Dried meat slice tenderizing process based on microorganism source protease

Abstract

The invention relates to the technical field of meat product processing, in particular to a dried meat slice tenderizing process based on microorganism source protease, which comprises the following steps: selecting fresh raw material meat, removing fascia, cutting into slices, putting into a NaCl solution, and carrying out ultrasonic treatment to remove blood and fishy smell; performing high-voltage pulse electric field treatment in pulse electric field treatment equipment; adding a compound microbial enzyme preparation for enzymolysis treatment, wherein the compound microbial enzyme preparation is prepared by compounding bacillus subtilis neutral protease and aspergillus oryzae acid protease according to the ratio of (1: 0.9)-(1: 1.1); putting the raw material meat subjected to enzymolysis treatment and the marinade into a vacuum tumbling machine, and performing vacuum tumbling to obtain a meat material; spreading the meat on a screen mesh, and baking to obtain semi-finished dried meat slices; and cooling, cutting, detecting and packaging the semi-finished dried meat slices to obtain finished dried meat slices. According to the invention, the food safety is ensured, the taste and flavor of the dried meat slice are obviously enhanced, and the requirements of consumers on high-quality meat products are met.

Description

Technical Field

[0001] The present invention relates to the technical field of meat product processing, and particularly to a process for tenderizing dried meat slices based on microbial protease. Background Art

[0002] As a traditional meat product deeply loved by consumers, dried meat slices are highly favored for their unique taste and flavor. However, there are some problems to be solved urgently in the production process of traditional dried meat slices. On the one hand, the tenderness of dried meat slices is insufficient, and the taste is too tough when eaten, affecting the consumption experience of consumers; on the other hand, the flavor of traditional dried meat slices is relatively single and difficult to meet the increasingly diverse taste requirements of consumers.

[0003] At present, in order to solve the problem of insufficient tenderness of dried meat slices, existing methods use chemical tenderizers, but the use of chemical tenderizers may bring potential food safety hazards; in terms of flavor improvement, existing methods often simply add seasonings and cannot form a unique and rich flavor level. Therefore, it is of great practical significance to develop a new method for making dried meat slices to solve the above problems existing in traditional dried meat slices. Summary of the Invention

[0004] The purpose of the present invention is to propose a process for tenderizing dried meat slices based on microbial protease. The dried meat slices produced by this method have the characteristics of high tenderness and rich flavor, and at least solve one of the problems raised in the background art.

[0005] To achieve the purpose of the present invention, the following technical solutions are adopted:

[0006] A process for tenderizing dried meat slices based on microbial protease includes the following steps:

[0007] Select fresh raw meat, cut it into thin slices after removing the fascia, and place it in an NaCl solution for ultrasonic treatment to remove blood and fishy smell;

[0008] Place the raw meat after removing blood and fishy smell in a pulsed electric field treatment device for high-voltage pulsed electric field treatment;

[0009] Add a compound microbial enzyme preparation to the raw meat after high-voltage pulsed electric field treatment for enzymatic hydrolysis. Among them, the compound microbial enzyme preparation is composed of subtilisin neutral protease from Bacillus subtilis and aspergillus oryzae acid protease in a ratio of 1:0.9 - 1:1.1;

[0010] Put the raw meat after enzymatic hydrolysis and the marinade into a vacuum tumbler for vacuum tumbling to obtain meat material. Among them, the marinade includes fish sauce, trehalose, compound phosphate, low-reaction-degree silkworm pupa flavor base material, monascus red, and disodium 5'-ribonucleotide;

[0011] Spread the meat material flat on a sieve for baking and ripening to obtain semi-finished dried meat slices;

[0012] The semi-finished meat jerky is cooled, cut, inspected and packaged to obtain the finished meat jerky.

[0013] A further improvement lies in that the method of spreading the meat material flat on a sieve mesh for baking and ripening to obtain semi-finished meat jerky includes:

[0014] Low-temperature shaping: Spread the meat material flat on a sieve mesh, spray a transglutaminase solution on the meat material, and then put it into a drying equipment for low-temperature drying. The drying temperature is controlled at 40 - 45 °C, and the drying time is 2 - 3 hours;

[0015] Medium-temperature drying: After the low-temperature shaping is completed, raise the temperature to 80 - 90 °C and continue drying for 1 - 2 hours;

[0016] High-temperature ripening: After the medium-temperature drying is completed, put the meat material into an oven for high-temperature baking. The baking temperature is 180 - 200 °C, and the baking time is 4 - 6 minutes.

[0017] A further improvement lies in that the method of spreading the meat material flat on a sieve mesh for baking and ripening to obtain semi-finished meat jerky further includes: performing flavor enhancement treatment after high-temperature ripening: spraying a medium / high reaction degree silkworm pupa flavor base material on the surface of the meat material, and then putting the meat material into an oven for secondary baking at a temperature of 150 - 160 °C for 1 - 2 minutes.

