Shredded mutton production method based on electric field assisted cryogenic quick-freezing and ice glaze freshness locking

Abstract

According to the hand-grabbed mutton production method based on electric field assisted cryogenic quick-freezing and ice glaze freshness locking, more water molecules in hand-grabbed mutton can form a nanoscale ice crystal structure through electromagnetic field assisted cryogenic quick-freezing, muscle fibers in the mutton are not torn, more myofibrillar protein is reserved, juice loss is reduced, and the meat quality is improved. According to the present invention, the meat boiling raw soup is adopted, such that the texture and the taste of the hand-grabbed mutton during eating are improved, the ice glaze layer is formed on the surface of the hand-grabbed mutton through the meat boiling raw soup, and the ice glaze layer is adopted to provide effects of freshness locking, freshness retaining, oxygen isolation, effective inhibition of the oxidation reaction of the mutton, and meat nourishing with the soup, loss and dissipation of flavor substances in the hand-grabbed mutton can be well reduced, the freshly-prepared flavor of the hand-grabbed mutton is restored to the maximum extent, the requirements of consumers for high-quality flavor are met, the problems that in existing industrial production of the hand-grabbed mutton, flavor loss is large, and texture quality is reduced are solved, and the market competitiveness of the hand-grabbed mutton is improved. According to the invention, the freshly prepared flavor and texture quality of the hand-grabbed mutton are reduced to the greatest extent in industrial production.

Description

Technical Field

[0001] The present invention relates to the technical field of frozen fresh-keeping of hand-pulled mutton, and in particular to a method for producing hand-pulled mutton based on electric field-assisted deep-freezing and ice glaze to keep it fresh. Background Art

[0002] Hand-pulled mutton is a traditional specialty food from Northwest my country. The unique regional environment and saline-alkaline grass-fed conditions give the mutton its distinctive flavor and quality. With the improvement of living standards and the shift to a faster-paced lifestyle, the industrial production of this traditional delicacy and the high-fidelity processing techniques for flavor preservation have become key technical challenges urgently needed for industrial development. Due to the lack of effective flavor preservation and quality-maintaining processes, traditional hand-pulled mutton, with its minimal seasoning and emphasis on the inherent flavor and texture of the mutton, is difficult to industrialize. Conventional frozen storage is used. However, due to the slow freezing rate, water molecules form large ice crystals during the freezing process. Upon thawing, this easily disrupts the muscle fiber structure of the meat, leading to the loss of myofibrillar protein and the exudation of excess juice, affecting the taste and texture of the hand-pulled mutton. Furthermore, the inosinic acid (umami compound) in the hand-pulled mutton degrades, and the unsaturated fatty acids are easily oxidized, significantly reducing the flavor and nutritional value of the meat. This makes it difficult to fully restore the unique original flavor and texture of the meat, failing to meet market demand for high-quality industrialized hand-pulled mutton. Summary of the Invention

[0003] In view of this, it is necessary to provide a method for producing hand-pulled mutton based on electric field-assisted deep freezing and ice glaze to lock in freshness, so as to solve the technical problem in the existing technology that it is difficult to maintain the original flavor and quality of hand-pulled mutton after frozen storage.

[0004] The technical solution adopted by the present invention to solve its technical problem is: A method for producing hand-pulled mutton based on electric field-assisted deep freezing and ice glaze to lock in freshness, comprising: Step S1: washing the fresh mutton to remove any residual blood, and then cooking the mutton. After the cooking is complete, separating the meat from the broth to obtain hand-pulled mutton and broth; Step S2: When the separated hand-pulled mutton is naturally cooled to a central temperature of 50°C, it is placed in a temperature field of -45°C and a high-voltage electric field is used to induce the water molecules in the hand-pulled mutton to be in a dipole-oriented state, and the hand-pulled mutton is quickly frozen to a central temperature of ≤-40°C; Step S3: naturally cooling the separated broth to 25°C-20°C, removing grease and impurities from the broth, and then refrigerating the broth to 0-4°C and keeping it in a liquid state for later use; Step S4: After the hand-pulled mutton is quickly frozen to a core temperature of -40°C, it is taken out and immersed in the reserved broth within 30 seconds and removed within 3-5 seconds, so that the broth solidifies into ice on the surface of the quick-frozen hand-pulled mutton, forming an ice coating layer with a thickness of 3-6 mm; Step S5: The glazed hand-pulled mutton is packaged in a controlled atmosphere and then stored in a low-temperature freezer at a temperature below -18°C.

