minutes.

[0055] The extracted dough samples were placed on a constant temperature operating table with the temperature controlled at 25℃ and left to stand. At the four time points of 5 minutes, 15 minutes, 30 minutes and 45 minutes, 40-gram small dough balls were cut from each group of samples.

[0056] Rheological tests were performed on small pieces of dough using a texture analyzer equipped with a gluten stretching probe assembly. The probe stretching speed was set to 1.5 mm / s, and the instrument automatically recorded the peak value of the maximum tensile resistance at the moment the dough was broken. This value directly reflects the residual strength of the gluten network inside the dough.

[0057] Each group was measured three times in parallel at each time point. After removing outliers, the arithmetic mean was calculated and recorded.

[0058] Table 1. Test data on the maximum tensile resistance of dough in each embodiment and comparative example over time (unit: N) ;in conclusion: Based on the data in Table 1 and the appendix Figure 1 The trend of dough tensile resistance changes shows that, throughout the entire 45-minute test period, the tensile resistance of the dough in Comparative Example 3, which did not contain the chemical and biological dual-effect gluten-reducing components, remained consistently above 6.3N. This excessively strong gluten network not only causes strong elastic shrinkage of the dough during the sheeting stage, but also causes wrinkles or even breakage on the surface of the shaped dough under internal stress, completely deviating from the process requirements of low extensibility and low elasticity for shortbread.

[0059] The resistance change curves of Example 1 and Comparative Example 2 in the figure show a high degree of overlap. This is because both doughs used the same chemical and biological gluten-reducing formulation system, and the biochemical degradation kinetics occurring within them were necessarily synchronized. In the initial mixing stage, the thiol groups carried by L-cysteine ​​rapidly cleaved some of the disulfide bonds between gluten protein molecules through a reduction reaction, disrupting the initial rigid structure of the three-dimensional macromolecular network. As time progressed, the biological enzyme system began to continuously exert its enzymatic effect to hydrolyze the polypeptide chains, causing the tensile resistance of both doughs to rapidly decrease to about 1.83 N at the 15-minute mark. This numerical range precisely constitutes the rheological window period most suitable for continuous rolling of shortcrust pastry, at which point the dough has both eliminated shrinkage stress and retained a microscopic physical framework sufficient to support subsequent gas-generating expansion.

[0060] The high degree of overlap between the curves of Example 1 and Comparative Example 2 precisely demonstrates the absolute necessity of limiting the time required for segmented forming operations in this invention. Example 1, by strictly adhering to a segmented sheeting process within 15 minutes for each portion of dough, ensures that dough in its optimal rheological state is promptly fed into the tunnel oven. High-temperature baking not only promotes the release and foaming of the leavening agent, but more importantly, it instantly causes thermal inactivation of proteases, fixing the gluten framework at its most ideal, moderately degraded state. Comparative Example 2, omitting the segmented operation and feeding a large volume of dough into the production line at once, means that the dough placed at room temperature later in the process will have a longer placement time of 30 minutes or even 45 minutes. As shown in the latter half of the overlapping curves in the figure, these piled-up, waiting doughs, under uncontrolled and continuous enzymatic hydrolysis, experience a decrease in tensile resistance to below 1N or even lower. The dough, losing its support, softens on the sheeting machine and, upon entering the oven, is unable to contain and maintain its internal porous structure, ultimately leading to large-area collapse and surface blistering, resulting in quality deterioration. This demonstrates that the segmented forming process effectively matches the dough's degradation rate.

[0061] Test Example 2: This test case aims to verify the supporting effect of the dual gas generation mechanism of the present invention, which is characterized by strong front and slow rear, on the specific volume and shape of the baked product.

[0062] Experimental steps: Finished pastries from Examples 1, 2, 3, and Comparative Example 4 that underwent a second baking and cooling process were selected as test subjects.

[0063] Fifteen finished products were randomly selected from the above groups of objects. The absolute mass of each sample was weighed using an analytical balance with an accuracy of 0.01 grams, and the data were recorded.