[0018] A further improvement lies in that the mass ratio of each component is as follows:

[0019] 100 parts of raw meat, 3 - 5 parts of fish sauce, 4 - 6 parts of trehalose, 0.1 - 0.3 parts of compound phosphate, 0.5 - 1.0 part of low reaction degree silkworm pupa flavor base material, 0.02 - 0.04 part of monascus red, 0.1 - 0.3 part of disodium 5'-ribonucleotide.

[0020] A further improvement lies in that during vacuum tumbling, the tumbling temperature is controlled at 0 - 4 °C, the vacuum degree is maintained at -0.08 MPa, the tumbling time is 30 - 40 minutes. During the tumbling process, combined with ultrasonic assistance, the ultrasonic frequency is set at 20 - 40 kHz, and the power is 200 - 300 W.

[0021] A further improvement lies in that a torque sensor and a current transformer are integrated in the drive motor circuit of the tumbler, which is used to monitor the resistance torque of the meat material on the drum in real time during tumbling, and dynamically adjust the motor speed and forward / reverse cycle according to the resistance torque data. In the initial stage, high speed is used for rapid mixing of the marinade, and when the resistance torque drops to a preset value, it automatically switches to low speed for shape preservation tumbling.

[0022] Further improvements are as follows: the addition amount of the compound microbial enzyme preparation is 0.2 - 0.4% of the meat weight, the enzymolysis temperature is 40 - 50 °C, and the enzymolysis time is controlled within 1.5 - 2.5 hours.

[0023] Further improvements are as follows: during the high-voltage pulsed electric field treatment, the electric field strength is 20 - 25 kV / cm, the pulse frequency is 100 - 150 Hz, the pulse width is 20 - 50 μs, and the treatment time is 3 - 5 min.

[0024] Further improvements are as follows: when cooling the semi-finished meat jerky, lay the semi-finished meat jerky flat on the conveyor mesh belt, use the conveyor mesh belt to send the semi-finished meat jerky into the cooling chamber, install electrodes at the top of the cooling chamber to generate a high-voltage electrostatic field, the conveyor mesh belt is made of conductive stainless steel and is reliably connected to the ground through copper wires to form an electric field path of "top electrode - meat jerky - mesh belt", and the electric field formed by the top electrode and the conveyor mesh belt generates a Coulomb attraction on the meat jerky, making the meat jerky adhere to the mesh belt and inhibiting the edge warping caused by moisture evaporation and shrinkage during the cooling of the meat jerky.

[0025] Further improvements are as follows: the marinade further includes red beet root powder and green tea extract.

[0026] The beneficial effects of the present invention are as follows:

[0027] The present invention provides a meat jerky tenderizing process based on microbial protease, which effectively solves the problems of insufficient tenderness and single flavor existing in traditional meat jerky through a series of innovative steps. First, ultrasonic treatment combined with soaking in NaCl solution is used to remove the blood and fishy smell in the raw meat. Subsequently, high-voltage pulsed electric field treatment is used to further improve the meat texture. A compound microbial enzyme preparation composed of Bacillus subtilis neutral protease and Aspergillus oryzae acidic protease is introduced for enzymolysis treatment, effectively improving the tenderness of the meat jerky and avoiding potential safety hazards that may be brought by chemical tenderizers. In terms of flavor enhancement, the present invention adds a marinade including various components such as fish sauce, trehalose, red beet root powder and green tea extract, and adopts staged baking and ripening techniques such as low-temperature shaping, medium-temperature drying, and high-temperature ripening, as well as final flavor enhancement treatment, successfully endowing the meat jerky with unique and rich flavor levels. In addition, by optimizing parameters such as temperature and vacuum degree during the vacuum tumbling process, and using a drive motor circuit with a torque sensor and a current transformer to adjust the tumbling conditions in real time, the quality of the meat jerky is further improved. The present invention not only ensures food safety, but also significantly enhances the taste and flavor of the meat jerky, meeting the needs of consumers for high-quality meat products. Description of the Drawings

[0028] Figure 1 It is a flow chart of the meat jerky tenderizing process based on microbial protease of the present invention. Detailed Embodiments

[0029] To deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0030] Please refer to the attached Figure 1 , an embodiment of the present invention provides a meat jerky tenderizing process based on microbial protease, including the following steps:

[0031] Step S1: Select fresh raw meat, cut it into thin slices after removing fascia, and place it in a NaCl solution with a concentration of 0.3%-0.5% for ultrasonic treatment for 10 minutes (frequency 40 kHz, power 200 W) to remove blood and fishy smell.

[0032] Specifically, the raw meat can be livestock and poultry meat such as pork, beef, and chicken.

[0033] It can be understood that ultrasonic waves can generate microbubble rupture, which can effectively destroy cell structure, help release and remove blood and fishy smell substances. The NaCl solution can reduce the surface tension of muscle, promote the dissolution of salt-soluble proteins, and provide a more uniform action substrate for subsequent enzymatic hydrolysis.

[0034] Step S2: Place the raw meat after removing blood and fishy smell in a pulsed electric field treatment device for high-voltage pulsed electric field treatment.

