A preservation method based on pre-harvest nutrition strengthening and post-harvest gas sterilization

Abstract

This invention relates to the field of agricultural product storage and preservation technology, and in particular to a preservation method for strawberries based on pre-harvest nutrient enhancement and post-harvest gas sterilization. The preservation method provided by this invention solves the problems of poor fruit quality and low yield of strawberries by spraying specific foliar fertilizers on strawberry plants before harvesting and using gas sterilization and covering with a mushroom-shaped film after harvesting. It increases the number of fruits per plant, yield per plant, average fruit weight, fruit firmness, and soluble solids content. Simultaneously, it extends the shelf life of the fruit, reduces the rate of decay, reduces respiration intensity, delays the decrease in firmness, and delays the decrease in soluble solids content. The combined effect of pre-harvest spraying and post-harvest antibacterial treatment can complement a complete cold chain and provides a flexible, efficient, and low-cost solution for ensuring fruit quality under different transportation conditions. It is suitable for facility cultivation and aligns with the realities of agricultural production.

Description

Technical Field

[0001] This invention relates to the field of agricultural product storage and preservation technology, and in particular to a preservation method for strawberries based on pre-harvest nutritional enhancement and post-harvest gas sterilization. Background Technology

[0002] strawberry( Fragaria × ananassa Duch. strawberries, with their vibrant color and unique flavor, are hailed as the "Queen of Fruits." Strawberries are typical berries, with high water content, extremely thin skin, and no outer protective peel, making them highly susceptible to mechanical damage and pathogens (such as gray mold). Botrytis cinerea Rhizopus Rhizopus stolonifer In addition, strawberries have a high metabolic rate after harvest and are extremely prone to wilting, softening, and rotting at room temperature, resulting in a very short shelf life. This severely restricts the off-site transportation and economic benefits of the strawberry industry.

[0003] Currently, strawberry preservation technologies are mainly divided into two stages: pre-harvest management and post-harvest processing. However, existing technologies still have significant limitations in practical applications. (1) Limitations of pre-harvest treatment techniques: Existing research shows that pre-harvest treatment agents such as plant growth regulators (gibberellins, salicylic acid, jasmonic acid, etc.), chitosan, and calcium salts can regulate post-harvest fruit quality, but the effect of a single pre-harvest treatment is limited, and there is a lack of systematic compound treatment schemes. In addition, with the increasing demand for functional agricultural products from consumers, traditional pre-harvest management lacks the ability to simultaneously improve the nutritional quality of fruits (such as selenium content). Although some studies have used conventional foliar fertilizers, there is still a lack of systematic research and mature technical solutions on how to combine specific biostimulants and trace elements to promote plant growth while improving the anti-aging ability of fruits after harvest.

[0004] (2) Pain points of postharvest sterilization technology: Postharvest disease control is the key to strawberry preservation. Among the existing technologies: Chemical fungicides: Although effective, they pose a risk of pesticide residues, which is not in line with the development trend of green food, and pathogens are prone to developing resistance. Biological antagonists (such as brewer's yeast): For example, Chinese patent CN103820343A discloses a method for preventing and controlling postharvest diseases of fruit using brewer's yeast. Although safe, biological agents take effect relatively slowly and have high requirements for environmental temperature and humidity, making it difficult to cope with the high load of pathogens in the early postharvest period. Physical irradiation (such as UV-C): For example, Chinese patent CN104351315A discloses a short-wave ultraviolet irradiation combined with cold air pre-cooling preservation technology for strawberry fruit. Although ultraviolet (UV-C) has a good sterilization effect, there is a significant "shadow effect" in actual operation—that is, ultraviolet rays can only kill surface pathogens that are directly irradiated by the light, and cannot effectively reach pathogens hidden in the depressions or stacks of strawberry fruit. In addition, UV-C treatment requires specific high-energy-consuming equipment, is complex to operate, and if the dosage is not properly controlled, it can easily cause fruit peel burn (browning) and even accelerate fruit aging.

