Method for postharvest preservation of litchi and prevention of pythium diseases
By treating litchi fruit with 10-undecenoic acid, the problems of high safety risks and high costs in post-harvest preservation technology for litchi were solved, and effective prevention and preservation of downy mildew were achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SOUTH CHINA BOTANICAL GARDEN CHINESE ACADEMY OF SCI
- Filing Date
- 2026-06-04
- Publication Date
- 2026-07-17
AI Technical Summary
Existing post-harvest preservation technologies for lychees suffer from high safety risks, limited preservation effects, and high costs, especially lacking effective methods for preventing downy mildew.
Lychee fruits are treated with natural 10-undecenoic acid by soaking or spraying to inhibit the infection of downy mildew. The preferred concentration is 250 mg/L and the preferred soaking time is 3 min.
It significantly reduces the incidence and disease index of diseases, delays fruit decay, maintains storage quality, and achieves prevention and control of downy mildew and post-harvest preservation, while being low in cost and highly safe.
Smart Images
Figure CN122397796A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of fruit storage and preservation technology, specifically to a method for post-harvest preservation of lychees and prevention of downy mildew. Background Technology
[0002] litchi( Litchi chinensis Lychee (Sonn.), a typical representative of the Sapindaceae family, is an important economic crop in tropical and subtropical regions. Its fruit is renowned for its bright red skin, translucent flesh, and unique flavor, holding a significant position in international fruit trade. my country, as the world's largest producer of lychees, ranks first globally in both planting scale and yield. However, the post-harvest physiological characteristics of lychees present severe challenges during storage and transportation: the fruit ripens during the high-temperature season, and its unique tissue structure makes it highly susceptible to enzymatic browning and microbial infection after harvest. Especially under normal temperature conditions, its commercial value is rapidly lost within 48-72 hours. This technical bottleneck severely restricts the long-distance sales and international trade development of the lychee industry.
[0003] Current post-harvest preservation technologies for litchi mainly fall into two categories: physical methods and chemical methods. Physical methods include heat treatment, low-temperature storage, modified atmosphere packaging, and irradiation; chemical methods involve fungicide soaking, sulfur dioxide fumigation, ozone treatment, and the application of biological agents. Although these technologies can delay fruit quality deterioration to varying degrees, they all have significant limitations: physical methods are costly and heavily reliant on equipment, while chemical methods face risks related to pesticide residues and food safety. For example, while sulfite treatment has a significant preservation effect, its use has been restricted by several importing countries due to excessive sulfur residues. Therefore, developing new preservation technologies that meet food safety standards and are commercially viable has become a critical issue that the litchi industry urgently needs to address.
[0004] 10-Undecenoic acid, a small molecule compound, is naturally found in plant tissues such as avocados and pine nuts. Its molecular structure contains both terminal olefinic bonds and carboxyl groups, both of which are active groups. 10-Undecenoic acid is receiving increasing attention from academia and industry; however, research on its application in the control of plant pathogens is currently limited, especially regarding its effects on oomycetes, which are not yet reported. Summary of the Invention
[0005] This invention provides a method for post-harvest preservation of litchi and prevention of downy mildew, which uses 10-undecenoic acid, a naturally sourced and inexpensive fungus, to treat litchi fruit, effectively inhibiting the fungus that causes litchi downy mildew. Peronophythora litchii This method significantly reduces the incidence and index of downy mildew, slows down the decay of fruit, maintains storage quality, and achieves both prevention and post-harvest preservation of litchi downy mildew. It solves the problems of high safety risks, limited preservation effects, and high costs associated with existing post-harvest preservation technologies for litchi.
[0006] This invention is achieved through the following technical solutions:
[0007] The first objective of this invention is to provide the use of 10-undecenoic acid in the preparation of formulations that inhibit Phytophthora downy mildew of litchi.
[0008] A second objective of this invention is to provide the application of 10-undecenoic acid in the preparation of formulations for the prevention and control of downy mildew in litchi.
[0009] A third objective of this invention is to provide the application of 10-undecenoic acid in the preparation of formulations for postharvest preservation of litchi fruit.
[0010] The fourth objective of this invention is to provide a method for preventing and controlling downy mildew of litchi by treating litchi fruit with 10-undecenoic acid.
[0011] Preferably, the concentration of the 10-undecenoic acid used is 250 mg / L.
[0012] Preferably, the treatment includes immersion or spraying. More preferably, the treatment is immersion for 3 minutes.
[0013] The fifth objective of this invention is to provide a method for postharvest preservation of litchi fruit by treating litchi fruit with 10-undecenoic acid.
