阅读说明：本技术 一种采用一氧化氮气体熏蒸提升猪肉品质的装置及其方法 (Device and method for improving pork quality by adopting nitric oxide gas fumigation ) 是由 刘瑞 杨伦 葛庆丰 李可悦 秦曼 吴满刚 王庆玲 于海 于 2021-08-21 设计创作，主要内容包括：本发明涉及一种采用一氧化氮气体熏蒸提升猪肉品质的装置及其方法,包括熏蒸容器、铝箔袋、三通阀；所述三通阀的上依次连接有第一管、第二管、注射管；第一管一端与三通阀贯通连接,另一端与铝箔袋贯通连接,且第一管上安装有单向阀门；第二管一端与三通阀贯通连接,另一端与熏蒸容器顶部贯通连接,且第二管上安装有进气阀；铝箔袋经第一管、单向阀门、三通阀、第二管、进气阀与熏蒸容器贯通；所述注射管一端与三通阀贯通连接,另一端连接有注射器；本发明操作简单、成本低廉、无有害化学残留物质,具有广阔的应用前景。(The invention relates to a device and a method for improving pork quality by adopting nitric oxide gas fumigation, comprising a fumigation container, an aluminum foil bag and a three-way valve; the three-way valve is sequentially connected with a first pipe, a second pipe and an injection pipe; one end of the first pipe is communicated with the three-way valve, the other end of the first pipe is communicated with the aluminum foil bag, and the first pipe is provided with a one-way valve; one end of the second pipe is communicated with the three-way valve, the other end of the second pipe is communicated with the top of the fumigation container, and an air inlet valve is arranged on the second pipe; the aluminum foil bag is communicated with the fumigation container through a first pipe, a one-way valve, a three-way valve, a second pipe and an air inlet valve; one end of the injection pipe is communicated with the three-way valve, and the other end of the injection pipe is connected with an injector; the method has the advantages of simple operation, low cost, no harmful chemical residual substances and wide application prospect.)

1. A device for improving pork quality by using nitric oxide gas fumigation is characterized by comprising a fumigation container (1), an aluminum foil bag (9) and a three-way valve (6);

the three-way valve (6) is sequentially connected with a first pipe (10-1), a second pipe (10-2) and an injection pipe (11); one end of the first pipe (10-1) is communicated with the three-way valve (6), the other end of the first pipe is communicated with the aluminum foil bag (9), and the first pipe (10-1) is provided with a one-way valve (8); one end of the second pipe (10-2) is communicated with the three-way valve (6), the other end of the second pipe is communicated with the top of the fumigation container (1), and the second pipe (10-2) is provided with an air inlet valve (5); the aluminum foil bag (9) is communicated with the fumigation container (1) through a first pipe (10-1), a one-way valve (8), a three-way valve (6), a second pipe (10-2) and an air inlet valve (5); one end of the injection pipe (11) is communicated with the three-way valve (6), and the other end of the injection pipe is connected with the injector (7);

a plastic screen plate (2) for placing pork slices (4) is arranged in the fumigation container (1), an exhaust pipe (12) is arranged on the side wall of the fumigation container (1) below the plastic screen plate (2), and an exhaust valve (3) is arranged on the exhaust pipe (12);

the device is also provided with a nitrogen steel cylinder and a nitrogen pipe, wherein a nitrogen pressure reducing valve is arranged on the nitrogen steel cylinder, one end of the nitrogen pipe is connected to the nitrogen pressure reducing valve, the other end of the nitrogen pipe is communicated with the aluminum foil bag (9) and the injector (7), and a rotor flow meter is arranged on the nitrogen pipe; the nitrogen steel cylinder is communicated with the aluminum foil bag (9) and the injector (7) through a reducing valve, a rotor flow meter and a nitrogen pipe;

the nitrogen oxide pressure reducing valve is arranged on the nitrogen oxide steel cylinder, one end of the nitrogen oxide pipe is connected to the nitrogen oxide pressure reducing valve, and the other end of the nitrogen oxide pipe is communicated with the aluminum foil bag (9); the nitric oxide steel cylinder is communicated with the aluminum foil bag (9) through a nitric oxide pressure reducing valve and a nitric oxide pipe;

a temperature controller is arranged in the fumigation container (1), and a sealing door is arranged on the fumigation container (1).

2. The device for improving the pork quality by fumigation of nitric oxide gas as claimed in claim 1, wherein the fumigation container (1) is a rectangular plastic preservation box made of polyethylene.

3. The device for improving the pork quality by using nitric oxide gas fumigation as claimed in claim 2, wherein the fumigation container (1) is 24.5cm long, 16cm wide, 8cm high and 3L in volume.

4. The apparatus for improving pork quality by fumigation of nitric oxide gas as claimed in claim 1, wherein nitrogen gas with a concentration of 99.9% is stored in the nitrogen gas cylinder.

5. The apparatus of claim 1, wherein the nitric oxide steel bottle stores a mixture of nitric oxide and nitrogen, and the concentration of nitric oxide is 1500 μ L/L.

6. The device for improving the pork quality by fumigation of nitric oxide gas as claimed in claim 1, wherein the volume of the aluminum foil bag (9) is 1L.