[0005] (3) Lack of a synergistic mechanism between pre-harvest and post-harvest: Current preservation solutions are often fragmented, either focusing only on pre-harvest yield or only on post-harvest sterilization. There is a lack of a systematic solution that goes from "enhancing the fruit's endogenous resistance before harvest" to "broad-spectrum antibacterial protection without blind spots after harvest". Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a strawberry preservation method based on pre-harvest nutrient fortification and post-harvest gas sterilization. This invention offers a synergistic preservation method for strawberries throughout the entire process, combining pre-harvest nutrient fortification to induce resistance with post-harvest plant-derived fumigation sterilization. This solves the problems of poor fruit quality and low yield in strawberries, while also extending fruit shelf life and reducing spoilage rates. The pre-harvest spraying and post-harvest antibacterial treatment complement existing end-to-end cold chain transportation, ensuring preservation while providing additional protection for fruit quality under different transportation conditions. More importantly, it provides a more flexible and cost-effective solution for production scenarios where end-to-end cold chain implementation is difficult, enabling its widespread application in greenhouse and other facility cultivation, better meeting the actual needs of agricultural production.

[0007] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a method for synergistic preservation of strawberries, comprising: spraying foliar fertilizer on strawberry plants before harvest, and storing strawberries after harvest by using gas sterilization and covering them with a mushroom film. The foliar fertilizer comprises the following components at the following concentrations: 0.5-2 g / L of medium-element fertilizer and 3-6 mg / L of selenium-enriched yeast; The medium-element fertilizer comprises the following components by weight percentage: calcium carbonate 60%-94.4%, magnesium carbonate 2%-5%, silicon dioxide 1%-3%, and the balance being trace elements; the trace elements include iron, potassium, manganese, zinc, copper, and molybdenum; The reagents used for gas sterilization include allyl isothiocyanate.

[0008] Preferably, the method for gas sterilization and covering the king oyster mushroom film includes: Dilute allyl isothiocyanate with water 2500-4000 times to obtain an allyl isothiocyanate solution. The adsorbent was immersed in the allyl isothiocyanate solution, and after the adsorbent containing the allyl isothiocyanate solution was placed in a strawberry packaging box, it was covered with a king oyster mushroom film.

[0009] Preferably, the absorbent comprises a cotton ball.

[0010] Preferably, the adsorbate containing allyl isothiocyanate solution does not directly contact the strawberry.

[0011] Preferably, the foliar fertilizer is sprayed from December to March of the following year, once every two weeks.

[0012] Preferably, the medium-element fertilizer includes PlantKang medium-element fertilizer.

[0013] Preferably, the strawberry varieties include Red Beauty and / or Monterey.

[0014] This invention provides the application of the preservation method described in the above technical solution in one or more of the following: 1) Promotes the growth and development of strawberry leaves; 2) Improves the photosynthetic capacity of strawberry plants; 3) Increases the number of fruits per strawberry plant; 4) Increases the yield per strawberry plant; 5) Increases the average weight of a single strawberry fruit; 6) Improves the firmness of strawberry fruits; 7) Increases the soluble solids content of strawberry fruits; 8) Extends the shelf life of strawberry fruits.

[0015] Preferably, promoting strawberry leaf growth and development includes increasing leaf length and / or width; improving the photosynthetic capacity of strawberry plants includes one or more of the following: increasing chlorophyll content, increasing net photosynthetic rate, increasing stomatal conductance, reducing intercellular CO2 concentration, and increasing transpiration rate.

[0016] Preferably, extending the shelf life of strawberry fruit includes one or more of the following: reducing the rot rate, reducing the respiration rate, delaying the decrease in firmness, and delaying the decrease in soluble solids content.

[0017] Beneficial effects: The method provided by this invention solves the problems of poor fruit quality and low yield of strawberries by spraying specific foliar fertilizer on strawberry plants before harvesting and using gas sterilization and covering with king oyster mushroom film after harvesting. It increases the number of fruits per plant, yield per plant, average fruit weight, fruit firmness, and soluble solids content. Simultaneously, it extends the shelf life of the fruit, reduces the rate of decay, decreases respiration intensity, delays the decrease in firmness, and delays the decrease in soluble solids content. This treatment method complements the existing end-to-end cold chain transportation, ensuring freshness while providing a more flexible and cost-effective solution for ensuring fruit quality under different transportation conditions. This allows for widespread application in greenhouse and other facility cultivation, better meeting the actual needs of agricultural production. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the embodiments will be briefly described below.

