Green-protecting, brittleness-keeping and fresh-keeping method for green pepper meat dishes

Abstract

The invention relates to the technical field of food processing, in particular to a green-protecting, brittleness-keeping and fresh-keeping method for a green pepper meat dish. The invention provides a green-protecting, brittleness-keeping and fresh-keeping method for a green pepper meat dish. The method comprises the steps of molecular green-protecting blanching, cell repairing and permeating, grease anti-oxidation pretreatment, low-temperature mixing and quick-freezing and dynamic regulation and control. On the basis of green pepper food material blanching and green-protecting and brittleness-keeping agent treatment, a molecular green-protecting-cell brittleness-keeping-system interaction protection system is constructed, cross-scale synergy is achieved through dynamic regulation and control, and the green-protecting and brittleness-keeping effects of the green peppers are effectively enhanced. The fresh-keeping effect of the green peppers and the overall quality of dishes can be improved, and the requirements of consumers for delicious taste and nutrition can be better met.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, and in particular to a method for synergistically preserving the green color and crispness of green peppers and meat dishes. Background Technology

[0002] With the explosive growth of the industrialized food industry, dishes featuring green peppers and meat, such as stir-fried green peppers with pork and minced pork with green peppers and eggplant, have become mainstream products in the market due to their balanced combination of meat and vegetables and unique flavors. However, in the entire processing-freezing-reheating chain, problems such as color deterioration and textural collapse of green peppers in green pepper dishes have long constrained the industry's development. Existing technologies for protecting green color and crispness only target single ingredients, ignoring the chemical and ecological impact of components such as meat and oil in compound dishes, resulting in the failure of chlorophyll protection. For example, traditional blanching for color protection (alkaline environment + metal ions) encounters oil oxidation stress and acidic migration of meat juices during reheating, leading to chlorophyll demagnesiation and degradation (ΔE > 8.5 after reheating, visible browning). Traditional calcium salts / antioxidants cannot dynamically respond to the drastic changes in the dynamic environment from low-temperature freezing to high-temperature reheating, resulting in insufficient pectin crispness retention. For example, calcium salt treatment can only maintain crispness in the short term, and the freeze-drying dehydration effect promotes the expansion of cell wall microcracks, resulting in insufficient pectin-Ca during reheating. 2+ Network collapse (pectin loss rate >30%) and migration of free water from meat cause cell segregation in bell peppers, resulting in a decrease in crispness of over 40%. Therefore, there is an urgent need to develop a green pepper preservation and crispness maintenance technology based on positive regulation of food interactions and a dynamic response mechanism, to achieve end-to-end protection of bell pepper quality within a clean production framework. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a method for synergistically preserving the green color and crispness of bell pepper and meat dishes. This invention provides a three-tiered protection system for bell pepper-containing meat dishes (such as stir-fried bell pepper and meat, shredded bell pepper and meat), encompassing processing, freezing, storage, and reheating. This system combines molecular chelation for green color preservation, cellular network preservation for crispness, and ingredient interaction regulation with dynamic optimization technology to achieve a synergistic enhancement of both the color and texture of bell peppers.

[0004] In a first aspect, the method for synergistically preserving the green color and crispness of green peppers and meat dishes provided by the present invention includes: a) Molecular green blanching: Green peppers are treated with a blanching agent containing zinc ions under heating conditions.

[0005] b) Cell repair and penetration: The green peppers treated in step a) were subjected to ultrasonic-micro-pressure directional penetration treatment under low temperature conditions using an soaking agent containing cellulose nanocrystals and a pH-responsive calcium ion delivery system.

[0006] c) Antioxidant pretreatment of oils and fats: The oils and fats are mixed with polyphenolic compounds and subjected to heat treatment.

[0007] d) Low-temperature mixing and quick-freezing: Mix the meat that has been stir-fried at high temperature, the oil processed in step c), and the green peppers processed in step b), seal them in oil, and freeze them.

[0008] e) Dynamic control: The parameters of any ingredient in steps a)-d) are monitored by the control system, and the processing conditions are dynamically controlled according to the detected parameter values.

[0009] Preferably, in step a), the mass concentration ratio of zinc to calcium in the bleaching agent is 1:1.8-2.

[0010] Preferably, in step a), the bleaching agent contains the following components in the indicated mass percentages: zinc lactate 0.05%-0.15%, sodium bicarbonate 0.4%-0.8%, calcium chloride 0.1%-0.3%, and CNC 0.01%-0.05%.

[0011] Preferably, in step a), the treatment temperature is 90-98℃, the treatment time is 80-100s, and the pH of the bleaching agent is 7.8-8.2.

[0012] Preferably, in step b), the soaking agent contains the following components in the indicated mass percentages: CMC 0.05%-0.15%, calcium lactate 0.1%-0.4%, and CNC 0.01%-0.04%.

[0013] Preferably, in step b), the ultrasonic-micropressure directional permeation treatment includes alternating treatment with 35-45kHz ultrasound and 0.3-0.5MPa micropressure for 6-10 minutes.

[0014] Preferably, the degree of carboxymethylation of the CNC is ≥90%.

[0015] Preferably, in step c), the polyphenol compound includes EGCG; preferably, the amount of EGCG added is 0.01%-0.03%.

[0016] Further preferably, EGCG is added during the heat treatment.

[0017] Preferably, in step c), the oil includes vegetable oil and animal oil, preferably soybean oil and lard in a mass ratio of 2-3:1.

[0018] Preferably, in step c), the heat treatment temperature is 145-155℃ and the time is 4-6 min; after the heat treatment, the temperature is cooled to 25-40℃.

[0019] Preferably, in step d), the high-temperature frying temperature is 145-155℃ and the time is 4-6 minutes.

[0020] Preferably, in step d), the mass ratio of green pepper, oil and meat is 4-5:2-4:2; the mixing temperature is 6-10℃; and the oil sealing time is 12-18min.

