Aseptic cold filling and preservation processing method for fruit and vegetable cans

Abstract

The application discloses a kind of fruit and vegetable cans aseptic cold filling fresh-keeping processing method, belong to fruit and vegetable canning technical field, this fruit and vegetable cans aseptic cold filling fresh-keeping processing method, including S1: fruit and vegetable are prewashed, correction, cutting and hypochlorous acid pre-disinfection;S2: fruit and vegetable are transferred into VC color protection liquid and are soaked;S3: using vacuum flash tank is to fruit and vegetable vacuum flash and is stored in low-temperature aseptic bin.The application is through micro-negative pressure pulse micro-bubble disinfection, low-temperature VC color protection and high-vacuum flash synergic treatment, quickly expels the air in fruit and vegetable, thoroughly degerming color protection, keeps fruit crisp and tender form, reduces initial bacterial number, provides clean stable raw material for subsequent process, the application is through multi-stage tank disinfection, gradient air conditioning replacement, micro-positive pressure aseptic filling and three-stage gradient HPP cold sterilization, constructs whole oxygen-free aseptic processing system, sterilization is mild and thorough, does not destroy nutrition flavor, realizes fruit and vegetable cans normal temperature long-acting fresh-keeping and high-quality retention.

Description

Technical Field

[0001] This invention belongs to the field of fruit and vegetable canning technology, specifically relating to a method for aseptic cold filling and preservation of canned fruits and vegetables. Background Technology

[0002] Canned fruits and vegetables are packaged foods made from fresh fruits and vegetables through pretreatment, filling, sealing, and sterilization. They retain the nutrients and flavor of the fruits and vegetables for a long time, are convenient to eat, and are not limited by season, making them widely used in daily diets and food processing. Currently, the mainstream filling and preservation method is hot-fill sterilization: after the raw materials are washed, cut, and pre-cooked for color protection, they are placed in clean containers, filled with prepared sugar or salt solution, and sealed while hot. High-temperature and high-pressure sterilization destroys microorganisms and enzyme activity, while the sealed container isolates external contamination, achieving long-term preservation at room temperature. In addition, there is aseptic cold-filling technology, which sterilizes the raw materials and packaging separately in a sterile environment before low-temperature filling and sealing, better preserving flavor and nutrients.

[0003] While the aforementioned traditional methods of canning and preserving fruits and vegetables can achieve sterilization and preservation, they still have the following drawbacks: 1. Insufficient disinfection and color protection efficiency: Normal pressure soaking is often used for disinfection, but the liquid cannot penetrate into the internal crevices of fruits and vegetables, resulting in incomplete sterilization. The initial bacterial count of raw materials is relatively high, which increases the pressure of subsequent sterilization. The static water soaking process can easily cause the fruit flesh to soften and lose flavor. In addition, the color protection treatment method is simple, and it is difficult to control the oxidation and browning of the cut surfaces of fruits and vegetables.

[0004] 2. Potential hazards in the packaging and filling environment: The disinfection process of packaging cans is relatively simple, with blind spots in sterilization, and the drying is not thorough, which can easily leave microorganisms and condensate, causing secondary pollution after filling. The filling process does not fully replace the oxygen in the can, resulting in a high residual oxygen concentration, which makes fruits and vegetables prone to oxidation and spoilage during storage.

[0005] 3. Sterilization methods have a significant impact on quality: Many processes rely on high-temperature heat sterilization, which, while effective, damages the cell structure of fruits and vegetables, leading to a soft, mushy texture, nutrient loss, and discoloration. Some processes use non-gradient ultra-high pressure treatment, which can easily damage the fruit pulp tissue due to sudden pressure changes, or cause packaging deformation and seal failure due to excessively rapid pressure release. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a method for aseptic cold filling and preservation of canned fruits and vegetables.