[0019] Figure 1 Results of 'Hongyan' fruit stored for 1 day after different foliar fertilizer treatments; Figure 2 Results of 'Monterey' fruit stored for 1 day after different foliar fertilizer treatments; Figure 3 Results of 'Hongyan' fruit stored for 9 days after different foliar fertilizer treatments; Figure 4 Results of 'Monterey' fruit stored for 9 days after different foliar fertilizer treatments; Figure 5 Results of storing 'Hongyan' fruit encapsulated in different packaging films up to day 1; Figure 6 Results of storing 'Hongyan' fruit encapsulated in different packaging films for up to 10 days; Figure 7 Results of storing 'Hongyan' fruit in different packaging films for up to 12 days; Figure 8 Results of 'Hongyan' fruit stored for 1 day after different antibacterial treatments; Figure 9 Results of 'Monterey' fruit stored for 1 day after different antibacterial treatments; Figure 10 Results of 'Hongyan' fruit stored for 4 days after different antibacterial treatments; Figure 11 Results of 'Monterey' fruit stored for 4 days after different antibacterial treatments; Figure 12 Results of storing 'Hongyan' fruit for 1 day under different treatment combinations; Figure 13Results of storing 'Monterey' fruit for 1 day under different treatment combinations; Figure 14 Results of different combinations of treatments for 'Hongyan' fruit stored up to day 4; Figure 15 Results of storing 'Monterey' fruit for 4 days under different treatment combinations. Detailed Implementation

[0020] This invention provides a method for synergistic preservation of strawberries, comprising: spraying foliar fertilizer on strawberry plants before harvest, and storing strawberries after harvest by using gas sterilization and covering them with a mushroom film. The foliar fertilizer comprises the following components at the following concentrations: 0.5-2 g / L of medium-element fertilizer and 3-6 mg / L of selenium-enriched yeast; The medium-element fertilizer comprises the following components by weight percentage: calcium carbonate 60%-94.4%, magnesium carbonate 2%-5%, silicon dioxide 1%-3%, and the balance being trace elements; the trace elements include iron, potassium, manganese, zinc, copper, and molybdenum; The reagents used for gas sterilization include allyl isothiocyanate.

[0021] In one embodiment, the foliar fertilizer comprises the following components at the following concentrations: 1-2 g / L of medium-element fertilizer and 4-5 mg / L of selenium-enriched yeast.

[0022] In one embodiment, the foliar fertilizer is applied from December to March of the following year, once every two weeks. In another embodiment, the medium-element fertilizer comprises the following components by weight percentage: calcium carbonate 94.4%, magnesium carbonate 2.56%, silicon dioxide 1.75%, and the balance being trace elements. In yet another embodiment, the medium-element fertilizer includes PlantKang medium-element fertilizer.

[0023] The plant-based fertilizer described in this invention is registered under Agricultural Fertilizer (2020) Approval No. 16055, and is classified as a "medium-element fertilizer" (its main components include calcium carbonate (94.4%), magnesium carbonate (2.56%), silicon dioxide (1.75%), etc., and also contain iron oxide, potassium oxide, and trace elements such as manganese, zinc, copper, and molybdenum). Its main raw material is calcite. Selenium-enriched yeast is rich in organic selenium, with an absorption efficiency 10-20 times that of inorganic selenium. It can induce antioxidant system activity, enhance cell membrane stability, and increase the activity of disease-resistant enzymes, while being non-toxic and non-irritating.

[0024] As one implementation method, the method of gas sterilization and covering king oyster mushroom film includes: Dilute allyl isothiocyanate with water 2500-4000 times to obtain an allyl isothiocyanate solution. The adsorbent is immersed in the allyl isothiocyanate solution. After placing the adsorbent containing the allyl isothiocyanate solution inside a strawberry packaging box, it is covered with a mushroom film. In one embodiment, the adsorbent includes cotton balls. In another embodiment, the adsorbent containing the allyl isothiocyanate solution does not directly contact the strawberries. The allyl isothiocyanate used in this invention can be a 20% water-in-oil emulsion, provided by Jiangsu Tenglong Biopharmaceutical Co., Ltd.

[0025] This invention abandons traditional irradiation and soaking methods, and instead uses a plant-derived antibacterial substance—allyl isothiocyanate (AITC)—for treatment. AITC is the main volatile component in horseradish or mustard, possessing extremely strong broad-spectrum bactericidal activity and significant killing effects on bacteria (Escherichia coli, Staphylococcus aureus) and fungi (Aspergillus niger). This invention utilizes its high volatility and good permeability, allowing it to rapidly penetrate the pores, lenticels, and even tiny cracks of the fruit peel in gaseous form, achieving 360-degree sterilization of the strawberry surface and hidden areas without dead angles. The process is carried out at room temperature and pressure, requiring no high-energy-consuming equipment and is simple to operate.