[0021] Preferably, in step d), the freezing temperature is -40±5℃.

[0022] Preferably, step d) further includes thawing and reheating; the thawing temperature is 3-5℃; the reheating is direct-fire reheating at a temperature of 180-220℃.

[0023] Preferably, step e) includes monitoring the chlorophyll spectral characteristics of the green peppers in step a), and adjusting the amount of zinc salt based on the monitored chlorophyll spectral characteristics.

[0024] Preferably, step e) includes monitoring the physical and mechanical modulus of the cell wall in step b) and adjusting the physical treatment parameters applied to the green pepper based on the physical and mechanical modulus of the cell wall.

[0025] Preferably, in step e), the control system includes an LSTM model.

[0026] As a preferred option, the chlorophyll matching model requires zinc addition to satisfy the following formula: Zn addition amount = 0.05 + 0.1 × σ(R 662 / 645−0.85); Where σ is the Sigmoid function and R662 / 645 is the ratio of the characteristic peaks of chlorophyll a to b.

[0027] Preferably, the calcium release kinetics satisfy the following formula: ; Wherein, [CMC] is the concentration of carboxymethyl chitosan; Ea is the cell wall modulus calculated by AFM; R is the gas constant (8.314 J / mol·K); T is the process ambient temperature; and DM is the degree of pectin methyl esterification.

[0028] As a basic release agent, carrier encapsulation technology reduces ineffective release compared to traditional calcium salt immersion.

[0029] This is the temperature response term; As a pH trigger, the absolute value design promotes release at both high and low pH, with 6.8 being the optimal stability point.

[0030] For pectin demand; the lower the DM, the greater the release.

[0031] Preferably, the calcium release increases by 200% when pH < 6.5 and decreases by 90% when pH > 7.0. The above formula can be used throughout the entire process of this invention, mainly including soaking, freezing, and reheating.

[0032] Secondly, this invention provides a pre-prepared vegetable product, which is prepared using the method described above for synergistic preservation of green color, crispness, and freshness in green pepper and meat dishes. The product obtained by this method has a bright color and a crisp, tender texture, and can better retain its original color, aroma, and flavor after freezing and reheating. It is widely applicable to high-quality processed products containing green pepper and meat dishes.

[0033] The beneficial effects of this invention are at least as follows: This invention provides a preservation method for meat dishes containing green peppers (such as stir-fried green peppers with meat, shredded green peppers with meat, etc.) throughout the entire process of processing, freezing, storage, and reheating. This method utilizes a three-level protection system of molecular chelation for green preservation, cell network for crispness preservation, and ingredient interaction regulation, combined with dynamic optimization technology, to achieve a synergistic improvement in the color and texture of green peppers. This invention effectively protects the chlorophyll and pectin content in green peppers, reduces water loss in green peppers, and strengthens the green preservation and crispness preservation effect of green peppers in green pepper meat dishes. It significantly enhances the green preservation and crispness preservation effect of green peppers. In thawed and reheated green peppers, the green preservation and crispness preservation treatment shows that the chlorophyll content, hardness, and pectin content are all improved, and the sensory evaluation scores are also higher. The color and taste of green peppers in dishes are effectively improved. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0035] Figure 1 The results provided in Experiment Examples 1, 2, and 3 of this invention are for the effect on the color (L) of green peppers. * The impact of ).

[0036] Figure 2 The results provided in Experimental Examples 1, 2, and 3 of this invention regarding the effect on the color of green peppers (a) * The impact of ).

[0037] Figure 3 The effects on chlorophyll content in green peppers provided in Experimental Examples 1, 2, and 3 of this invention.

[0038] Figure 4 The effect on the loss rate of green pepper juice provided in Experiment Examples 1, 2, and 3 of this invention.

[0039] Figure 5The effect on the hardness of green peppers provided in Experiment Examples 1, 2, and 3 of this invention.

[0040] Figure 6 The effects of experimental examples 1, 2, and 3 of this invention on the pectin content in green peppers are provided.

[0041] Figure 7 The effects on the microstructure of green peppers provided in Experimental Examples 1, 2, and 3 of this invention are shown.

[0042] Figure 8 The effects on the sensory evaluation of freshly processed green peppers provided in Experimental Examples 1, 2, and 3 of this invention.

[0043] Figure 9 The effects on the sensory evaluation of thawed green peppers provided in Experiment Examples 1, 2, and 3 of this invention.

[0044] Figure 10 The effects of reheat treatment on the sensory evaluation of green peppers provided in Experiment Examples 1, 2, and 3 of this invention. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0046] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0047] Unless otherwise specified, the techniques or conditions described in the embodiments of this invention shall be performed in accordance with the techniques or conditions described in the literature in this field, or in accordance with the product instructions. Devices, instruments, reagents, etc., without specified manufacturers, are all conventional products that can be purchased through legitimate channels. All experimental reagents and raw materials involved are commercially available products, and all reagents are analytical grade products.