[0005] Preferably, in step S1, the fresh mutton is cleaned by ultrasonic cleaning at a frequency of 40-60 kHz and a power density of 0.2-0.5 W / cm² for 10-15 minutes to remove residual blood.

[0006] Preferably, in step S2, the electric field strength applied by the high-voltage electric field is 20-30 kV, and the electric field spacing is maintained at 10-15 cm.

[0007] Preferably, in step S3, 0.5-1% w / w nisin powder and 0.5-1% w / w vitamin E are added to the reserved broth, and the mixture is dissolved and mixed by ultrasonication.

[0008] Preferably, in step S3, during the refrigeration cooling process, ultrasonic waves of 20 to 40 kHz are applied to the broth to inhibit gel formation.

[0009] Preferably, in step S4, the hand-pulled mutton with the ice coating is immersed in pure water at a temperature of 0-1°C in a liquid state within 5-10 seconds and taken out within 1-3 seconds, so that two layers of ice coating are formed on the surface of the hand-pulled mutton.

[0010] Preferably, in step S4, 0.5-1% w / w nisin powder and 0.5-1% w / w vitamin E are added to purified water, and the mixture is dissolved and mixed by ultrasonication.

[0011] The present invention employs the above-mentioned technical solution, which has the beneficial effects of: using a high-voltage electric field to assist deep freezing, the water molecules in the hand-pulled mutton are more likely to form nano-scale ice crystal structures, preventing the muscle fibers in the meat from being torn, retaining more myofibrillar protein, and reducing juice loss, thereby significantly improving the texture and mouthfeel of the hand-pulled mutton when consumed. Furthermore, by using the broth to form an ice glaze on the surface of the hand-pulled mutton, the glaze locks in and preserves the mutton's freshness, isolates it from oxygen, effectively inhibits oxidation and putrefaction, and nourishes the meat with the broth, effectively reducing the loss and dissipation of flavor substances in the hand-pulled mutton. This effectively restores the freshly prepared flavor of the hand-pulled mutton to the greatest extent possible, meeting consumers' demand for high-quality flavor. This solves the problems of significant flavor loss, degraded texture, oxidation, and discoloration due to water loss that exist in existing industrialized hand-pulled mutton production, achieving the maximum restoration of the freshly prepared flavor and texture of the hand-pulled mutton in industrialized production, extending the product's shelf life, and enhancing product market competitiveness and the company's economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a flow chart of the method for producing hand-pulled mutton based on electric field-assisted deep-freezing and ice glaze to lock in freshness. DETAILED DESCRIPTION

[0013] The technical solutions and technical effects of the present invention are further described in detail below with reference to the accompanying drawings of the present invention.

[0014] like Figure 1 As shown, an embodiment of the present invention provides a method for producing hand-pulled mutton based on electric field-assisted deep freezing and ice glaze to lock in freshness. It mainly uses integrated fusion production technologies such as cleaning, cooking, broth separation, high-voltage electric field-assisted deep freezing, ice glaze formation and modified atmosphere packaging, combined with antioxidants, to form an ice glaze on the surface of the hand-pulled mutton to lock in freshness protection, thereby achieving efficient preservation and flavor restoration of the hand-pulled mutton, and comprehensively ensuring the quality of the hand-pulled mutton.

[0015] The production method of hand-pulled mutton based on electric field-assisted deep freezing and ice glaze to lock in freshness is specifically implemented in the following steps: Step S1: Ultrasonic cleaning of the fresh mutton is performed for 10-15 minutes using ultrasonic waves at a frequency of 40-60kHz and a power density of 0.2-0.5W / cm². Natural antioxidants such as Sichuan peppercorns and ginger, along with common meat-cooking seasonings, are then added for cooking. After cooking, the meat and broth are separated to produce the hand-pulled mutton and broth. Ultrasonic cleaning utilizes the cavitation effect generated by high-frequency vibrations, penetrating deep into the crevices and microstructures of the mutton, removing residual blood stains from the surface and crevices of the meat.

