A comprehensive preservation method for fresh-cut Agaricus bisporus and its application

Abstract

The present invention belongs to the field of edible fungus preservation technology, and discloses a method and application for comprehensive preservation of fresh-cut Agaricus bisporus. The steps are as follows: pretreatment, selecting and grading mushrooms, selecting fresh mushrooms, and neatly arranging the selected mushrooms; soaking in 3% H2O2 for 60s and cutting into thin slices; configuring a p-CA+SH mixed solution and soaking the mushroom slices; fumigating and packaging with 5μmol / L CAR, punching holes for heat dissipation and moisture removal, and storing. The method of the present invention starts from the three levels of "suppressing lesions"-"reducing browning"-"retaining nutrition", and utilizes the antibacterial, browning-reducing, and moisturizing effects of p-CA, CAR, and SH. It effectively improves the disease-resistant and fresh-keeping quality of Agaricus bisporus from the three levels of inhibiting pathogen infection (lesions), reducing the degree of browning (browning), and reducing the loss of nutrients (nutrition). It is a new method for improving the storage quality of Agaricus bisporus, and can also provide a reference for the storage and preservation of edible fungi.

Description

Technical Field

[0001] The present invention belongs to the technical field of edible fungus preservation, in particular to a method and application for comprehensive preservation of fresh-cut Agaricus bisporus, and more particularly to a method and application for improving the preservation quality of edible fungi by combining p-coumaric acid and carvacrol in a sodium hyaluronate matrix. Background Art

[0002] Agaricus bisporus (Agaricus bisporus) is a favorite among consumers both domestically and internationally for its rich nutritional profile. Reportedly, dried Agaricus bisporus powder contains nearly 40% crude protein and only 1.5% fat. It also contains 17 amino acids, including eight essential amino acids, which contribute to 40% of the total amino acid content. Agaricus bisporus is also rich in vitamins and minerals, far surpassing other fruits and vegetables in nutritional value, earning it the nickname "plant meat." In addition to its rich nutritional profile, Agaricus bisporus also contains a variety of active ingredients, including carbohydrates, phenols, and lectins, which have anti-cancer, antioxidant, anti-obesity, and anti-inflammatory properties. Agaricus bisporus has a moisture content between 85% and 95%, a respiration rate exceeding 200mg / kg / h at room temperature, and lacks the protective stratum corneum, leading to intense metabolic activity and a high concentration of phenolic compounds. This makes it susceptible to enzymatic browning, dehydration, shrinkage, and bacterial infection after harvest, resulting in a decline in storage quality. The shelf life is only 1-3 days and 5-7 days when stored at room temperature (20-25°C) or refrigerated (0-2°C).

[0003] Agaricus bisporus differs significantly from other fruits and vegetables. Due to its unique growth characteristics, it continues to grow even after being picked, with its stem elongating, its cap expanding, and its gills gradually opening. Furthermore, it lacks protective tissue like a peel and is pure white, making it susceptible to discoloration. Currently, the primary method for preserving Agaricus bisporus is refrigeration, with an optimal temperature of 0-4°C. Below 0°C, Agaricus bisporus suffers from frostbite. However, even at 0-4°C, the shelf life is limited to a maximum of one week. Compared to whole mushrooms, the storage and preservation of fresh-cut Agaricus bisporus is more challenging: fresh-cut handling causes severe mechanical damage, leading to cell and tissue loss. Furthermore, Agaricus bisporus contains a large amount of browning-related substances, which rapidly brown when mechanically damaged, causing slices to discolor quickly. Furthermore, fresh-cut Agaricus bisporus has a high water content, increasing its specific surface area and rapidly increasing water loss, accelerating wilting. This also increases the likelihood of contamination by pathogenic microorganisms and exacerbates disease problems. Even refrigeration can only alleviate these problems but cannot effectively extend the storage period. While chemical preservation technologies offer advantages such as high efficiency, low cost, and wide application, the use of synthetic chemical preservatives on fresh-cut vegetables is significantly limited due to safety concerns. Therefore, there is currently no safe and effective method to prevent the development of lesions, browning, and water loss during storage of fresh-cut Agaricus bisporus. Finding green, safe, environmentally friendly, and effective methods for preventing and preserving these problems remains urgent.

[0004] p-Coumaric acid (p-CA), a natural plant-derived preservative, is an endogenous substance in plants and a key intermediate in the phenylpropanoid metabolic pathway. It exhibits antioxidant, anti-browning, anti-inflammatory, immunomodulatory, anti-tumor, cardiovascular disease prevention, and diabetes regulation properties. It also has inhibitory effects against various pathogens, inhibits melanin formation, and slows skin aging. Carvacrol (CAR), a monoterpene phenolic compound, is a major component of many volatile essential oils and has broad-spectrum antimicrobial properties, demonstrated in numerous studies. CAR also exhibits anticancer, antioxidant, and immunomodulatory activities, and has been approved as a food additive. Sodium hyaluronate (SH) is widely found in human skin and joint soft tissues. SH's safety has been recognized, with approval as a new resource food in 2008 and a new food ingredient in 2021, expanding its application in food. Numerous studies have demonstrated SH's hydrating and lubricating properties, cosmetic benefits, healing and repair, and antioxidant properties.