[0007] The technical solution adopted to solve the above-mentioned technical problems is: a method for aseptic cold filling and preservation of canned fruits and vegetables, comprising the following steps: S1: Pre-clean, trim, cut, and pre-disinfect fruits and vegetables with hypochlorous acid; S2: Soak fruits and vegetables in VC color-protecting solution; S3: Use a vacuum flash evaporator to perform vacuum flash evaporation on fruits and vegetables and store them in a low-temperature sterile silo; S4: Disinfect the packaging cans; S5: Pre-fill the packaging can with gas to replace oxygen; S6: Fill the fruit and vegetable containers with sterile sugar and then seal the containers; S7: Perform HPP gradient pressure sterilization on the sealed canned goods; S8: Store canned goods after inspection.

[0008] Furthermore, in step S1, after the fruits and vegetables are washed, trimmed, and cut, they are placed in a sealed soaking tank; 50~120ppm of food-grade hypochlorous acid aqueous solution is injected into the sealed soaking tank to completely submerge the fruits and vegetables; relying on a food-grade vacuum pumping unit, the upper space of the tank is pumped to a slight negative pressure of -0.02~-0.05MPa, and relying on a pulse control system and a microbubble aeration disc, the hypochlorous acid aqueous solution is pulsed and aerated with microbubbles.

[0009] Through the above technical solution, under a slightly negative pressure environment, the air inside the fruits and vegetables expands and is replaced by the hypochlorous acid aqueous solution. The air in the interstitial spaces and cross-sections is quickly discharged due to the pressure difference, allowing the hypochlorous acid aqueous solution to fully contact the surface and tiny crevices of the fruits and vegetables. This significantly improves the uniformity and thoroughness of sterilization, effectively killing pathogenic bacteria, molds, and other microorganisms attached to the skin, and greatly reducing the initial total number of colonies in the raw materials. Pulsed microbubble aeration can avoid the softening of the fruit flesh caused by soaking in static water, and can also enhance the turbulent flow of the disinfectant solution, improving the disinfection efficiency. At the same time, it reduces the amount of hypochlorous acid used and the contact time, reducing the risk of residue. This pretreatment method is gentle and non-damaging, and can maintain the original texture and flavor of the fruits and vegetables to the greatest extent. It provides a clean and stable raw material foundation for subsequent color protection, vacuum flash removal, and aseptic cold filling processes, effectively reducing the sterilization load of the downstream HPP process and ensuring the commercial sterility and long-term freshness of the canned products.

[0010] Furthermore, in step S2, the fruits and vegetables are removed and transferred to a 0.1-0.3% (w / v) ascorbic acid solution, and soaked at a low temperature of 10-15°C for 1-3 minutes for color protection treatment.

[0011] The above technical solution involves short-term soaking of fruits and vegetables in an ascorbic acid solution of appropriate concentration at low temperatures. The strong reducing properties of ascorbic acid rapidly inhibit polyphenol oxidase activity, preventing enzymatic browning of the cut surfaces of fruits and vegetables from contacting oxygen, thus maintaining the original color and bright appearance of the flesh. The low-temperature environment further slows down the respiration and oxidation rate of fruits and vegetables, preventing softening of the flesh and loss of juice during the color protection process. At the same time, it does not damage the cell structure and nutrients of fruits and vegetables. Short-term soaking can achieve a stable color protection effect without causing ascorbic acid residue or flavor changes. It provides a semi-finished product with uniform color and stable quality for subsequent vacuum flash-out and aseptic filling, improving the sensory consistency and shelf-life appearance stability of the finished product.

[0012] Furthermore, in S3, the vacuum degree of vacuum flash removal is controlled at -0.07MPa to -0.09MPa, and the flash removal treatment time is 15 seconds to 30 seconds, to remove free moisture and residual ascorbic acid solution from the surface of fruits and vegetables.

[0013] By employing the aforementioned technical solutions, short-term flash dehydration of fruits and vegetables under high vacuum conditions can quickly remove surface free moisture and residual ascorbic acid solution. This avoids problems such as excess liquid accumulation leading to dilution of the juice after filling and easy growth of microorganisms. By strictly controlling the vacuum level and processing time, surface moisture can be efficiently removed without damaging the fruit pulp tissue, causing the fruits and vegetables to lose water and shrink or lose nutrients, thus maintaining their original crisp and tender taste and intact shape. After flash dehydration, the surface of the fruits and vegetables is dry and clean, and they can be directly transferred to a low-temperature aseptic silo for temporary storage, effectively reducing the risk of subsequent filling contamination. At the same time, it improves the stability of the solid content in canned goods, providing uniform materials for aseptic cold filling and HPP sterilization processes, ensuring the taste and shelf-life stability of the finished product.

