Normal-temperature long-time preservation method

Abstract

The invention relates to the field of fresh-cut vegetable processing and fresh-keeping, and discloses a normal-temperature long-time fresh-keeping method, which comprises the following steps: an irradiation disinfection module is used for disinfecting cut vegetables, controlling irradiation disinfection equipment and an ejector, spraying a natural fresh-keeping agent, performing auxiliary sterilization by using ultraviolet rays, and controlling the irradiation disinfection equipment and the ejector to spray the natural fresh-keeping agent; therefore, the purpose of efficient combined preservation is achieved. And the on-line monitoring unit is used for detecting the disinfected vegetables in real time through a sensor, ensuring that the disinfection of the vegetables meets the production standard, and transmitting a detected result to the automatic feedback module. A natural preservative combination is screened to completely replace a traditional chemical preservative, zero chemical addition is achieved, the food safety risk and taste influence caused by chemical agent residues are avoided, and meanwhile natural components have the characteristics of no toxicity and environment friendliness and better meet the healthy consumption requirement.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fresh-cut vegetable processing and preservation technology, in particular to a normal-temperature long-time preservation method. BACKGROUND

[0002] Fresh-cut vegetables, as an important category of convenience foods, have seen a surge in demand in the catering, retail and other fields due to their direct edibility after peeling, cutting and other pretreatments. Their preservation technology is the core of ensuring product quality (such as taste, nutrition) and extending shelf life, which is directly related to food safety, supply chain efficiency and industrial economic benefits.

[0003] To solve the problems of microbial contamination, browning and nutrient loss of fresh-cut vegetables caused by mechanical damage, existing technologies have formed a series of preservation methods: by adding edible acid (such as citric acid) and synthetic chemical agents (such as sodium hypochlorite, ClO2) to inhibit microbial reproduction, combined with acidification, pasteurization and other processes to extend the shelf life, for example, some technologies adjust the pH to below 4.6 to enhance the sterilization effect; after pasteurization, it needs to be quickly cooled to below 13°C and continuously refrigerated to delay spoilage, extending the shelf life to 7-14 days; using a standardized production line of "cleaning-peeling-disinfection-cutting", sodium hypochlorite is commonly used in the disinfection process, and the treatment is completed by presetting parameters such as concentration and time.

[0004] The existing fresh-cut vegetable preservation technology has the following defects:

[0005] Fresh-cut vegetables are prone to microbial contamination, browning and nutrient loss due to mechanical damage caused by peeling, cutting and other processing, and have a short shelf life and rely on chemical preservatives and cold chain systems. Chemical preservatives rely on: Most preservation methods (such as acidification, pasteurization) require the addition of edible acid (such as citric acid) or synthetic chemical agents (such as sodium hypochlorite, ClO2) to inhibit microorganisms, but residual chemicals may affect food safety and taste. For example, the existing patent (US6,596,331B1) uses acidification and pasteurization to process pasta, the pH needs to be adjusted to below 4.6, and relies on heat treatment and refrigeration; similarly, sodium hypochlorite is commonly used for disinfection in fresh-cut vegetable processing, but chemical residue may cause secondary pollution.

[0006] Cold storage necessity: existing preservation technologies (as described) require rapid cooling to about 2-8°C below after pasteurization and continuous refrigeration to extend the shelf life to 7-14 days. However, this increases energy consumption and cost, and cold chain disruption can easily cause product deterioration.

[0007] Short shelf life: The shelf life of traditional fresh-cut vegetables is only 3-5 days, even if the process is optimized (such as using the biological preservative Nisin) it is difficult to exceed 7 days at room temperature, and still relies partly on chemical additives.

[0008] Limitations of the device: The existing production line (such as cleaning-peeling-disinfection-cutting) lacks intelligent control, sodium hypochlorite is used in the disinfection process, and the preservation parameters (such as concentration and pH) cannot be adjusted, resulting in low efficiency and abuse of chemicals.

[0009] In response to the above problems, the present invention proposes an innovative solution: by screening natural preservatives, developing efficient combination devices and irradiation disinfection technology, "0 chemical preservatives" and long-term preservation at room temperature are achieved, overcoming the bottleneck of existing technologies. Summary of the Invention

[0010] In view of the shortcomings of the existing technology, the present invention provides a long-term preservation method at room temperature, which solves the problems of existing fresh-cut vegetable preservation technology such as reliance on chemical preservatives, need for cold chain, short shelf life and lack of intelligent control of the device.