[0005] Through searching, no patent publication documents related to the patent application of the present invention have been found. Summary of the Invention

[0006] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a method and application for comprehensive preservation of fresh-cut Agaricus bisporus.

[0007] The technical solution adopted by the present invention to solve its technical problem is:

[0008] A method for improving the preservation quality of edible fungi by combining p-coumaric acid and carvacrol in a sodium hyaluronate matrix, comprising the following steps:

[0009] Step 1: Pre-processing: Select and grade the mushrooms. Choose fresh mushrooms with no mechanical damage, no disease spots, white fruiting bodies, intact caps, and a diameter of 3-4 cm. Remove excess stems and set aside.

[0010] Step 2: Soak the selected mushrooms in a 3% H2O2 solution for 60 seconds, place them on fruit and vegetable wrap to dry, and slice the dried Agaricus bisporus for later use; select 2-3 slices in the middle containing the gills, flesh, and stem for later use;

[0011] Step 3: Prepare a mixed solution of p-coumaric acid and sodium hyaluronate, wherein the concentration of p-coumaric acid is 37.5 mg / L and the mass concentration of sodium hyaluronate is 1%, and the solvent is water. Soak the surface of the mushroom slices in the solution. The specific method is as follows:

[0012] Soak the mushroom slices in a mixture of p-coumaric acid and sodium hyaluronate at room temperature for 2 minutes, then place them on plastic wrap to absorb for 20-30 minutes.

[0013] Step 4: Carvacrol fumigation packaging with 5 μmol / L carvacrol. The specific method is as follows:

[0014] Mix carvacrol with distilled water, shake vigorously to form a water-oil balance solution, spray it on the fruit and vegetable cling film, cover the cling film on the surface of the Agaricus bisporus slices obtained in step 3, the fumigation concentration is 5 μmol / L, and the cling film is wrapped and stored at 4±1°C.

[0015] Furthermore, in the step 1, 0.5±0.2 cm of the stipe is retained after the stipe is removed.

[0016] Furthermore, in step three, the soaking ratio is 48 slices of mushroom soaked in 300 mL of the mixed solution.

[0017] Furthermore, in the step 4, 5 μmol / L carvacrol fumigation is a volume fumigation concentration, which is calculated according to the carvacrol concentration in the water-oil balance solution of carvacrol, the density of carvacrol, the spraying amount of the water-oil balance solution of carvacrol on the fresh-keeping paper, and the volume of the packaging box.

[0018] Furthermore, in step 4, after wrapping with plastic wrap, several small holes are punched on the top to evacuate the heat of the mushrooms' breathing and control the humidity.

[0019] Application of the above method in the prevention and treatment of bacterial brown spot disease of post-harvest edible fungi.

[0020] Application of the above method in preserving edible fungi.

[0021] The advantages and positive effects achieved by the present invention are:

[0022] 1. Edible mushrooms are very prone to bacterial infection after being harvested. The method of the present invention starts with "inhibiting pathological changes" and adds natural plant-derived antibacterial ingredients p-CA and CAR to provide efficient antibacterial and bactericidal effects, avoiding infection by pathogens and ensuring that there is no pathogen infection during storage. The use concentrations are relatively low, only at the mg / L and μmol / L levels, respectively, which is in line with the original intention of the invention, improving the storage quality of Agaricus bisporus after harvest while controlling costs.

[0023] 2. Color protection and freshness preservation are common key technical issues that must be addressed in the post-harvest storage and production of Agaricus bisporus. The method of the present invention starts from the level of "reducing browning" and utilizes the antioxidant and anti-browning effects of p-CA and CAR. After 5 days of storage, the L* values ​​of the flesh, gills, and stipes of fresh-cut Agaricus bisporus increased by 7.16, 11.33, and 6.52, respectively. The browning index (BI) decreased by 23%, 28%, and 28%, respectively, and the color difference value (ΔE) decreased by 57.6%, 44.6%, and 36%, respectively. In addition, the activity of the browning-related enzyme (PPO) was effectively reduced, and the activity of the antioxidant-related enzymes (CAT, SOD, and POD) was increased. Ultimately, the browning degree of the mushrooms was effectively reduced, and the fresh-keeping quality of the mushrooms was maintained. This is a new method for reducing browning of fresh-cut Agaricus bisporus, providing a new approach for color protection and freshness preservation of fresh-cut Agaricus bisporus.