[0014] Furthermore, in step S4, the packaging can is first preliminarily washed with water; then the packaging can is disinfected by soaking in peracetic acid solution; then the packaging can is rinsed with sterile water; finally, the packaging can is sterilized by irradiating the inside and outside of the packaging can with UV lamp, while the packaging can is dried with hot air.

[0015] The above technical solution employs a multi-stage synergistic process involving water washing, peracetic acid chemical disinfection, sterile water rinsing, UV sterilization, and hot air drying. This process removes impurities and microorganisms from the surface of the packaging cans layer by layer, achieving comprehensive sterilization both inside and outside the cans. Peracetic acid immersion effectively kills bacteria, mold, and spores, while sterile water rinsing thoroughly eliminates disinfectant residues, preventing any impact on product flavor and safety. UV irradiation further enhances sterilization in hard-to-reach areas, and hot air drying removes moisture while maintaining a dry environment inside the can, preventing secondary contamination caused by condensation. The multi-stage disinfection process is tightly integrated, eliminating the risk of cross-contamination and providing a reliable sterile packaging carrier for subsequent pre-filling, filling, and sealing processes, ensuring the overall sterility and storage safety of the canned goods.

[0016] Furthermore, in step S5, a mixture of sterile CO2 and N2 gas is sequentially introduced into the tank for gradient replacement, controlling the volume ratio of CO2 to N2 to be 1:4, so that the residual oxygen concentration in the tank is ≤0.2%, thus creating an anaerobic filling environment.

[0017] The above technical solution uses a gradient gas replacement of the tank air with a mixture of carbon dioxide and nitrogen in a 1:4 ratio. This allows for the rapid and uniform removal of oxygen from the tank, keeping the residual oxygen concentration stably below 0.2% and creating a stable anaerobic environment. CO2 reduces pH fluctuations inside the tank and inhibits the activity of aerobic microorganisms, while N2, as an inert gas, acts as a physical barrier, protecting the color and flavor of the fruit. The synergy of these two technologies prevents oxidative browning and nutrient loss in fruits and vegetables during filling and subsequent storage, while also reducing the risk of canned food bloating and spoilage. Combined with subsequent aseptic filling and HPP sterilization, this further enhances product stability and extends the shelf life at room temperature.

[0018] Furthermore, in step S6, the fruits and vegetables in the low-temperature aseptic silo are filled into the packaging can using the micro-positive pressure filling and sealing machine; aseptic soup is filled into the packaging can using the micro-positive pressure filling and sealing machine; and the packaging can is sealed with micro-positive pressure gas compensation using the micro-positive pressure filling and sealing machine.

[0019] The above technical solution utilizes a micro-positive pressure filling and sealing machine to complete the integrated operation of fruit and vegetable filling, aseptic broth filling, and micro-positive pressure compensation sealing. This allows for precise filling of materials under completely sealed and clean conditions, preventing secondary contamination caused by external air and bacteria. The micro-positive pressure environment maintains a stable preset gas atmosphere inside the can, preventing residual oxygen from rising and further ensuring the anaerobic preservation effect. At the same time, it avoids problems such as broth overflow and pressure imbalance inside the can, ensuring the tightness of the seal and the consistency of filling. This process is smooth and highly controllable, effectively improving the reliability of can sealing and the product qualification rate, laying a stable foundation for subsequent HPP ultra-high pressure sterilization and long-term room temperature storage.

[0020] Furthermore, in step S7, relying on the ultra-high pressure sterilization equipment, the sealed canned goods are subjected to a three-stage gradient pressurization, with the pressure successively increasing to 150MPa, 350MPa, and 500~600MPa; the pressure is maintained at 500~600MPa for 4~6 minutes to achieve ultra-high pressure sterilization; then the pressure is gradually depressurized, with the pressure successively decreasing to 350MPa, 150MPa, and atmospheric pressure, and the canned goods are removed after the depressurization is completed.