[0035] Specifically, when performing high-voltage pulsed electric field treatment, the electric field strength is 20-25 kV / cm, the pulse frequency is 100-150 Hz, the pulse width is 20-50 μs, and the treatment time is 3-5 min.

[0036] It can be understood that high-voltage pulsed electric field treatment can destroy the muscle fiber structure, making proteins more easily enzymatically hydrolyzed, thereby improving the tenderness of the meat quality.

[0037] Step S3: Add a compound microbial enzyme preparation to the raw meat after high-voltage pulsed electric field treatment for enzymatic hydrolysis. Among them, the compound microbial enzyme preparation is composed of Bacillus subtilis neutral protease and Aspergillus oryzae acid protease in a ratio of 1:0.9-1:1.1, and the total enzyme activity ≥10,000 U / g.

[0038] Specifically, the addition amount of the compound microbial enzyme preparation is 0.2-0.4% of the meat weight, the enzymatic hydrolysis temperature is 40-50 °C, and the enzymatic hydrolysis time is controlled within 1.5-2.5 hours. During the enzymatic hydrolysis process, the microbial enzyme can specifically decompose connective tissues such as collagen and elastin in the meat, significantly improving the tenderness of the meat, and at the same time generating some flavor precursor substances, adding a unique flavor to the meat jerky.

[0039] Specifically, microbial proteases (Bacillus subtilis neutral protease and Aspergillus oryzae acidic protease) can specifically decompose the proteins in muscle, especially myofibrillar proteins. These enzymes can cut specific peptide bonds on the protein chain, resulting in smaller protein molecules, thereby changing the muscle fiber structure and making it softer. Significantly improving the tenderness and taste of meat products, making the meat jerky easier to chew and enhancing the consumer's eating experience. During the enzymatic hydrolysis process, macromolecular proteins are decomposed into smaller peptide segments and amino acids. Some of these small molecules have strong umami or sweet tastes, which can increase the overall flavor complexity of the food, and the flavor substances generated by enzymatic hydrolysis enhance the basic flavor of the meat jerky. In addition, due to the change in protein structure, the muscle tissue becomes looser, which is conducive to the deep penetration of marinade components into the meat interior, improving the marinating efficiency and ensuring uniform distribution of taste throughout the product.

[0040] Step S4: Put the enzymatically hydrolyzed raw meat and marinade into a vacuum tumbler for vacuum tumbling to obtain meat material. Among them, the marinade includes fish sauce, trehalose, compound phosphate, low-reaction-degree silkworm pupa flavor base, monascus red, and disodium 5'-ribonucleotide.

[0041] It can be understood that fish sauce can endow the meat jerky with a delicious flavor. Trehalose can not only increase the sweetness of the meat jerky but also has a certain moisture retention effect, helping to maintain the moisture of the meat jerky; compound phosphate can improve the water retention of the meat, making the meat jerky more juicy; the silkworm pupa flavor base can add a unique flavor and rich taste to the meat jerky. The low-reaction-degree silkworm pupa flavor base refers to a food additive extracted or processed from silkworm pupae with a specific flavor but limited processing. This base retains the unique flavor and nutritional components of silkworm pupae, but its flavor intensity, complexity, or reactivity with other components is relatively low. Monascus red can improve the color of the meat jerky, making it show an attractive red; disodium 5'-ribonucleotide can enhance the umami of the meat jerky and act synergistically with other flavor substances to enhance the overall flavor of the meat jerky.

[0042] Specifically, the mass ratios of each component are as follows: 100 parts of raw meat, 3 - 5 parts of fish sauce, 4 - 6 parts of trehalose, 0.1 - 0.3 parts of compound phosphate, 0.5 - 1.0 parts of low-reaction-degree silkworm pupa flavor base, 0.02 - 0.04 parts of monascus red, and 0.1 - 0.3 parts of disodium 5'-ribonucleotide.

[0043] During vacuum tumbling, the tumbling temperature is controlled at 0 - 4°C, the vacuum degree is maintained at -0.08 MPa, and the tumbling time is 30 - 40 minutes. During the tumbling process, ultrasonic assistance is combined, the ultrasonic frequency is set at 20 - 40 kHz, and the power is 200 - 300 W.

[0044] It can be understood that through vacuum tumbling and ultrasonic assistance, the marinade can better penetrate into the interior of the meat, be evenly distributed in the muscle tissue, improve the pickling effect, and further enhance the flavor and tenderness of the meat jerky.

[0045] Step S5: Spread the meat material flat on a sieve and perform baking to obtain semi-finished meat jerky.

[0046] Step S6: Cool, cut, inspect, and package the semi-finished meat jerky to obtain the finished meat jerky. Ensure that the product meets food safety standards, is convenient for storage and transportation, and also improves the convenience of consumption for consumers.

[0047] In a preferred embodiment of the present example, the method of spreading the meat material flat on a sieve and performing baking to obtain semi-finished meat jerky in step S5 includes:

[0048] Step S51: Low-temperature shaping: Spread the meat material flat on a sieve, spray a transglutaminase solution on the meat material, and then place it in a drying device for low-temperature drying. The drying temperature is controlled at 40 - 45°C, and the drying time is 2 - 3 hours.