[0026] In one implementation, the strawberry varieties include Red Beauty and / or Monterey. This invention uses Red Beauty, the main winter-grown variety, and Monterey, the main summer-grown variety, as examples for experimental illustration, but this should not be construed as limiting the scope of protection of this invention. The method of this invention is applicable to all strawberry varieties.

[0027] The method provided by this invention solves the problems of poor fruit quality and low yield of strawberries by spraying specific foliar fertilizer on strawberry plants before harvesting and using gas sterilization and covering with king oyster mushroom film after harvesting. It increases the number of fruits per plant, yield per plant, average weight of single fruit, fruit firmness, and soluble solids content. At the same time, it can also extend the shelf life of the fruit, reduce the rate of decay, reduce the respiration rate, delay the decrease in firmness, and delay the decrease in soluble solids content. It can complement the whole cold chain and provide a flexible, efficient, and low-cost solution for ensuring fruit quality under different transportation conditions. It is suitable for facility cultivation and fits the actual needs of agricultural production.

[0028] Based on the above advantages, the present invention provides the application of the preservation method described in the above technical solution in one or more of the following: 1) Promotes the growth and development of strawberry leaves; 2) Improves the photosynthetic capacity of strawberry plants; 3) Increases the number of fruits per strawberry plant; 4) Increases the yield per strawberry plant; 5) Increases the average weight of a single strawberry fruit; 6) Improves the firmness of strawberry fruits; 7) Increases the soluble solids content of strawberry fruits; 8) Extends the shelf life of strawberry fruits.

[0029] As one implementation method, promoting strawberry leaf growth and development includes increasing leaf length and / or width; improving the photosynthetic capacity of strawberry plants includes one or more of the following: increasing chlorophyll content, increasing net photosynthetic rate, increasing stomatal conductance, reducing intercellular CO2 concentration, and increasing transpiration rate.

[0030] As one implementation method, extending the shelf life of strawberry fruit includes one or more of the following: reducing the rot rate, reducing the respiration rate, delaying the decrease in firmness, and delaying the decrease in soluble solids content.

[0031] To further illustrate the present invention, the following detailed description, in conjunction with embodiments and accompanying drawings, provides a method for preserving strawberries based on preharvest nutrient enhancement and postharvest gas sterilization, but these descriptions should not be construed as limiting the scope of protection of the present invention.

[0032] Preparation Example The measurement indicators and methods involved in the embodiments of the present invention are as follows: (1) Agronomic traits were measured: plant height, crown diameter, leaf length and leaf width were measured with a ruler. Plant stem diameter was measured with a vernier caliper and the number of leaves was visually counted.

[0033] (2) Chlorophyll content determination: The TYS-4N plant nutrient analyzer of Zhejiang Top Cloud Agriculture was used to measure the chlorophyll content of the central leaflet of the third leaf from the center of the strawberry plant.

[0034] (3) Photosynthetic capacity measurement: The Li-6400 portable photosynthesis instrument of Li-COR Corporation, USA, was used. The central leaflet of the third leaf from the center of the central unfolded leaf of the strawberry plant was selected. The indicators measured were net photosynthetic rate, stomatal conductance, intercellular CO2 concentration and transpiration rate.

[0035] (4) Fruit phenotype and soluble solids determination: The yield per plant, number of fruits per plant, average weight of single fruit, fruit firmness, and soluble solids were determined for each treatment at different times in February, March, and April. The weight of the fruit was determined using an electronic balance. The firmness of the fruit was determined using a FUDOH rheometer (physical property analyzer) RTC. The soluble solids of a single mature strawberry fruit was determined using an ATAGOPAL-1 handheld portable refractometer.

[0036] (5) Total sugar content, total acid content and sugar-acid ratio: Soluble sugar in strawberry fruit was determined by liquid chromatography; total sugar content (mg / g) = M fructose + M sucrose + M glucose, total acid content (mg / g) = M citric acid + M malic acid, sugar-acid ratio = total sugar content / total acid content.

[0037] (6) Fruit weight loss rate, rot rate and respiration intensity: The weight of the fruit was measured and the weight loss rate was calculated using an electronic balance. The rot rate was observed and calculated visually. The respiration intensity was measured using CheckMate3.