7. The method for improving the pork quality by using the device for improving the pork quality by fumigating the nitric oxide gas in any one of claims 1 to 6, is characterized by comprising the following steps of:

1) opening a sealing door on the fumigation container (1), flatly placing the pork slices (4) above the plastic mesh plate (2) in the fumigation container (1), and then closing the sealing door;

2) and nitrogen flushing: opening a nitrogen steel cylinder, rotating a nitrogen pressure reducing valve, adjusting the nitrogen flow rate through a rotor flow meter, and introducing nitrogen into the aluminum foil bag (9) and the injector (7) through a nitrogen pipe; adjusting the one-way valve (8), the three-way valve (6) and the air inlet valve (5) to ensure that the aluminum foil bag (9) and the injector (7) are communicated with the fumigation container (1), and opening the exhaust valve (3) on the fumigation container (1);

nitrogen in the aluminum foil bag (9) flows into the fumigation container (1) through the first pipe (10-1), the three-way valve (6), the second pipe (10-2) and the air inlet valve (5), nitrogen in the injector (7) flows into the fumigation container (1) through the injection pipe (11), the three-way valve (6) and the second pipe (10-2), and due to the action of the one-way valve (8), the nitrogen in the injector (7) cannot flow into the aluminum foil bag (9) through the first pipe (10-1), and the nitrogen flowing out of the aluminum foil bag (9) cannot flow back into the aluminum foil bag (9) through the first pipe (10-1); the nitrogen flowing in is discharged out of the fumigation container (1) through an exhaust valve (3); thereby realizing that the fumigation container (1), the aluminum foil bag (9) and the injector (7) are flushed by nitrogen, exhausting residual air in the fumigation container (1), the aluminum foil bag (9) and the injector (7), and ensuring an oxygen-free environment;

then the exhaust valve (3) is closed, and the one-way valve (8), the three-way valve (6) and the air inlet valve (5) are adjusted, so that the aluminum foil bag (9), the injector (7) and the fumigation container (1) are not communicated with each other;

3) and nitric oxide gas fumigation: opening a nitric oxide steel cylinder, rotating a nitric oxide pressure reducing valve, injecting nitric oxide gas into the aluminum foil bag (9) through a nitric oxide pipe for later use, and closing the nitric oxide pressure reducing valve; adjusting the three-way valve (6) and the one-way valve (8) to enable the injector (7) and the aluminum foil bag (9) to be communicated, extracting nitric oxide gas from the aluminum foil bag (9) by using the injector (7), storing the nitric oxide gas into the injector (7), and then closing the one-way valve (8) to enable the injector (7) and the aluminum foil bag (9) not to be communicated;

adjusting the three-way valve (6) and the air inlet valve (5) to enable the injector (7) and the fumigation container (1) to be communicated, injecting nitric oxide gas in the injector (7) into the fumigation container (1), controlling the concentration of nitric oxide in the fumigation container (1) to be 40-80 mu L/L, and then closing the three-way valve (6) and the air inlet valve (5); controlling the temperature in the fumigation container (1) to be 20-25 ℃ through a temperature controller in the fumigation container (1), and fumigating the pork slices (4) for 2 hours in an environment with nitric oxide concentration of 40-80 mu L/L and temperature of 20-25 ℃;

4) pork packaging and storage: and taking out the pork slices (4) in the fumigation container (1) after the fumigation is finished.

8. The method according to claim 7, characterized in that in step 1), the pork slices (4) are obtained by:

removing fascia and fat on the surface of the longest muscle part of the back of a fresh pig within 6h after slaughtering, and trimming to 5 × 5 × 2cm³The pork slices (4) are 60g in weight, and the pork slices are flatly placed above a plastic net in the fumigation container.

9. The method according to claim 7, further comprising a step 5) of vacuum packaging the pork fillet (4) taken out of the fumigation container (1) and storing at 4 ℃ for 1, 4 or 7 days.

Technical Field

The invention relates to a device and a method for improving pork quality by adopting nitric oxide gas fumigation, belonging to the technical field of pork processing.

Background

Pork plays an important role in dietary life of people and is also the meat food which is most consumed by residents in China. At present, with the improvement of living standard of people, high-quality fresh meat gradually becomes a primary target pursued by meat production enterprises and consumers. However, the low gradation and instability of pork quality currently affects the development of manufacturing enterprises and consumer satisfaction. Drip loss is an important index of pork quality, and is reported to be up to 5% higher than that of pork in China, which is averagely higher than that of developed countries by more than 1.5%, and moreover, excessive drip loss of pork negatively affects other quality indexes of the pork, such as color, tenderness, juiciness, mouthfeel and the like. Therefore, effective measures are sought to reduce drip loss of the slaughtered pork to the maximum extent, pork quality is improved, and the method has important significance for the economic value of enterprises and the satisfaction degree of consumers.

The existing measures for improving the pork quality can be classified into pre-slaughter measures and post-slaughter measures, the pre-slaughter measures comprise pig genetic breeding, pre-slaughter management, slaughter technologies and the like, researches show that the pork quality can be effectively improved and the economic value of pork is improved by applying the pre-slaughter technologies, but the defects of long research period, large workload, much investment and the like exist. The post-slaughter measures comprise lactic acid spraying, quick cooling, acid discharge and the like, and the commercial pigs are subjected to relevant industrial application at present, but the phenomena of high incidence rate of poor pork, unstable quality and the like of the pork are still found. The acid discharge of the current commercial pig factory is generally 24 hours, muscle cells of the slaughtered pork in the pig carcass maturation process can generate a series of complex physiological and biochemical reactions, mainly including glycolysis, pH reduction, muscle contraction, stress reaction, apoptosis, protease activation, protein degradation and other processes, and the control measures for improving the pork quality generally change the fresh meat maturation process by influencing the post-slaughter biochemical metabolism process.