[0048] The method for synergistic preservation of green pepper and meat dishes, provided in some embodiments of the present invention, includes: a) Molecular greening blanching: treating green peppers with a blanching agent containing zinc ions under heating conditions. b) Cell repair and penetration: subjecting the green peppers treated in step a) to ultrasonic-micro-pressure directional penetration treatment under low-temperature conditions using an soaking agent containing cellulose nanocrystals and a pH-responsive calcium ion delivery system. c) Oil antioxidant pretreatment: mixing oils and polyphenolic compounds and heat-treating them. d) Low-temperature mixing and quick-freezing: mixing the meat cooked at high temperature, the oil treated in step c), and the green peppers treated in step b), sealing them in oil, and freezing them. e) Dynamic control: monitoring the parameters of any ingredient in steps a)-d) through a control system, and dynamically controlling the processing conditions based on the detected parameter values. This invention proposes a synergistic preservation technology for green peppers and meat dishes, constructing a three-tiered synergistic protection system of "molecule-cell-system": Molecular chlorophyll protection: Through zinc ion chelation, chlorophyll is converted into a highly thermally stable chlorophyll-zinc core; simultaneously, the polymer nanoshell formed by oil and polyphenols during heat treatment provides dual protection against oxidation and freezing. Cellular crispness preservation: Employing a biomimetic repair strategy, cellulose nanocrystals fill and repair microscopic cracks in the cell wall caused by freezing; and utilizing pH-responsive chitosan as a smart switch to dynamically regulate calcium ion release, thereby constructing an adaptive pectin network structure to maintain tissue crispness. System interaction regulation: High-temperature treatment locks in moisture and pre-treated oils in the meat to reduce oxidative stress, conversely inhibiting negative interactions between different ingredients. Simultaneously, the synergistic use of ultrasound-micro-pressure technology greatly improves the penetration efficiency of active ingredients into the green pepper tissue. The entire three-level system is coordinated by a dynamic control center, which, based on real-time analysis of data such as chlorophyll spectrum, cell wall mechanical modulus, and water migration status, controls process parameters at each level to achieve intelligent quality control across the entire chain.

[0049] In a preferred embodiment, in step a), the mass concentration ratio of zinc to calcium in the bleaching agent is 1:1.8-2. Preferably, in step a), the bleaching agent contains the following components in the following mass percentages: zinc lactate 0.05%-0.15%, sodium bicarbonate 0.4%-0.8%, calcium chloride 0.1%-0.3%, and CNC 0.01%-0.05%. In step a), the treatment temperature is 90-98℃, the treatment time is 80-100s, and the pH of the bleaching agent is 7.8-8.2.

[0050] In a preferred embodiment, in step b), the soaking agent comprises the following components in the indicated mass percentages: CMC 0.05%-0.15%, calcium lactate 0.1%-0.4%, and CNC 0.01%-0.04%. In step b), the ultrasonic-micropressure directional penetration treatment includes alternating treatment with 35-45 kHz ultrasound and 0.3-0.5 MPa micropressure for 6-10 minutes. Preferably, the CNC has a carboxymethylation degree ≥90%.

[0051] In a preferred embodiment, in step c), the polyphenolic compound includes EGCG; preferably, the amount of EGCG added is 0.01%-0.03%. More preferably, EGCG is added during the heat treatment. Preferably, in step c), the oil includes vegetable oil and animal oil, preferably soybean oil and lard in a mass ratio of 2-3:1. Preferably, in step c), the heat treatment temperature is 145-155°C, and the time is 4-6 minutes; the heat treatment is then cooled to 25-40°C.

[0052] In a preferred embodiment, in step d), the high-temperature stir-frying temperature is 145-155℃, and the time is 4-6 minutes. Preferably, in step d), the mass ratio of green peppers, oil, and meat is 4-5:2-4:2; the mixing temperature is 6-10℃, and the oil-sealing time is 12-18 minutes. Preferably, in step d), the freezing temperature is -40±5℃. Preferably, step d) further includes thawing and reheating; the thawing temperature is 3-5℃; the reheating is direct-heat reheating at a temperature of 180-220℃.

[0053] In a preferred embodiment, step e) includes monitoring the chlorophyll spectral characteristics of the green peppers in step a), and adjusting the amount of zinc salt based on the monitored chlorophyll spectral characteristics. Preferably, step e) includes monitoring the physical and mechanical modulus of the cell wall in step b), and adjusting the physical treatment parameters applied to the green peppers based on the physical and mechanical modulus of the cell wall. Preferably, in step e), the control system includes an LSTM model.

[0054] As a preferred option, the chlorophyll matching model requires zinc addition to satisfy the following formula: Zn addition amount = 0.05 + 0.1 × σ(R 662 / 645−0.85); Where σ is the Sigmoid function and R662 / 645 is the ratio of the characteristic peaks of chlorophyll a to b.

[0055] Preferably, the calcium release kinetics satisfy the following formula: ; Wherein, [CMC] is the concentration of carboxymethyl chitosan; Ea is the cell wall modulus calculated by AFM; R is the gas constant (8.314 J / mol·K); T is the process ambient temperature; and DM is the degree of pectin methyl esterification.

[0056] As a basic release agent, carrier encapsulation technology reduces ineffective release compared to traditional calcium salt immersion.

[0057] This is the temperature response term; As a pH trigger, the absolute value design promotes release at both high and low pH, with 6.8 being the optimal stability point.

[0058] For pectin demand; the lower the DM, the greater the release.

[0059] Preferably, the calcium release increases by 200% when pH < 6.5 and decreases by 90% when pH > 7.0. The above formula can be used throughout the entire process of this invention, mainly including soaking, freezing, and reheating.

[0060] Some embodiments of the present invention also provide a pre-prepared vegetable product, which is prepared using the method of preserving the green color, crispness, and freshness of the green pepper and meat dish. The product obtained by the method of the present invention has a bright color and a crisp and tender texture, and can better retain its original color, aroma, and flavor after freezing and reheating. It can be widely used in the processing of high-quality green pepper and meat dishes.

[0061] This invention provides a preservation method for meat dishes containing green peppers (such as stir-fried green peppers with meat, shredded green peppers with meat, etc.) throughout the entire process of processing, freezing, storage, and reheating. This method utilizes a three-tiered protection system: molecular chelation for green preservation, cellular network for crispness maintenance, and ingredient interaction regulation. Combined with dynamic optimization technology, it achieves a synergistic improvement in the color and texture of green peppers. This invention effectively protects the chlorophyll and pectin content in green peppers, reduces moisture loss, and enhances the green preservation and crispness maintenance effects of green peppers in meat dishes. The green preservation and crispness maintenance treatment significantly improves the chlorophyll content, hardness, and pectin content of thawed and reheated green peppers, resulting in higher sensory evaluation scores. The color and taste of the green peppers in the dishes are effectively improved.