[0064] The rapeseed displacement method was used to operate the volume analyzer. The sample was completely buried in rapeseed of standard particle size. The volume of the sample after the rapeseed was displaced was measured and recorded. The specific volume parameters of each sample were calculated by combining the mass data from the previous step.

[0065] Place the sample flat on a horizontal testing platform and use a high-precision digital vernier caliper to vertically measure the maximum thickness at the geometric center of each pastry as the center height data.

[0066] Remove the extreme values ​​at both ends of each test group and then perform an arithmetic average on the remaining valid data.

[0067] Table 2. Test data on the volume and center height of the baked products of each embodiment and comparative example. ;in conclusion: Based on the data in Table 2 and the appendix Figure 2The distribution of indicators shows that Comparative Example 4, without added glucono-δ-lactone, exhibited data collapse in both specific volume and center height. Comparative Example 4 relied on a large dose of ammonium bicarbonate as the sole leavening agent. This heat-sensitive gas source undergoes violent decomposition in the high-temperature initial stage when the dough enters the tunnel oven, instantly generating large amounts of ammonia and carbon dioxide, thus expanding the dough. Due to the lack of follow-up gas production support in the later stages, when the ammonia rapidly evaporates and the protein network inside the dough has not yet fully solidified, the originally expanded internal air chambers shrink and fall back under the influence of their own gravity and external atmospheric pressure, ultimately resulting in a smaller finished product volume and a significant depression in the central area.

[0068] Examples 1 to 3 achieved a continuous dual foaming mechanism in both the initial and final stages by introducing a composite system of glucono-δ-lactone and sodium bicarbonate. Ammonium bicarbonate played a role in shortcrust pastrying and initial expansion during the early stages of baking. As the baking process progressed towards the middle of the tunnel oven, glucono-δ-lactone, dissolved in the dough moisture, was slowly hydrolyzed by heat into gluconic acid. This gently released organic acid then neutralized with the sodium bicarbonate pre-reserved in the system, continuously releasing carbon dioxide gas at a gradual rate.

[0069] This slow, mid-to-late-stage gas production provides continuous gas pressure support for the pores inside the dough, effectively offsetting the structural negative pressure left after the initial intense gas production and overflow. This process is accompanied by deep gelatinization of the starch inside the dough and complete thermal denaturation and shaping of the protein backbone, allowing the example groups to maintain maximum porosity before the tissue solidifies. In terms of macroscopic physical properties, the specific volume of all three examples remained stable at 3.36 cm³. 3 With a weight of over / g and a center height exceeding 18 mm, the pastry has a full appearance and a uniformly distributed internal pore structure, demonstrating the engineering effectiveness of the relay-type gas generation mechanism in terms of anti-collapse and shaping support.

[0070] Test Example 3: This test case aims to test the effect of the moisturizing lipid composition of the present invention on delaying the loss of moisture in baked products and improving their texture and softness.

[0071] Experimental steps: The finished pastries from each embodiment and comparative example, after being cooled, packaged, and stored at room temperature for 24 hours, were used as test subjects to ensure that their internal moisture distribution reached a natural equilibrium.

[0072] Five pieces of the finished product were randomly selected and crushed in a mortar. About 5 grams of powder were weighed and placed in the heating pan of a halogen rapid moisture analyzer. The powder was heated to constant weight at 105°C. The instrument automatically read and recorded the absolute moisture content percentage of the sample.

[0073] Select finished products with complete shape and uniform thickness from the same batch of samples and place them on the horizontal test stage of the texture analyzer. Install a P / 36R cylindrical flat-bottom probe to perform full texture analysis and double compression penetration test.

[0074] The probe movement speed was set to 1.0 mm / s before, during, and after the test; the compressibility deformation was set to 30% of the initial sample thickness; and the interval between two pressing operations was set to 5 seconds.

[0075] The instrument software automatically captures the peak value of the maximum resistance during the first press of the probe as the hardness parameter of the sample. At the same time, it calculates the deformation recovery ability based on the stress-strain curve and outputs it as a dimensionless recovery parameter. Each group is tested in parallel 8 times and the arithmetic mean is recorded.

