Straw mushroom fresh-keeping transportation method based on quick-freezing fresh-returning synergistic effect

Abstract

The invention discloses a straw mushroom fresh-keeping transportation method based on a quick-freezing fresh-returning synergistic effect, which is characterized by comprising the following steps: S1, pre-cooling straw mushrooms with unbroken pellicle and pileus diameter of 2-3cm to inhibit breathing heat; s2, the pre-cooled straw mushrooms are taken out of the soaking solution, and the straw mushrooms are air-dried through cold air, so that a protective film is formed on the surfaces of the straw mushrooms through the dried solution; s3, quickly freezing the volvariella volvacea treated in the step S2 in stages until the diameter of ice crystals on the surface of the volvariella volvacea is less than or equal to S4, putting the volvariella volvacea treated in the step S3 into a constant-temperature warehouse to promote the volvariella volvacea to complete cell dehydration and dormancy; and S5, packaging the volvariella volvacea processed in the step S4, and then transporting by using a cold chain. According to the method, the preservation effect of the straw mushrooms can be remarkably improved, the method has the advantages of being easy and convenient to operate, low in cost, high in practicability and the like, the preservation effect advantage is obvious, then the transportation radius of the straw mushrooms is expanded to 1500 km from 300 km, and the loss rate is reduced to 6.7% from 35%.

Description

Technical Field

[0001] The invention relates to the technical field of edible fungus preservation, and in particular to a straw mushroom preservation and transportation method based on the synergistic effect of quick freezing and freshness recovery. Background Art

[0002] Volvariella volvacea is a high-temperature, high-humidity edible fungus. After the fruiting bodies are harvested at 30-32°C, their metabolic activity remains vigorous. Within 24 hours after harvesting, the cap will continue to grow, the stipe will continue to elongate, and the mycelium surrounding the fruiting bodies will rupture, changing their appearance from oval to umbrella-shaped. The nutrient content of Volvariella volvacea is highest during the oval stage. As the fruiting bodies elongate and open, the nutritional value and commercial value of Volvariella volvacea decrease significantly. Autolysis is a significant characteristic of Volvariella volvacea that makes them intolerant to low-temperature storage. After a period of storage at conventional low temperatures, the surface of Volvariella volvacea fruiting bodies will show signs of water seepage, browning, and decay. This characteristic severely limits the circulation of fresh Volvariella volvacea and their low-temperature refrigeration preservation, thereby affecting export earnings and restricting the development of the Volvariella volvacea industry in China and even the world. Therefore, the preservation of Volvariella volvacea has become a technical problem that needs to be urgently solved in the development of the industry. Summary of the Invention

[0003] The object of the present invention is to provide a method for preserving and transporting straw mushrooms based on the synergistic effect of quick freezing and freshness recovery, so as to solve the problems raised in the above background technology.

[0004] To achieve the above object, the present invention provides the following technical solution: a method for preserving and transporting straw mushrooms based on the synergistic effect of quick freezing and freshness recovery, characterized by comprising the following steps: S1: precooling straw mushrooms with intact mycelium and cap diameter of 2-3 cm to suppress respiratory heat;

[0005] S2: removing the pre-cooled straw mushrooms from the soaking solution and air-drying the straw mushrooms with cold air so that the dried solution forms a protective film on the surface of the straw mushrooms;

[0006] S3: Quick-freezing the straw mushrooms processed in step S2 in stages until the diameter of ice crystals on the surface of the straw mushrooms is ≤50 μm;

[0007] S4: placing the straw mushrooms processed in step S3 into a constant temperature storage to facilitate cell dehydration and dormancy of the straw mushrooms;

[0008] S5: The straw mushrooms obtained in step S4 are packaged and then transported using a cold chain.

[0009] As a preferred technical solution of the present invention: the pre-cooling method of step S1 is to use a vacuum pre-cooling machine to reduce the core temperature of the straw mushroom to 2°C within 5 minutes.

[0010] As a preferred technical scheme of the present application: the formula of the soaking solution in step S2 is 0.8% edible gelatin, 0.5% sodium alginate, and 0.1% calcium ascorbate by weight, and water is used to dissolve the edible gelatin, sodium alginate, and calcium ascorbate.