[0016] Step S2: When the separated hand-pulled mutton is naturally cooled to a center temperature of 50°C, the hand-pulled mutton is placed in a temperature field of -45°C (superfreezing equipment), and a high-voltage field strength of 20-30kV (DC or AC) is applied to the hand-pulled mutton in the temperature field by arranging needle-plate electrodes and flat-plate electrodes in the temperature field. The electric field spacing is maintained at 10-15cm. Under the induction of the high-voltage electric field, the hand-pulled mutton is quickly frozen to a center temperature of ≤-40°C.

[0017] Step S3: When the separated broth is naturally cooled to 25°C-20°C, the upper layer of floating oil in the broth is first removed by static stratification, and then filtered through a 200-300 mesh filter to remove solid impurities. The broth is then refrigerated to 0-4°C (close to freezing point) and kept in a liquid state for later use.

[0018] Step S4: After taking out the hand-pulled mutton that has been quick-frozen to a core temperature of -40°C, completely immerse it in a reserved broth at a temperature of 0-4°C within 30 seconds and take it out of the broth within 3-5 seconds, so that the broth adheres to the surface of the hand-pulled mutton. Under the action of low-temperature conduction, the broth forms an ice coating with a thickness of 3-6 mm on the surface of the quick-frozen hand-pulled mutton.

[0019] Since the broth (the original soup for cooking meat) contains the same nutrients and a large amount of collagen as the hand-pulled lamb, the ice coating layer made from the original soup for cooking meat can effectively isolate oxygen, reduce the contact between the hand-pulled lamb and microorganisms, and effectively prevent the hand-pulled lamb from oxidation and dehydration and discoloration. It can also nourish the meat with the soup and will not damage the flavor of the hand-pulled lamb, so that the hand-pulled lamb can restore the fresh flavor and texture quality to the greatest extent in industrial production.

[0020] Step S5: The glazed hand-pulled lamb is packaged in a modified atmosphere (MA) gas mixture containing 80-90% nitrogen and 5-15% carbon dioxide. The meat is then stored at a low temperature, maintained below -18°C. The MA packaging equipment can be nitrogen-filled, carbon dioxide-filled, or mixed-gas MA packaging machines. MA packaging reduces oxygen concentration, inhibiting the growth of aerobic microorganisms, slowing fat oxidation and vitamin degradation, thereby preserving the color, flavor, and nutritional value of the hand-pulled lamb and facilitating transportation and sales.

[0021] In step S2, the electric field spacing is preferably 10 cm.

[0022] Furthermore, in step S3, during the refrigeration process of the broth, the collagen contained in the broth forms a gel structure under low temperature conditions. The formation of broth gel is generally related to the interaction of protein molecules, such as protein cross-linking and aggregation, forming a network structure that fixes water and thus forms a gel. To prevent the collagen in the broth from gelling and improve the fluidity of the broth under low temperature conditions, 20-40kHz ultrasonic waves are applied to the broth. Ultrasound waves are mechanical elastic vibration waves that produce unique effects when propagating in liquids, such as cavitation, mechanical action, thermal effects, and microfluidics. When 20-40kHz ultrasound is applied to the broth, the cavitation effect and mechanical vibration generated by the ultrasound can cause continuous disturbance of the protein molecules in the broth, hindering the orderly aggregation of the protein molecules, making it difficult for the protein molecules to arrange and combine in the manner required to form a gel, destroying the structure of the protein molecules in the broth, and weakening the interactions between the protein molecules that can originally form a gel, such as hydrogen bonds and hydrophobic interactions, thereby inhibiting the formation of a gel. In addition, the cavitation effect and mechanical vibration of the ultrasound can also promote a more even dispersion of the components in the broth, avoiding local enrichment of components such as proteins, and can also reduce the supercooling of the initial nucleation of the broth, so that the broth maintains fluidity and uniformity under low temperature conditions. Furthermore, in step S4, the broth can form a uniform ice coating on the surface of the hand-pulled lamb.