[0049] It can be understood that at this stage, the moisture in the meat gradually evaporates, and the protein begins to form a preliminary network structure. The addition amount of transglutaminase is 0.1 - 0.2% of the meat weight, preferably 0.15%. The transglutaminase can be dissolved in an appropriate amount of water according to a certain ratio to prepare a solution, and the solution is evenly sprayed on the surface of the meat using a spraying device. Transglutaminase can catalyze the covalent cross-linking reaction between protein molecules, making the protein in the meat form a more compact network structure, thereby improving the texture and elasticity of the meat jerky and giving it a better taste. Low-temperature drying can help remove some moisture while not causing the surface of the meat to harden rapidly, which is beneficial to maintaining the internal softness and structural stability.

[0050] Step S52: Medium-temperature drying: After the low-temperature shaping is completed, raise the temperature to 80 - 90°C and continue drying for 1 - 2 hours.

[0051] Specifically, continuing to dry at medium temperature can further reduce the moisture content in the meat material and prepare for subsequent high-temperature baking.

[0052] Step S53: High-temperature ripening: After the medium-temperature drying is completed, place the meat material in an oven for high-temperature baking. The baking temperature is 180 - 200°C, and the baking time is 4 - 6 minutes.

[0053] It can be understood that under the action of high temperature, the Maillard reaction occurs on the surface of the meat jerky, forming a unique caramel flavor and attractive color.

[0054] Step S54: Perform flavor enhancement treatment after high-temperature aging: Sprinkle 0.3 - 0.5 parts of medium / high reaction degree silkworm pupa flavor base material on the surface of the meat material, and then put the meat material into an oven and perform secondary baking at a temperature of 150 - 160 °C for 1 - 2 minutes.

[0055] It can be understood that through secondary baking, the silkworm pupa flavor base material can better combine with the meat jerky, further enhancing the flavor of the meat jerky and making the flavor of the meat jerky more intense and unique.

[0056] In a preferred embodiment of this example, the marinade further includes 0.8 - 2 parts of red beetroot powder and 0.2 - 0.5 parts of green tea extract (calculated based on 100 parts of raw meat).

[0057] It can be understood that red beetroot powder is rich in natural pigment - betacyanin, which is an effective antioxidant, and also contains rich dietary fiber, minerals, vitamin C, etc. Red beetroot powder can not only bring a natural and attractive red or purple color tone to the meat jerky, but also its antioxidant properties can help maintain this color and prevent color degradation caused by oxidation. Green tea extract contains rich catechins, which are a powerful antioxidant. In addition, since betacyanin in red beetroot powder is sensitive to light, heat and pH value and is prone to fading during processing and storage, the polyphenol components in green tea extract have a certain light protection effect, which can help stabilize the color of betacyanin and reduce degradation caused by light. The combined addition of green tea extract and red beetroot powder can not only add nutrition and flavor to the meat jerky, but also bring a natural and attractive color to the meat jerky.

[0058] In a preferred embodiment of this example, a torque sensor and a current transformer are integrated in the drive motor circuit of the tumbler, which is used to monitor the resistance torque of the meat material on the drum (reflecting the change of the viscoelasticity of the meat material) in real time during the tumbling process, and dynamically adjust the motor speed (5 - 20 rpm) and the forward and reverse cycle according to the resistance torque data. Specifically, in the initial stage, high speed (such as 15 rpm) is used to quickly mix the marinade, and when the resistance torque drops to a preset value, it is automatically switched to low speed (such as 8 rpm) for shape-preserving tumbling.

[0059] It can be understood that by monitoring the change of the resistance torque, the degree of marinade penetration can be accurately judged. Using a higher rotational speed at the initial stage can quickly and evenly distribute the marinade into the meat material. As the marinade gradually penetrates into the interior of the meat tissue, the resistance torque will decrease. At this time, reducing the rotational speed helps to complete the marinating process more delicately and ensure uniform seasoning. In addition, dynamically adjusting the motor rotational speed and the forward and reverse cycle can help better manage the viscoelasticity and fiber structure of the meat material. The high-speed stage helps to break some muscle fibers and promote marinade absorption; while the low-speed shape-preserving stage helps to maintain the shape and texture of the meat material and prevent structural damage caused by over-stirring. By adjusting the forward and reverse cycle, it is possible to prevent the meat material from accumulating on one side and ensure that all materials are evenly processed.

[0060] In a preferred solution of this embodiment, when cooling the semi-finished meat jerky in step S6, the semi-finished meat jerky is laid flat on the conveyor belt, and the conveyor belt is used to send the semi-finished meat jerky into the cooling chamber. An electrode is installed at the top of the cooling chamber to generate a high-voltage electrostatic field (such as a 5-10 kV DC electric field). The conveyor belt is made of conductive stainless steel (surface roughness Ra≤0.8 μm) and is reliably connected to the ground through a copper wire to form an electric field path of "top electrode - meat jerky - belt". The electric field formed by the top electrode (positive electrode) and the conveyor belt (negative electrode) generates a Coulomb attraction force on the meat jerky, causing the meat jerky to fit tightly to the belt and suppressing the edge warping caused by moisture evaporation and shrinkage when the meat jerky is cooled.

