Preparation method of compound enzyme for preventing steamed bun skin from being softened

Abstract

The invention relates to the technical field of food processing, in particular to a preparation method of a compound enzyme for preventing steamed bun skin from being softened. The compound enzyme preparation is prepared by compounding the following enzyme preparations in parts by weight: 30-50 parts of fungal alpha-amylase, 20-35 parts of maltogenic amylase, 15-25 parts of glucose oxidase and 5-15 parts of lipase, and the compound enzyme preparation contains phosphate buffer salt which accounts for 1-3% of the total weight of the enzyme preparations and serves as a stabilizer. Comprising the following steps: pretreating and metering raw materials; pretreating a stabilizer; primarily mixing; performing secondary mixing; adding a stabilizer and performing final mixing; and packaging and storing. According to the application of the compound enzyme agent in preparation of the steamed bun skin, the compound enzyme agent, water, flour and other ingredients are added together for dough kneading in the flour stirring stage according to the adding amount of 0.1-0.3% of the weight of the flour. The invention provides a compound enzyme formula which is strong in pertinence, high in stability and easy to apply and a preparation method of the compound enzyme formula so as to fundamentally improve the texture stability of the steamed bun wrappers.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, and in particular to a method for preparing a compound enzyme to prevent the crust of roujiamo (Chinese hamburger) from becoming soggy. Background Technology

[0002] As a traditional Chinese food, the texture and taste of the roujiamo (meat sandwich) directly affect its quality and consumer acceptance. During processing and storage, the bread crust is prone to softening due to moisture absorption or starch retrogradation, leading to a deterioration in texture and loss of crispness, becoming a significant factor restricting product quality stability and shelf life. Currently, the industry typically slows down softening by adjusting process parameters or using food additives, but the effects are limited and fail to meet the consumer demand for natural and safe products.

[0003] In existing technologies, the problem of dough products resisting softening is mostly addressed through physical regulation or chemical additives, such as optimizing baking conditions and adding emulsifiers or humectants. However, these methods often fail to specifically solve the texture deterioration caused by starch retrogradation and moisture migration, and may introduce non-natural ingredients, which does not align with the trend towards clean labeling. Enzymes, as biocatalysts, have the advantages of high efficiency, specificity, and environmental safety; however, the effect of a single enzyme is limited, and enzyme preparations are prone to activity loss during compounding due to compatibility and stability issues, making it difficult to achieve large-scale application. Furthermore, conventional methods of adding enzyme preparations often result in uneven dispersion in the dough, further affecting the consistency of their effects. Summary of the Invention

[0004] This invention provides a highly targeted, stable, and easy-to-apply compound enzyme formulation and its preparation method to fundamentally improve the textural stability of roujiamo (Chinese hamburger) bread crust.

[0005] The technical solution adopted in this invention is as follows: a compound enzyme to prevent the crust of roujiamo (Chinese hamburger) from softening, which is composed of the following enzyme preparations in parts by weight: 30-50 parts of fungal α-amylase, 20-35 parts of maltose amylase, 15-25 parts of glucose oxidase, and 5-15 parts of lipase. The compound enzyme preparation contains 1%-3% of phosphate buffer salt as a stabilizer in the total weight of the enzyme preparation.

[0006] A method for preparing a compound enzyme to prevent the crust of a roujiamo (Chinese hamburger) from softening includes the following steps:

[0007] Step 1, Raw material pretreatment and measurement: Take the required weights of fungal α-amylase, maltose amylase, glucose oxidase and lipase respectively, and place them in an environment with a temperature of 15-25℃ and a relative humidity of less than 45% for at least 2 hours to equilibrate.

[0008] Step 2, stabilizer pretreatment: Pass 1%-3% of the total weight of the enzyme preparation of phosphate buffer salt through a 100-mesh sieve and set aside;

[0009] Step 3, initial mixing: First, place the fungal α-amylase and maltose amylase in a three-dimensional mixer and mix at 20-30 rpm for 10-15 minutes to obtain initial mixed powder A;

[0010] Step 4, secondary mixing: Add glucose oxidase and lipase to the initial mixed powder A, and continue mixing for 15-20 minutes under the same mixing equipment and speed to obtain intermediate mixed powder B;

[0011] Step 5, Add stabilizer and final mix: Slowly and evenly sprinkle the pretreated phosphate buffer salt from step 2 into intermediate mixed powder B, then increase the mixer speed to 35-45 rpm and mix for 25-35 minutes to ensure extremely uniform distribution and obtain the final mix;

[0012] Step 6, Packaging and Storage: Quickly dispense the final mixture into light-proof aluminum foil bags under low temperature and low humidity conditions, fill with nitrogen and seal, and store in a cool, dry place at 4-10℃.