[0011] As a preferred technical scheme of the present application: the water temperature is 2℃.

[0012] As a preferred technical scheme of the present application: the rapid cooling method in step S3 includes the following steps: S6: rapidly freezing the straw mushroom at 2℃ in an environment at -10℃ for 5 minutes; and S7: deep-freezing the rapidly frozen straw mushroom at -30℃ for 15 minutes until the ice crystal diameter on the surface of the straw mushroom is ≤50μm, and the ice crystals are fine needles under a microscope.

[0013] As a preferred technical scheme of the present application: the constant temperature refrigeration in step S4 is performed in a constant temperature refrigerator at -18℃, with a humidity of 85-90% and a refrigeration time of 12-24 hours.

[0014] As a preferred technical scheme of the present application: the method further includes fresh activation of the straw mushroom, and the specific steps are as follows: S8: thawing the refrigerated straw mushroom in an environment at 4℃ for two hours; and S9: placing the thawed straw mushroom in a humid environment at a temperature of 8℃ for one hour to facilitate the straw mushroom to fully absorb water until the center temperature of the straw mushroom is between 0±0.5℃.

[0015] As a preferred technical scheme of the present application: the thawing rate in step S8 is ≤2℃ / min.

[0016] As a preferred technical scheme of the present application: the humidity of the humid environment in step S9 is 95%.

[0017] As a preferred technical scheme of the present application: the packaging method in step S5 is as follows: the straw mushroom is packaged in a microporous PE bag, the packaged straw mushroom is placed in a polyurethane incubator, and a phase change cold storage box is stored in the polyurethane incubator; and the transportation temperature zone fluctuates between 0-2℃ and is monitored by a temperature recorder throughout the process.

[0018] With the above technical scheme, the present application has the advantages of significantly improving the preservation effect of the straw mushroom, being simple and easy to operate, being low in cost, being highly practical, and having obvious preservation effect advantages, thereby expanding the transportation radius of the straw mushroom. DETAILED DESCRIPTION

[0019] Embodiments of the present application are described below in detail, a fresh-keeping and transporting method of Volvariella volvacea based on the synergistic effect of quick freezing and fresh-keeping, characterized in that it comprises the following steps: S1: pre-cooling Volvariella volvacea with unbroken gill membrane and 2-3 cm in diameter to inhibit respiratory heat; S2: taking the pre-cooled Volvariella volvacea out of the soaking solution and using cold air to dry the Volvariella volvacea so that a protective film is formed on the surface of the dried Volvariella volvacea; S3: quick-freezing the Volvariella volvacea treated in step S2 in stages until the ice crystal diameter on the surface of the Volvariella volvacea is ≤50 μm; S4: placing the Volvariella volvacea treated in step S3 into a constant-temperature library to make the Volvariella volvacea complete cell dehydration and dormancy; and S5: packaging the Volvariella volvacea treated in step S4 and then transporting it by using a cold chain.

[0020] In summary, the method can significantly improve the fresh-keeping effect of Volvariella volvacea and has the advantages of simple operation, low cost, strong practicability, etc., especially, the fresh-keeping effect is obviously superior, thereby expanding the transportation radius of Volvariella volvacea.

[0021] Preferably, the pre-cooling method in step S1 is to use a vacuum pre-cooling machine to reduce the center temperature of the Volvariella volvacea to 2℃ within 5 min, so that the Volvariella volvacea can be rapidly cooled to reduce its respiratory intensity, thereby facilitating the preservation thereof.

[0022] To improve the fresh-keeping ability of the Volvariella volvacea and reduce the problems of deterioration and damage of the Volvariella volvacea, the formula of the soaking solution in step S2 comprises 0.8% edible gelatin, 0.5% sodium alginate and 0.1% calcium ascorbate by weight, and water is used to dissolve the edible gelatin, sodium alginate and calcium ascorbate. The formula has the advantages that the edible gelatin is beneficial to film formation on the surface of the Volvariella volvacea; the sodium alginate can inhibit bacteria and improve the toughness of the Volvariella volvacea to avoid damage of the Volvariella volvacea; and the calcium ascorbate can prevent the Volvariella volvacea from browning. Therefore, the formula provides reliable technical support for the preservation and transportation of the Volvariella volvacea.