[0011] To achieve the above objectives, the present invention is implemented through the following technical solutions: A control system for a room temperature long-term preservative, comprising:

[0012] Irradiation disinfection module: The irradiation disinfection module is responsible for disinfecting the cut vegetables. The irradiation disinfection module controls the irradiation disinfection equipment and the injector, spraying natural preservatives while using ultraviolet rays for auxiliary sterilization, thereby achieving the purpose of efficient combined preservation;

[0013] Online monitoring unit: The online monitoring unit uses sensors to perform real-time detection on the vegetables being sterilized to ensure that the vegetable sterilization meets the production standards, and transmits the detection results to the automatic feedback module;

[0014] Automatic feedback module: receives the detection values ​​from the online monitoring unit and adjusts the irradiation dose and preservative flow rate according to the detection values ​​and adjustment plan.

[0015] A method for long-term preservation at room temperature, comprising the following steps:

[0016] S1. Natural preservative screening: Extracts are obtained from natural plants through standardized extraction processes. Combined with taste, antibacterial effect, nutrient retention and other indicators, the optimal natural preservative combination with no chemical additives, safety and high efficiency is screened out to provide the core raw material foundation for subsequent preservation.

[0017] S101, Raw materials and extraction: Based on the existing vegetable combination, extracts are obtained from natural plants using standardized extraction processes;

[0018] The existing vegetable combination includes leafy vegetables and root vegetables;

[0019] The standardized extraction process includes water extraction or alcohol extraction;

[0020] The natural plants include tea polyphenols and konjac glucomannan sources;

[0021] S102. Index testing: Using taste, browning rate, total bacteria count, and nutrient retention as measurement indicators, conduct in vitro antibacterial tests to screen out the optimal natural preservative combination;

[0022] The total number of bacteria includes coliforms and Staphylococcus aureus;

[0023] The nutrition retention includes VC, total acid

[0024] The optimal natural preservative combination includes compound ascorbic acid, tea polyphenols and salicylic acid, wherein the ratio of the compound ascorbic acid, tea polyphenols and salicylic acid is 300mg / L:30mg / L:10mg / L. Its antibacterial effect is better than that of a single chemical agent, and it is non-toxic and environmentally friendly.

[0025] S2. Multi-factor controlled variable preservation process: Design multi-factor orthogonal experiments for different vegetable varieties, with the goal of inhibiting browning, reducing bacteria, and retaining nutrients, to optimize the concentration of natural preservatives and irradiation dose parameters;

[0026] S201. Experimental design: Conduct a multi-factor orthogonal experiment for different vegetable varieties, wherein the variables of the multi-factor orthogonal experiment include: natural preservative concentration, irradiation dose, treatment time, and ambient temperature;

[0027] The different vegetable varieties include lettuce and carrots;

[0028] S202. Optimization goal: Determine the efficient combination parameters with browning inhibition rate ≥ 90%, bacterial reduction rate ≥ 95%, and nutrient retention rate ≥ 85% as indicators;

[0029] The highly effective combination parameters include: irradiation disinfection combined with natural preservative spray, which can replace sodium hypochlorite and significantly reduce microbial contamination;

[0030] S3, efficient combination processing: According to the efficient combination parameters determined in step S2, the cut vegetables are processed in sequence, specifically:

[0031] First, the irradiation disinfection module controls the irradiation disinfection equipment, and then sterilizes the vegetables for 1-10 minutes according to the initial irradiation dose determined by S2. Finally, the injector is started synchronously to evenly spray the natural preservative selected by S1. At the same time, the ultraviolet lamp is turned on to assist in sterilization, forming a "irradiation + natural preservative" synergistic treatment;

[0032] S4. Online monitoring and dynamic adjustment: The online monitoring unit's pH sensor, bacteria concentration sensor, and temperature sensor are used to conduct real-time testing of the vegetables being processed, focusing on monitoring pH, total bacteria count, and ambient temperature, and dynamically optimize and adjust according to the adjustment plan;

[0033] S5. Storage at room temperature: After the above treatment, the vegetables are sealed and packaged and stored at room temperature of 15-25℃.