[0013] As a further improvement of the present invention, in step two, the phosphate buffer salt is a mixture of sodium pyrophosphate, disodium hydrogen phosphate and sodium dihydrogen phosphate in a weight ratio of 2:2:1.

[0014] As a further improvement of the present invention, in steps three and four, the loading amount of the three-dimensional mixer is 50%-70% of its total volume.

[0015] As a further improvement of the present invention, in step five, the phosphate buffer salt is added by means of an ultrasonic vibrating screen feeder with a vibration frequency of 25-30kHz.

[0016] As a further improvement of the present invention, in step five, when the rotation speed is increased for final mixing, the internal temperature of the mixer is controlled below 20°C by the cooling jacket.

[0017] The application of a compound enzyme to prevent the dough of roujiamo (Chinese hamburger) from softening in the preparation of roujiamo dough involves adding the compound enzyme at a rate of 0.1%-0.3% of the flour weight, along with water, flour, and other ingredients, during the flour mixing stage.

[0018] As a further improvement of the present invention, during the dough kneading process, the dough temperature needs to be controlled at 26-30℃, the compound enzyme needs to be pre-mixed evenly with a portion of the flour before being added to the dough kneading machine, and the kneading time should be no less than 10 minutes to ensure that the enzyme is evenly dispersed in the dough.

[0019] The beneficial effects of this invention are as follows: This invention utilizes a scientific compound of fungal α-amylase, maltose amylase, glucose oxidase, and lipase, along with a strictly controlled humidity and temperature pretreatment, a stepwise three-dimensional mixing process, and a specific phosphate buffer solution as a stabilizer. These components work synergistically on the starch and gluten network, effectively inhibiting moisture migration and starch retrogradation in the bread crust during storage, significantly improving the product's resistance to softening and its crisp texture. Simultaneously, processes such as ultrasonic feeding, low-temperature final mixing, and nitrogen packaging greatly ensure the activity stability of the compound enzyme preparation during preparation and storage, resulting in uniform dispersion and consistent effects during application. Ultimately, this achieves the goal of extending the product's shelf life and meeting clean label requirements. Detailed Implementation

[0020] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0021] This invention provides a compound enzyme to prevent the crust of roujiamo (Chinese hamburger) from softening, which is composed of the following enzyme preparations in parts by weight: 30-50 parts of fungal α-amylase, 20-35 parts of maltose amylase, 15-25 parts of glucose oxidase, and 5-15 parts of lipase. The compound enzyme preparation contains 1-3% of phosphate buffer salt as a stabilizer.

[0022] A method for preparing a compound enzyme to prevent the crust of a roujiamo (Chinese hamburger) from softening includes the following steps:

[0023] Step 1, Raw material pretreatment and measurement: Take the required weights of fungal α-amylase, maltose amylase, glucose oxidase and lipase respectively, and place them in an environment with a temperature of 15-25℃ and a relative humidity of less than 45% for at least 2 hours to equilibrate.

[0024] Step 2, stabilizer pretreatment: Pass 1%-3% of the total weight of the enzyme preparation of phosphate buffer salt through a 100-mesh sieve and set aside;

[0025] Step 3, initial mixing: First, place the fungal α-amylase and maltose amylase in a three-dimensional mixer and mix at 20-30 rpm for 10-15 minutes to obtain initial mixed powder A;

[0026] Step 4, secondary mixing: Add glucose oxidase and lipase to the initial mixed powder A, and continue mixing for 15-20 minutes under the same mixing equipment and speed to obtain intermediate mixed powder B;

[0027] Step 5, Add stabilizer and final mix: Slowly and evenly sprinkle the pretreated phosphate buffer salt from step 2 into intermediate mixed powder B, then increase the mixer speed to 35-45 rpm and mix for 25-35 minutes to ensure extremely uniform distribution and obtain the final mix;

[0028] Step 6, Packaging and Storage: Quickly dispense the final mixture into light-proof aluminum foil bags under low temperature and low humidity conditions, fill with nitrogen and seal, and store in a cool, dry place at 4-10℃.