[0076] Table 3. Test data on moisture content and textural properties of finished products from each embodiment and comparative example. ;in conclusion: Based on the data in Table 3 and the appendix Figure 3 The distribution of various indicators shows that, in Comparative Example 5 (without the moisturizing lipid composition), a significant drop in absolute water content was observed. The lack of emulsifying molecular encapsulation in the microstructure leads to substantial water loss during high-temperature baking. The dehydrated starch chains rapidly recrystallize upon product cooling, triggering a deep aging reaction. This internal phase transition directly translates into a deterioration of the macroscopic texture; a hardness value as high as 6457 grams and a resilience of only 0.18 result in a dry, hard, and brittle texture in the pastry.

[0077] Comparative Example 1, which uses a traditional combination of sodium metabisulfite and ammonium alum, shows that although the gluten network was partially severed by chemical reagents, the introduction of pure inorganic salts failed to construct a flexible and buffering lubricating layer within the dough. The forcibly severed protein clusters, after losing free water upon heating, underwent rigid physical cross-linking, resulting in a sample hardness approaching 6000 grams. This loss of elastic deformation capability due to the microporous structure led to a hard texture.

[0078] In the example group, a microscopic barrier was successfully established at the water-oil interface through the precise compounding of emulsification systems such as glyceryl monostearate and soybean lecithin. When the dough was subjected to thermal shock in the tunnel oven, the molten lipid complex penetrated and encapsulated the gluten skeleton and starch granules, retaining most of the free water within the network structure. The test results showed that the absolute moisture content of all examples remained at a high level of over 4.8%. The locked-in moisture acted as an excellent internal plasticizer, giving the finished product a low hardness between 2400g and 2800g and a deformation recovery of up to 0.46. This overcame the defect of traditional shortbread cookies that easily become dry and crumbly, achieving efficient water retention in the internal structure and a fluffy and soft texture.

[0079] Test Example 4: This test case aims to verify the effectiveness of the formulation system of the present invention in eliminating heavy metal and sulfur-containing compound residues, as well as the effect of the secondary baking and gas dissipation steps on removing ammonia residues generated by the decomposition of large doses of ammonium bicarbonate.

[0080] Experimental steps: The finished pastries of Example 1, Comparative Example 1, and Comparative Example 8, which were stored in sealed packaging at room temperature for 48 hours, were selected as the test subjects for physicochemical safety indicators.

[0081] An airtight sampling probe with a micro-syringe was used to puncture the packaging film and extract the internal gas. The gas was then introduced into a gas chromatograph equipped with a gas chromatograph that is sensitive to ammonia, and the concentration of gaseous ammonia in the packaging microenvironment was measured and recorded in ppm.

[0082] Remove the product packaging bag, put the pastry into a small grinder and grind it into a uniform powder that can pass through a 60-mesh standard sieve. Accurately weigh 2.05 grams of sample powder and place it in a round-bottom distillation flask. Add hydrochloric acid solution of the set concentration for matrix acidification treatment.

[0083] Heating and starting the distillation apparatus allows the gaseous sulfur dioxide released after acidification to enter the condenser along with the water vapor and be completely captured by the absorbent in the end receiving bottle. The absolute content of residual sulfur dioxide in the sample is calculated based on the volume of titrant consumed using acid-base titration.

[0084] Another 1.02 g of sample powder was placed in the polytetrafluoroethylene high-pressure digestion vessel of the microwave digester, and a mixed solution of nitric acid and hydrogen peroxide was added for high-temperature and high-pressure digestion to completely destroy the organic matrix structure inside the sample.

[0085] The digested clear solution was brought to a final volume and introduced into an inductively coupled plasma mass spectrometer. High-temperature plasma was used to atomize and ionize the atoms. The amount of aluminum remaining in the system was calculated based on the intensity of the ion peak with a specific mass-to-charge ratio detected by the mass analyzer.