[0034] Preferably, the irradiation disinfection equipment in the irradiation disinfection module includes: an ultraviolet lamp or an electron beam irradiation source.

[0035] Preferably, the sensors in the online monitoring unit include: a pH sensor, a bacteria concentration sensor, and a temperature sensor.

[0036] Preferably, the real-time detection in the online monitoring unit includes: detecting the pH, bacteria concentration and temperature of the vegetables.

[0037] Preferably, the adjustment scheme in the automatic feedback module includes:

[0038] When the bacterial concentration is greater than 5 CFU / g, the irradiation agent will be automatically increased by 1 kGy while the preservative flow rate remains unchanged;

[0039] When the pH is less than 4.5, the flow rate of acidic natural preservative is reduced and the flow rate of neutral preservative is increased. When the pH is greater than 6.0, the flow rate of ascorbic acid is increased to stabilize the pH.

[0040] When the temperature is greater than 25°C, the linked conveyor belt will slow down, thereby extending the irradiation time by 5-10 seconds, and at the same time increasing the amount of preservative spray by 10% to enhance antioxidant capacity.

[0041] The present invention provides a method for long-term preservation at room temperature, which has the following beneficial effects:

[0042] 1. The present invention completely replaces traditional chemical preservatives by screening a combination of natural preservatives, achieving "0 chemical additions" and avoiding food safety risks and taste impacts caused by chemical residues. At the same time, natural ingredients are non-toxic and environmentally friendly, which is more in line with healthy consumer needs.

[0043] 2. The present invention adopts the synergistic process of "irradiation disinfection + natural preservative spray", combined with a storage design at room temperature of 15-25°C, without relying on refrigeration, overcoming the traditional technology's dependence on the cold chain, reducing the energy consumption and costs related to the cold chain, and avoiding the problem of product deterioration that may be caused by cold chain breaks.

[0044] 3. The present invention uses an online monitoring and automatic feedback system to dynamically adjust parameters such as irradiation dose (such as increasing 1kGy), preservative flow rate (such as increasing the spray volume by 10%), and processing time (such as extending 5-10 seconds) based on real-time detected pH, bacterial concentration (such as when >5CFU / g), and temperature (such as >25°C). This solves the limitations of traditional production lines with fixed parameters and low efficiency, improves the accuracy and stability of fresh-keeping treatment, and can adapt to the needs of different vegetable varieties. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is a system flow chart of the present invention;

[0046] Figure 2 Flow chart of the method of the present invention. DETAILED DESCRIPTION

[0047] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the present specification. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0048] Please see the attached Figure 1 -Attached Figure 2 The embodiment of the present invention provides a control system for a room temperature long-term preservative, comprising:

[0049] Irradiation disinfection module: The irradiation disinfection module is responsible for disinfecting the cut vegetables. The irradiation disinfection module controls the irradiation disinfection equipment and the injector, spraying natural preservatives while using ultraviolet rays for auxiliary sterilization, thereby achieving the purpose of efficient combined preservation;

[0050] The irradiation disinfection equipment includes an ultraviolet lamp or an electron beam irradiation source;

[0051] Online monitoring unit: The online monitoring unit uses sensors to perform real-time detection on the vegetables being sterilized to ensure that the vegetable sterilization meets the production standards, and transmits the detection results to the automatic feedback module;

[0052] The sensors include: pH sensor, bacteria concentration sensor, temperature sensor;

[0053] The real-time detection includes: detecting the pH, bacterial concentration and temperature of vegetables;

[0054] Automatic feedback module: receives the detection value from the online monitoring unit and adjusts the irradiation dose and preservative flow rate according to the detection value and the adjustment plan. The adjustment plan is specifically as follows:

[0055] When the bacterial concentration is greater than 5 CFU / g, the irradiation agent will be automatically increased by 1 kGy while the preservative flow rate remains unchanged;

[0056] When the pH is less than 4.5, the flow rate of acidic natural preservative is reduced and the flow rate of neutral preservative is increased. When the pH is greater than 6.0, the flow rate of ascorbic acid is increased to stabilize the pH.