[0061] In addition, the high-voltage electric field can also cause partial ionization of the air. The generated positive and negative ions move directionally in the electric field to form a weak ion wind, which destroys the stagnant boundary layer on the surface of the meat jerky and improves the convective heat transfer coefficient, thereby enhancing the cooling efficiency.

[0062] Specifically, the top electrode uses a food-grade 316L stainless steel mesh electrode, which is distributed in a matrix pattern and covers 80% of the area at the top of the cooling chamber. The top electrode is connected through an insulating cable by a DC high-voltage power supply (equipped with a short-circuit protection module), and pulse width modulation (PWM) technology can be used to output a stable DC voltage.

[0063] It can be understood that when the high-voltage electrostatic field is applied, the meat jerky will carry charges due to electrostatic induction in the electric field. These charges are affected by the electric field force, causing the meat jerky to be adsorbed on the conveyor belt below. Using the Coulomb attraction force to make the meat jerky adhere to the belt avoids the problem of edge warping caused by uneven moisture evaporation during the cooling process and improves the appearance quality and flatness of the meat jerky. At the same time, the presence of the electrostatic field also changes the air flow characteristics in the cooling chamber, promotes the movement and directionality of air molecules, enhances the air convection heat transfer efficiency, and speeds up the heat transfer from the meat jerky to the cooling medium (air), thereby shortening the cooling time.

[0064] In a preferred solution of this embodiment, after spreading the meat material flat on the screen in step S5 and baking it to obtain semi-finished meat jerky, it further includes using a high-precision camera and image processing algorithm to evaluate the spreading condition of the meat material. The specific method includes:

[0065] Install the camera at a position after the meat material spreading process and before entering the baking process, ensuring that the camera can capture the surface information of the meat material from the best angle.

[0066] Capture the meat material image in real time, and perform preprocessing through techniques such as denoising and brightness adjustment to enhance the image clarity and contrast.

[0067] Apply edge detection algorithm and texture analysis algorithm to accurately identify the irregularities and unspread parts on the surface of the meat material, and mark all abnormalities.

[0068] Display the analysis results through the user interface, automatically mark the places that need to be adjusted, and trigger an alarm to remind the staff to make adjustments, improving the appearance quality of the product.

[0069] Specifically, the edge detection algorithm is used to identify the boundary of the meat material and determine its shape. The edge detection algorithm can adopt Canny, Sobel or Laplacian operator, etc.

[0070] Specifically, the method of the texture analysis algorithm is as follows:

[0071] Selection of texture descriptors: Use methods such as gray-level co-occurrence matrix (GLCM), local binary pattern (LBP) or Gabor filter to describe the texture features of the surface of the meat material.

[0072] Feature extraction: Extract key features from the texture descriptors, such as contrast, correlation, energy and entropy, etc., to characterize the uniformity and structural characteristics of the surface of the meat material.

[0073] Classification and recognition: Classify different texture features through a trained machine learning model (such as support vector machine SVM, random forest or deep learning network) to distinguish the normal area from the abnormal area (such as the unspread part).

[0074] Specifically, when marking all abnormalities, a series of rules can be set to determine which features represent abnormal situations, such as irregular edges, texture features significantly different from the surrounding areas, etc., and use image processing software to automatically mark all detected abnormal areas on the original image.

[0075] Example 1:

[0076] Select 10 kg of fresh pork, cut it into thin slices after removing the fascia, and soak it in a 0.4% NaCl solution for ultrasonic treatment (40 kHz, 200 W) for 10 minutes.

[0077] Drain the sliced meat and put it into the pulsed electric field equipment. Set the electric field strength at 22.5 kV / cm, the pulse frequency at 125 Hz, the pulse width at 35 μs, and the treatment time at 4 minutes.

[0078] Add 0.3% (by meat weight) of a compound microbial enzyme preparation (Bacillus subtilis neutral protease: Aspergillus oryzae acid protease = 1:1), and carry out enzymatic hydrolysis treatment at 45 °C for 2 hours.

[0079] Mix the enzymatically hydrolyzed pork with the marinade (the marinade includes 400 g of fish sauce, 500 g of trehalose, 20 g of compound phosphate, 75 g of low-reaction silkworm pupa flavor base, 3 g of monascus red, and 20 g of 5'-ribonucleotide disodium), place it in a vacuum tumbler (vacuum degree -0.08 MPa, temperature 2 °C) and tumble for 35 minutes, with simultaneous ultrasonic treatment (ultrasonic frequency 30 kHz, power 250 W).

[0080] Spread the meat mixture flat on a sieve for baking to obtain semi-finished meat jerky, specifically including:

[0081] Low-temperature shaping: Spread the meat mixture flat on a sieve, spray 0.15% of transglutaminase solution on the meat mixture, and then put it into a drying equipment for low-temperature drying. Control the drying temperature at 43 °C and the drying time at 2.5 hours.