[0086] For each detection index of Example 1, Comparative Example 1 and Comparative Example 8, three parallel replicate groups were set up, and the arithmetic mean of each measurement result was recorded.

[0087] Table 4. Physicochemical safety and ammonia residue test data of finished products from each embodiment and comparative example. ;in conclusion: Based on the data in Table 4 and the appendix Figure 4The distribution patterns of residual pollutant concentrations are shown. Comparative Example 1 exhibited excessive levels of physicochemical indicators in routine testing. Comparative Example 1 used sodium metabisulfite for gluten reduction and added ammonium alum as a basic gas-generating component in the leavening and foaming system, resulting in sulfur dioxide levels as high as 68.45 mg / kg and aluminum ions at 124.73 mg / kg in the finished product. Inorganic salt reagents exhibit incomplete volatilization and decomposition residues during the high-temperature baking of dough. Metal ions and sulfur-containing compounds are fixed within the dehydrated and solidified starch macromolecular network, leading to severe aluminum and sulfur dioxide contamination issues in the product. Such residual levels pose a clear food safety hazard and fail to meet current production standards in the baking industry for eliminating such harmful additives.

[0088] Example 1 and Comparative Example 8 utilized the synergistic biochemical degradation of L-cysteine ​​and protease to replace sulfur-containing reagents, employing an aluminum-free foaming system of gluconate-δ-lactone composite ammonium bicarbonate and sodium bicarbonate, thus cutting off the introduction pathway of inorganic contaminants at the raw material compatibility stage. The test results demonstrated that the sulfur dioxide and aluminum residue levels in Example 1 and Comparative Example 8 were both within a low background fluctuation range below 0.5 mg / kg, eliminating the interference of heavy metal and sulfide residues on product quality.

[0089] To address the issue of significant ammonia retention due to the thermal decomposition of large doses of ammonium bicarbonate, Comparative Example 8 omitted the secondary baking and forced gas dissipation processes. This resulted in the high-temperature gaseous ammonia generated during the initial baking expansion stage of the dough being trapped inside the hardened crust of the rapidly cooling pastry. The ammonia concentration within the packaging microenvironment accumulated to 45.86 ppm after storage, producing a pungent odor upon opening and compromising the fundamental sensory experience of the shortbread pastry. Example 1, by adding a short-duration secondary baking process at 125°C, allowed the product's core temperature to cross the boiling point of ammonia volatilization again, forcing dissolved or adsorbed gaseous molecules deep within the microporous network to expand and release outwards. The 30-minute air exposure at the end of the process provided time for the free ammonia molecules to diffuse outwards. The concentration gradient inside and outside the porous medium continuously drove the residual ammonia molecules to migrate and desorb into the ambient air, reducing the ammonia concentration within the packaging microenvironment to a lower level of 0.38 ppm. The multi-process integrated exhaust mechanism ensures the powerful puffing and expanding function of ammonium bicarbonate while removing the pungent ammonia smell remaining inside the pastry, restoring the original baking aroma of the product.

[0090] Test Example 5: This test case aims to verify the effect of the precise addition of citric acid in the formulation of this invention on the control of the degree of invert sugar formation in the mixed sugar water, and the resulting impact on the Maillard reaction color and appearance smoothness of the finished product.

[0091] Cooled finished pastries from Example 1, Comparative Example 6, and Comparative Example 7, produced under the same baking parameters, were selected as experimental samples for color and appearance evaluation.

[0092] The surface color of the finished product was objectively measured using a precision colorimeter calibrated with a standard white board. The test probe was placed close to the center area and four edge areas of each sample, and the L values ​​were recorded respectively. * Value (representing brightness, the lower the value, the darker it is) and a * The value (representing red-green hue, with higher positive values ​​indicating a stronger reddish-brown tint) is used to calculate the arithmetic mean of all measurement points for a single sample.