[0023] In the above embodiment, the broth can be cooled to 0~4℃ (close to the freezing point) with the assistance of ultrasound while maintaining fluidity and uniformity. In step S4, the optimal implementation temperature of the broth is 0℃. The temperature fluctuation of the broth on the surface of the hand-pulled mutton in the low temperature state is small. When the broth combines with the surface of the hand-pulled mutton, it can quickly form an ice coating layer on the surface of the hand-pulled mutton, which can reduce the damage caused by the broth to the surface of the hand-pulled mutton.

[0024] Furthermore, in step S3, by adding antioxidants such as nisin powder and vitamin E at a concentration of 0.5-1% w / w to the broth and dissolving and mixing them with the assistance of ultrasound, the broth combines with the surface of the hand-pulled mutton, and an ice coating layer of antimicrobial peptides can be formed on the surface of the hand-pulled mutton, which can improve the effects of locking in freshness, preserving freshness, antibacterial and regulating the surface microenvironment.

[0025] In a further scheme, in order to improve the freshness-locking and antibacterial effects, in step S4, the hand-pulled lamb with an ice coating formed by the broth is immersed in pure water in a liquid state at a temperature of 0~1°C again within 5~10 seconds, and taken out within 1~3 seconds. The low temperature of the hand-pulled lamb is used to make the pure water form a second ice coating on the surface of the ice coating, and the first ice coating is wrapped by the second ice coating to prevent the ice coating formed by the broth from being exposed. In addition, in this step, by adding 0.5-1% w / w nisin powder and 0.5-1% w / w vitamin E to the pure water and dissolving and mixing them by ultrasonic wave, the hand-pulled lamb can be treated as a double-layer isolation, thereby improving the overall antibacterial properties.

[0026] Moreover, during storage and transportation, the double-layer ice coating can provide a stable external environment for the hand-pulled lamb, reducing the squeezing and damage of the lamb tissue structure by external forces, thereby maintaining the elasticity and chewiness of the hand-pulled lamb after thawing, allowing consumers to experience a good taste when eating.

[0027] This industrialized production method of hand-pulled mutton uses a high-voltage electric field to deep-freeze the hand-pulled mutton, which can induce the aggregation and orderly arrangement of water molecules in the hand-pulled mutton, promote the formation of ice nuclei, accelerate freezing, increase the rate and stability of ice nucleation, and change the local structure and energy state of water molecules. The water molecules in the hand-pulled mutton form more nano-scale ice crystal structures, and obtain ice of a specific size (for example, smaller ice crystals to reduce damage to biological tissues) or shape (more regular crystal structure), so that the muscle fibers in the meat are not torn. Retaining more myofibrillar protein and reducing juice loss can effectively reduce the loss and dispersion of flavor substances in hand-pulled lamb, and adding natural antioxidants (nisin powder and vitamin E) to the broth to form a nano-scale antibacterial peptide ice coating on the surface of the hand-pulled lamb by cooking the original meat soup. The ice coating layer is used to effectively isolate oxygen and reduce the contact of the hand-pulled lamb with the outside air, which plays a role in locking and preserving freshness. In addition, the ice coating layer made with the original meat soup can also nourish the meat with the soup, which can effectively reduce the loss and dispersion of flavor substances in the hand-pulled lamb, better preserve the original flavor of the hand-pulled lamb, and be closer to the fresh state, so that the hand-pulled lamb can restore the fresh flavor and texture quality to the greatest extent in industrial production, allowing consumers to taste the deliciousness that is closer to freshly made hand-pulled lamb.

[0028] The same quality of hand-pulled lamb was stored in a low-temperature environment for 60 days using conventional freezing and deep-frozen quick-frozen ice glaze to lock in freshness. The same technical means were used to compare and analyze the flavor and nutrient retention of the two groups of hand-pulled lamb after 60 days of storage:

[0029] Comparative analysis shows that the industrialized hand-pulled lamb production method employed in this embodiment, compared to conventional frozen preservation methods, can reduce the degradation rate of inosinic acid (an umami substance) in the meat by over 50%, reduce the oxidation rate of unsaturated fatty acids by 20%, increase the elastic modulus by 40% compared to slow freezing, and control the juice loss rate to less than 3%, resulting in an overall flavor retention rate exceeding 85%, making the meat closer to its freshest state when consumed. This method reduces the damage to the cellular structure of the meat caused by sharp ice crystals formed during traditional freezing, retains more myofibrillar proteins, and reduces juice loss, achieving a "cellular-level preservation" effect and significantly improving the texture and taste of the meat.