[0029] In step two of this invention, the phosphate buffer salt is a mixture of sodium pyrophosphate, disodium hydrogen phosphate, and sodium dihydrogen phosphate in a weight ratio of 2:2:1.

[0030] In steps three and four of this invention, the loading capacity of the three-dimensional mixer is 50%-70% of its total volume.

[0031] In step five of this invention, the phosphate buffer salt is added using an ultrasonic vibrating screen feeder with a vibration frequency of 25-30kHz.

[0032] In step five of this invention, when the rotation speed is increased for final mixing, the internal temperature of the mixer is controlled below 20°C by the cooling jacket.

[0033] The application of a compound enzyme to prevent the dough of roujiamo (Chinese hamburger) from softening in the preparation of roujiamo dough involves adding the compound enzyme at a rate of 0.1%-0.3% of the flour weight, along with water, flour, and other ingredients, during the flour mixing stage.

[0034] During the dough mixing process of this invention, the dough temperature needs to be controlled at 26-30℃. The compound enzyme needs to be pre-mixed evenly with some flour before being added to the dough mixer. The mixing time should be no less than 10 minutes to ensure that the enzyme is evenly dispersed in the dough.

[0035] Example 1:

[0036] Weigh out 40 kg of fungal α-amylase, 28 kg of maltose amylase, 20 kg of glucose oxidase, and 10 kg of lipase, and equilibrate them for 3 hours in a constant temperature and humidity room at 20℃ and 40% relative humidity. Separately weigh out 2.94 kg of phosphate buffer (prepared by mixing 1.176 kg of sodium pyrophosphate, 1.176 kg of disodium hydrogen phosphate, and 0.588 kg of sodium dihydrogen phosphate in a 2:2:1 ratio), and pass it through a 100-mesh sieve for later use.

[0037] The balanced fungal α-amylase and maltose amylase were added to a 150L three-dimensional mixer (65% load) and mixed at 25 rpm for 12 minutes to obtain initial powder A. Then glucose oxidase and lipase were added, and the mixture was kept at the same speed for another 18 minutes to obtain intermediate powder B.

[0038] The pretreated phosphate buffer salt was evenly added to the mixer using an ultrasonic vibrating screen feeder (vibration frequency 28kHz). The rotation speed was increased to 40rpm, and the cooling jacket was turned on to maintain the mixing temperature at 18℃. The mixture was mixed for 30 minutes to obtain the final mixture.

[0039] In a packaging environment with relative humidity ≤35% and temperature 15℃, the final mixture is dispensed into aluminum foil bags, filled with nitrogen, heat-sealed, and stored in a cool warehouse at 6℃.

[0040] Application Experiment: 150g of the compound enzyme preparation was pre-mixed with 50kg of high-gluten flour, then 23kg of water and other ingredients were added and fed into a dough mixer. The dough temperature was controlled at 28℃, and the dough was mixed for 12 minutes. After baking, the resulting steamed buns were stored at 25℃ and 60% humidity for 72 hours before texture analysis. The results showed that the hardness retention rate was ≥85%, the elasticity coefficient was ≥0.92, the sensory evaluation score was 42% higher than that of the group without the enzyme, and there was no visible mold growth.

[0041] Example 2:

[0042] Weigh out 35 kg of fungal α-amylase, 32 kg of maltose amylase, 18 kg of glucose oxidase, and 12 kg of lipase, and equilibrate them for 2.5 hours in a constant temperature and humidity chamber at 18℃ and 42% relative humidity. The total weight of the enzyme preparation is 97 kg. Separately weigh out 1.94 kg of phosphate buffer (composed of 0.776 kg of sodium pyrophosphate, 0.776 kg of disodium hydrogen phosphate, and 0.388 kg of sodium dihydrogen phosphate in a 2:2:1 ratio), accounting for 2.0% of the total weight of the enzyme preparation, and pass it through a 100-mesh sieve for later use.

[0043] The balanced fungal α-amylase and maltose amylase were added to a 150L three-dimensional mixer (60% load) and mixed at 28 rpm for 10 minutes to obtain initial powder A. Then, glucose oxidase and lipase were added, and the mixture was continued at the same speed for 20 minutes to obtain intermediate powder B.

[0044] The pretreated phosphate buffer salt was evenly added to the mixer using an ultrasonic vibrating screen feeder (vibration frequency 30kHz). The rotation speed was increased to 38rpm, and the cooling jacket was turned on to maintain the mixing temperature at 16℃. The mixture was mixed for 28 minutes to obtain the final mixture.