[0093] 150 finished products are randomly selected from each production batch and inspected by quality control personnel in a standard light source observation box to check their appearance flatness. Unqualified samples with obvious wrinkles, local scorch spots, or overall pale gray color are picked out.

[0094] The number of defective products in each group is counted, and the appearance pass rate of the batch of products is obtained by calculating the percentage difference between the total number of samples and the number of defective products.

[0095] L collected by the colorimeter * Value and a * After removing outliers, the average parameter of each group is calculated and recorded and archived together with the pass rate data.

[0096] Table 5. Test data on surface color difference and appearance pass rate of finished products in each embodiment and comparative example. ;in conclusion: Based on the data in Table 5 and the appendix Figure 5 The distribution trends of various indicators show that adding different doses of anhydrous citric acid during the mixed sugar syrup cooking stage leads to fluctuations in the final product's appearance quality. In Comparative Example 6, due to the excessive addition of citric acid, the sugar syrup system exhibited a strongly acidic environment, causing a large amount of sucrose to be hydrolyzed into glucose and fructose during cooking. Because fructose has extremely high activity in the Maillard reaction during baking, the surface of the dough rapidly browned after entering the tunnel oven. The instrument measured the L... * The value dropped to 43.18, and it represents reddish-brown a. * The higher the value, the darker the color of the pastry surface, or even the blackening of some areas, as observed by the naked eye, leading to an increase in the proportion of pastries judged as unqualified due to scorch marks.

[0097] Comparative Example 7 represents the other extreme; insufficient citric acid resulted in a low sucrose hydrolysis conversion rate, and the sugar syrup lacked enough reducing sugars to support the subsequent baking and browning process. The dough could not undergo sufficient non-enzymatic browning at standard oven temperatures, and the surface L... *The value was as high as 79.52, showing a pale white color due to insufficient baking. The low invert sugar content also weakened the moisturizing and hygroscopic properties of the syrup itself. The surface moisture of the dough lost too quickly when it came into contact with the oven. The surface crust formed due to premature dehydration, and under the pressure of the internal gas expansion, a large number of irregular wrinkles were generated. This is the main reason why the appearance qualification rate of this batch dropped to 74.2%.

[0098] In Example 1, the amount of citric acid added was strictly controlled at a specific ratio of 3.0g per 36.6kg of sugar syrup. This slightly acidic environment effectively limited the sucrose conversion rate within a suitable range. The appropriate amount of invert sugar generated during the cooking process provided a suitable substrate for the subsequent Maillard reaction, resulting in L... * The value stabilized at 64.27, a * The value was 11.53, indicating a normal baking and browning effect. Simultaneously, the invert sugars, with their hygroscopic properties, effectively delayed moisture loss and drying of the dough surface during the initial exposure to high temperatures. The surface maintained necessary physical elasticity as the internal gases expanded and pushed outwards, thus preventing wrinkles and cracks. This resulted in a 98.4% appearance qualification rate for the final product, fully meeting the quality control requirements for mass production in the factory.

Claims

1. A type of shortbread pastry, characterized in that, Made from raw materials comprising the following parts by weight: 100 portions of low-gluten flour; L-cysteine ​​0.10-0.14 parts; 0.04-0.06 parts of protease; 0.60-0.72 parts of gluconate-δ-lactone; 1.40-2.00 parts of ammonium bicarbonate; Sodium bicarbonate 0.44-0.56 parts; Soy lecithin 0.16-0.30 parts; 0.60-0.80 parts of food-grade emulsifier composition; Mixed sugar syrup 70.0-74.0 parts; The L-cysteine ​​and the protease work together to reduce the strength of the gluten structure inside the dough; the glucono-δ-lactone, the ammonium bicarbonate, and the sodium bicarbonate work together to release gas during heating, causing the dough to expand; and the soybean lecithin and the food-grade emulsifier composition work together to establish a water-oil interface and lock in internal moisture.

2. The shortbread pastry according to claim 1, characterized in that, The protease is selected from papain, bromelain, or fungal protease.