[0021] The above technical solution employs a three-stage gradient pressurization and gradient depressurization ultra-high pressure treatment method. This avoids the impact damage to fruit and vegetable tissues caused by sudden pressure changes, preserving the integrity and crisp texture of the fruit. Gradual pressurization ensures even pressure distribution inside the can, effectively killing heat-resistant spores and inactivating enzymes under 500-600 MPa pressure, achieving commercial sterility. Furthermore, the entire process is carried out at room temperature without damaging nutrients or flavor. Gradual depressurization prevents excessive pressure differences between the inside and outside of the can, which could lead to packaging deformation, leaks, or liquid spillage, ensuring the can's seal integrity. This gentle yet efficient cold sterilization method ensures thorough sterilization while maximizing the preservation of the freshness of fruits and vegetables, achieving long-term room-temperature preservation. Moreover, the ultra-high pressure sterilization, combined with the initial hypochlorous acid aeration disinfection and VC color-protecting solution immersion, forms a highly efficient synergy, comprehensively improving the sterilization effect and quality of the canned goods. In terms of quality stability and shelf life, the initial hypochlorous acid pulse microbubble aeration can effectively reduce the initial bacterial count of fruits and vegetables, reducing the ultra-high pressure sterilization load. This eliminates the need for excessive pressure increases and extended treatment times, saving energy and preventing damage to the fruit pulp. The reducing properties of the VC color-protecting solution can pre-inactivate some oxidases, which, combined with the enzyme inactivation effect of ultra-high pressure, doublely inhibits browning of fruits and vegetables, maintaining their bright color even after long-term storage. At the same time, ultra-high pressure can further kill heat-resistant spores that have not been completely eliminated by hypochlorous acid, compensating for the limitations of surface disinfection. The VC color-protecting solution can also mitigate the slight oxidation risk that ultra-high pressure treatment may bring. The three work together to achieve a closed loop of "surface sterilization, color protection, and deep sterilization," ensuring commercial sterility while maximizing the preservation of the nutrients and crisp texture of fruits and vegetables, significantly improving the quality and shelf-life stability of canned products.

[0022] Furthermore, in step S8, the canned food is placed in a constant temperature environment of 10℃~15℃ and left to stand for 10~15 minutes. After passing leak detection and light inspection, it is stored at room temperature.

[0023] Through the above technical solutions, the internal state of canned goods can be effectively stabilized after being kept at a low temperature and constant temperature. Combined with leak detection and light inspection, sealing and quality defects can be identified in a timely manner, unqualified products can be removed, the quality of finished products can be guaranteed to meet the standards, safe storage at room temperature can be achieved, and product stability and shelf life can be improved.

[0024] Furthermore, in S1, the temperature of the food-grade hypochlorous acid aqueous solution is controlled at 10-20°C, the pH value is 5.0-6.5, and the entire process is carried out at low temperature to avoid softening and browning of fruits and vegetables. In S7, the ultra-high pressure sterilization is carried out in a closed system with room temperature water as the pressure transmission medium.

[0025] By strictly controlling the parameters of the hypochlorous acid aqueous solution and treating it at low temperatures throughout the process, the softening and browning of fruits and vegetables can be effectively prevented, thus maintaining their quality. Ultra-high pressure sterilization uses a closed system with room temperature water pressure transmission, resulting in gentle and uniform sterilization that better preserves the taste and nutrition of the product, thereby improving the quality and safety of the finished product.

[0026] The beneficial effects of this invention are as follows: 1. This invention utilizes a combination of micro-negative pressure pulse microbubble disinfection, low-temperature VC color protection, and high-vacuum flash removal to quickly expel air from the inside of fruits and vegetables, thoroughly sterilize and protect the color, maintain the crisp and tender shape of the fruit flesh, reduce the initial bacterial count, and provide clean and stable raw materials for subsequent processes. 2. This invention constructs a fully anaerobic and aseptic processing system through multi-stage can sterilization, gradient modified atmosphere replacement, micro-positive pressure aseptic filling, and three-stage gradient HPP cold sterilization. The sterilization is gentle and thorough, without damaging the nutrition and flavor, and achieves long-term preservation and high-quality retention of canned fruits and vegetables at room temperature. Attached Figure Description