[0038] The preparation methods for different foliar fertilizers are as follows: Plant-based soluble compound dissolves directly in water.

[0039] Selenium-enriched yeast (Bioss, D10482) was dissolved in water and ultrasonically vibrated until completely dissolved.

[0040] Dissolve chitosan powder (Yuan Ye, S11160-100g) in water and vibrate it with an ultrasonic machine until it is completely dissolved.

[0041] Nano-silica (Shanghai Pantian Powder Materials Co., Ltd., diameter 20nm) was dissolved in water and ultrasonically shaken in an ice bath for 1 hour.

[0042] Example 1: Effects of different fertilizers on strawberry growth and storage The strawberry varieties used were 'Hongyan' and 'Monterey'. Strawberries were conventionally cultivated and planted on September 27, 2023, using a double-row planting method with raised beds and ridges. The ridge width was 60 cm, the furrow width was 25 cm, and the ridge height was 20 cm. The row and plant spacing was 25 × 25 cm. A 1 m protective row was set up around the perimeter of the experimental area. The planting depth of the strawberries was ideally "deep enough not to bury the crown, shallow enough not to expose the roots." Weeding and pesticide spraying were carried out regularly according to the actual conditions of the experimental site, and normal field management was maintained. Foliar fertilizer was sprayed every two weeks from December to March of the following year, using foliar spraying until the leaves were moist but not dripping. The foliar fertilizer used and the control group are as follows: T0: Clean water; T1: 2g / L Plant-based Kang; T2: 2g / L Plant-based Kang and 4g / L Chitosan; T3: 2g / L Plant-based Kang and 50mg / L Nano Silica; T4: 2g / L PlantLife and 5mg / L Selenium-enriched yeast; T5: 2g / L Plant-based phytochemicals, 4g / L chitosan, 50mg / L nano-silica, and 5mg / L selenium-enriched yeast.

[0043] The measurement results of different detection indicators in different treatment groups are as follows: Table 1 Effects of different foliar fertilizers on the growth traits of 'Hongyan' plants

[0044] Note: Plant height is in cm, stem diameter is in mm, crown diameter is in cm, leaf length is in cm, leaf width is in cm, and leaf area is in cm². 2 The same applies to the table below.

[0045] Table 2 Effects of different foliar fertilizers on photosynthetic parameters of 'Hongyan' plants

[0046] Note: Chlorophyll content is measured in SPAD value, and net photosynthetic rate is measured in μmol·CO2·m. -2 ·s -1 The unit of stomatal conductance is mol·H₂O·m. -2 ·s -1 The unit of intercellular CO2 concentration is μmol·CO2·mol. -1 The unit of transpiration rate is mmol·H₂O·m -2 ·s -1 The same applies to the table below.

[0047] The results showed that T5 had the most significant effect on improving net photosynthetic rate, stomatal conductance, and transpiration rate; T5 had a positive effect on the growth of crown diameter, leaf width, and leaf area of ​​'Hongyan'; T1 had the most significant effect on increasing chlorophyll content. The T5 treatment group was comprehensively superior in terms of growth, photosynthetic efficiency, stomatal regulation, and transpiration capacity; although its nutrition and pigment content were slightly lower than T1, the difference was not significant and was much higher than T0.

[0048] Table 3 Effects of different foliar fertilizers on the growth traits of 'Monterey' variegated plants

[0049] Table 4. Effects of different foliar fertilizers on photosynthetic parameters of 'Monterrey' plants

[0050] The results showed that T3 had the most significant effect on increasing chlorophyll content; T5 had the most significant effect on increasing net photosynthetic rate, stomatal conductance, and transpiration rate; T5 performed better in terms of crown diameter, leaf width, net photosynthesis, stomatal conductance, and transpiration rate; the T3 treatment group only had better results in leaf area and chlorophyll content, but there was no significant difference compared with T5.

[0051] Table 5. Effects of different fertilizers on the yield of individual plants of 'Hongyan' and 'Monterey' in different months.

[0052] The results showed that the 'Hongyan' T4 treatment group had the most significant effect on increasing yield per plant. 'Monterey' showed the most significant effect on increasing yield per plant in April.

[0053] Table 6. Effects of different fertilizers on the single fruit weight of 'Hongyan' and 'Monterui' varieties in different months.