3. The shortbread pastry according to claim 1, characterized in that, The method for preparing the mixed sugar water includes the following steps: Prepare the first pot of sugar water and the second pot of sugar water separately. Add granulated sugar, water and anhydrous citric acid to the first pot and mix well. Add granulated sugar, water and anhydrous citric acid to the second pot and mix well. The mass ratio of the white sugar to the water added to the first pot and the second pot is 2:1, and the mass ratio of the anhydrous citric acid to the white sugar is 0.012:100-0.0133:

100. Heat the sugar water in the first pot and the sugar water in the second pot separately and boil them uncovered for 2-3 minutes. Do not cover the pot while boiling. After boiling, cool the sugar water in the first pot to room temperature for later use, and keep the sugar water in the second pot warm for later use. Take the cooled sugar water from the first pot and mix it with the warm sugar water from the second pot, and adjust the temperature to 85℃-95℃ to obtain the mixed sugar water.

4. The shortbread pastry according to claim 1, characterized in that, The preparation method of the food-grade emulsifier composition includes the following steps: The food-grade emulsifier composition is prepared by mixing glyceryl monostearate with soybean lecithin, sucrose fatty acid ester or diacetyl tartaric acid mono- and diglycerides in a 1:1 mass ratio, heating and stirring at 50℃-60℃ until fully melted and composited, and then cooling.

5. The shortbread pastry according to claim 1, characterized in that, The raw materials also include additional ingredients selected from one of the following: 0.09 parts by weight of cream flavoring, 1.0 part by weight of sourdough starter, 3.6 parts by weight of cocoa powder, or 5.0 parts by weight of yam powder.

6. The method for preparing shortbread according to any one of claims 1-5, characterized in that, Includes the following steps: Take 5%-15% of the total weight of the low-gluten flour as a premix carrier, add the L-cysteine, the protease, the glucono-δ-lactone, the ammonium bicarbonate, the sodium bicarbonate and the soybean lecithin, and stir thoroughly to obtain a premix powder. Mix the premix powder with the remaining low-gluten flour and stir thoroughly again to obtain a dry powder mixture. The dry powder mixture is put into a dough mixer, the mixed sugar water and the food-grade emulsifier composition are added, and the mixture is quickly stirred into a dough to obtain the initial dough. Take out the initial dough, cover it with a film to keep it warm, and place it for processing to obtain the dough to be processed; The dough to be processed is divided into multiple portions, which are then pressed into sheets and shaped to obtain shaped dough discs. The shaped dough is placed in a tunnel oven for a first baking to obtain a pre-baked dough; After the initial baked dough is cooled, it is baked a second time to obtain a rebaked dough. The re-baked dough is forced to cool down and exposed to air to dissipate gas, and finally packaged to obtain the shortbread pastry.

7. The method for preparing shortbread according to claim 6, characterized in that, When adding the mixed sugar syrup, the temperature of the mixed sugar syrup should be adjusted to 85℃-95℃ beforehand; The temperature of the initial dough was controlled between 35°C and 45°C. The placement process involves standing for 10-12 minutes or fermenting for 2.5 hours at a temperature of 20℃-45℃.

8. The method for preparing shortbread according to claim 6, characterized in that, The time from the start of pressing to the completion of forming for each batch of dough is limited to 15 minutes, and the dough that has not been pressed into sheets is continuously covered with a film to keep it warm and moist.

9. The method for preparing shortbread according to claim 6, characterized in that, The temperature of the bottom heat in the first baking is 280℃-295℃, the temperature of the middle bottom heat is 260℃-280℃, the temperature of the rear bottom heat is 260℃-280℃, the temperature of the top heat is 310℃-325℃, the temperature of the middle top heat is 295℃-310℃, the temperature of the rear top heat is 295℃-310℃, and the baking time is 1min28s-1min38s.

10. The method for preparing shortbread according to claim 6, characterized in that, The secondary baking temperature is 115℃-125℃, and the time is 10s-20s; The forced cooling temperature control of the re-baked dough is below 40°C, and the time for air dissipation is 15-30 minutes.

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