Nitric Oxide (NO), an important endogenous small molecule in the pig body, can diffuse and transmit freely in cell membranes and cell structures, and acts as a second messenger in the process of signal transmission. NO reacts with a variety of substances including protein cysteine sulfhydryls, metal ions such as iron and copper ions, and reactive oxygen species. NO-modified proteins are widely classified and mainly include signaling proteins, ion channels, receptors, enzymes, and transcription and translation factors, and thus NO can regulate various metabolic activities in living organisms. In the biochemical metabolism of the slaughtered pork, NO can participate in regulating and controlling glycolysis process, calcium ion release process and calpain activity in the post-slaughter maturation process. Specifically, enzymes in the glycolysis process, such as phosphofructokinase, aldolase, enolase, 3-glyceraldehyde phosphate dehydrogenase and the like, can be subjected to nitrosation modification in the slaughtered pork under the mediation of NO, and the nitrosation modification of glycogen phosphorylase, 3-glyceraldehyde phosphate dehydrogenase and pyruvate kinase remarkably inhibits the activity thereof, thereby inhibiting the glycolysis process of the slaughtered muscle. NO reacts with the key protein ryanodine receptor of the calcium channel and the sarcoplasmic endoplasmic reticulum calcium ion adenosine triphosphatase to form the normal operation of the nitrosylation modification control channel. Research shows that NO can inhibit autolysis and activity of calpain 1 through nitrosation modification, and in addition, NO can modify calpain 1 in the presence of calpain inhibitory protein, so that nitrosation strength is improved, redox state change is caused, and activity, autolysis and myofibrillar protein degradation of calpain 1 are further inhibited. Therefore, a feasible way for improving the pork quality can be provided by regulating the biochemical metabolic process after slaughter by using the nitric oxide.

At present, the nitric oxide gas is applied to food and is mainly found in the preservation of fruits and vegetables, and the putrefaction process is slowed down mainly by regulating and controlling the concentration of ethylene and the like in plant cells, so that the storage period is delayed. However, no relevant research application of the nitric oxide gas in animal-derived foods, particularly pork, exists. Therefore, the invention provides the device and the method for improving the pork quality by adopting the nitric oxide gas fumigation, which improve the color, the tenderness, the chewiness and the water-retaining quality of the pork and inhibit the growth activity of microorganisms. The method has the advantages of simple operation, low cost, no harmful chemical residual substances and wide application prospect.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, and provides a device and a method for improving the pork quality by adopting nitric oxide gas fumigation for improving the fresh meat quality in the mature process of slaughtered pork.

The invention is realized by the following steps: a device for improving pork quality by using nitric oxide gas fumigation is characterized by comprising a fumigation container, an aluminum foil bag and a three-way valve;

the three-way valve is sequentially connected with a first pipe, a second pipe and an injection pipe; one end of the first pipe is communicated with the three-way valve, the other end of the first pipe is communicated with the aluminum foil bag, and the first pipe is provided with a one-way valve; one end of the second pipe is communicated with the three-way valve, the other end of the second pipe is communicated with the top of the fumigation container, and an air inlet valve is arranged on the second pipe; the aluminum foil bag is communicated with the fumigation container through a first pipe, a one-way valve, a three-way valve, a second pipe and an air inlet valve; one end of the injection pipe is communicated with the three-way valve, and the other end of the injection pipe is connected with an injector;

a plastic screen plate for placing pork slices is arranged in the fumigation container, an exhaust pipe is arranged on the side wall of the fumigation container below the plastic screen plate, and an exhaust valve is arranged on the exhaust pipe;

the device is also provided with a nitrogen steel cylinder and a nitrogen pipe, wherein a nitrogen pressure reducing valve is arranged on the nitrogen steel cylinder, one end of the nitrogen pipe is connected to the nitrogen pressure reducing valve, the other end of the nitrogen pipe is communicated with the aluminum foil bag and the injector, and a rotor flow meter is arranged on the nitrogen pipe; the nitrogen steel cylinder is communicated with the aluminum foil bag and the injector through a pressure reducing valve, a rotor flow meter and a nitrogen pipe;

the nitrogen oxide pressure reducing valve is arranged on the nitrogen oxide steel cylinder, one end of the nitrogen oxide pipe is connected to the nitrogen oxide pressure reducing valve, and the other end of the nitrogen oxide pipe is communicated with the aluminum foil bag; the nitric oxide steel cylinder is communicated with the aluminum foil bag through a nitric oxide pressure reducing valve and a nitric oxide pipe;

a temperature controller is arranged in the fumigation container, and a sealing door is arranged on the fumigation container.

The fumigation container is a rectangular plastic preservation box made of polyethylene.

The fumigation container has a length of 24.5cm, a width of 16cm, a height of 8cm and a volume of 3L.

The nitrogen cylinder stores 99.9% nitrogen.