[0082] Medium-temperature drying: After the low-temperature shaping is completed, raise the temperature to 85 °C and continue drying for 1.5 hours.

[0083] High-temperature ripening: After the medium-temperature drying is completed, put the meat mixture into an oven for high-temperature baking. The baking temperature is 190 °C and the baking time is 5 minutes.

[0084] After high-temperature ripening, carry out flavor enhancement treatment: Spray 40 g of medium-reaction silkworm pupa flavor base on the surface of the meat mixture, and then put the meat mixture into an oven for secondary baking at a temperature of 155 °C for 1.5 minutes.

[0085] Cool, cut, inspect, and package the semi-finished meat jerky to obtain the finished meat jerky.

[0086] Example 2:

[0087] Select 10 kg of fresh pork, remove the fascia and cut it into thin slices, soak it in a 0.4% NaCl solution and carry out ultrasonic treatment (40 kHz, 200 W) for 10 minutes.

[0088] Drain the sliced meat and put it into the pulsed electric field equipment. Set the electric field strength at 25 kV / cm, the pulse frequency at 150 Hz, the pulse width at 50 μs, and the treatment time at 5 minutes.

[0089] Add 0.3% (by meat weight) of a compound microbial enzyme preparation (Bacillus subtilis neutral protease: Aspergillus oryzae acidic protease = 1:1), and enzymatically hydrolyze at 50 °C for 2.5 hours.

[0090] Mix the enzymatically hydrolyzed pork with the marinade (the marinade includes 400 g of fish sauce, 500 g of trehalose, 20 g of compound phosphate, 75 g of low-reaction silkworm pupa flavor base, 3 g of monascus red, 20 g of disodium 5'-ribonucleotide, 200 g of red beet root powder, and 50 g of green tea extract), place it in a vacuum tumbler (vacuum degree -0.08 MPa, temperature 2 °C) and tumble for 35 minutes, with simultaneous ultrasonic treatment (ultrasonic frequency 30 kHz, power 250 W).

[0091] Spread the meat mixture flat on a sieve for baking to obtain semi-finished meat jerky, specifically including:

[0092] Low-temperature shaping: Spread the meat mixture flat on a sieve, spray 0.15% of a transglutaminase solution on the meat mixture, and then place it in a drying equipment for low-temperature drying. Control the drying temperature at 43 °C and the drying time at 2.5 hours.

[0093] Medium-temperature drying: After low-temperature shaping, raise the temperature to 85 °C and continue drying for 1.5 hours.

[0094] High-temperature ripening: After medium-temperature drying is completed, place the meat mixture in an oven for high-temperature baking. The baking temperature is 200 °C and the baking time is 6 minutes.

[0095] After high-temperature ripening, perform flavor enhancement treatment: Spray 40 g of medium-reaction silkworm pupa flavor base on the surface of the meat mixture, and then place the meat mixture in an oven for secondary baking at a temperature of 160 °C for 2 minutes.

[0096] Cool, cut, inspect, and package the semi-finished meat jerky to obtain the finished meat jerky.

[0097] Example 3:

[0098] Select 10 kg of fresh pork, cut it into thin slices after removing the fascia, and soak it in a 0.4% NaCl solution for ultrasonic treatment (40 kHz, 200 W) for 10 minutes.

[0099] After draining the meat slices, put them into a pulsed electric field device, set the electric field strength at 20 kV / cm, the pulse frequency at 100 Hz, the pulse width at 20 μs, and the treatment time at 3 minutes.

[0100] Add 0.3% (by meat weight) of a compound microbial enzyme preparation (Bacillus subtilis neutral protease: Aspergillus oryzae acidic protease = 1:1), and enzymatically hydrolyze at 40 °C for 1.5 hours.

[0101] Mix the enzymatically hydrolyzed pork with the marinade (the marinade includes 400 g of fish sauce, 500 g of trehalose, 20 g of compound phosphate, 75 g of low-reaction silkworm pupa flavor base, 3 g of monascus red, 20 g of disodium 5'-ribonucleotide, 80 g of red beet root powder, and 20 g of green tea extract), place it in a vacuum tumbler (vacuum degree -0.08 MPa, temperature 2°C) and tumble for 35 minutes, with simultaneous ultrasonic treatment (ultrasonic frequency 30 kHz, power 250 W).

[0102] Spread the meat mixture evenly on a sieve for baking to obtain semi-finished meat jerky, specifically including:

[0103] Low-temperature shaping: Spread the meat mixture evenly on a sieve, spray 0.15% transglutaminase solution on the meat mixture, and then place it in a drying equipment for low-temperature drying, with the drying temperature controlled at 43°C and the drying time being 3 hours.

[0104] Medium-temperature drying: After the low-temperature shaping is completed, raise the temperature to 80°C and continue drying for 2 hours.

[0105] High-temperature cooking: After the medium-temperature drying is completed, place the meat mixture in an oven for high-temperature baking, with the baking temperature being 180°C and the baking time being 4 minutes.