[0062] In some embodiments of the present invention, a synergistic preservation technology for green pepper and meat dishes is reconstructed from a three-level dimension of molecular green protection, cellular crispness preservation, and system interaction: Molecular green protection construction: based on Zn 2+A chlorophyll-zinc heat-resistant core was constructed using chelation (conversion rate >90%), while the polyphenol nanoshell (EGCG polymer product) was thermally oxidized at 150℃ using oil, achieving dual protection against oxidation and freezing, increasing chlorophyll retention to 96% and ΔE ≤1.9; Cellular biomimetic repair: Cell wall frostbite cracks were repaired using cellulose nanocrystals (CNC) (repair rate 92%), and pH-responsive chitosan dynamically regulated Ca2+. 2+ Release and construct an adaptive pectin network (pectin loss rate <9%); system efficiency leap: by stir-frying meat at 150℃ to lock in moisture (free water reduced by 40%) and pre-treating oils with antioxidant properties (POV reduced by 60%), the negative effects of food interactions are suppressed in reverse. In conjunction with the ultrasonic-micro-pressure process (40kHz / 0.3MPa), the active ingredients are driven to penetrate in a targeted manner, improving efficiency by 300%. With dynamic regulation as the intelligent hub, an LSTM fusion model based on chlorophyll spectrum, cell wall AFM modulus, and water migration entropy is constructed to regulate the three levels of parameters in real time.

[0063] In some embodiments of this invention, a dual-targeted system for protecting chlorophyll and preventing brittleness is employed. A novel zinc-calcium synergistic system is developed, in which zinc ions directionally chelate the chlorophyll porphyrin ring Mg. 2+ (Protecting green color) prevents demagnesiation and browning; calcium ions layer to construct a pectin network (maintaining crispness), maintaining the structural integrity of cell wall pectin (especially protopectin and calcium-bridged cross-linked low-methoxyl pectin), preventing excessive depolymerization and softening (β-elimination reaction, pectinase hydrolysis, acid hydrolysis, ion loss). The two do not interfere with each other in a weakly alkaline environment of pH 8.0±0.5.

[0064] In some embodiments of this invention, the green-protecting and crispness-preserving agent is added in stages. It is added during blanching and is called a blanching agent, while it is added in ice water after blanching and is called a soaking agent. This invention achieves molecular chelation and pectin pretreatment during blanching at approximately 95°C; and cell repair and microenvironment optimization (low-temperature curing control effect) are achieved in ice water at approximately 2°C. This is combined with the synergistic effect of the blanching agent. The main components of the blanching agent include zinc lactate (0.05%-0.15%) + NaHCO3 (0.4%-0.8%, pH 8.0) + CaCl2 (0.1%-0.3%) + CNC (0.01%-0.05%, particle size 5-20nm, carboxymethylation degree ≥90%), with the zinc / calcium concentration ratio locked at approximately 1:2 (e.g., 0.1%:0.2%) to avoid ion antagonistic effects. A weakly alkaline environment is created by sodium bicarbonate, inhibiting chlorophyllase activity and delaying the demagnesiation reaction; zinc lactate promotes Zn under heat shock. 2+ Replacement of Mg in the chlorophyll porphyrin ring 2+ This forms stable zinc chlorophyll (increasing heat resistance by 200% and producing a bright green color); calcium chloride, when scalded, can increase cell membrane permeability, Ca... 2+CNCs penetrate the cell wall and bind to pectin carboxyl groups, forming an initial calcium bridge network. CNCs further synergize with calcium salts to form an in-situ regeneration system of pectin-cellulose nanocrystals. CNCs (5-20 nm in diameter) fill the micropores in the cell wall formed by freezing, interacting with pectin-calcium... 2+ The network cross-links form a "reinforced concrete" structure, increasing compressive strength by more than 30%. At the same time, the hydroxyl groups on the CNC surface form a hydrogen bond network with water molecules, reducing free water migration (ice crystal volume is reduced by 40%).

[0065] In some embodiments of the present invention, the soaking agent exhibits intelligent response. The main components of the soaking agent include CMC (degree of deacetylation ≥85%, 0.05%-0.15%) + calcium lactate (0.1%-0.4%) + sodium isoascorbate (0.03%-0.08%) + CNC (particle size 5-20nm, 0.01%-0.04%) + trehalose (0.3%-0.8%). The soaking agent, combined with ice water treatment, achieves low-temperature curing and microenvironment optimization. Utilizing the effects of low-temperature inhibition of enzyme activity and pre-curing regulation, and optimizing the microenvironment of green pepper tissue through a soaking agent, this study employed a method that combines low-temperature inhibition of enzyme activity with pre-curing regulation. The soaking agent contains sodium isoascorbate (0.05%) to quench reactive oxygen species, prevent chlorophyll oxidative degradation, maintain pH 7.5-8.0, and protect the zinc structure of chlorophyll. It also contains pH-sensitive carboxymethyl chitosan (CMC, 0.1%) to construct a carboxymethyl chitosan-calcium ion switching system, achieving pH-responsive crispness retention. When the dish reaches pH 6.2-6.5, the CMC contracts and releases calcium ions. 2+ It preferentially repairs ice crystal damage; at pH 7.0-7.5, CMC swells and absorbs H₂. + Maintaining pectin esterification >65% (avoiding excessive deesterification and softening) can reduce calcium salt usage by 50% and eliminate the bitterness problem caused by traditional high-calcium diets.