[0027] Figure 1 This is a flowchart of the present invention; Figure 2 This is a schematic diagram of S1 of the present invention; Figure 3 This is a schematic diagram of S4 of the present invention; Figure 4 This is a schematic diagram of S6 of the present invention; Figure 5 This is a schematic diagram of S7 of the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0029] like Figures 1-5As shown, a method for aseptic cold-filling and preservation of canned fruits and vegetables includes S1: pre-cleaning, trimming, cutting, and hypochlorous acid pre-disinfection of the fruits and vegetables. In S1, after cleaning, trimming, and cutting, the fruits and vegetables are placed in a sealed soaking tank; a food-grade hypochlorous acid aqueous solution of 50~120ppm is injected into the sealed soaking tank to completely submerge the fruits and vegetables; using a food-grade vacuum pump, the upper space of the tank is evacuated to a slight negative pressure of -0.02~-0.05MPa; using a pulse control system and a microbubble aeration disc, the hypochlorous acid aqueous solution is pulsed and microbubble aerated. Under the slight negative pressure environment, the air inside the fruits and vegetables expands and is replaced by the hypochlorous acid aqueous solution, and the air in the interstitial spaces and cross-sections is rapidly eliminated due to the pressure difference. Rapid discharge ensures that the hypochlorous acid solution fully contacts the surface and tiny crevices of fruits and vegetables, significantly improving the uniformity and thoroughness of sterilization. It effectively kills pathogenic bacteria, molds, and other microorganisms attached to the skin, greatly reducing the initial total bacterial count of the raw materials. Pulsed microbubble aeration avoids the softening of fruit flesh caused by stagnant water soaking, while also enhancing the turbulent flow of the disinfectant solution, improving disinfection efficiency. At the same time, it reduces the amount of hypochlorous acid used and the contact time, reducing the risk of residue. This pretreatment method is gentle and non-damaging, and can maintain the original texture and flavor of fruits and vegetables to the greatest extent. It provides a clean and stable raw material foundation for subsequent color protection, vacuum flash removal, and aseptic cold filling processes, effectively reducing the sterilization load of the downstream HPP process and ensuring the commercial sterility and long-term freshness of the canned products.

[0030] like Figure 1 As shown, S2: The fruits and vegetables are immersed in the VC color-protecting solution. In S2, the fruits and vegetables are removed and transferred to a 0.1~0.3% (w / v) ascorbic acid solution. They are then immersed at a low temperature of 10~15℃ for 1~3 minutes for color protection treatment. Using an appropriate concentration of ascorbic acid solution for short-term immersion of fruits and vegetables at low temperature utilizes the strong reducing properties of ascorbic acid to rapidly inhibit the activity of polyphenol oxidase, blocking the contact between the cut surface of fruits and vegetables and oxygen to prevent enzymatic browning, thus maintaining the original color and bright appearance of the flesh. The low temperature environment can further slow down the respiration and oxidation rate of fruits and vegetables, avoiding softening of the flesh and loss of juice during the color protection process. At the same time, it does not damage the cell structure and nutrients of fruits and vegetables. Short-term immersion can achieve a stable color protection effect without causing ascorbic acid residue or flavor changes, providing a semi-finished product with uniform color and stable quality for subsequent vacuum flash-out and aseptic filling, improving the sensory consistency and shelf-life appearance stability of the finished product.

[0031] like Figure 1As shown, S3: Fruits and vegetables are vacuum flash-dehydrated using a vacuum flash evaporator and then stored in a low-temperature sterile silo. In S3, the vacuum degree of the flash evaporation is controlled at -0.07MPa to -0.09MPa, and the flash evaporation time is 15 to 30 seconds. This removes free moisture and residual ascorbic acid solution from the surface of the fruits and vegetables. Short-time flash dehydration under high vacuum conditions quickly removes free surface moisture and residual ascorbic acid solution, preventing excess liquid accumulation that could lead to dilution of the juice after bottling and increased susceptibility to microbial growth. To address issues such as bacterial growth, strict control of vacuum levels and processing time ensures efficient removal of surface moisture without damaging the fruit's flesh, causing dehydration, shrinkage, or nutrient loss. This maintains the fruit's original crisp texture and intact shape. After flash-freezing, the fruit and vegetables are dry and clean, allowing them to be directly transferred to a low-temperature aseptic silo for temporary storage. This effectively reduces the risk of contamination during subsequent filling and improves the stability of the solids content in canned goods. It also provides uniform materials for aseptic cold filling and HPP sterilization processes, ensuring the taste and shelf-life stability of the finished product.