[0030] This invention utilizes a combination of high-voltage electric field-assisted deep freezing, ice glaze to lock in freshness, and modified atmosphere packaging, all integrated into production technologies. This technology maximizes the flavor of freshly prepared hand-pulled lamb, meeting consumer demand for high-quality flavor. It addresses existing issues of flavor loss, quality degradation, oxidation, and discoloration due to water loss in the industrialized production of hand-pulled lamb, extending the product's shelf life. This enables high-quality industrialized production of hand-pulled lamb, enhancing product competitiveness and the company's economic benefits. It also provides an efficient and feasible technical solution for the industrialized development of hand-pulled lamb.

[0031] The above disclosure is only a preferred embodiment of the present invention, and it is certainly not intended to limit the scope of the present invention. A person skilled in the art can understand that all or part of the processes of the above embodiment and equivalent changes made in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A method for producing hand-pulled mutton based on electric field-assisted deep freezing and ice glaze to lock in freshness, characterized in that: include: Step S1: washing the fresh mutton to remove any residual blood, and then cooking the mutton. After the cooking is complete, separating the meat from the broth to obtain hand-pulled mutton and broth; Step S2: When the separated hand-pulled mutton is naturally cooled to a central temperature of 50°C, it is placed in a temperature field of -45°C and a high-voltage electric field is used to induce the water molecules in the hand-pulled mutton to be in a dipole-oriented state, and the hand-pulled mutton is quickly frozen to a central temperature of ≤-40°C; Step S3: naturally cooling the separated broth to 25°C-20°C, removing grease and impurities from the broth, and then refrigerating the broth to 0-4°C and keeping it in a liquid state for later use; Step S4: After the hand-pulled mutton is quickly frozen to a core temperature of -40°C, it is taken out and immersed in the reserved broth within 30 seconds and removed within 3-5 seconds, so that the broth solidifies into ice on the surface of the quick-frozen hand-pulled mutton, forming an ice coating layer with a thickness of 3-6 mm; Step S5: The glazed hand-pulled mutton is packaged in a controlled atmosphere and then stored in a low-temperature freezer at a temperature below -18°C.

2. The method for producing hand-pulled mutton based on electric field-assisted deep freezing and ice glaze to lock in freshness according to claim 1, characterized in that: In step S1, the fresh mutton is cleaned by ultrasonic cleaning at a frequency of 40-60 kHz and a power density of 0.2-0.5 W / cm² for 10-15 minutes to remove blood residue.

3. The method for producing hand-pulled mutton based on electric field-assisted deep freezing and ice glaze to lock in freshness according to claim 1, characterized in that: In step S2, the electric field strength of the high-voltage electric field is 20-30 kV, and the electric field spacing is 10-15 cm.

4. The method for producing hand-pulled mutton based on electric field-assisted deep freezing and ice glaze to lock in freshness according to claim 1, characterized in that: In step S3, 0.5-1% w / w nisin powder and 0.5-1% w / w vitamin E are added to the reserved broth, and the mixture is dissolved and mixed by ultrasonication.

5. The method for producing hand-pulled mutton based on electric field-assisted deep freezing and ice glaze to lock in freshness according to claim 1 or 4, characterized in that: In step S3, during the refrigeration cooling process, ultrasonic waves of 20 to 40 kHz are applied to the broth to suppress gel formation.

6. The method for producing hand-pulled mutton based on electric field-assisted deep freezing and ice glaze to lock in freshness according to claim 1, characterized in that: In step S4, the glazed hand-pulled mutton is immersed in pure water at a temperature of 0-1°C for 5-10 seconds and taken out within 1-3 seconds, so that a second glaze layer is formed on the surface of the mutton.

7. The method for producing hand-pulled mutton based on electric field-assisted deep freezing and ice glaze to lock in freshness according to claim 6, characterized in that: In step S4, 0.5-1% w / w nisin powder and 0.5-1% w / w vitamin E are added to purified water, and the mixture is dissolved and mixed by ultrasonication.

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