[0045] In a packaging environment with relative humidity ≤30% and temperature 12℃, the final mixture is dispensed into aluminum foil bags, filled with nitrogen, heat-sealed, and stored in a cool warehouse at 5℃.

[0046] Application Experiment: 25g of the compound enzyme preparation was pre-mixed with 25kg of high-gluten flour, then 11.5kg of water and other ingredients were added and fed into a dough mixer. The dough temperature was controlled at 30℃, and the dough was mixed for 15 minutes. After baking, the resulting steamed buns were stored at 25℃ and 60% humidity for 96 hours before texture analysis. The results showed that the hardness retention rate was ≥80%, the elasticity coefficient was ≥0.89, the sensory evaluation score was 38% higher than that of the group without the enzyme, and there was no visible mold growth. The water activity value remained stable below 0.74.

[0047] Example 3:

[0048] Weigh out 32 kg of fungal α-amylase, 22 kg of maltose amylase, 16 kg of glucose oxidase, and 8 kg of lipase, and equilibrate them for 4 hours in a constant temperature and humidity room at 15℃ and 40% relative humidity. The total weight of the enzyme preparation is 78 kg. Separately weigh out 0.78 kg of phosphate buffer (composed of 0.312 kg of sodium pyrophosphate, 0.312 kg of disodium hydrogen phosphate, and 0.156 kg of sodium dihydrogen phosphate in a 2:2:1 ratio), accounting for 1.0% of the total weight of the enzyme preparation, and pass it through a 100-mesh sieve for later use.

[0049] The balanced fungal α-amylase and maltose amylase were added to a 150L three-dimensional mixer (50% load) and mixed at 20 rpm for 15 minutes to obtain initial powder A. Then glucose oxidase and lipase were added, and the mixture was kept at the same speed for another 15 minutes to obtain intermediate powder B.

[0050] The pretreated phosphate buffer salt was evenly added to the mixer using an ultrasonic vibrating screen feeder (vibration frequency 25kHz). The rotation speed was increased to 35rpm, and the cooling jacket was turned on to maintain the mixing temperature at 19℃. The mixture was mixed for 25 minutes to obtain the final mixture.

[0051] In a packaging environment with relative humidity ≤40% and temperature 10℃, the final mixture is dispensed into aluminum foil bags, filled with nitrogen, heat-sealed, and stored in a cool warehouse at 8℃.

[0052] Application Experiment: 25g of the compound enzyme preparation was pre-mixed with 25kg of high-gluten flour, then 11.5kg of water and other ingredients were added and fed into a dough mixer. The dough temperature was controlled at 26℃, and the dough was mixed for 10 minutes. After baking, the resulting steamed buns were stored at 25℃ and 60% humidity for 120 hours before texture analysis. The results showed that the hardness retention rate was ≥75%, the elasticity coefficient was ≥0.86, the sensory evaluation score was 35% higher than that of the group without the enzyme, and there was no visible mold growth. The water activity value remained stable below 0.76.

[0053] As can be seen from Examples 1-3 above, the compound enzyme preparation and its preparation method provided by the present invention, through implementation with different ratio parameters (such as 32-40 parts of fungal α-amylase, 22-32 parts of maltose amylase, 16-20 parts of glucose oxidase, 8-12 parts of lipase, and 1%-3% of stabilizer addition) and process conditions (such as mixing speed 20-40 rpm, mixing time 25-30 minutes, and mixing temperature 16-19℃), can significantly improve the textural properties of steamed buns after storage at 25℃ and 60% humidity for 72-120 hours. The hardness retention rate is ≥75%, the elasticity coefficient is ≥0.86, the sensory score is improved by more than 35%, and the water activity value is stable below 0.76. This effectively proves the significant effect and process stability of the compound enzyme formulation and stepwise mixing process in inhibiting starch retrogradation and controlling moisture migration. At the same time, its application can meet the requirements of clean labeling.