[0023] Further, since the water temperature of the water is 2℃, the respiration of the Volvariella volvacea can be further inhibited without affecting the effects of other components in the solution, thereby avoiding the respiration of the Volvariella volvacea due to rewarming.

[0024] The quick-freezing method in step S3 comprises the following steps: S6: quickly freezing the 2℃ Volvariella volvacea in a-10℃ environment for 5 min; and S7: deep-freezing the quickly frozen Volvariella volvacea in a-30℃ environment for 15 min until the ice crystal diameter on the surface of the Volvariella volvacea is ≤50 μm, and the ice crystal is fine needle-like under a microscope. In this way, the Volvariella volvacea can be rapidly frozen to inhibit its respiration, thereby ensuring the fresh-keeping effect of the Volvariella volvacea and providing technical support for long-distance transportation of the Volvariella volvacea.

[0025] Furthermore, the constant temperature refrigeration conditions in step S4 are: a constant temperature warehouse at -18°C, a humidity of 85-90%, and a refrigeration time of 12-24 hours. Therefore, under these conditions, critical point freezing of the straw mushrooms can be achieved, and the dehydration dormancy of the cells can be completed. Due to the stable structure of the dormant cells, the transportation loss can be reduced to less than 8%.

[0026] On the basis of the above scheme, the freshness activation of straw mushrooms is also included, and the specific steps are as follows: S8: thawing the refrigerated straw mushrooms in an environment of 4°C for two hours; S9: placing the straw mushrooms thawed in step S8 in a humid environment at a temperature of 8°C for one hour to allow the straw mushrooms to fully absorb moisture, until the center temperature of the straw mushrooms is between 0±0.5°C.

[0027] Because the core temperature of straw mushrooms is between 0±0.5°C, they are at a metabolically static point, ensuring optimal moisture retention. This not only maintains the freshness of the mushrooms after activation, but also prevents them from becoming soft and rotten due to thawing. Furthermore, through ice crystal morphology control and step-by-step freshness recovery, the recovery rate of straw mushrooms exceeds 90%.

[0028] Furthermore, since the thawing rate in step S8 is ≤2°C / min, the rupture of the straw mushroom cells can be avoided, thereby further preventing the straw mushrooms from becoming soft and rotten.

[0029] At the same time, the humidity of the humid environment in step S9 is 95%. In this humid environment, the straw mushrooms can fully absorb the moisture in the environment, making them more tender and thus ensuring the freshness of the straw mushrooms.

[0030] To ensure the proper length of the straw mushrooms for transport, the packaging method in step S5 is as follows: the straw mushrooms are packaged in microporous PE bags, placed in a polyurethane insulated box, and then placed in a phase-change cold storage box within the polyurethane insulated box. The transport temperature fluctuates between 0-2°C and is monitored throughout the process by a temperature recorder. This reduces the risk of deterioration of the straw mushrooms due to temperature fluctuations during transport. The interior of the phase-change cold storage box is filled with a -1°C phase-change material. The microporous PE bags preferably have a pore size of 0.2mm to prevent condensation on the straw mushrooms.

[0031] The experimental data are compared as follows:

[0032] Index Traditional refrigeration The invention Lifting amplitude Fresh-keeping period 3-5 days 8-21 days 400% Umbrella opening inhibition rate 45% 93% 107% Recovery rate after thawing 62% 91% 47% Transportation cost / 500km ￥8.2 / kg ￥3.5 / kg -57%

[0033] Through the data analysis of the above table, the method can effectively prolong the transportation radius of the straw mushroom, has a longer preservation period, and has a higher recovery rate. In particular, the transportation cost of the straw mushroom can be reduced, and the content of the table can be obtained. The preservation time is prolonged, and the loss is low, so that the transportation radius of the straw mushroom is expanded from 300km to 1500km, and the loss rate is reduced from 35% to 6.7%.