[0066] In some embodiments of the present invention, ultrasonic-micropressure directional permeation is employed. The soaking process utilizes ultrasonic-micropressure (alternating ultrasonic treatment at 40kHz and micropressure at 0.3MPa) directional permeation. The cavitation effect of ultrasound opens cell channels, increasing zinc ion absorption by 80%, while alternating micropressure propels CNC / CMC deep into the cell wall, increasing calcium bridge density by 45%, and reducing soaking time from the traditional 30min to 8min.

[0067] In some embodiments of this invention, the interaction between oils and fats is positively regulated. The oils (animal or vegetable) used in the processing of green pepper and meat dishes must be heated to 150°C, elevating the process from simple "cooking" to a crucial step in creating a protective microenvironment and flavor precursors. Thermal oxidation produces aldehydes (such as hexanal), ketones, and tocopherol polymers, reducing the oxidative stress on the oil system itself and encapsulating the green pepper to form an antioxidant barrier (TBARS value reduced by 30%). Simultaneously, cooling the oil forms a semi-solid film, blocking oxygen and moisture migration. During the oil processing, 0.02% epigallocatechin gallate (EGCG) is added to construct a chlorophyll-polyphenol core-shell encapsulation technology system, achieving dynamic protection. During frozen storage, the polyphenol shell quenches free radicals (ORAC value increased by 150%), preventing mechanical damage from ice crystals; during reheating, the shell gradually degrades at high temperatures, controllably releasing EGCG to inhibit thermal oxidation (TBARS value reduced by 60%). Chlorophyll retention is increased from 78% in traditional processes to 95%.

[0068] In some embodiments of the present invention, the moisture in the meat is locked. In the stir-frying of green peppers and meat dishes, the oil temperature is 150°C, and the meat is continuously stirred for 5 minutes, then allowed to cool. This fixes the moisture and migratable substances in the meat, reducing their negative impact on the green peppers. Moisture locking is achieved through: protein denaturation forming a gel network, reducing free water by 40%, thus reducing migration to the green peppers during frozen storage; and the inactivation of pro-oxidation factors: inactivating lipoxygenase (LOX activity ↓95%) and fixing metal ions (Fe). 2+ ↓70%).

[0069] In some embodiments of the present invention, a low-temperature mixed quick-freezing process is employed. The present invention involves mixing, packaging, and quick-freezing at low temperatures (e.g., <10°C) to maximally inhibit microbial and enzyme activity, while simultaneously reducing mechanical damage to the cell wall (pectin structure) caused by freezing, minimizing chemical changes caused by water migration and concentration effects (such as localized pH changes and dramatic increases in ion concentration), protecting chlorophyll stability and pectin structure, and ensuring a stable structure formed through pre-freezing regulation (chelation, cross-linking, embedding).

[0070] In some embodiments of the present invention, thawing-reheating is synergistically controlled. Dishes must be thawed before reheating; direct reheating is not possible. Direct reheating from a frozen state can lead to external overheating (chlorophyll degradation, excessive pectin softening) while the interior remains underheated. Thawing ensures a more uniform temperature, reducing the risk of localized overheating and lowering the risk of chlorophyll degradation by 60%. Reheating is performed over direct heat before consumption. Direct heat provides instantaneous high temperatures and rapid heat penetration, shortening the exposure time of green peppers at high temperatures (stir-fry effect), maximizing the preservation of the green color of zinc chlorophyll and vitamins. Simultaneously, rapid high-temperature reheating quickly inactivates trace enzyme activities (such as pectinase) that may recover during thawing and rapidly heat-sets the pectin-calcium cross-linked network, increasing crispness recovery by 25% and avoiding prolonged mild heating that leads to continued pectin softening and further cell separation.

[0071] In some embodiments of the present invention, a greening protection technology based on chlorophyll state is dynamically matched. Zn is dynamically matched according to different chlorophyll a / b ratios (characteristic peaks 662nm / 645nm) on the surface of green peppers. 2+ The chelation strength is calculated using the following formula: Zn addition amount = 0.05 + 0.1 × σ(R 662 / 645 − 0.85), where σ is the Sigmoid function and R 662 / 645 is the ratio of chlorophyll a / b characteristic peaks. If R 662 / 645 < 0.9, the risk of chlorophyll degradation increases, σ(x) approaches 1, and Zn... 2+ The addition amount should be increased to 0.15%; when R662 / 645 > 0.9, the chlorophyll state is stable, σ(x) approaches 0, and Zn 2+ Maintain the baseline value at 0.05%.

[0072] In some embodiments of the present invention, a crispness-preserving technology based on pectin properties is dynamically matched. Ca is precisely controlled according to the degree of pectin methyl esterification (DM) in different green peppers. 2+ Release kinetics, the formula is as follows: in Based on the release term, the higher the CMC concentration, the more Ca can be released. 2+ The larger the total amount, such as when [CMC]=0.1%, the basal rate=0.02 mmol / (L·min), the more ineffective the carrier encapsulation technology is compared with traditional calcium salt immersion. For the temperature response term, the technical logic is that as temperature increases, molecular thermal motion increases, leading to Ca... 2+ Release acceleration; As a pH trigger, it increases the release rate when the pH decreases (such as during freezing) (to repair ice crystal damage), and decreases the release rate when the pH increases (such as during reheating) (to prevent excessive cross-linking). The absolute value design promotes release at both high and low pH. For pectin demand, when DM > 50%, it indicates that the degree of pectin esterification is high (relatively stable), maintaining the basic release (coefficient ≈ 1). As DM decreases, stability changes, and the release amount needs to be increased (coefficient > 1).

[0073] Example 1 This embodiment provides a method for preserving the green color and crispness of green peppers based on the interaction of meat ingredients. The steps are as follows: (1) Raw material pretreatment Green bell pepper preparation: Select fresh green bell peppers, remove the stems and seeds, and cut them into chunks (2×2cm).

[0074] Meat preparation: Slice pork tenderloin into 3mm thick slices and refrigerate at 4℃ for later use.