[0024] 3. The method of the present invention starts from the "nutrient retention" level and utilizes the antioxidant, anti-browning and moisturizing activities of p-CA, CAR and SH to reduce the weight loss rate by 13.4% after 5 days of storage, increase the soluble solids content by 20%, and increase the soluble protein content by 12%, effectively reducing the loss of nutrients and providing a reference for maintaining the storage quality of fresh-cut Agaricus bisporus.

[0025] 4. Post-harvest edible mushrooms are prone to multiple problems, including enzymatic browning, water loss and shrinkage, and bacterial infection, which can lead to a decline in their quality. However, a single treatment can only solve a single problem. The present method addresses the significant need for edible mushroom storage and preservation in my country, addressing three key aspects: "suppressing disease," "reducing browning," and "retaining nutrients." This method, developed for the first time, combines the plant endogenous substances p-CA and CAR with the moisturizing ingredient SH. This system directly addresses the challenges of enzymatic browning, water loss and shrinkage, and bacterial infection during post-harvest storage, achieving breakthroughs in each of these areas and synergistically improving the disease resistance and preservation of post-harvest mushrooms. The optimal p-CA and CAR combination in an SH matrix is ​​determined to be 1% SH + 37.5 mg / L p-CA + 5 μmol / L CAR, providing a new, comprehensive, and highly effective disease resistance and preservation method for the edible mushroom industry.

[0026] 5. The active ingredients added in the present invention are of safe origin. Both p-CA and CAR are plant-derived extracts with multiple activities such as antioxidant, anti-browning, and antibacterial. They are used for the storage and preservation of fresh-cut edible fungi for the first time.

[0027] 6. The present invention has a wider scope of application, is simple to operate, is easier to apply in factories, and can be quickly implemented even for ordinary households. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a technical roadmap for preserving fresh-cut Agaricus bisporus using the p-CA+CAR+SH combined system in the present invention;

[0029] Figure 2 This is a photograph of the appearance of fresh-cut Agaricus bisporus during storage after being treated by the method of the present invention;

[0030] Figure 3 This is an appearance evaluation diagram of fresh-cut Agaricus bisporus treated by the method of the present invention during storage;

[0031] Figure 4 This is a chromaticity diagram of fresh-cut Agaricus bisporus treated by the method of the present invention during storage; wherein, (A) L* value; (B) BI value; (C) ΔE value;

[0032] Figure 5 This is a graph showing the weight loss rate of fresh-cut Agaricus bisporus during storage after being treated by the method of the present invention;

[0033] Figure 6 This is a graph showing the soluble solids content of fresh-cut Agaricus bisporus during storage after being treated by the method of the present invention;

[0034] Figure 7 This is a graph showing the PPO enzyme activity of fresh-cut Agaricus bisporus during storage after being treated by the method of the present invention;

[0035] Figure 8This is a graph showing the activity of antioxidant-related enzymes (CAT, SOD, POD) during storage of fresh-cut Agaricus bisporus treated with the method of the present invention; wherein, (A) CAT enzyme activity; (B) SOD enzyme activity; (C) POD enzyme activity;

[0036] Figure 9 This is a standard control curve diagram of protein concentration in the present invention;

[0037] Figure 10 This is a graph showing the soluble protein content of fresh-cut Agaricus bisporus during storage after being treated with the method of the present invention. DETAILED DESCRIPTION

[0038] The present invention will be further described below with reference to the following examples. The following examples are descriptive rather than restrictive, and the scope of protection of the present invention cannot be limited by the following examples.

[0039] The various experimental operations involved in the specific embodiments are all routine techniques in the field. For parts not specifically annotated in this document, ordinary technicians in this field can refer to various commonly used reference books, scientific literature or related instructions, manuals, etc. before the filing date of this invention to implement them.

[0040] A method for improving the preservation quality of edible fungi by combining p-coumaric acid and carvacrol in a sodium hyaluronate matrix, comprising the following steps:

[0041] Step 1: Pre-processing: Select and grade the mushrooms. Choose fresh mushrooms with no mechanical damage, no disease spots, white fruiting bodies, intact caps, and a diameter of 3-4 cm. Remove excess stems and set aside.

[0042] Step 2: Soak the selected mushrooms in a 3% H2O2 solution for 60 seconds, place them on fruit and vegetable wrap to dry, and slice the dried Agaricus bisporus for later use; select 2-3 slices in the middle containing the gills, flesh, and stem for later use;

[0043] Step 3: Prepare a mixed solution of p-coumaric acid and sodium hyaluronate, wherein the concentration of p-coumaric acid is 37.5 mg / L, the mass concentration of sodium hyaluronate is 1%, and the solvent is water, and soak the surface of the mushroom slices in the solution. The specific method is as follows:

[0044] Soak the mushroom slices in a mixture of p-coumaric acid and sodium hyaluronate at room temperature for 2 minutes, then place them on plastic wrap to absorb for 20-30 minutes.