[0034] The above describes the embodiments of the present application in detail, but the present application is not limited to the described embodiments. For those skilled in the art, various changes, modifications, replacements and variations of the embodiments can be made without departing from the principles and spirits of the present application, and still fall within the protection scope of the present application.

Claims

1. A method for preserving and transporting straw mushrooms based on the synergistic effect of quick freezing and freshness recovery, characterized in that: The following steps are involved: S1: Pre-cool the mushrooms with intact mycelium and cap diameter of 2-3 cm to suppress respiratory heat; S2: removing the pre-cooled straw mushrooms from the soaking solution and air-drying the straw mushrooms with cold air so that the dried solution forms a protective film on the surface of the straw mushrooms; S3: Quick-freezing the straw mushrooms processed in step S2 in stages until the diameter of ice crystals on the surface of the straw mushrooms is ≤50 μm; S4: placing the straw mushrooms processed in step S3 into a constant temperature storage to facilitate cell dehydration and dormancy of the straw mushrooms; S5: The straw mushrooms obtained in step S4 are packaged and then transported using a cold chain.

2. The method for preserving and transporting straw mushrooms based on the synergistic effect of quick freezing and freshness recovery according to claim 1, characterized in that: The pre-cooling method of step S1 is to use a vacuum pre-cooling machine to reduce the core temperature of the straw mushroom to 2° C. within 5 minutes.

3. The method for preserving and transporting straw mushrooms based on the synergistic effect of quick freezing and freshness recovery according to claim 1, characterized in that: The formula of the soaking solution in step S2 is 0.8% edible gelatin, 0.5% sodium alginate, and 0.1% calcium ascorbate by weight, and water is used to dissolve the edible gelatin, sodium alginate, and calcium ascorbate.

4. The method for preserving and transporting straw mushrooms based on the synergistic effect of quick freezing and freshness recovery according to claim 3, characterized in that: The water temperature of the water was 2°C.

5. The method for preserving and transporting straw mushrooms based on the synergistic effect of quick freezing and freshness recovery according to claim 1, characterized in that: The rapid cooling method in step S3 includes the following steps: step S6: quick-freezing the straw mushrooms at 2°C in a -10°C environment for 5 minutes; step S7: deep-freezing the quick-frozen straw mushrooms in a -30°C environment for 15 minutes until the diameter of the ice crystals on the surface of the straw mushrooms is ≤50 μm, and the ice crystals appear as fine needles under a microscope.

6. The method for preserving and transporting straw mushrooms based on the synergistic effect of quick freezing and freshness recovery according to claim 1, characterized in that: The constant temperature refrigeration conditions in step S4 are: a constant temperature warehouse at -18°C, a humidity of 85-90%, and a refrigeration time of 12-24 hours.

7. A method for preserving and transporting straw mushrooms based on the synergistic effect of quick freezing and freshness recovery according to any one of claims 1 to 6, characterized in that: The method also includes revitalizing straw mushrooms, and the specific steps are as follows: S8: thawing the refrigerated straw mushrooms in a 4°C environment for two hours; S9: placing the straw mushrooms thawed in step S8 in a humid environment at 8°C for one hour to allow the straw mushrooms to fully absorb moisture, until the center temperature of the straw mushrooms is between 0±0.5°C.

8. The method for preserving and transporting straw mushrooms based on the synergistic effect of quick freezing and freshness recovery according to claim 7, characterized in that: The thawing rate in step S8 is ≤2°C / min.

9. The method for preserving and transporting straw mushrooms based on the synergistic effect of quick freezing and freshness recovery according to claim 8, characterized in that: The humidity of the humid environment in step S9 is 95%.

10. The method for preserving and transporting straw mushrooms based on the synergistic effect of quick freezing and freshness recovery according to claim 9, characterized in that: The packaging method in step S5 is as follows: the straw mushrooms are packaged in microporous PE bags, the packaged straw mushrooms are placed in a polyurethane insulation box, and then a phase change cold storage box is placed in the polyurethane insulation box; wherein, the transportation temperature zone fluctuates between 0-2°C and is monitored throughout the process using a temperature recorder.