[0075] Oil preparation: Soybean oil: Lard = 3:1 (by volume).

[0076] (2) Bleaching and greening protection and calcium bridge pre-crosslinking Blanching agent formulation: Heat the blanching solution to 90℃-98℃, pH 7.8-8.2, add green bell pepper pieces, maintain the temperature for 90 seconds, then quickly remove (holding time <5 seconds). Zn 2+ Chelating and converting chlorophyll zinc, CNC and Ca 2+ A "reinforced concrete" network is formed.

[0077] (3) Intelligent repair by immersion in ice water Bell pepper pieces were placed in ice water and subjected to directional osmosis using ultrasound-micropressure (alternating ultrasound 40kHz 30s-micropressure 0.3MPa 30s for 8min). When pH < 6.5 (freezing period), the calcium release by CMC increased to 200%; when AFM modulus < 8MPa, the micropressure was increased to 0.5MPa; when DM < 45%, CNC was added to 0.05%.

[0078] (4) Antioxidant pretreatment of oils Heat the mixed oil to 150℃ (±2℃) and maintain for 5 minutes. Add 0.02% EGCG and stir until completely dissolved. Allow to cool naturally to 40℃ (to form a semi-solid film).

[0079] (5) Locking in the moisture of meat The meat slices are stir-fried in oil at 150℃, constantly stirred, for 5 min ± 30 s, then left to cool to reduce free water by 40% (water activity 0.85 → 0.71).

[0080] (6) Low-temperature mixed quick-freezing Green bell pepper: oil: meat = 5:3:2 (mass ratio); mixing temperature: 8℃; oil sealing time: 15 minutes. After mixing, pre-cool to 0℃, then at -40℃, ice crystal diameter ≤20μm (cell damage rate <5%).

[0081] (7) Thawing and reheating control Thawing at 4℃: until ice crystals completely disappear, time control: 4 hours / 500g (temperature gradient <2℃ / cm).

[0082] Direct heat reheating: Pot temperature: 200±10℃ (infrared temperature measurement); Stir-frying time: ≤90 seconds; Standard for removing from the pot: center temperature ≥75℃.

[0083] Example 2 This embodiment provides a method for preserving the green color and crispness of green peppers based on the interaction of meat ingredients, and the resulting product (stir-fried green peppers with meat). The method of Embodiment 1 is adopted, and the specific raw materials and processes are shown in the table below.

[0084] Table 1 Raw Materials and Processes

[0085] Table 2. Record of Regulatory Events

[0086] Table 3 Comparison of Effects

[0087] Detection standards: Chlorophyll (HPLC), fragility (TA.XT Plus texture analyzer puncture mode). Experimental Example 1: Fresh group (only blanched and soaked, then quick-frozen and refrozen). (1) Wash the dirt off the green peppers, remove the stem and seed set, and cut them into uniform pieces.

[0088] (2) Explanation of the treatment control group Fresh control: This refers to green peppers that have only been blanched. Blanch the green peppers in boiling water for 5 seconds, then quickly soak them in cold water (5~10℃) for 15 minutes and drain.

[0089] Fresh treatment: Based on the control, the bleaching and soaking processes were respectively treated with the bleaching and greening protection, calcium bridge pre-crosslinking, and ice water soaking for intelligent repair as described in the above embodiments. Other treatment methods were the same as the control. Specific parameters were the same as in the above embodiments, and the midpoint values ​​were taken from the numerical range.

[0090] Experimental Example 2: Oil-based group (based on the fresh group, it was stir-fried and then quick-frozen and reheated) Oil system control: Fresh green peppers were used as a control. After undergoing the above-mentioned oil antioxidant pretreatment, meat moisture locking, and low-temperature mixing processes, they were quick-frozen or quick-frozen and refrigerated before relevant index testing. Specific parameters were the same as in the above examples, with the median values ​​taken from the range.

[0091] Oil system treatment: Freshly processed green peppers were used, and the same treatment as the oil system control was applied.

[0092] Experiment Example 3: Meat system group (based on the fresh group, it was stir-fried and then quick-frozen and refrigerated) Meat system control: Animal fat was used instead of mixed oil for oil sealing, and other aspects were the same as the oil system control.

[0093] Meat system processing: Animal fat is used instead of mixed oil for oil sealing, and other processes are the same as for oil system processing.

[0094] (3) Quick-freezing: Pre-cool the green pepper dish package to 0°C and freeze it in a -40°C freezer for 24 hours.

[0095] (4) Reheating: Remove the green pepper vegetable package and place it in a 4°C refrigerator until the ice crystals disappear. Then reheat it over direct heat. The experimental results are as follows.

[0096] 1. Effects on the color of green peppers To compare the color changes of green peppers in different treatment groups, the lightness value (L) of the green pepper surface was measured. * ) and redness value (a * ), where a * When the value is positive, the larger the absolute value, the redder it is; a * When the value is negative, the larger the absolute value, the greener it is. For example... Figure 1 As shown, in the fresh group, the brightness value of the fresh control bell peppers that only underwent blanching was 34.21, while the brightness value of the bell peppers treated with freshness increased by 4.15. Oil and meat treatments had no effect on the brightness value of the fresh bell peppers, but both oil and meat treatments increased the brightness of the bell peppers in both the thawed and reheated groups. In the thawed group, the brightness value of the freshly treated bell peppers was [missing value]. * The value was 31.93, compared to the fresh control L. * The value increased by 2.32. Green peppers treated with green preservation and crispness retention under both oil and meat systems showed better results than freshly treated green peppers. * Increased by 6.03 and 6.30. In the reheating group, the freshly processed green peppers L * The value is 27.50. Under oil and meat systems, green peppers treated with a green preservation and crispness-maintaining process are comparable to fresh green peppers (L). * The values ​​increased by 8.06 and 8.40. * Changes such as Figure 2 As shown, there was no significant difference in the green color of all green peppers that had not undergone freezing and thawing. However, after thawing, both the oil-based control and the oil-based treatment groups preserved the green color of the green peppers better, with the oil-based treatment group showing the best effect compared to freshly treated green peppers. * The decrease of 1.75 indicates an increase of 1.75 in the green value. After reheating treatment, the oil system treatment group a *The green value decreased by 1.33 compared to the freshly treated group, indicating an improvement in the greenness. This suggests that oil sealing treatment can further enhance the greenness of green peppers after freezing, thawing, and reheating, building upon blanching and color-protecting treatments.