[0054] The results showed that for 'Hongyan', the T4 treatment group had a more significant effect on the average single fruit weight in all months. For 'Monterey', the T3 treatment group had a more significant increase in single fruit weight in February and March, while the T4 treatment group had a significant increase in April.

[0055] Table 7. Effects of different fertilizers on fruit firmness of 'Hongyan' and 'Monterui' varieties at different months.

[0056] The results showed that the 'Hongyan' T4 treatment group had a significant effect on improving fruit firmness in February and March. The 'Monterey' T4 treatment group only showed the best effect on improving fruit firmness in February.

[0057] Table 8. Effects of different fertilizers on the soluble solids content of 'Hongyan' and 'Monterui' varieties in different months.

[0058] Table 9. Effects of different fertilizers on total sugar, total acid, and sugar-acid ratio of 'Hongyan' and 'Monterui' varietal fruits in February.

[0059] Table 10 Effects of different fertilizers on total sugar, total acid, and sugar-acid ratio of 'Hongyan' and 'Monterui' varietal fruits in March.

[0060] Table 11 Effects of different fertilizers on total sugar, total acid, and sugar-acid ratio of 'Hongyan' and 'Monterui' cultivars in April.

[0061] The results showed that the 'Hongyan' 'T4' treatment group had the highest yield per plant in March and April, at 110.7g and 73.4g respectively; the highest hardness was 18.3 N / cm in February and March. 2 9.8 N / cm 2 The T4 treatment group exhibited the lowest field harvesting losses; its soluble solids content in April was 10.76%, indicating high market acceptance of its flavor. Furthermore, the T4 treatment group had the highest sugar-acid ratio in February and March. Therefore, the T4 treatment group was superior in terms of fruit quality. For 'Monterey': the T4 treatment group achieved a yield of 120.5 g per plant and an average fruit weight of 28.9 g in April, significantly higher than other groups; fruit firmness was high in February and March; and soluble solids content was highest in March and April. It achieved double peaks in March and April in terms of yield, fruit weight, firmness, and soluble solids content. However, its sugar-acid ratio in March and April was slightly lower than that of the T1 treatment group. In summary, the T4 treatment group showed better overall improvement for both 'Hongyan' and 'Monterey' varieties.

[0062] Different groups of strawberries were stored at 22℃ for 9 days with a humidity of approximately 60%. Weight loss rate, rot rate, respiration rate, post-storage firmness, and soluble solids content were measured. The results are shown in Table 12. Figures 1-4 .

[0063] Table 12 Effects of different fertilizers on the storage effects of 'Hongyan' and 'Monterui' varietals

[0064] The results showed that for 'Hongyan' fruit, both T4 and T5 had the lowest rot rate at 16.7%, a 70% reduction compared to T0; the T4 treatment group had the lowest weight loss rate, with no obvious wrinkling on the fruit surface; the T5 treatment group had slightly higher firmness, but the T4 treatment group had a firmness of 18.0 N / cm. 2 The T4 treatment group showed significantly better performance than other groups; it had the highest soluble solids content (10.78%) and the best flavor retention. In summary, T4 outperformed other groups in terms of spoilage rate, weight loss, firmness, and flavor. 'Monterrey': T4 and T2 had the lowest spoilage rate (55.6%), approximately 23% lower than T0; the T4 treatment group had the highest firmness (21.96 N / cm). 2 The T4 and T5 treatment groups showed significantly better results than other groups; the T4 and T5 treatment groups had the highest soluble solids content; although there was no significant difference in weight loss rate, the T4 treatment group still had the lowest at 0.75%. In summary, the T4 treatment group (2g / L PlantLife + 5mg / L selenium-enriched yeast) can effectively extend the shelf life of fruits and reduce the rate of decay.

[0065] Example 2: Effects of different plastic wraps on strawberry storage The tested variety was 'Hongyan', which was 80% ripe.

[0066] Harvesting date: December 25, 2024.

[0067] Storage time: 12 days.

[0068] Test film: G1: Ordinary supermarket PE food storage bag (4 holes); G2: Ordinary supermarket PE food storage bag (no holes); G3: No. 1 film; G4: No. 2 film; G5: King oyster mushroom film; G6: Chili film; G7: Shenkai film; Among them, G3-G7 were provided by Ms. Luo Shufen from the Equipment Institute of Jiangsu Academy of Agricultural Sciences.