[0057] When the temperature is greater than 25°C, the conveyor belt will be decelerated, thereby extending the irradiation time by 5-10 seconds and increasing the amount of preservative spray by 10% to enhance the antioxidant capacity;

[0058] A method for long-term preservation at room temperature, comprising the following steps:

[0059] S1. Natural preservative screening: Extracts are obtained from natural plants through standardized extraction processes. Combined with taste, antibacterial effect, nutrient retention and other indicators, the optimal natural preservative combination with no chemical additives, safety and high efficiency is screened out to provide the core raw material foundation for subsequent preservation.

[0060] S101, Raw materials and extraction: Based on the existing vegetable combination, extracts are obtained from natural plants using standardized extraction processes;

[0061] The existing vegetable combination includes leafy vegetables and root vegetables;

[0062] The standardized extraction process includes water extraction or alcohol extraction;

[0063] The natural plants include tea polyphenols and konjac glucomannan sources;

[0064] S102. Index testing: Using taste, browning rate, total bacteria count, and nutrient retention as measurement indicators, conduct in vitro antibacterial tests to screen out the optimal natural preservative combination;

[0065] The total number of bacteria includes coliforms and Staphylococcus aureus;

[0066] The nutrition retention includes VC, total acid

[0067] The optimal natural preservative combination includes compound ascorbic acid, tea polyphenols and salicylic acid, wherein the ratio of the compound ascorbic acid, tea polyphenols and salicylic acid is 300mg / L:30mg / L:10mg / L. Its antibacterial effect is better than that of a single chemical agent, and it is non-toxic and environmentally friendly.

[0068] S2. Multi-factor controlled variable preservation process: Design multi-factor orthogonal experiments for different vegetable varieties, with the goal of inhibiting browning, reducing bacteria, and retaining nutrients, to optimize the concentration of natural preservatives and irradiation dose parameters;

[0069] S201. Experimental design: Conduct a multi-factor orthogonal experiment for different vegetable varieties, wherein the variables of the multi-factor orthogonal experiment include: natural preservative concentration, irradiation dose, treatment time, and ambient temperature;

[0070] The different vegetable varieties include lettuce and carrots;

[0071] S202. Optimization goal: Determine the efficient combination parameters with browning inhibition rate ≥ 90%, bacterial reduction rate ≥ 95%, and nutrient retention rate ≥ 85% as indicators;

[0072] The highly effective combination parameters include: irradiation disinfection (3 kGy) combined with natural preservative spray, which can replace sodium hypochlorite and significantly reduce microbial contamination;

[0073] S3, efficient combination processing: According to the efficient combination parameters determined in step S2, the cut vegetables are processed in sequence, specifically:

[0074] First, the irradiation disinfection module controls the irradiation disinfection equipment, and then sterilizes the vegetables for 1-10 minutes according to the initial irradiation dose determined by S2. Finally, the injector is started synchronously to evenly spray the natural preservative selected by S1. At the same time, the ultraviolet lamp is turned on to assist in sterilization, forming a "irradiation + natural preservative" synergistic treatment;

[0075] S4. Online monitoring and dynamic adjustment: The online monitoring unit's pH sensor, bacteria concentration sensor, and temperature sensor are used to conduct real-time testing of the vegetables being processed, focusing on monitoring pH, total bacterial count (CFU / g), and ambient temperature, and dynamically optimize and adjust according to the adjustment plan;

[0076] S5. Storage at room temperature: After the above treatment, the vegetables are sealed and packaged and stored at room temperature of 15-25℃.

[0077] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A control system for a room temperature long-term preservative, characterized in that: include: Irradiation disinfection module: The irradiation disinfection module is responsible for disinfecting the cut vegetables. The irradiation disinfection module controls the irradiation disinfection equipment and the injector, spraying natural preservatives while using ultraviolet rays for auxiliary sterilization, thereby achieving the purpose of efficient combined preservation; Online monitoring unit: The online monitoring unit uses sensors to perform real-time detection on the vegetables being sterilized to ensure that the vegetable sterilization meets the production standards, and transmits the detection results to the automatic feedback module; Automatic feedback module: receives the detection values ​​from the online monitoring unit and adjusts the irradiation dose and preservative flow rate according to the detection values ​​and adjustment plan.