The nitric oxide steel bottle is internally stored with mixed gas of nitric oxide and nitrogen, and the concentration of the nitric oxide gas is 1500 mu L/L.

The volume of the aluminum foil bag is 1L.

The method for improving the pork quality by using the device for improving the pork quality by using the nitric oxide gas fumigation is characterized by comprising the following steps of:

1) opening a sealing door on the fumigation container, flatly placing pork slices above a plastic screen plate in the fumigation container, and then closing the sealing door;

2) and nitrogen flushing: opening a nitrogen steel cylinder, rotating a nitrogen pressure reducing valve, regulating the flow rate of nitrogen through a rotor flow meter, and introducing nitrogen into the aluminum foil bag and the injector through a nitrogen pipe; adjusting the one-way valve, the three-way valve and the air inlet valve to enable the aluminum foil bag and the injector to be communicated with the fumigation container, and opening an exhaust valve on the fumigation container;

the nitrogen in the aluminum foil bag flows into the fumigation container through the first pipe, the three-way valve, the second pipe and the air inlet valve, and the nitrogen in the injector flows into the fumigation container through the injection pipe, the three-way valve and the second pipe; and because of the function of the one-way valve, the nitrogen in the injector can not flow into the aluminum foil bag through the first pipe, and the nitrogen flowing out of the aluminum foil bag can not flow back into the aluminum foil bag through the first pipe; the nitrogen flowing in is discharged out of the fumigation container through an exhaust valve; therefore, the fumigation container, the aluminum foil bag and the injector are flushed by nitrogen, residual air in the fumigation container, the aluminum foil bag and the injector is exhausted, and an oxygen-free environment is ensured;

then closing the exhaust valve, and adjusting the one-way valve, the three-way valve and the air inlet valve to ensure that the aluminum foil bag, the injector and the fumigation container are not communicated with each other;

3) and nitric oxide gas fumigation: opening a nitric oxide steel cylinder, rotating a nitric oxide pressure reducing valve, injecting nitric oxide gas into the aluminum foil bag through the nitric oxide pipe for later use, and closing the nitric oxide pressure reducing valve; adjusting the three-way valve and the one-way valve to enable the injector and the aluminum foil bag to be communicated, extracting nitric oxide gas from the aluminum foil bag by using the injector, storing the nitric oxide gas into the injector, and then closing the one-way valve to enable the injector and the aluminum foil bag not to be communicated;

adjusting a three-way valve and an air inlet valve to enable the injector and the fumigation container to be communicated, injecting nitric oxide gas in the injector into the fumigation container, controlling the concentration of nitric oxide in the fumigation container to be 40-80 mu L/L, and then closing the three-way valve and the air inlet valve; controlling the temperature in the fumigation container to be 20-25 ℃ by a temperature controller in the fumigation container, and fumigating the pork slices in an environment with nitric oxide concentration of 40-80 mu L/L and temperature of 20-25 ℃ for 2 h;

4) pork packaging and storage: and taking out the pork slices in the fumigation container after the fumigation is finished.

In step 1), the pork slices are obtained by:

removing fascia and fat on the surface of the longest muscle part of the back of a fresh pig within 6h after slaughtering, and trimming to 5 × 5 × 2cm³The pork slices are 60g in weight and are flatly placed above a plastic net in the fumigation container.

Further comprises step 5), vacuum packaging the pork slices taken out of the fumigation container, and storing at low temperature of 4 ℃ for 1, 4 or 7 days.

Compared with the prior art, the invention has the following beneficial technical effects: the method for improving the pork quality by adopting the nitric oxide gas fumigation effectively regulates and controls the after-slaughter ripening process of the pork by controlling the content of the nitric oxide gas in the closed container. The method has the advantages of simple operation, low cost and no harmful chemical residual substances. On the 4 th day and the 7 th day of storage, compared with pork not treated by nitric oxide, the red value of the pork treated by nitric oxide fumigation at 40-60 mu L/L is increased by 8%, the shearing force is reduced by 13%, the hardness is reduced by 8%, the chewiness is reduced by 18%, the storage loss is reduced by 8%, the total number of bacterial colonies is reduced by 20%, and the quality of the pork during storage is improved. The method has the advantages of simple operation, low cost, no harmful chemical residual substances and wide application prospect.

Drawings

Fig. 1 is a schematic structural view of the present invention.

FIG. 2 is a graph showing the results of the storage loss measurement of pork fumigated with nitric oxide gas of different concentrations in examples 2 to 5 of the present invention.

FIG. 3 is a graph showing the results of measuring the shearing force of pork fumigated with nitric oxide gas of different concentrations in examples 2 to 5 of the present invention.

FIG. 4 is a graph showing the results of hardness measurements of pork fumigated with nitric oxide gas of different concentrations in examples 2 to 5 of the present invention.

FIG. 5 is a graph showing the results of measuring the chewiness of pork fumigated with nitric oxide gas of different concentrations in examples 2 to 5 of the present invention.

FIG. 6 is a graph showing the results of measuring the total number of colonies of pork fumigated with nitric oxide gas of different concentrations in examples 2 to 5 of the present invention.

FIG. 7 is a graph showing the results of measuring nitrite in pork fumigated with nitric oxide gas of different concentrations in examples 2 to 5 of the present invention.