[0045] Step 4: Carvacrol fumigation packaging with 5 μmol / L carvacrol. The specific method is as follows:

[0046] Mix carvacrol with distilled water, shake vigorously to form a water-oil balance solution, spray it on the fruit and vegetable cling film, cover the cling film on the surface of the Agaricus bisporus slices obtained in step 3, the fumigation concentration is 5 μmol / L, and the cling film is wrapped and stored at 4±1°C.

[0047] Preferably, in step 1, 0.5±0.2 cm of the stipe is retained after the stipe is removed.

[0048] Preferably, in step 3, the soaking ratio is 48 slices of mushrooms soaked in 300 mL of the mixed solution.

[0049] Preferably, in step 4, 5 μmol / L carvacrol fumigation concentration is the volume fumigation concentration, which is calculated according to the carvacrol concentration in the water-oil balance solution of carvacrol, the density of carvacrol, the spraying amount of the water-oil balance solution of carvacrol on the fresh-keeping paper, and the volume of the packaging box.

[0050] Preferably, in step 4, after wrapping with plastic wrap, a few small holes are punched on the top to evacuate the heat of the mushrooms and control the humidity.

[0051] Application of the above method in the prevention and treatment of bacterial brown spot disease of post-harvest edible fungi.

[0052] Application of the above method in preserving edible fungi.

[0053] Specifically, the relevant preparation and detection are as follows:

[0054] 1. A method for treating Agaricus bisporus by combining p-CA and CAR in an SH matrix, comprising the following steps:

[0055] Step 1: Pre-processing: Select and grade the mushrooms. Choose fresh mushrooms with no mechanical damage, no disease spots, white fruiting bodies, unopened caps, complete mushroom bodies, and a diameter of 3-4 cm. Keep 0.5±0.1 cm of the stem, cut off the excess part, and set aside for later use.

[0056] Step 2: Soak the selected mushrooms in a 3% H₂O₂ solution for 60 seconds. Place them on a piece of fruit and vegetable wrap to dry. After drying, slice the mushrooms. Select 2-3 slices in the middle, containing the gills, flesh, and stem.

[0057] Step 3: Prepare a p-CA and HA mixed solution (0.5% SH, 1% SH, 37.5 mg / L p-CA + 0.5% SH, 75 mg / L p-CA + 0.5% SH, 37.5 mg / L p-CA + 1% SH, 75 mg / L p-CA + 1% SH, all percentages are by mass concentration, and the solvent is water) and soak the surface of the mushroom slices. The specific method is as follows:

[0058] At room temperature, soak the mushroom slices in the p-CA+SH solution for 2 minutes, with the soaking ratio being 48 slices of mushroom soaked in 300 mL of the mixed solution. Remove the slices and place them on plastic wrap to absorb for 20-30 minutes.

[0059] Step 4: Carry out 5μmol / L CAR fumigation packaging. The specific method is as follows:

[0060] Mix CAR with distilled water, shake vigorously to form a water-oil balance solution, spray it on the fruit and vegetable cling film, and cover the cling film on the surface of the Agaricus bisporus slices; the fumigation concentration is 5μmol / L, and 5μmol / L CAR fumigation is a volume fumigation concentration, which is calculated according to the CAR concentration in the CAR water-oil balance solution, CAR density, the amount of CAR water-oil balance solution sprayed on the cling film, and the volume of the packaging box; after wrapping with cling film, poke a few small holes in the upper cling film to evacuate the respiratory heat of the mushrooms, control the humidity, and store at 4±1℃. Figure 1 shown.

[0061] 2. The sensory quality of mushrooms treated by the method of the present invention was determined as follows:

[0062] Take photos of the mushroom slices during the storage period and conduct a sensory evaluation according to the following scoring criteria.

[0063] Table 1 Sensory scoring criteria for storage of fresh-cut Agaricus bisporus after harvest

[0064]