[0106] After high-temperature cooking, conduct flavor enhancement treatment: Spray 40 g of medium-reaction silkworm pupa flavor base on the surface of the meat mixture, then place the meat mixture in an oven and conduct secondary baking at a temperature of 150°C for 1 minute.

[0107] Cool, cut, inspect, and package the semi-finished meat jerky to obtain the finished meat jerky.

[0108] Comparative Example 1: Omit the ultrasonic treatment in Step 1, soak it only in a 0.4% NaCl solution for 10 minutes, and omit the pulsed electric field treatment step in Step 2, with the remaining steps and ingredients being the same as in Example 1.

[0109] Comparative Example 2: Replace the compound enzyme with a single enzyme preparation, only use Bacillus subtilis neutral protease (addition amount 0.3%), and omit Aspergillus oryzae acidic protease, with the remaining steps and ingredients being the same as in Example 1.

[0110] Comparative Example 3: Without ultrasonic-assisted tumbling, the ultrasonic assistance is not used during the vacuum tumbling process, with the remaining steps and ingredients being the same as in Example 1.

[0111] Experimental data comparison:

[0112] Tenderness Index (Shear Force): To evaluate the tenderness of the meat jerky, we used a texture analyzer to measure its shear force value in Newtons (N). The lower the shear force value, the tenderer the texture of the meat jerky. Each sample was tested five times repetitively, and the final result was the average of these measured values as the representative value of the sample.

[0113] Taste and Flavor Score: For the taste and flavor quality of the meat jerky, a team consisting of ten professionally trained food sensory evaluators was organized to conduct the scoring. The scoring range was set from 1 to 10 points. Among them, 1 point indicated that the taste and flavor were very poor, the meat was extremely hard to chew and had an unpleasant flavor; while 10 points meant that the taste was excellent, the meat jerky was tender, had a rich and natural fragrance, and an outstanding flavor. The evaluation content covered multiple dimensions such as tenderness and chewing experience.

[0114] Color Score: The appearance color of the meat jerky was also one of the important sensory indicators. Therefore, these ten evaluators were also invited to score the color of the meat jerky. The scoring standard was from 1 to 10 points. Among them, 1 point indicated that the color was not good, such as dull, uneven, or showing an abnormal color tone; 10 points meant that the color was uniform, natural, and attractive, meeting the visual expectations of consumers for high-quality meat jerky. The evaluation content included the brightness, uniformity of the color, and the overall visual effect.

[0115] The results obtained from the above tests and scoring are shown in Table 1 below:

[0116] Comparison items Example 1 Example 2 Example 3 Comparative example 1 Comparative example 2 Comparative example 3 Shearing force (N) 32.5 28.7 35.2 45.8 41.3 40.2 Taste and flavor (1 - 10) 8.5 8.9 8.2 6.8 7.3 7.5 Color and luster (1 - 10) 8.0 8.8 7.8 6.5 7.0 7.2

[0117] Table 1

[0118] Result Analysis:

[0119] Tenderness: The shear forces of Examples 1 - 3 were all lower than those of the control group. Among them, Example 2 (high pulsed electric field + complex enzyme) had the best tenderness, verifying the effects of pulsed electric field on destroying muscle fibers and the synergistic enzymatic hydrolysis of complex enzymes.

[0120] Taste, Flavor and Color: Example 2 (adding red beetroot powder and green tea extract) had the highest score, indicating that red beetroot powder and green tea extract helped to improve the naturalness of the color and the layering of the flavor; Comparative Example 1 (soaking in NaCl solution without ultrasonic treatment and pulsed electric field treatment) had significantly deteriorated taste and flavor due to blood residue and low enzymatic hydrolysis efficiency.

[0121] Generally speaking, the present invention provides a meat jerky tenderizing process based on microbial protease, which effectively solves the problems of insufficient tenderness and single flavor existing in traditional meat jerky through a series of innovative steps. First, ultrasonic treatment combined with soaking in NaCl solution is used to remove blood and fishy smell from raw meat, and then high-voltage pulsed electric field treatment is utilized to further improve the meat texture. A composite microbial enzyme preparation composed of Bacillus subtilis neutral protease and Aspergillus oryzae acidic protease is introduced for enzymatic hydrolysis treatment, effectively improving the tenderness of meat jerky and avoiding potential safety hazards that may be brought by chemical tenderizers. In terms of flavor enhancement, the present invention adds marinades including various ingredients such as fish sauce, trehalose, red beet root powder and green tea extract, and adopts staged baking and cooking techniques such as low-temperature shaping, medium-temperature drying and high-temperature cooking, as well as final flavor intensification treatment, successfully endowing the meat jerky with unique and rich flavor levels. In addition, by optimizing parameters such as temperature and vacuum degree in the vacuum tumbling process, and using a drive motor circuit with a torque sensor and a current transformer to adjust the tumbling conditions in real time, the quality of the meat jerky is further improved. The present invention not only ensures food safety, but also significantly enhances the taste and flavor of the meat jerky, meeting the needs of consumers for high-quality meat products.