2. A method for long-term preservation at room temperature according to claim 1, characterized in that: The following steps are involved: S1. Natural preservative screening: Extracts are obtained from natural plants through standardized extraction processes. Combined with taste, antibacterial effect, nutrient retention and other indicators, the optimal natural preservative combination with no chemical additives, safety and high efficiency is screened out to provide the core raw material foundation for subsequent preservation. S101, Raw materials and extraction: Based on the existing vegetable combination, extracts are obtained from natural plants using standardized extraction processes; The existing vegetable combination includes leafy vegetables and root vegetables; The standardized extraction process includes water extraction or alcohol extraction; The natural plants include tea polyphenols and konjac glucomannan sources; S102. Index testing: Using taste, browning rate, total bacteria count, and nutrient retention as measurement indicators, conduct in vitro antibacterial tests to screen out the optimal natural preservative combination; The total number of bacteria includes coliforms and Staphylococcus aureus; The nutrition retention includes VC, total acid The optimal natural preservative combination includes compound ascorbic acid, tea polyphenols and salicylic acid, wherein the ratio of the compound ascorbic acid, tea polyphenols and salicylic acid is 300mg / L:30mg / L:10mg / L. Its antibacterial effect is better than that of a single chemical agent, and it is non-toxic and environmentally friendly. S2. Multi-factor controlled variable preservation process: Design multi-factor orthogonal experiments for different vegetable varieties, with the goal of inhibiting browning, reducing bacteria, and retaining nutrients, to optimize the concentration of natural preservatives and irradiation dose parameters; S201. Experimental design: Conduct a multi-factor orthogonal experiment for different vegetable varieties, wherein the variables of the multi-factor orthogonal experiment include: natural preservative concentration, irradiation dose, treatment time, and ambient temperature; The different vegetable varieties include lettuce and carrots; S202. Optimization goal: Determine the efficient combination parameters with browning inhibition rate ≥ 90%, bacterial reduction rate ≥ 95%, and nutrient retention rate ≥ 85% as indicators; The highly effective combination parameters include: irradiation disinfection combined with natural preservative spray, which can replace sodium hypochlorite and significantly reduce microbial contamination; S3, efficient combination processing: According to the efficient combination parameters determined in step S2, the cut vegetables are processed in sequence, specifically: First, the irradiation disinfection module controls the irradiation disinfection equipment, and then sterilizes the vegetables for 1-10 minutes according to the initial irradiation dose determined by S2. Finally, the injector is synchronously started to evenly spray the natural preservative selected by S1. At the same time, the ultraviolet light is turned on to assist in sterilization, forming a "irradiation + natural preservative" synergistic treatment; S4. Online monitoring and dynamic adjustment: The online monitoring unit's pH sensor, bacteria concentration sensor, and temperature sensor are used to conduct real-time testing of the vegetables being processed, focusing on monitoring pH, total bacteria count, and ambient temperature, and dynamically optimize and adjust according to the adjustment plan; S5. Storage at room temperature: After the above treatment, the vegetables are sealed and packaged and stored at room temperature of 15-25℃.

3. A method for long-term preservation at room temperature according to claim 2, characterized in that: The irradiation disinfection equipment in the irradiation disinfection module includes: an ultraviolet lamp or an electron beam irradiation source.

4. A method for long-term preservation at room temperature according to claim 2, characterized in that: The sensors in the online monitoring unit include: a pH sensor, a bacteria concentration sensor, and a temperature sensor.

5. A method for long-term preservation at room temperature according to claim 2, characterized in that: The real-time detection in the online monitoring unit includes: detecting the pH, bacteria concentration and temperature of the vegetables.

6. A method for long-term preservation at room temperature according to claim 2, characterized in that: The adjustment scheme in the automatic feedback module includes: When the bacterial concentration is greater than 5 CFU / g, the irradiation agent will be automatically increased by 1 kGy while the preservative flow rate remains unchanged; When the pH is less than 4.5, the flow rate of acidic natural preservative is reduced and the flow rate of neutral preservative is increased. When the pH is greater than 6.0, the flow rate of ascorbic acid is increased to stabilize the pH. When the temperature is greater than 25°C, the linked conveyor belt will slow down, thereby extending the irradiation time by 5-10 seconds, and at the same time increasing the amount of preservative spray by 10% to enhance antioxidant capacity.

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