[0014] Preferably, the concentration of the 10-undecenoic acid used is 250 mg / L.
[0015] Preferably, the treatment includes immersion or spraying. More preferably, the treatment is immersion for 3 minutes.
[0016] Beneficial effects:
[0017] 1. This invention discovers that 10-undecenoic acid has a significant inhibitory effect on Phytophthora downyensis, the causal agent of litchi. Artificial inoculation experiments show that treatment of litchi fruits with 10-undecenoic acid effectively inhibits Phytophthora downyensis infection, reducing disease incidence and disease index. Natural storage experiments at room temperature show that treatment of litchi fruits with 10-undecenoic acid effectively reduces the severity of disease, delays fruit decay, maintains storage quality, and achieves both prevention and control of litchi downyensis and post-harvest preservation.
[0018] 2. The 10-undecenoic acid used in this invention is naturally derived and has the advantages of high safety and low cost, providing a new solution for the prevention and control of postharvest diseases and preservation of litchi. Attached Figure Description
[0019] Figure 1This is a comparison of the disease phenotypes of litchi fruits in the control group and treatment group after artificial inoculation with Phytophthora litchii and storage at 25°C in Example 1 of the present invention.
[0020] Figure 2 This is a statistical chart showing the incidence of disease in litchi fruits from the control and treatment groups after artificial inoculation with Phytophthora lychee during storage at 25°C in Example 1 of this invention.
[0021] Figure 3 This is a statistical chart showing the disease index of litchi fruits in the control group and treatment group after artificial inoculation with Phytophthora lychee during storage at 25°C in Example 1 of the present invention.
[0022] Figure 4 This is a comparison chart of the disease incidence of litchi fruits in the control group and the treatment group during natural storage at 25℃ in Example 2 of the present invention.
[0023] Figure 5 This is a statistical chart showing the incidence of diseases in litchi fruits from the control group and the treatment group during natural storage at 25℃ in Example 2 of the present invention.
[0024] Figure 6 This is a statistical chart showing the disease index of litchi fruits in the control group and treatment group during natural storage at 25℃ in Example 2 of the present invention. Detailed Implementation
[0025] To ensure that the objectives, technical solutions, and advantages of this invention are clearer and more complete, the technical solutions in the embodiments of this invention will be described in more detail below with reference to the accompanying drawings. Specific embodiments are further illustrations of this invention and are not intended to limit it. Based on the embodiments of this invention, embodiments obtained by those skilled in the art without inventive technical improvements will be considered to fall within the scope of protection of this invention.
[0026] Example 1: Inhibitory effect of 10-undecenoic acid on downy mildew of litchi
[0027] 1. Experimental Methods
[0028] (1) Fruit pretreatment: Select Huaizhi litchi fruits with uniform maturity, no mechanical damage or pests and diseases, wash the surface dirt with tap water, then soak them in 2% w / v (i.e. 20 mg / mL) sodium hypochlorite solution for 2 min for sterilization, take them out and rinse the surface residue with sterile distilled water, and air dry them naturally under sterile conditions for later use.
[0029] (2) Grouping and treatment: The prepared fruits were randomly divided into a control group and a treatment group, with 90 fruits in each group. Control group: soaked in water for 3 min; treatment group: soaked in 250 mg / L 10-undecenoic acid solution for 3 min (Note: 10-undecenoic acid was pre-dissolved in a small amount of ethanol as a co-solvent, and then diluted with deionized water to the specified concentration). After treatment, the fruits were taken out and air-dried naturally.
[0030] (3) Inoculation and culture: Prepare a concentration of 1×10 5 downy mildew spores / mL ( Peronophythora litchii The spore suspension was evenly sprayed onto the surface of two groups of litchi fruits, with approximately 1 mL of suspension used per fruit. The inoculated fruits were placed in sterilized preservation boxes with a sterile plastic support frame at the bottom and an appropriate amount of sterile water added to maintain a high humidity environment of 85±10%. The fruits were cultured at 25℃, and the disease incidence was observed and recorded daily.
[0031] (4) Evaluation indicators:
[0032] Disease incidence rate (%) = (number of diseased fruits / total number of fruits) × 100%; the result is the average of three repeated experiments.
[0033] Disease Index: Divided into five levels according to the severity of disease, the calculation formula is: Disease Index = Σ (Disease Level × Number of Fruits at That Level) / (Highest Level × Total Number of Fruits). The grading standards are: Level 0, no disease; Level 1, diseased area ≤ 25% of the total fruit peel area; Level 2, 25% < diseased area ≤ 50%; Level 3, 50% < diseased area ≤ 75%; Level 4, diseased area > 75%.