FIG. 8 is a graph showing the results of measuring the nitrate content of pork fumigated with nitric oxide gas of different concentrations in examples 2 to 5 of the present invention.

In the figure: 1 fumigating container, 2 plastic mesh plates, 3 exhaust valves, 4 pork slices, 5 air inlet valves, 6 three-way valves, 7 injectors, 8 one-way valves, 9 aluminum foil bags, 10-1 first pipes, 10-2 second pipes, 11 injection pipes and 12 exhaust pipes.

Detailed Description

The invention is further described below with reference to the accompanying drawings.

The structure of the invention is as follows:

a device for improving pork quality by using nitric oxide gas fumigation comprises a fumigation container 1, an aluminum foil bag 9 and a three-way valve 6; the three-way valve 6 is sequentially connected with a first pipe 10-1, a second pipe 10-2 and an injection pipe 11; one end of the first pipe 10-1 is communicated with the three-way valve 6, the other end is communicated with the aluminum foil bag 9, and the first pipe 10-1 is provided with a one-way valve 8; one end of the second pipe 10-2 is communicated with the three-way valve 6, the other end is communicated with the top of the fumigation container 1, and the second pipe 10-2 is provided with an air inlet valve 5; the aluminum foil bag 9 is communicated with the fumigation container 1 through a first pipe 10-1, a one-way valve 8, a three-way valve 6, a second pipe 10-2 and an air inlet valve 5; one end of the injection pipe 11 is communicated with the three-way valve 6, and the other end is connected with the injector 7. A plastic screen 2 for placing pork slices 4 is arranged in the fumigation container 1, an exhaust pipe 12 is arranged on the side wall of the fumigation container 1 below the plastic screen 2, and an exhaust valve 3 is arranged on the exhaust pipe 12.

The device is also provided with a nitrogen steel cylinder and a nitrogen pipe, wherein a nitrogen pressure reducing valve is arranged on the nitrogen steel cylinder, one end of the nitrogen pipe is connected to the nitrogen pressure reducing valve, the other end of the nitrogen pipe is communicated with the aluminum foil bag 9 and the injector 7, and a rotor flow meter is arranged on the nitrogen pipe; the nitrogen steel cylinder is communicated with the aluminum foil bag 9 and the injector 7 through a reducing valve, a rotor flow meter and a nitrogen pipe;

the nitrogen oxide pressure reducing valve is arranged on the nitrogen oxide steel cylinder, one end of the nitrogen oxide pipe is connected to the nitrogen oxide pressure reducing valve, and the other end of the nitrogen oxide pipe is communicated with the aluminum foil bag 9; the nitric oxide steel cylinder is communicated with the aluminum foil bag 9 through a nitric oxide pressure reducing valve and a nitric oxide pipe; a temperature controller is arranged in the fumigation container 1, and a sealing door is arranged on the fumigation container 1.

Further, the fumigation container 1 is a rectangular plastic preservation box made of polyethylene. The fumigation container 1 has a length of 24.5cm, a width of 16cm, a height of 8cm and a volume of 3L. The nitrogen cylinder stores 99.9% nitrogen. The nitric oxide steel bottle is internally stored with mixed gas of nitric oxide and nitrogen, and the concentration of the nitric oxide gas is 1500 mu L/L. The aluminum foil bag 9 has a volume of 1L.

Example 1: a device for improving the pork quality by adopting nitric oxide gas fumigation;

1) opening a sealing door on the fumigation container 1, flatly placing the pork slices 4 above the plastic mesh plate 2 in the fumigation container 1, and then closing the sealing door;

2) and nitrogen flushing: opening a nitrogen steel cylinder, wherein the concentration of nitrogen in the steel cylinder is 99.9%, rotating a nitrogen pressure reducing valve, adjusting the flow rate of nitrogen through a rotor flow meter, and introducing the nitrogen into the aluminum foil 9 and the injector 7 through a nitrogen pipe; adjusting the one-way valve 8, the three-way valve 6 and the air inlet valve 5 to enable the aluminum foil bag 9 and the injector 7 to be communicated with the fumigation container 1, and opening the exhaust valve 3 on the fumigation container 1; nitrogen in the aluminum foil bag 9 flows into the fumigation container 1 through the first pipe 10-1, the three-way valve 6, the second pipe 10-2 and the air inlet valve 5, and nitrogen in the injector 7 flows into the fumigation container 1 through the injection pipe 11, the three-way valve 6 and the second pipe 10-2; due to the action of the one-way valve 8, nitrogen in the injector 7 cannot flow into the aluminum foil bag 9 through the first pipe 10-1, and nitrogen flowing out of the aluminum foil bag 9 cannot flow back into the aluminum foil bag 9 through the first pipe 10-1; the nitrogen flowing in is discharged out of the fumigation container 1 through an exhaust valve 3; thereby realizing that the fumigation container 1, the aluminum foil bag 9 and the injector 7 are flushed by nitrogen, exhausting residual air in the fumigation container 1, the aluminum foil bag 9 and the injector 7, and ensuring an oxygen-free environment; then the exhaust valve 3 is closed, and the one-way valve 8, the three-way valve 6 and the air inlet valve 5 are adjusted, so that the aluminum foil bag 9, the injector 7 and the fumigation container 1 are not communicated with each other;