[0097] 2. Effects on chlorophyll content in green peppers Chlorophyll is an important pigment in vegetables, crucial for their green color. In the fresh group, the cooking methods showed no significant difference in chlorophyll content of green peppers. However, in the thawed and reheated groups, the effects of the green preservation and crispness-maintaining treatment on chlorophyll content of green peppers were significantly different compared to the control. In the thawed group, green peppers in the oil and meat systems without green preservation and crispness-maintaining treatment had chlorophyll content 0.006 and 0.005 mg / g higher than the fresh control, respectively. After green preservation and crispness-maintaining treatment, combined with oil and meat system treatments, the chlorophyll content could be further increased, with the oil system treatment showing a better improvement in the reheated group. Figure 3 ).

[0098] 3. Effect on juice loss rate The thawing and reheating process of green peppers involves juice loss, and significant juice loss can lead to quality deterioration. After thawing, the juice loss rate of freshly treated green peppers was 19.75%, which was 4.4% lower than that of the fresh control group. The treated group had a lower juice loss rate than the control group, indicating better maintenance of cell moisture. While oil-based and meat-based treatments had no significant effect on juice loss during thawing, they significantly inhibited juice loss after reheating. Figure 4 ).

[0099] 4. Effect on hardness In the fresh group, the cooking system had no significant effect on the hardness of green peppers. In the thawed group, the hardness of freshly treated green peppers increased by 0.36 N compared to the fresh control. The oil and meat systems increased the hardness of freshly treated green peppers by 0.02 and 0.07 N, respectively. The effect of reheating on the hardness of green peppers was significant (P<0.05). In the reheated group, the hardness of freshly treated green peppers increased by 0.77 N compared to the fresh control. The oil and meat systems increased the hardness by 0.17 and 0.21 N, respectively. The oil and meat systems increased the hardness of green peppers by 0.41 and 0.35 N, respectively, compared to the oil and meat system control. Figure 5 ).

[0100] 5. Effect on pectin content in green peppers Pectin is closely related to the texture of green peppers. Extraction using deionized water, chelating agents, and dilute alkaline solutions yields water-soluble pectin (WSP), alkali-soluble pectin (NSP), and covalently soluble pectin (CSP). A significant negative correlation exists between the firmness of green peppers and WSP content, while a positive correlation exists between WSP and NSP and CSP. The figure shows that treatment with a green-protecting and crisp-preserving agent significantly reduces WSP content while increasing NSP and CSP content. This enhancement effect is also achieved after treatment with oil and meat systems. Furthermore, based on the green-protecting and crisp-preserving agent treatment, further treatment with oil and meat systems can reduce WSP content while increasing NSP and CSP content, thus strengthening the green-protecting and crisp-preserving effect. Figure 6 ).

[0101] 6. Effects on the microstructure of green peppers After freezing and thawing, cell shape and adhesion between adjacent cells change. For example... Figure 7 As shown, ac represents the fresh control, oil system control, and meat system control in the thawing group; df represents the fresh control, oil system control, and meat system control in the reheating group; gi represents the fresh treatment, oil system treatment, and meat system treatment in the thawing group; and jl represents the fresh treatment, oil system treatment, and meat system treatment in the reheating group. In the thawing group, the green peppers were affected by ice crystals, resulting in cell deformation and damage. The green peppers in the oil system and meat system controls had fewer cell folds and more intact cell structures than the fresh green pepper controls, indicating that the oil and meat systems protected the green pepper cells. Under the oil and meat systems, the treated green peppers had more intact cell walls, fewer folds, and better texture than the control green peppers, further demonstrating the protective effect of the treatment on the cells. In the reheating group, the green peppers treated with the oil and meat systems for maintaining green color and crispness had more intact cell wall structures and lower cell wall damage than the oil and meat system controls, maintaining the crispness of the green peppers, indicating that the treatment improved the texture quality of the green peppers. During the reheating process, the green peppers softened, and the oil and meat systems improved the texture of the green peppers, resulting in a more intact cell structure. In the oil and meat systems, the intercellular spaces of the control green peppers were larger, the adhesion was worse, the cells collapsed, and the firmness decreased compared to the treated green peppers. This is consistent with the results of the firmness index in the experiment. From a microscopic perspective, the green peppers treated with the oil and meat systems had better cell structure.

[0102] 7. Impact on the sensory evaluation of green peppers Sensory evaluation can directly reflect product quality. Sensory evaluations of color, aroma, taste, and texture can reflect the edible quality of green peppers in oil-based or meat-based dishes. The influence of the culinary system on the sensory evaluation of green peppers is as follows: Figure 8-10 As shown.

[0103] Depend on Figure 8It can be seen that, in terms of color, aroma, and texture, freshly treated green peppers scored higher than fresh control peppers, indicating that the green peppers maintained a better green color and original aroma under the action of additives, and had better crispness after treatment, resulting in better quality before freezing. In terms of taste, freshly treated green peppers scored lower than fresh control peppers, possibly because the use of additives affected the unique flavor of the green peppers. In terms of overall acceptability, the green peppers soaked in additives had a higher acceptability rate of 87.6, possibly indicating that the treatment improved their quality.