[0032] like Figure 1 and Figure 3 As shown, S4: Disinfecting the packaging cans. In S4, the packaging cans are first initially washed with water; then, they are immersed in peracetic acid solution for disinfection; then, they are rinsed with sterile water; finally, the packaging cans are sterilized by irradiating them inside and out with UV lamps, while simultaneously drying them with hot air. This multi-stage synergistic treatment, consisting of water washing, peracetic acid chemical disinfection, sterile water rinsing, UV sterilization, and hot air drying, can remove impurities and microorganisms from the surface of the packaging cans layer by layer, achieving complete sterilization inside and outside the cans. Peracetic acid immersion can effectively kill bacteria, mold, and spores, while sterile water rinsing thoroughly eliminates disinfectant residues, avoiding any impact on product flavor and safety. UV lamp irradiation further enhances sterilization in dead corners, and hot air drying removes moisture while maintaining a dry environment inside the can, preventing secondary contamination caused by condensation. The multi-stage disinfection process is closely linked, eliminating the risk of cross-contamination and providing a reliable sterile packaging carrier for subsequent pre-filling, filling, and sealing processes, ensuring the overall sterility and storage safety of the canned goods.

[0033] like Figure 1As shown, S5: Pre-filling the packaging can with oxygen. In S5, a mixture of sterile CO2 and N2 gas is sequentially introduced into the can for gradient replacement, controlling the volume ratio of CO2 to N2 to be 1:4, so that the residual oxygen concentration in the can is ≤0.2%, creating an anaerobic filling environment. The gradient replacement of the air in the can with a mixture of carbon dioxide and nitrogen in a 1:4 ratio can quickly and evenly remove the oxygen in the can, and stably control the residual oxygen concentration below 0.2%, forming a stable anaerobic protective environment. CO2 can reduce pH fluctuations inside the can and inhibit the activity of aerobic microorganisms, while N2, as an inert gas, plays a role in physical oxygen isolation and protecting the color and flavor of the fruit pulp. The two work together to avoid oxidative browning and nutrient loss of fruits and vegetables during filling and subsequent storage, and can reduce the risk of can bloating and spoilage. Combined with subsequent aseptic filling and HPP sterilization, the product stability is further improved and the shelf life at room temperature is extended.

[0034] like Figure 1 and Figure 4 As shown, S6: Fruits and vegetables are filled into the packaging can, sterile sugar is added, and then the can is sealed. In S6, the fruits and vegetables in the low-temperature sterile silo are filled into the packaging can using a micro-positive pressure filling and sealing machine; sterile broth is filled into the packaging can using the micro-positive pressure filling and sealing machine; and the packaging can is sealed with micro-positive pressure gas compensation using the micro-positive pressure filling and sealing machine. The micro-positive pressure filling and sealing machine completes the integrated operation of fruit and vegetable filling, sterile broth filling, and micro-positive pressure compensation sealing. It can achieve accurate filling of materials under a completely closed and clean environment, avoiding secondary pollution caused by the intrusion of external air and bacteria. The micro-positive pressure environment can maintain a stable preset gas atmosphere inside the can, prevent residual oxygen from rising, and further ensure the anaerobic preservation effect. At the same time, it can avoid problems such as broth overflow and pressure imbalance inside the can, ensuring the tightness of the seal and the consistency of filling. This process is smooth and highly controllable, effectively improving the sealing reliability and product qualification rate of canned goods, and laying a stable foundation for subsequent HPP ultra-high pressure sterilization and long-term room temperature storage.