3) and nitric oxide gas fumigation: opening a nitric oxide steel cylinder, wherein the concentration of nitric oxide gas in the nitric oxide steel cylinder is 1500 mu L/L, rotating a nitric oxide pressure reducing valve, injecting the nitric oxide gas into the aluminum foil bag 9 through a nitric oxide pipe for later use, and closing the nitric oxide pressure reducing valve to enable 60-70% of nitric oxide gas to be stored in the aluminum foil bag 9; adjusting the three-way valve 6 and the one-way valve 8 to enable the injector 7 and the aluminum foil bag 9 to be communicated, extracting nitric oxide gas from the aluminum foil bag 9 by using the injector 7, storing the nitric oxide gas into the injector 7, and then closing the one-way valve 8 to enable the injector 7 and the aluminum foil bag 9 not to be communicated;

adjusting the three-way valve 6 and the air inlet valve 5 to enable the injector 7 and the fumigation container 1 to be communicated, injecting nitric oxide gas in the injector 7 into the fumigation container 1, controlling the concentration of nitric oxide in the fumigation container 1 to be 40-80 mu L/L, and then closing the three-way valve 6 and the air inlet valve 5; controlling the temperature in the fumigation container 1 to be 20-25 ℃ through a temperature controller in the fumigation container 1, and fumigating the pork slices 4 for 2 hours in an environment with nitric oxide concentration of 40-80 mu L/L and temperature of 20-25 ℃;

4) pork packaging and storage: and taking out the pork slices 4 in the fumigation container 1 after the fumigation is finished.

Further, in step 1), the pork slices 4 are obtained by: removing fascia and fat on the surface of the longest muscle part of the back of a fresh pig within 6h after slaughtering, and trimming to 5 × 5 × 2cm³The pork slices (4) are evenly placed above a plastic net in the fumigation container, and the weight of the pork slices (4) is 60 g.

Further comprises a step 5) of vacuum packaging the pork slices 4 taken out of the fumigation container 1 and storing at low temperature of 4 ℃ for 1, 4 or 7 days.

Example 2: control treatment of fresh pork without fumigation with nitric oxide gas;

step 1), pork pretreatment: removing fascia and fat on the surface of the longest muscle part of the back of a fresh pig within 6h after slaughtering, and trimming to 5 × 5 × 2cm³(60 g) pieces of meat (pork pieces) are placed flat on top of a plastic mesh inside the fumigation container.

Flushing with nitrogen: opening a nitrogen steel cylinder, rotating a nitrogen pressure reducing valve, regulating the flow rate of nitrogen through a rotor flow meter, and introducing nitrogen into the aluminum foil 9 and the injector 7 through a nitrogen pipe; adjusting the one-way valve 8, the three-way valve 6 and the air inlet valve 5 to enable the aluminum foil bag 9 and the injector 7 to be communicated with the fumigation container 1, and opening the exhaust valve 3 on the fumigation container 1; nitrogen in the aluminum foil bag 9 flows into the fumigation container 1 through the first pipe 10-1, the three-way valve 6, the second pipe 10-2 and the air inlet valve 5, and nitrogen in the injector 7 flows into the fumigation container 1 through the injection pipe 11, the three-way valve 6 and the second pipe 10-2; due to the action of the one-way valve 8, nitrogen in the injector 7 cannot flow into the aluminum foil bag 9 through the first pipe 10-1, and nitrogen flowing out of the aluminum foil bag 9 cannot flow back into the aluminum foil bag 9 through the first pipe 10-1; the nitrogen flowing in is discharged out of the fumigation container 1 through an exhaust valve 3; thereby realizing that the fumigation container 1, the aluminum foil bag 9 and the injector 7 are flushed by nitrogen, exhausting residual air in the fumigation container 1, the aluminum foil bag 9 and the injector 7, and ensuring an oxygen-free environment; flushing with nitrogen: opening a nitrogen steel cylinder, rotating a nitrogen pressure reducing valve, regulating the flow rate of nitrogen through a rotor flow meter, and introducing nitrogen into the aluminum foil 9 and the injector 7 through a nitrogen pipe; adjusting the one-way valve 8, the three-way valve 6 and the air inlet valve 5 to enable the aluminum foil bag 9 and the injector 7 to be communicated with the fumigation container 1, and opening the exhaust valve 3 on the fumigation container 1; nitrogen in the aluminum foil bag 9 flows into the fumigation container 1 through the first pipe 10-1, the three-way valve 6, the second pipe 10-2 and the air inlet valve 5, nitrogen in the injector 7 flows into the fumigation container 1 through the injection pipe 11, the three-way valve 6 and the second pipe 10-2, and the nitrogen flowing in is discharged out of the fumigation container 1 through the air outlet valve 3; thereby realizing that the fumigation container 1, the aluminum foil bag 9 and the injector 7 are flushed by nitrogen, exhausting residual air in the fumigation container 1, the aluminum foil bag 9 and the injector 7, and ensuring an oxygen-free environment; then the exhaust valve 3 is closed, and the one-way valve 8, the three-way valve 6 and the air inlet valve 5 are adjusted, so that the aluminum foil bag 9, the injector 7 and the fumigation container 1 are not communicated with each other;

step 3), placing pork for 2 h: and placing the pork on a plastic net in the fumigation container for 2 hours in an environment of 20-25 ℃.