[0065] The flesh, gills and stems of fresh-cut Agaricus bisporus after soaking in the combined system were monitored. Figure 2 It can be seen that after only 1 day of storage, the slices of mushrooms in the Control group began to turn brown, as evidenced by the color of the mushroom flesh beginning to turn slightly yellow, the color of the gills deepening and gradually turning brown, and slight yellow spots appearing on the stipes. This phenomenon did not occur in other groups treated with different proportions of the SH+p-CA+CAR combined system. As the storage time prolonged, all groups showed browning and wilting, among which the degree of browning and wilting in the Control group was the most serious. The fresh-cut Agaricus bisporus mushroom flesh and stipes in the 1% SH+37.5mg / L p-CA+5μmol / L CAR treatment group were white, and the gills were pink-brown, with the best preservation effect. In order to more intuitively observe the storage quality of each group of mushrooms, the sensory quality of Agaricus bisporus during storage was quantitatively scored. Figure 3As shown, with prolonged storage, the color, aroma, and texture of the flesh, gills, and stipes of each group showed a gradual decline. The color scores of the flesh, gills, and stipes decreased more significantly, while the aroma and texture scores only slightly decreased. Among all treatments, the control group consistently scored the lowest, while the 1% SH + 37.5 mg / L p-CA + 5 μmol / L CAR group consistently scored the highest. This indicates that the combined use of p-CA and CAR in an SH matrix effectively maintains the sensory quality of Agaricus bisporus. In particular, on the fifth day of storage, the gills of the control group turned dark brown, with a sensory score of only 2.25. In contrast, the gills of the 1% SH + 37.5 mg / L p-CA + 5 μmol / L CAR group remained pinkish brown, with a sensory score of 3.75, a gill score 1.6 times higher than that of the control group. This indicates that the 1% SH + 37.5 mg / L p-CA + 5 μmol / L CAR combination effectively maintains the sensory quality of fresh-cut Agaricus bisporus, especially for gill color.

[0066] At the same time, it can also be seen that in the method of the present invention, 1% SH+37.5 mg / L p-CA+5 μmol / L CAR have a synergistic effect and can synergistically improve the fresh-keeping quality of edible fungi.

[0067] 3. Determination of color in mushrooms treated by the method of the present invention. The specific experiment is as follows:

[0068] Five fresh-cut Agaricus bisporus pieces were randomly selected from each group. L*, a*, and b* values ​​were measured on the gills, flesh, and stipe using a WR-18 colorimeter. Each tissue location was measured three times. Browning index (BI) and ΔE were calculated using the following formulas.

[0069] BI=[100×(X-0.31)] / 0.172

[0070]

[0071] Where: X = (a* + 1.75L*) / (5.645L* + a* - 3.012b*)

[0072] ΔL*, Δa*, and Δb* are the differences in L*, a*, and b* between each sample and the Control group, respectively.

[0073] To more clearly compare the degree of browning of the flesh, gills, and stipes of Agaricus bisporus in each group, we monitored the color changes of the flesh, gills, and stipes. Detailed data are shown in Tables 2, 3, and 4. The color trends of the flesh, gills, and stipes were consistent. With extended storage, the L* values ​​of the flesh, gills, and stipes decreased, while the BI values ​​and ΔE values ​​increased across all groups, indicating a progressively more severe browning of the Agaricus bisporus. The L* values ​​of the combined treatment group remained consistently higher, and the BI and ΔE values ​​were consistently lower than those of the control group. In particular, the 1% SH+37.5mg / L p-CA+5μmol / L CAR treatment group had the best preservation effect. On the fifth day of storage, the L* values ​​of the flesh, gills, and stipes in the control group were only 81.04±0.6, 37.39±0.64, and 76.86±1.34, while the L* values ​​of the flesh, gills, and stipes in the 1% SH+37.5mg / L p-CA+5μmol / L CAR treatment group were 88.20±0.89, 48.72±0.87, and 83.38±0.57, which were 7.16, 11.33, and 6.52 higher than those in the control group, respectively. Figure 4 As shown, the L*, BI, and ΔE values ​​of the Agaricus bisporus flesh, gills, and stipes in the 1% SH + 37.5 mg / L p-CA + 5 μmol / L CAR treatment group were consistently significantly superior to those in the control group. Furthermore, the addition of 37.5 mg / L p-CA + 5 μmol / L CAR to the combined system enhanced the anti-browning effect compared to the 1% SH treatment alone, with the effect being even more pronounced in the gills, resulting in gill L* values ​​reaching 1.3 times that of the control group, while BI and ΔE values ​​were reduced to 72% and 55.3% of the control group, respectively. This suggests that the combined use of 1% SH, 37.5 mg / L p-CA, and 5 μmol / L CAR has a synergistic effect, synergistically enhancing antioxidant activity and maintaining the storage quality of fresh-cut Agaricus bisporus. Based on these results, 1% SH+37.5 mg / L p-CA+5 μmol / L CAR is the best combination system, which can effectively alleviate the browning problem of Agaricus bisporus during storage and maintain the sensory quality.

[0074] 4. The weight loss rate of mushrooms treated by the method of the present invention is determined as follows:

[0075] The mushroom slices were weighed every day during storage and the weight loss rate was calculated according to the following formula.

[0076] Weight loss rate (%) = (G1-G2) / G1×100

[0077] Where: G1 is the mass of Agaricus bisporus before storage, g; G2 is the mass of Agaricus bisporus after storage, g.