[0035] like Figure 1 and Figure 5As shown, S7: The sealed canned goods undergo HPP gradient pressurization sterilization. In S7, relying on ultra-high pressure sterilization equipment, the sealed canned goods undergo three-stage gradient pressurization, with the pressure successively increasing to 150MPa, 350MPa, and 500-600MPa; maintaining a pressure of 500-600MPa for 4-6 minutes to achieve ultra-high pressure sterilization; then, gradient depressurization is performed, with the pressure successively decreasing to 350MPa, 150MPa, and atmospheric pressure. After depressurization, the canned goods are removed. The ultra-high pressure treatment method with pressure relief avoids the impact damage to the fruit and vegetable flesh caused by sudden pressure changes, maintaining the integrity and crisp texture of the fruit. Gradual pressure increase allows the pressure to be evenly transmitted to the inside of the can. Under high pressure of 500-600MPa, heat-resistant spores are effectively killed and enzymes are inactivated, achieving commercial sterility. Moreover, the entire process is carried out at room temperature, which does not destroy nutrients and flavor. Gradual pressure relief can prevent excessive pressure difference between the inside and outside of the can from causing packaging deformation, leakage, or liquid leakage, ensuring the integrity of the can's seal. This gentle and efficient cold sterilization method ensures both sterilization and... Thorough sterilization while preserving the freshness of fruits and vegetables to the greatest extent, achieving long-term preservation of canned goods at room temperature. Furthermore, the ultra-high pressure sterilization, combined with the initial hypochlorous acid aeration disinfection and VC color-protecting solution immersion, forms a highly efficient synergy, comprehensively improving the sterilization effect, quality stability, and shelf life of the canned goods. The initial hypochlorous acid pulse microbubble aeration effectively reduces the initial bacterial count of fruits and vegetables, lessening the load on the ultra-high pressure sterilization process. This eliminates the need for excessive pressure increases and extended sterilization times, saving energy and preventing damage to the fruit flesh. The reducing properties of the VC color-protecting solution can pre-passivate some oxidation. The combined effects of enzymes and ultra-high pressure inactivation of enzymes doubly inhibit browning of fruits and vegetables, allowing them to maintain their bright color even after long-term storage. At the same time, ultra-high pressure can further kill heat-resistant spores that have not been completely removed by hypochlorous acid, compensating for the limitations of surface disinfection. Meanwhile, the VC color-protecting solution can alleviate the slight oxidation risk that ultra-high pressure treatment may bring. The three work together to achieve a closed loop of "surface sterilization, color protection, and deep sterilization", which not only ensures commercial sterility, but also preserves the nutrition and crisp texture of fruits and vegetables to the greatest extent, significantly improving the quality and shelf-life stability of canned products.

[0036] like Figure 1 and Figure 5As shown, S8: After the canned goods are inspected, they are stored. In S8, the canned goods are placed in a constant temperature environment of 10℃~15℃ and left to stand for 10~15 minutes. After passing the leak detection and light inspection, they are stored at room temperature. After standing at a low temperature, the state inside the can is effectively stabilized. Combined with leak detection and light inspection, sealing and quality defects can be identified in time, unqualified products can be removed, the quality of the finished product can be guaranteed, safe storage at room temperature can be achieved, and the product stability and shelf life can be improved. In S1, the temperature of the food-grade hypochlorous acid aqueous solution is controlled at 10~20℃, the pH value is 5.0~6.5, and the whole process is low temperature treatment to avoid softening and browning of fruits and vegetables. In S7, the ultra-high pressure sterilization is carried out in a closed system with room temperature water as the pressure transmission medium. The parameters of the hypochlorous acid aqueous solution are strictly controlled and the whole process is low temperature treatment, which can effectively prevent softening and browning of fruits and vegetables and maintain quality. The ultra-high pressure sterilization uses closed room temperature water pressure transmission, and the sterilization is gentle and uniform, better preserving the taste and nutrition of the product and improving the quality and safety of the finished product.

[0037] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention.