Step 4), pork packaging and storage: after the fumigation is finished, taking out the pork in the fumigation container, carrying out vacuum packaging, storing at a low temperature of 4 ℃, taking out after 1, 4 and 7 days of storage, and measuring the color, texture, shearing force, storage loss, total bacterial colony number and the contents of nitrite and nitrate of the pork sample.

Example 3: fumigating fresh pork by nitric oxide gas with the concentration of 40 mu L/L;

step 1), pork pretreatment: removing fascia and fat on the surface of the longest muscle part of the back of a fresh pig within 6h after slaughtering, and trimming to 5 × 5 × 2cm³(60 g) pieces of meat (pork pieces) are placed flat on top of a plastic mesh inside the fumigation container.

Step 2), nitrogen flushing device: opening a nitrogen steel cylinder, rotating a nitrogen pressure reducing valve, regulating the flow rate of nitrogen through a rotor flow meter, and introducing nitrogen into the aluminum foil 9 and the injector 7 through a nitrogen pipe; adjusting the one-way valve 8, the three-way valve 6 and the air inlet valve 5 to enable the aluminum foil bag 9 and the injector 7 to be communicated with the fumigation container 1, and opening the exhaust valve 3 on the fumigation container 1; nitrogen in the aluminum foil bag 9 flows into the fumigation container 1 through the first pipe 10-1, the three-way valve 6, the second pipe 10-2 and the air inlet valve 5, and nitrogen in the injector 7 flows into the fumigation container 1 through the injection pipe 11, the three-way valve 6 and the second pipe 10-2; due to the action of the one-way valve 8, nitrogen in the injector 7 cannot flow into the aluminum foil bag 9 through the first pipe 10-1, and nitrogen flowing out of the aluminum foil bag 9 cannot flow back into the aluminum foil bag 9 through the first pipe 10-1; the nitrogen flowing in is discharged out of the fumigation container 1 through an exhaust valve 3; thereby realizing that the fumigation container 1, the aluminum foil bag 9 and the injector 7 are flushed by nitrogen, exhausting residual air in the fumigation container 1, the aluminum foil bag 9 and the injector 7, and ensuring an oxygen-free environment; flushing with nitrogen: opening a nitrogen steel cylinder, rotating a nitrogen pressure reducing valve, regulating the flow rate of nitrogen through a rotor flow meter, and introducing nitrogen into the aluminum foil 9 and the injector 7 through a nitrogen pipe; adjusting the one-way valve 8, the three-way valve 6 and the air inlet valve 5 to enable the aluminum foil bag 9 and the injector 7 to be communicated with the fumigation container 1, and opening the exhaust valve 3 on the fumigation container 1; nitrogen in the aluminum foil bag 9 flows into the fumigation container 1 through the first pipe 10-1, the three-way valve 6, the second pipe 10-2 and the air inlet valve 5, nitrogen in the injector 7 flows into the fumigation container 1 through the injection pipe 11, the three-way valve 6 and the second pipe 10-2, and the nitrogen flowing in is discharged out of the fumigation container 1 through the air outlet valve 3; thereby realizing that the fumigation container 1, the aluminum foil bag 9 and the injector 7 are flushed by nitrogen, exhausting residual air in the fumigation container 1, the aluminum foil bag 9 and the injector 7, and ensuring an oxygen-free environment; then the exhaust valve 3 is closed, and the one-way valve 8, the three-way valve 6 and the air inlet valve 5 are adjusted, so that the aluminum foil bag 9, the injector 7 and the fumigation container 1 are not communicated with each other.

Step 3), nitric oxide gas fumigation: opening the nitrogen monoxide steel bottle, rotating the nitrogen monoxide pressure reducing valve, and injecting the nitrogen monoxide into the aluminum foil bag for later use. And (3) pumping 80mL of nitric oxide gas from the aluminum foil bag by using an injector through controlling a three-way valve, injecting the nitric oxide gas into the fumigation container to ensure that the concentration of the nitric oxide in the fumigation container is 40 mu L/L, and fumigating for 2 hours at the temperature of 20-25 ℃.

Step 4), pork packaging and storage: after the fumigation is finished, taking out the pork in the fumigation container, carrying out vacuum packaging, storing at a low temperature of 4 ℃, taking out after 1, 4 and 7 days of storage, and measuring the color, texture, shearing force, storage loss, total bacterial colony number and the contents of nitrite and nitrate of the pork sample.

Example 4: fumigating fresh pork by nitric oxide gas with the concentration of 60 mu L/L;

step 1), pork pretreatment: removing fascia and fat on the surface of the longest muscle part of the back of a fresh pig within 6h after slaughtering, and trimming to 5 × 5 × 2cm³(60 g) meat slices (pork slices) which are flatly placed on the plastic net inside the fumigation container;

step 2), nitrogen flushing device: and opening a nitrogen steel cylinder, rotating a nitrogen pressure reducing valve, regulating the nitrogen flow rate through a rotor flow meter, introducing nitrogen into the fumigation container, the aluminum foil bag and the injector, flushing the container, the aluminum foil bag and the injector, exhausting residual air in the device and ensuring an anaerobic environment.