[0078] The weight loss rate of Agaricus bisporus in each treatment group during storage is shown in Table 5. The weight loss rate of each treatment group increased with the extension of storage time. The weight loss rate of the Control group was significantly higher than that of the other 8 groups with SH addition. As the amount of SH added increased, the weight loss rate gradually decreased. The four groups of Agaricus bisporus treated with the 1% SH matrix combination system (1% SH, 1% SH + 5μmol / L CAR, 1% SH + 37.5mg / L p-CA + 5μmol / L CAR, 1% SH + 75mg / L p-CA + 5μmol / L CAR) were more significantly different from the Control group, among which the weight loss rate of 1% SH + 75mg / L p-CA + 5μmol / L CAR was the lowest. Figure 5 As shown, after 3 days of storage, the weight loss rate of the group treated with 1% SH, 37.5 mg / L p-CA, and 5 μmol / L CAR was only 76% of that of the control group. After 5 days of storage, the weight loss rate of the control group reached 7.7%, while that of the group treated with 1% SH, 37.5 mg / L p-CA, and 5 μmol / L CAR was only 6.6%, a 13.4% reduction. These results demonstrate that SH significantly retains moisture during postharvest storage of Agaricus bisporus, effectively reducing the weight loss rate of fresh-cut Agaricus bisporus and improving its storage quality. The combined use of 1% SH, 37.5 mg / L p-CA, and 5 μmol / L CAR exhibits a synergistic effect, synergistically improving the shelf-stable qualities of the prepared edible fungi.

[0079] 5. Determination of soluble solids content of mushrooms treated by the method of the present invention:

[0080] Weigh 1 g of mushroom sample, add 2 mL of distilled water, grind thoroughly with a mortar, centrifuge at 4000 rpm for 10 min, and take the filtrate for measurement using a handheld refractometer.

[0081] As shown in Table 6, the soluble solids content of each treatment group gradually decreased with prolonged storage time, with the Control group experiencing the most severe decline. However, the decline in each SH+p-CA+CAR treatment group was alleviated, remaining higher than the Control group. At the same p-CA and CAR concentrations, the 1% SH combination system showed higher soluble solids content than the 0.5% SH system. The 1% SH+37.5 mg / L p-CA+5 μmol / L CAR treatment group showed the best results. Figure 6As shown, on the fifth day of storage, the soluble solids content of the 1% SH + 37.5 mg / L p-CA + 5 μmol / L CAR treatment group was the highest, at 1.8%, while the control group was 1.5%, an increase of 20%. This effectively reduced the loss of soluble solids during storage of Agaricus bisporus and ensured the storage quality. That is, the combined use of the three conditions of 1% SH, 37.5 mg / L p-CA, and 5 μmol / L CAR has a synergistic effect and can synergistically improve the storage quality of fresh-cut Agaricus bisporus. VI. The browning-related enzyme activity (PPO) and antioxidant-related enzyme activity (POD, CAT, SOD) in the mushrooms treated by the method of the present invention were determined as follows:

[0082] Weigh 1 g of sample and add 9 mL of 50 mmol / L phosphate buffer (pH 7.0, containing 1% PVP and 1 mmol / L DTT). Grind on ice and centrifuge at 8500 rpm for 5 min at 4°C. The supernatant was used for later use. All four enzyme assays were performed using the corresponding enzyme kits developed by the Nanjing Jiancheng Bioengineering Institute.

[0083] like Figure 7 As shown, PPO activity gradually increased, reaching a peak of 54.34 U / mg protein on day 5 in the control group. During storage days 1-3, PPO activity in the 1% SH treatment group showed no significant difference compared to the control group. However, PPO activity in the 1% SH + 37.5 mg / L p-CA + 5 μmol / L CAR treatment group remained significantly lower than that in the control group. On day 2, in particular, PPO activity in the control group reached 1.4 times that of the 1% SH + 37.5 mg / L p-CA + 5 μmol / L CAR treatment group. These results indicate that SH has a weak effect on reducing PPO activity, while 37.5 mg / L p-CA + 5 μmol / L CAR significantly prevents the increase in PPO activity. The combined 1% SH + 37.5 mg / L p-CA + 5 μmol / L CAR system prevents the increase in PPO activity, inhibits browning, and maintains the storage quality of fresh-cut Agaricus bisporus.

[0084] like Figure 8As shown in the results, the activities of CAT, SOD, and POD all showed an increasing trend. The CAT, SOD, and POD enzyme activities in the 1% SH treatment group increased significantly compared to the control group. The increase was even greater after the addition of 37.5 mg / L p-CA + 5 μmol / L CAR. The CAT, SOD, and POD enzyme activities in the 1% SH + 37.5 mg / L p-CA + 5 μmol / L CAR treatment group reached peak values ​​of 164.37 U / mg prot, 390.71 U / mg prot, and 83.72 U / mg prot at 5 days, 5 days, and 3 days, respectively. These were 2.2, 1.2, and 1.4 times higher than those in the control group at the same storage time. These results indicate that the 1% SH + 37.5 mg / L p-CA + 5 μmol / L CAR combination system improves the antioxidant capacity in the fruiting body and reduces oxidative damage. That is, the joint use of the three conditions of mass concentration 1% SH, 37.5 mg / L p-CA and 5 μmol / L CAR has a synergistic effect, which can synergistically improve the antioxidant capacity of fresh-cut Agaricus bisporus and improve the storage quality.