[0069] The information about the film used for king oyster mushrooms is published in the article "Ren Kai, He Xue, Xu Chang, et al. Effects of different film packaging on the post-harvest shelf quality of bok choy [J / OL]. Food and Fermentation Industries"; The chili pepper film was published in the article "[Hu Huali, Li Pengxia, Wang Yuning. Effects of different film packaging on postharvest senescence physiology of Pleurotus ostreatus [J]. Food and Fermentation Industries, 2012, 38(07):196-200.]". The second type of film was published in the article "[Li Chunhong, Zhang Leigang, Luo Shufen, et al. Effects of different polyethylene film packaging on the storage quality of red peppers[J]. Packaging Engineering, 2018, 39(03):64-71.]" Shenkai film is supplied by Jiangsu Shenkai Packaging High-Tech Co., Ltd.; No. 1 film is supplied by Changzhou Yingzhong Nanotechnology Co., Ltd.

[0070] Test method: Strawberries wrapped in different films were stored at 22℃. Rotting and accelerated weight loss occurred on the 10th day. After 12 days of storage, the weight loss rate, rotting rate, respiration rate, post-storage firmness, and soluble solids content were measured. The results are shown in Table 13. Figures 5-7 .

[0071] Table 13. Detection results of different indicators in different treatment groups after 12 days of storage.

[0072] The results showed that G1 (control 4-well membrane) and G5 (King Oyster Mushroom membrane) did not show any signs of rotting, but G1 (control 4-well membrane) had a higher weight loss rate. Figure 6 G5 (King Oyster Mushroom Membrane) was the best in terms of overall color and area of ​​decay. Therefore, G5 membrane was selected for subsequent experiments. Figure 7 However, the repeatability of the second group processed by G5 was poor, which may be due to unsealed packaging or uneven packaging material.

[0073] Analysis of weight loss rate, decay rate, respiration rate, hardness, and solids content indicates that G5 (King Oyster Mushroom Membrane) performed better. Furthermore, considering the color, brightness, and lesion area in photos taken on the last day of storage, G5 (King Oyster Mushroom Membrane) is more suitable for extending the shelf life of strawberries.

[0074] Example 3: Effects of different antibacterial treatments on the postharvest shelf life of strawberries The tested varieties were 'Hongyan' and 'Monterey', which were 80% ripe.

[0075] Harvesting date: March 20, 2025.

[0076] Storage time: 4 days.

[0077] Grouping: Control group (CK): No treatment received; UVC irradiation treatment (UVC): Postharvest fruit is irradiated with a UVC lamp (wavelength: 253.7nm; power: 15W-30W) for 30s; Allyl isothiocyanate treatment (AITC): Dilute allyl isothiocyanate (20% water-in-oil emulsion, provided by Jiangsu Tenglong Biopharmaceutical Co., Ltd.) 4000 times. Take a cotton ball with a diameter of 1-2 cm and immerse it completely in the diluted solution for 10 minutes. Then place 3 moistened cotton balls in the strawberry packaging box, without direct contact with the strawberries. AITC sterilizes by slowly releasing gas.

[0078] Test method: Strawberries from different groups were treated and stored at 22℃. On the fourth day of storage, the weight loss rate, rot rate, respiration rate, post-storage firmness, and soluble solids content were measured. The results are shown in Table 14. Figures 8-11 .

[0079] Table 14 Effects of different antibacterial treatments on physiological indicators of 'Hongyan' and 'Monterui' fruits during storage.

[0080] The results showed that for both 'Hongyan' and 'Monterey' cultivars, treatment with allyl isothiocyanate diluted 4000 times was optimal. Compared with the control group, it reduced weight loss by 10.8% and 5.7%, respectively; and reduced decay rate by 35.7% and 50%, respectively. It also reduced respiration intensity during storage and slowed the decline in firmness and soluble solids. In conclusion, allyl isothiocyanate treatment (4000-fold dilution) effectively extended the shelf life of fruit and reduced decay rate.

[0081] Example 4 The strawberries to be tested in this embodiment were harvested on April 21, 2025.