[0104] Depend on Figure 9 It can be seen that, after thawing, the green peppers treated with oil showed the best color, scoring 16.8, which is consistent with the previous color index results. Regarding aroma and taste, freshly treated peppers scored higher, while those treated with oil and meat systems for preserving green color and crispness scored lower, possibly due to oil oxidation producing unpleasant odors and reducing the sensory quality of the peppers. In terms of texture, the green peppers treated with oil scored the highest, consistent with the previous hardness index results. The overall acceptability of freshly treated green peppers was 59.4, while the overall acceptability of green peppers treated with oil and meat systems were 64.6 and 65.4, respectively. The overall acceptability of thawed green peppers was lower than that of fresh green peppers, which is consistent with the fact that food quality decreases after freezing.

[0105] Depend on Figure 10 It can be seen that, after reheating, in terms of color, the green peppers treated with oil and meat systems had better color scores of 12.2 and 12.2 respectively, which was 0.8 higher than the color of freshly treated green peppers. The control green peppers in the oil and meat systems had color scores of 10.4 and 10.4, which was 2.4 higher than the color of fresh control green peppers. In terms of aroma, the oil system treatment had a higher aroma score of 14.6, which may be due to the aroma produced by the oil during the heating process. In terms of taste, the meat system treatment had a higher taste score of 15. In terms of texture, the oil and meat systems treatment had better texture scores of 12 and 12.2 respectively. In terms of overall acceptability, the meat system treatment had higher acceptability, which was 0.8 higher than the oil system treatment. Therefore, from a sensory perspective, after direct-fire reheating, the green peppers treated with meat systems had a higher sensory score.

[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for synergistically preserving the green color, crispness, and freshness of green peppers and meat dishes, characterized in that, include: a) Molecular green-protecting blanching: Green peppers are treated with a blanching agent containing zinc ions under heating conditions; b) Cell repair and penetration: The green peppers treated in step a) were subjected to ultrasonic-micro-pressure directional penetration treatment under low temperature conditions using an soaking agent containing cellulose nanocrystals and a pH-responsive calcium ion delivery system; c) Antioxidant pretreatment of oils and fats: Mixing oils and fats with polyphenolic compounds and then subjecting them to heat treatment; d) Low-temperature mixing and quick-freezing: Mix the meat that has been stir-fried at high temperature, the oil processed in step c), and the green peppers processed in step b), seal them in oil, and freeze them; e) Dynamic control: The parameters of any ingredient in steps a)-d) are monitored by the control system, and the processing conditions are dynamically controlled according to the detected parameter values.

2. The method according to claim 1, characterized in that, In step a), the mass concentration ratio of zinc to calcium in the bleaching agent is 1:1.8-2; And / or, the bleaching agent contains the following components in the indicated mass percentages: zinc lactate 0.05%-0.15%, sodium bicarbonate 0.4%-0.8%, calcium chloride 0.1%-0.3%, and CNC 0.01%-0.05%; And / or, the treatment temperature is 90-98℃, the treatment time is 80-100s, and the pH of the bleaching agent is 7.8-8.

2.

3. The method according to claim 1 or 2, characterized in that, In step b), the soaking agent contains the following components in the indicated mass percentages: CMC 0.05%-0.15%, calcium lactate 0.1%-0.4%, and CNC 0.01%-0.04%.

4. The method according to claim 2 or 3, characterized in that, In step b), the ultrasonic-micropressure directional permeation treatment includes alternating treatment with 35-45kHz ultrasound and 0.3-0.5MPa micropressure for 6-10 minutes.

5. The method according to any one of claims 1-4, characterized in that, In step c), the polyphenol compound includes EGCG, and the amount of EGCG added is 0.01%-0.03%. And / or, in step c), the oils include vegetable oils and animal oils; And / or, in step c), the heat treatment temperature is 145-155°C and the time is 4-6 min; the heat treatment is followed by cooling to 25-40°C.

6. The method according to any one of claims 1-5, characterized in that, In step d), the high-temperature frying temperature is 145-155℃ and the time is 4-6 minutes; And / or, in step d), the mass ratio of green peppers, oil and meat is 4-5:2-4:2; the mixing temperature is 6-10℃; and the oil sealing time is 12-18 min.

7. The method according to any one of claims 1-6, characterized in that, In step d), the freezing temperature is -40±5℃; And / or, step d) further includes thawing and reheating; the thawing temperature is 3-5℃; the reheating is direct-fire reheating.

8. The method according to any one of claims 1-7, characterized in that, Step e) includes monitoring the chlorophyll spectral characteristics of the green peppers in step a), and adjusting the amount of zinc salt based on the monitored chlorophyll spectral characteristics. And / or, including monitoring the physical and mechanical modulus of the cell wall in step b), and adjusting the physical treatment parameters applied to the green peppers based on the physical and mechanical modulus of the cell wall; And / or, the control system includes an LSTM model.

9. The method according to claim 8, characterized in that, Chlorophyll matching model: Zinc addition amount satisfies the following formula: Zn addition amount = 0.05 + 0.1 × σ(R 662 / 645−0.85); Where σ is the Sigmoid function, and R662 / 645 is the chlorophyll a / b characteristic peak ratio; The input variable k of the Sigmoid function is optimized through online learning, with a response latency of ≤0.5 seconds; And / or, calcium release kinetics satisfy the following formula: ； Wherein, [CMC] is the concentration of carboxymethyl chitosan; Ea is the cell wall modulus calculated by AFM, R is the gas constant, T is the process ambient temperature, and DM is the degree of pectin methyl esterification. This is the temperature response term; pH triggering term; For pectin demand; When pH < 6.5, the amount of calcium released increases by 200%, and when pH > 7.0, the amount of calcium released decreases by 90%.

10. A pre-cooked food product, characterized in that, The green pepper and meat dish is prepared using the method described in any one of claims 1-9 for synergistic preservation of green color, crispness, and freshness.

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