[0085] VII. The method for determining the soluble protein content in Agaricus bisporus treated by the method of the present invention comprises the following specific steps:

[0086] Step 1: Take approximately 1 g of tissue sample, add 6 mL of 0.05 mol / L pH 7.0 phosphate buffer (containing 1% PVP, 1 mmol / L DTT), grind and homogenize on ice, centrifuge at 8000 rpm, 4°C for 15 min, transfer the supernatant to a clean, sterile 2 mL centrifuge tube, and store in an ice box until testing;

[0087] Step 2: Completely dissolve the protein standard, take 10 μL, and dilute to 250 μL with 0.05 M pH 7.0 phosphate buffer (containing 1% PVP, 1 mmol / L DTT) to a final concentration of 0.2 g / L.

[0088] Step 3: Mix 5×G250 staining solution (Beijing Solebow) by inverting 3-5 times before use. Take 1 mL of 5×G250 staining solution, add 4 mL of 0.05 mol / L pH 7.0 phosphate buffer, and mix to make 1×G250 staining solution.

[0089] Step 4: Add 0, 2, 4, 6, 8, 12, 16, and 20 μL of the standard to a 96-well plate, add 0.05 mol / L pH 7.0 phosphate buffer (containing 1% PVP, 1 mmol / L DTT) to make up to 20 μL, and measure the absorbance at 595 nm using a microplate reader to obtain a standard curve. The regression equation is: Y = 0.002X + 0.0149;

[0090] Step 5: Add 20 μL of sample to the sample wells of a 96-well plate, add 200 μL of diluted 1×G250 staining solution to each well, let stand at room temperature for 3-5 minutes, and measure the absorbance at 595 nm using a microplate reader;

[0091] Step 6: Calculate the protein concentration in the sample according to the regression equation.

[0092] like Figure 9 As shown, the soluble protein content of each treatment group gradually decreased with prolonged storage, with the control group experiencing the most severe decline. However, the decline in the 1% SH + 37.5 mg / L p-CA + 5 μmol / L CAR group moderated, remaining above the control group. On the fifth day of storage, the 1% SH + 37.5 mg / L p-CA + 5 μmol / L CAR treatment group achieved the highest soluble protein content, 1.2 times that of the control group. This effectively reduced soluble protein loss during storage of Agaricus bisporus and ensured its quality. This suggests that the combined use of 1% SH, 37.5 mg / L p-CA, and 5 μmol / L CAR concentrations synergistically improves the shelf-stable qualities of the prepared edible fungi.

[0093] The Control group mentioned above is the control example, and the specific processing is as follows:

[0094] Conventional storage and preservation techniques were used, including soaking the selected mushrooms in a 3% H2O2 solution for 60 seconds, placing them on fruit and vegetable cling wrap to dry, slicing them for later use, soaking them in tap water for 2 minutes, placing them on absorbent paper to dry, placing them in a fresh-keeping box, wrapping them in cling wrap, and storing them at 4±1°C.

[0095] Regular spot checks are carried out during storage. The items for sampling and testing mainly include sensory indicators such as color difference, weight loss rate, morphology, as well as changes in the activity of PPO and antioxidant-related enzymes (POD, CAT, SOD), and nutritional indicators such as soluble solids and soluble protein content.

[0096] Table 2 L* values ​​of different tissue parts of Agaricus bisporus

[0097]

[0098]

[0099] Note: Data are mean ± standard error (n = 3). Different capital letters in the same row represent significant differences between different combination systems (P < 0.05); different lowercase letters in the same column represent significant differences between different time points (P < 0.05).

[0100] Table 3 BI values ​​of different tissue parts of Agaricus bisporus

[0101]

[0102]

[0103] Note: Data are mean ± standard error (n = 3). Different capital letters in the same row represent significant differences between different combination systems (P < 0.05); different lowercase letters in the same column represent significant differences between different time points (P < 0.05).

[0104] Table 4 ΔE values ​​of different tissue parts of Agaricus bisporus

[0105]

[0106]

[0107] Note: Data are mean ± standard error (n = 3). Different capital letters in the same row represent significant differences between different combination systems (P < 0.05); different lowercase letters in the same column represent significant differences between different time points (P < 0.05).

[0108] Table 5 Effect of combined system on weight loss rate of Agaricus bisporus during storage

[0109]

[0110]

[0111] Note: Data are mean ± standard error (n = 3). Different capital letters in the same row represent significant differences between different combination systems (P < 0.05); different lowercase letters in the same column represent significant differences between different time points (P < 0.05).