[0054] In summary, the compound enzyme preparation method for preventing the crust of roujiamo (Chinese hamburger) from softening, as presented in this invention, not only scientifically solves the technical bottleneck of the crust's tendency to soften during storage, but also possesses broad prospects for industrial application and significant socio-economic value. The compound enzyme preparation prepared by this method can effectively adapt to the processes of modern central kitchens and large-scale food processing plants. Through standardized application, it can significantly improve the quality consistency and shelf stability of traditional Chinese pastries, providing a reliable technical solution for chain restaurants, pre-prepared meals, and the snack food industry, and promoting the industrialization and standardization of traditional cuisine. Simultaneously, its "clean label" attribute highly aligns with current consumer demand for healthy and natural ingredients, helping to enhance product market competitiveness. In the future, the application of this technology system can be further expanded to other moisture-sensitive rice and flour products that require maintaining a crisp texture (such as sesame seed cakes, European-style bread, and biscuits), providing a new technical path for product innovation and quality upgrading in the entire baking industry, and having a positive and far-reaching significance for inheriting traditional Chinese food culture and reducing food waste.

[0055] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A compound enzyme for preventing the crust of a roujiamo (Chinese hamburger) from softening, characterized in that, It is a compound enzyme preparation composed of the following parts by weight: 30-50 parts of fungal α-amylase, 20-35 parts of maltose amylase, 15-25 parts of glucose oxidase, and 5-15 parts of lipase. The compound enzyme preparation contains 1%-3% of phosphate buffer salt as a stabilizer as the total weight of the enzyme preparation.

2. A method for preparing a compound enzyme to prevent the crust of a roujiamo (Chinese hamburger) from softening, characterized in that, Includes the following steps: Step 1, Raw material pretreatment and measurement: Take the required weights of fungal α-amylase, maltose amylase, glucose oxidase and lipase respectively, and place them in an environment with a temperature of 15-25℃ and a relative humidity of less than 45% for at least 2 hours to equilibrate. Step 2, stabilizer pretreatment: Pass 1%-3% of the total weight of the enzyme preparation of phosphate buffer salt through a 100-mesh sieve and set aside; Step 3, initial mixing: First, place the fungal α-amylase and maltose amylase in a three-dimensional mixer and mix at 20-30 rpm for 10-15 minutes to obtain initial mixed powder A; Step 4, secondary mixing: Add glucose oxidase and lipase to the initial mixed powder A, and continue mixing for 15-20 minutes under the same mixing equipment and speed to obtain intermediate mixed powder B; Step 5, Add stabilizer and final mix: Slowly and evenly sprinkle the pretreated phosphate buffer salt from step 2 into intermediate mixed powder B, then increase the mixer speed to 35-45 rpm and mix for 25-35 minutes to ensure extremely uniform distribution and obtain the final mix; Step 6, Packaging and Storage: Quickly dispense the final mixture into light-proof aluminum foil bags under low temperature and low humidity conditions, fill with nitrogen and seal, and store in a cool, dry place at 4-10℃.

3. The method for preparing a compound enzyme to prevent the crust of a roujiamo (Chinese hamburger) from softening according to claim 2, characterized in that, In step two, the phosphate buffer salt is a mixture of sodium pyrophosphate, disodium hydrogen phosphate, and sodium dihydrogen phosphate in a weight ratio of 2:2:

1.

4. The method for preparing a compound enzyme to prevent the crust of a roujiamo (Chinese hamburger) from softening according to claim 2, characterized in that, In steps three and four, the loading capacity of the three-dimensional mixer is 50%-70% of its total volume.

5. The method for preparing a compound enzyme to prevent the crust of a roujiamo (Chinese hamburger) from softening according to claim 2, characterized in that, In step five, the phosphate buffer salt is added using an ultrasonic vibrating screen feeder with a vibration frequency of 25-30kHz.

6. The method for preparing a compound enzyme to prevent the crust of a roujiamo (Chinese hamburger) from softening according to claim 2, characterized in that, In step five, when the rotation speed is increased for final mixing, the internal temperature of the mixer is controlled below 20°C by the cooling jacket.

7. The application of a complex enzyme for preventing the dough of a roujiamo (Chinese hamburger) from softening in the preparation of the dough, characterized in that, The compound enzyme is added at a rate of 0.1%-0.3% of the flour weight, along with water, flour, and other ingredients, during the flour mixing stage.

8. The application of the compound enzyme for preventing the dough of roujiamo (Chinese hamburger) from softening according to claim 7 in the preparation of roujiamo dough, characterized in that, During the kneading process, the dough temperature needs to be controlled at 26-30℃. The compound enzyme needs to be pre-mixed evenly with some flour before being added to the dough mixer. The kneading time should be no less than 10 minutes to ensure that the enzyme is evenly dispersed in the dough.