Claims

1. A method for aseptic cold filling and preservation processing of canned fruits and vegetables, characterized in that: Includes the following steps: S1: Pre-clean, trim, cut, and pre-disinfect fruits and vegetables with hypochlorous acid; S2: Soak fruits and vegetables in VC color-protecting solution; S3: Use a vacuum flash evaporator to perform vacuum flash evaporation on fruits and vegetables and store them in a low-temperature sterile silo; S4: Disinfect the packaging cans; S5: Pre-fill the packaging can with gas to replace oxygen; S6: Fill the fruit and vegetable containers with sterile sugar and then seal the containers; S7: Perform HPP gradient pressure sterilization on the sealed canned goods; S8: Store canned goods after inspection.

2. The aseptic cold-filling and preservation processing method for canned fruits and vegetables according to claim 1, characterized in that, In step S1, after the fruits and vegetables are washed, trimmed, and cut, they are placed in a sealed soaking tank. A food-grade hypochlorous acid aqueous solution of 50-120 ppm is injected into the sealed soaking tank to completely submerge the fruits and vegetables. Using a food-grade vacuum pump, the upper space of the tank is evacuated to a slight negative pressure of -0.02 to -0.05 MPa. The hypochlorous acid aqueous solution is then pulsed and aerated using a pulse control system and a microbubble aeration disc.

3. The aseptic cold-filling and preservation processing method for canned fruits and vegetables according to claim 1, characterized in that, In step S2, the fruits and vegetables are removed and transferred to a 0.1-0.3% (w / v) ascorbic acid solution, and soaked at a low temperature of 10-15°C for 1-3 minutes for color protection treatment.

4. The aseptic cold-filling and preservation processing method for canned fruits and vegetables according to claim 1, characterized in that, In step S3, the vacuum degree of the vacuum flash removal is controlled at -0.07MPa to -0.09MPa, and the flash removal treatment time is 15 seconds to 30 seconds, removing free moisture and residual ascorbic acid solution from the surface of fruits and vegetables.

5. The aseptic cold-filling and preservation processing method for canned fruits and vegetables according to claim 1, characterized in that, In step S4, the packaging can is first preliminarily washed with water; then it is disinfected by soaking in peracetic acid solution, then rinsed with sterile water; finally, the packaging can is sterilized by irradiating the inside and outside of the packaging can with UV lamp, while the packaging can is dried with hot air.

6. The aseptic cold-filling and preservation processing method for canned fruits and vegetables according to claim 1, characterized in that, In step S5, a mixture of sterile CO2 and N2 gas is sequentially introduced into the tank for gradient replacement, and the volume ratio of CO2 to N2 is controlled at 1:4 to ensure that the residual oxygen concentration in the tank is ≤0.2%, thereby creating an anaerobic filling environment.

7. The aseptic cold-filling and preservation processing method for canned fruits and vegetables according to claim 1, characterized in that, In step S6, the fruits and vegetables in the low-temperature aseptic silo are filled into the packaging can using the micro-positive pressure filling and sealing machine; aseptic soup is filled into the packaging can using the micro-positive pressure filling and sealing machine; and the packaging can is sealed with micro-positive pressure gas compensation using the micro-positive pressure filling and sealing machine.

8. The aseptic cold-filling and preservation processing method for canned fruits and vegetables according to claim 1, characterized in that, In step S7, the sealed canned goods are subjected to a three-stage pressure increase using ultra-high pressure sterilization equipment, with the pressure successively increasing to 150MPa, 350MPa, and 500-600MPa; the pressure is maintained at 500-600MPa for 4-6 minutes to achieve ultra-high pressure sterilization; then the pressure is gradually released, decreasing to 350MPa, 150MPa, and atmospheric pressure, and the canned goods are removed after the pressure release is completed.

9. The aseptic cold-filling and preservation processing method for canned fruits and vegetables according to claim 1, characterized in that, In step S8, the canned food is placed in a constant temperature environment of 10℃~15℃ and left to stand for 10~15 minutes. After passing the leak test and light inspection, it is stored at room temperature.

10. The aseptic cold-filling and preservation processing method for canned fruits and vegetables according to claim 1, characterized in that, In step S1, the temperature of the food-grade hypochlorous acid aqueous solution is controlled at 10-20°C, the pH value is 5.0-6.5, and the entire process is carried out at low temperature to avoid softening and browning of fruits and vegetables. In step S7, the ultra-high pressure sterilization is carried out in a closed system with room temperature water as the pressure transmission medium.

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