[0082] The optimal methods of Examples 1-3 were used to treat the strawberry varieties ('Hongyan' and 'Monterey') before and after harvest (denoted as E2). Specifically, the strawberry plants were foliar sprayed using the method T4 in Example 1. After harvesting, the strawberries were treated with allyl isothiocyanate as in Example 3 and then wrapped in the mushroom film as in Example 2 before being stored at 22°C. At the same time, a control group (denoted as E1) was set up, as follows: the strawberry plants were foliar sprayed using the method T0 in Example 1. After harvesting, the strawberries were treated with the control group method as in Example 3 and then wrapped in ordinary supermarket PE preservation bags (without perforation) as in Example 2 before being stored at 22°C.

[0083] Weight loss, decay rate, respiration rate, post-storage hardness, and soluble solids content were measured on the 4th day of storage. The results are shown in Table 15 and 16. Figures 12-15 .

[0084] Table 15 Effects of different treatment combinations on physiological indicators of 'Hongyan' and 'Monterui' fruits during storage.

[0085] The results showed that for 'Hongyan', different treatment combinations resulted in a 42% reduction in weight loss rate compared to E1; a 42.86% reduction in decay rate; a 54.74% reduction in respiration rate; and a 19.74% and 15.24% reduction in hardness and soluble solids, respectively. For 'Monterey', different treatment combinations resulted in a 57.14% reduction in weight loss rate compared to E1; a 50% reduction in decay rate; a 30.87% reduction in respiration rate; and a 7.87% and 22.37% reduction in hardness and soluble solids, respectively.

[0086] In summary, the E2 treatment group significantly reduced fruit weight loss and decay rates, decreased respiration intensity during storage, and slowed down the decrease in firmness and soluble solids.

[0087] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preserving strawberries based on pre-harvest nutrient enhancement and post-harvest gas sterilization, characterized in that, include: Before harvesting, foliar fertilizer is sprayed onto the strawberry plants. After harvesting, the strawberries are stored by using gas sterilization and covering them with king oyster mushroom film. The foliar fertilizer comprises the following components at the following concentrations: 0.5-2 g / L of medium-element fertilizer and 3-6 mg / L of selenium-enriched yeast; The medium-element fertilizer comprises the following components by weight percentage: calcium carbonate 60%-94.4%, magnesium carbonate 2%-5%, silicon dioxide 1%-3%, and the balance being trace elements; the trace elements include iron, potassium, manganese, zinc, copper, and molybdenum; The reagents used for gas sterilization include allyl isothiocyanate.

2. The preservation method according to claim 1, characterized in that, The method for gas sterilization and covering king oyster mushrooms with a membrane includes: Dilute allyl isothiocyanate with water 2500-4000 times to obtain an allyl isothiocyanate solution. The adsorbent was immersed in the allyl isothiocyanate solution, and after the adsorbent containing the allyl isothiocyanate solution was placed in a strawberry packaging box, it was covered with a king oyster mushroom film.

3. The preservation method according to claim 2, characterized in that, The absorbent includes all porous materials that can absorb water and effectively lock in liquids, including cotton balls.

4. The preservation method according to claim 2 or 3, characterized in that, The adsorbate containing allyl isothiocyanate solution does not directly contact the strawberry.

5. The preservation method according to claim 1, characterized in that, The foliar fertilizer should be applied from December to March of the following year, once every two weeks.

6. The preservation method according to claim 1 or 5, characterized in that, The medium-element fertilizer mentioned includes Plantcare medium-element fertilizer.

7. The preservation method according to claim 1, characterized in that, The strawberry varieties mentioned include Red Beauty and / or Monterey.

8. The application of the preservation method according to any one of claims 1-7 in one or more of the following: 1) Promotes the growth and development of strawberry leaves; 2) Improves the photosynthetic capacity of strawberry plants; 3) Increases the number of fruits per strawberry plant; 4) Increases the yield per strawberry plant; 5) Increases the average weight of a single strawberry fruit; 6) Improves the firmness of strawberry fruits; 7) Increases the soluble solids content of strawberry fruits; 8) Extends the shelf life of strawberry fruits.

9. The application according to claim 8, characterized in that, The promotion of strawberry leaf growth and development includes increasing leaf length and / or width; the improvement of strawberry plant photosynthetic capacity includes one or more of the following: increasing chlorophyll content, increasing net photosynthetic rate, increasing stomatal conductance, reducing intercellular CO2 concentration, and increasing transpiration rate.

10. The application according to claim 8, characterized in that, The method of extending the shelf life of strawberry fruit includes one or more of the following: reducing the rate of decay, reducing the respiration rate, delaying the decrease in firmness, and delaying the decrease in soluble solids content.

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