[0034] 2. Experimental Results and Analysis
[0035] like Figure 1 As shown in the figure, physical observation reveals that, compared with the water control group, treatment with a 250 mg / L 10-undecenoic acid solution significantly slowed down the progression of downy mildew in litchi fruit, demonstrating a good disease resistance and preservation effect.
[0036] Further analysis Figure 2 and Figure 3It can be seen that during storage, the incidence and disease index of litchi fruits in both groups showed an increasing trend with the extension of storage time, indicating that the disease worsened with the increase of storage time. However, all disease indicators in the treatment group were consistently significantly lower than those in the control group. Specifically, on the 2nd, 3rd, and 4th days of storage, the disease incidence rates in the control group were 25.56%, 82.22%, and 100%, respectively, while those in the treatment group were only 11.11%, 60.00%, and 88.89%, respectively, representing significant reductions of 14.45%, 22.22%, and 11.11% compared to the control group. Figure 2 Meanwhile, at the same time points, the disease indices of the control group were 0.07, 0.47, and 0.84, respectively, while the disease indices of the treatment group significantly decreased to 0.03, 0.34, and 0.71. Figure 3 The above data fully confirm that 10-undecenoic acid treatment can effectively inhibit the occurrence and spread of downy mildew in litchi.
[0037] Example 2: Preservation effect of 10-undecenoic acid under normal temperature storage conditions
[0038] 1. Experimental Methods
[0039] Referring to Example 1, the Huaizhi litchi fruit was subjected to step (1) fruit pretreatment and step (2) grouping and treatment: control group (soaked in water for 3 min) and treatment group (soaked in 250 mg / L 10-undecenoic acid solution for 3 min).
[0040] (3) Storage conditions: The fruits treated in step (2) were packaged in 0.015 mm thick polyethylene (PE) film bags, with 30 fruits per bag and 3 bags in each group. The packaged fruits were stored in an environment with a temperature of 25℃ and a relative humidity of 85±10% for 6 days. The disease incidence of the fruits was observed and recorded.
[0041] 2. Experimental Results and Analysis
[0042] like Figure 4 As shown in the results of physical observation, compared with the water control group, the litchi fruits treated with 10-undecenoic acid had a brighter appearance and the incidence of diseases was significantly reduced.
[0043] like Figure 5 and Figure 6 As shown, quantitative analysis revealed that during storage at room temperature, the disease incidence and disease index of the treated fruit were significantly lower than those of the control group. Specifically, on days 2, 4, and 6 of storage, the disease incidence rates in the control group were 16.67%, 71.11%, and 100%, respectively, while the disease incidence rates in the treated group decreased to 7.78%, 57.78%, and 92.22%, representing reductions of 8.89%, 13.33%, and 7.78% compared to the control group. Figure 5 During the same period, the disease indices of the control group were 0.05, 0.37, and 0.85, respectively, while the disease indices of the treatment group were significantly reduced to 0.02, 0.29, and 0.70. Figure 6 ).
[0044] Based on the experimental data above, it can be seen that 10-undecenoic acid not only has a significant disease resistance effect under artificial inoculation conditions, but also significantly reduces the incidence and disease index of litchi under normal temperature natural storage conditions. It has significant application potential for extending the post-harvest shelf life of litchi and inhibiting downy mildew.
Claims
1,10-Undecenoic acid in the preparation of a treatment for inhibiting Phytophthora downy mildew (a pathogen that causes downy mildew on litchi). Peronophythora litchii Application in formulations of ).
2. Application of 1,0-Undecenoic acid in the preparation of formulations for the prevention and control of downy mildew in litchi.
3. Application of 1,0-Undecenoic acid in the preparation of formulations for postharvest preservation of litchi fruit.
4. A method for preventing and controlling downy mildew of litchi, characterized in that, Litchi fruits were treated with 10-undecenoic acid.
5. The method according to claim 4, characterized in that, The concentration of 10-undecenoic acid used is 250 mg / L.
6. The method according to claim 4 or 5, characterized in that, The treatment includes soaking or spraying.
7. The method according to claim 6, characterized in that, The treatment is an immersion treatment, and the immersion time is 3 minutes.
8. A method for post-harvest preservation of litchi fruit, characterized in that, Litchi fruits were treated with 10-undecenoic acid.
9. The method according to claim 8, characterized in that, The concentration of 10-undecenoic acid used is 250 mg / L.
10. The method according to claim 8 or 9, characterized in that, The treatment includes soaking or spraying; preferably, the treatment is soaking, and the soaking time is 3 minutes.