[0112] Table 6 Effect of combined use on soluble solids content of Agaricus bisporus during storage

[0113]

[0114] Note: Data are mean ± standard error (n = 3). Different capital letters in the same row represent significant differences between different combination systems (P < 0.05); different lowercase letters in the same column represent significant differences between different time points (P < 0.05).

[0115] Existing Agaricus bisporus preservation technologies mostly focus on whole mushroom storage, with methods primarily focusing on applying preservatives, coatings, and controlled atmosphere preservation. These methods primarily address the short shelf life of Agaricus bisporus and aim to extend its shelf life. However, there are few preservation technologies specifically designed for fresh-cut Agaricus bisporus, and these technologies primarily focus on addressing color protection and browning issues. The present invention's detection indicators cover multiple preservation indicators related to fresh-cut Agaricus bisporus, including color (L* value, ΔE value), browning (BI value, PPO enzyme activity), antioxidants (CAT, SOD, POD enzyme activity), and nutritional content (weight loss rate, soluble solids, soluble protein), demonstrating the efficient preservation effect of the inventive method from multiple perspectives. Currently, there are examples of arginine being used to preserve fresh-cut Agaricus bisporus. However, after treatment with 0.4 mmol / L arginine, the L* value of fresh-cut Agaricus bisporus only increased by approximately 3, and the ΔE value decreased by approximately 11%. In contrast, the present invention increased the L* value of fresh-cut Agaricus bisporus gills by 11.33 and reduced the ΔE value by 55.4%, achieving superior color preservation. Compared to other similar fruit and vegetable preservation technologies, 82 mg / L p-CA applied to tomatoes increased the soluble solids content by 4.5%. In this combined system, the p-CA concentration was reduced to 37.5 mg / L, while simultaneously increasing the soluble solids content of fresh-cut Agaricus bisporus by 20%, achieving even better preservation results. Furthermore, CAR is rarely used in fruit and vegetable preservation, and to overcome its volatility limitations, it is often formulated into emulsions or microcapsules to extend its preservation effect. Prior art uses of cyclodextrin carvacrol microcapsules for peach preservation reduced weight loss by approximately 0.5% and increased soluble solids content by approximately 1.8%. However, the present invention directly leverages the volatility of CAR, combining it with p-CA and SH to reduce weight loss by 1.06% and increase soluble solids content by 20% in fresh-cut Agaricus bisporus. This results in improved preservation, simple operation, and reduced costs. This invention demonstrates that the combined use of p-CA, CAR, and SH enhances the preservation efficacy of p-CA and CAR, demonstrating a synergistic preservation effect.

[0116] Although the embodiments of the present invention are disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, changes and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments.

Claims

1. A method for improving the fresh-keeping quality of edible fungi by combining p-coumaric acid and carvacrol in a sodium hyaluronate matrix, characterized in that: The steps include: Step 1: Pre-processing: Select and grade the mushrooms. Choose fresh mushrooms with no mechanical damage, no disease spots, white fruiting bodies, intact caps, and a diameter of 3-4 cm. Remove excess stems and set aside. Step 2: Soak the selected mushrooms in a 3% H2O2 solution for 60 seconds, place them on fruit and vegetable wrap to dry, and slice the dried Agaricus bisporus for later use; select 2-3 slices in the middle containing the gills, flesh, and stem for later use; Step 3: Prepare a mixed solution of p-coumaric acid and sodium hyaluronate, wherein the concentration of p-coumaric acid is 37.5 mg / L and the mass concentration of sodium hyaluronate is 1%, and the solvent is water. Soak the surface of the mushroom slices in the solution. The specific method is as follows: Soak the mushroom slices in a mixture of p-coumaric acid and sodium hyaluronate at room temperature for 2 minutes, then place them on plastic wrap to absorb for 20-30 minutes. Step 4: Carvacrol fumigation packaging with 5 μmol / L carvacrol. The specific method is as follows: Mix carvacrol with distilled water, shake vigorously to form a water-oil balance solution, spray it on the fruit and vegetable cling film, cover the cling film on the surface of the Agaricus bisporus slices obtained in step 3, and use a fumigation concentration of 5 μmol / L. Wrap the solution in cling film and store at 4±1°C.

2. The method according to claim 1, wherein: In the step 1, after the stipe is removed, 0.5±0.2 cm of the stipe is retained.

3. The method according to claim 1, wherein: In the step 3, the soaking ratio is 48 mushroom slices soaked in 300 mL of the mixed solution.

4. The method according to any one of claims 1 to 3, characterized in that: In the fourth step, after the mushrooms are wrapped in plastic wrap, a few small holes are punched on the top to evacuate the heat generated by the mushrooms' breathing and control the humidity.

5. Use of the method according to any one of claims 1 to 4 in preserving edible fungi.

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