[0122] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A meat tenderizing process based on microbial protease, characterized in that: The following steps are involved: Select fresh raw meat, remove the fascia and cut into thin slices, and place in NaCl solution for ultrasonic treatment to remove blood and fishy smell; The raw meat after removing blood and fishy smell is placed in a pulse electric field treatment device for high-voltage pulse electric field treatment; Adding a composite microbial enzyme preparation to the raw meat treated with a high-voltage pulse electric field for enzymatic hydrolysis, wherein the composite microbial enzyme preparation is composed of a mixture of Bacillus subtilis neutral protease and Aspergillus oryzae acid protease in a ratio of 1:0.9-1:1.1; Putting the enzymatically treated raw meat and marinade into a vacuum tumbling machine for vacuum tumbling to obtain meat material, wherein the marinade includes fish sauce, trehalose, complex phosphate, low-reaction silkworm pupa flavor base, red yeast rice, and 5'-flavor nucleotide disodium; The meat material is spread on the sieve and baked to obtain a semi-finished meat jerky; The semi-finished meat jerky is cooled, cut, tested and packaged to obtain the finished meat jerky.

2. The process for tenderizing jerky meat based on microbial protease according to claim 1, characterized in that: The method of spreading the meat material onto a screen and baking it to obtain a semi-finished meat jerky comprises: Low temperature shaping: spread the meat material onto the sieve, spray the meat material with glutamine transaminase solution, and then put it into the drying equipment for low temperature drying. The drying temperature is controlled at 40-45℃ and the drying time is 2-3 hours. Medium temperature drying: After low temperature setting, raise the temperature to 80-90℃ and continue drying for 1-2 hours; High temperature aging: After medium temperature drying is completed, the meat is placed in the oven for high temperature baking. The baking temperature is 180-200℃ and the baking time is 4-6 minutes.

3. The process for tenderizing jerky meat based on microbial protease according to claim 2, characterized in that: The method of spreading the meat material onto a sieve and baking it to obtain a semi-finished meat jerky also includes: performing a flavor enhancement treatment after high-temperature maturation: spraying a medium / high-reaction silkworm pupa flavor base on the surface of the meat material, and then placing the meat material in an oven and baking it for a second time at a temperature of 150-160°C for 1-2 minutes.

4. The process for tenderizing jerky meat based on microbial protease according to claim 1, characterized in that: The mass ratio of each component is as follows: 100 parts of raw meat, 3-5 parts of fish sauce, 4-6 parts of trehalose, 0.1-0.3 parts of complex phosphate, 0.5-1.0 parts of low-reaction silkworm pupa flavor base, 0.02-0.04 parts of red yeast rice, and 0.1-0.3 parts of 5'-flavor ribonucleotide disodium.

5. The process for tenderizing jerky meat based on microbial protease according to claim 1, characterized in that: During vacuum tumbling, the tumbling temperature is controlled at 0-4°C, the vacuum degree is maintained at -0.08MPa, the tumbling time is 30-40 minutes, and during the tumbling process, ultrasonic assistance is used, the ultrasonic frequency is set to 20-40kHz, and the power is 200-300W.

6. The process for tenderizing jerky meat based on microbial protease according to claim 1, characterized in that: The driving motor circuit of the tumbling machine is integrated with a torque sensor and a current transformer, which are used to monitor the resistance torque of the meat material to the drum in real time during the tumbling process, and dynamically adjust the motor speed and forward and reverse rotation cycles according to the resistance torque data. In the initial stage, the marinade is mixed quickly at a high speed, and when the resistance torque drops to a preset value, it automatically switches to low-speed shape-preserving tumbling.

7. The process for tenderizing jerky meat based on microbial protease according to claim 1, characterized in that: The addition amount of the composite microbial enzyme preparation is 0.2-0.4% of the meat weight, the enzymolysis temperature is 40-50℃, and the enzymolysis time is controlled at 1.5-2.5 hours.

8. The process for tenderizing jerky meat based on microbial protease according to claim 1, characterized in that: During the high-voltage pulse electric field treatment, the electric field strength is 20-25 kV / cm, the pulse frequency is 100-150 Hz, the pulse width is 20-50 μs, and the treatment time is 3-5 min.

9. The process for tenderizing jerky meat based on microbial protease according to claim 1, characterized in that: When cooling the semi-finished meat jerky, spread it flat on the conveyor mesh belt, and use the conveyor mesh belt to send the semi-finished meat jerky into the cooling chamber. An electrode is installed on the top of the cooling chamber to generate a high-voltage electrostatic field. The conveyor mesh belt is made of conductive stainless steel and is reliably connected to the ground through copper wire, forming an electric field path of "top electrode-meat jerky-mesh belt". The electric field formed by the top electrode and the conveyor mesh belt produces Coulomb attraction on the meat jerky, making the meat jerky fit the mesh belt, thereby suppressing the edge warping caused by water evaporation and shrinkage when the meat jerky is cooled.

10. The process for tenderizing jerky meat based on microbial protease according to claim 1, characterized in that: The marinade also includes red beetroot powder and green tea extract.

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