Step 3), nitric oxide gas fumigation: and opening the nitric oxide steel cylinder, rotating the nitric oxide pressure reducing valve, and injecting nitric oxide gas into the aluminum foil bag for later use. And (3) pumping 120mL of nitric oxide gas from the aluminum foil bag by using an injector through controlling a three-way valve, injecting the nitric oxide gas into the fumigation container to ensure that the concentration of the nitric oxide in the fumigation container is 60 mu L/L, and fumigating for 2 hours at the temperature of 20-25 ℃.

Step 4), pork packaging and storage: after the fumigation is finished, taking out the pork in the fumigation container, carrying out vacuum packaging, storing at a low temperature of 4 ℃, taking out after 1, 4 and 7 days of storage, and measuring the color, texture, shearing force, storage loss, total bacterial colony number and the contents of nitrite and nitrate of the pork sample.

Example 5: fumigating fresh pork by nitric oxide gas with the concentration of 80 mu L/L;

step 1), pork pretreatment: removing fascia and fat on the surface of the longest muscle part of the back of a fresh pig within 6h after slaughtering, and trimming to 5 × 5 × 2cm³(60 g) pieces of meat (pork pieces) are placed flat on top of a plastic mesh inside the fumigation container.

Step 2), nitrogen flushing device: and opening a nitrogen steel cylinder, rotating a pressure reducing valve, regulating the nitrogen flow rate through a rotor flow meter, introducing nitrogen into the fumigation container, the aluminum foil bag and the injector, flushing the container, the aluminum foil bag and the injector, exhausting residual air in the device and ensuring an anaerobic environment.

Step 3), nitric oxide gas fumigation: and opening the nitric oxide steel cylinder, rotating the pressure reducing valve, and injecting nitric oxide gas into the aluminum foil bag with the volume of 1L for later use. And (3) pumping 160mL of nitric oxide gas from the aluminum foil bag by using an injector through controlling a three-way valve, injecting the nitric oxide gas into the fumigation container to ensure that the concentration of the nitric oxide in the fumigation container is 80 mu L/L, and fumigating for 2 hours at the temperature of 20-25 ℃.

Step 4), pork packaging and storage: after the fumigation is finished, taking out the pork in the fumigation container, carrying out vacuum packaging, storing at a low temperature of 4 ℃, taking out after 1, 4 and 7 days of storage, and measuring the color, texture, shearing force, storage loss, total bacterial colony number and the contents of nitrite and nitrate of the pork sample.

The control group without fumigation treatment in examples 2-5 and the experimental group with fumigation treatment of three nitric oxide gases with different concentrations were stored in an environment of 4 ℃ for 1, 4 and 7 days. Table 1 shows the results of color measurements of a control group without fumigation and three experimental groups with different concentrations of nitric oxide gas fumigation after 1, 4 and 7 days of storage.

TABLE 1 pork color measurement results

Different lower case letters indicate significant differences (P < 0.05) between treatment groups for the same storage time.

As can be seen from table 1, the red value a of the experimental group fumigated with nitric oxide gas significantly increased compared to the control group not fumigated with nitric oxide gas, and the red value a of the pork sample increased with the increase in the concentration of nitric oxide gas. Experiments show that the nitric oxide gas fumigation treatment of the invention ensures that the pork maintains better ruddy color during the storage period.

As can be seen from FIG. 2, the storage loss of the experimental group fumigated with nitric oxide gas at a concentration of 40, 60. mu.L/L was significantly reduced compared to the control group not fumigated with nitric oxide gas. Experiments show that the nitric oxide gas fumigation treatment with the concentration of 40 and 60 mu L/L improves the water retention performance of pork, reduces the juice loss of the pork during storage and controls the nutrition loss of a pork sample during storage.

As can be seen from FIG. 3, the shear force was significantly reduced in the experimental group fumigated with nitric oxide gas at a concentration of 40, 60. mu.L/L, compared to the control group not fumigated with nitric oxide gas. Experiments show that the nitrogen monoxide fumigation treatment with the concentration of 40 and 60 mu L/L improves the tenderness of pork.

As can be seen from fig. 4, the hardness values of the experimental group fumigated with nitric oxide gas at concentrations of 40 and 60 μ L/L were significantly reduced compared to the control group not fumigated with nitric oxide gas, and the hardness variation tendency of the differently treated pork samples corresponded to the shear force variation tendency.

As can be seen from FIG. 5, the chewiness of the experimental group fumigated with nitric oxide gas at a concentration of 40, 60. mu.L/L was significantly reduced compared to the control group not fumigated with nitric oxide gas. Experiments show that the nitrogen monoxide fumigation treatment with the concentration of 40 and 60 mu L/L improves the chewiness of pork.

As can be seen from fig. 6, the total number of colonies of the experimental group fumigated with nitric oxide gas was significantly reduced, and the total number of colonies of the pork sample decreased as the concentration of nitric oxide gas increased, compared to the control group not fumigated with nitric oxide gas. Experiments show that the nitric oxide gas fumigation treatment inhibits the growth and reproduction of microorganisms in the pork sample, so that the degree of microbial contamination of the pork during storage is reduced.

As can be seen from fig. 7 and 8, the nitrite content was significantly reduced and the nitrate content was significantly increased in the experimental group fumigated with nitric oxide gas at a concentration of 40, 60 μ L/L, as compared to the control group not fumigated with nitric oxide gas.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the protection scope of the present invention, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.