Application of nicotinamide in prevention and treatment of postharvest diseases of fruits

Abstract

The invention belongs to the technical field of fruit disease prevention and treatment, and particularly relates to application of nicotinamide in prevention and treatment of postharvest diseases of fruits. The invention discloses an action mechanism and optimal use concentration of nicotinamide for preventing and treating postharvest diseases of fruits such as apples, pears, oranges, kiwi fruits, strawberries and bananas, and compared with the traditional prevention and treatment means, the nicotinamide is more environment-friendly, safer, more economical and more applicable.

Description

Technical Field

[0001] This invention belongs to the technical field of fruit disease control, and specifically relates to the application of nicotinamide in the control of postharvest fruit diseases. Background Technology

[0002] Nicotinamide, also known as 3-pyridinecarboxamide, is the water-soluble amide form of vitamin B3 (niacin). Its structural formula is [structural formula missing], and its molecular formula is C6H6N2O. It is a white crystalline granule or powder. The national food safety standard GB1903.45 lists nicotinamide as a food fortifier, and it is widely used in the domestic functional beverage market. Nicotinamide is also widely used in cosmetics for whitening and reducing melanin. It is also widely used in pharmaceuticals for treating pellagra, stomatitis, and cardiovascular diseases. Literature reports that nicotinamide has inhibitory activity against various human pathogenic fungi, including Candida albicans and Aspergillus fumigatus. Currently, the postharvest decay loss rate of fruit exceeds 20%. Production mainly relies on chemical pesticides combined with low-temperature storage technology to reduce the occurrence of postharvest diseases. However, the food safety and environmental problems caused by chemical pesticides force people to seek safe and environmentally friendly prevention and control methods. No reports have been found on the application of nicotinamide in the prevention and control of postharvest diseases in fruit. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention proposes the application of nicotinamide in the prevention and control of postharvest diseases in fruits. By exploring the antibacterial effects and mechanisms of nicotinamide, the inventors have provided a new solution for the prevention and control of postharvest diseases in fruits.

[0004] The technical solution of this invention is: Application of nicotinamide in the prevention and control of postharvest diseases in fruits; Preferably, the effective final concentration of the nicotinamide is 100-300 mM; Preferably, the postharvest disease of the fruit is caused by fungi, specifically Penicillium expansum and / or Penicillium fingernail and / or anthracnose; blue mold is also included.

[0005] Preferably, the application includes products for the preparation of postharvest disease control of fruits, and the product is used in any of the following forms: direct spraying solution, soaking treatment, preparation into a coating agent, slow-release formulation, or compounding with other fungicides; Preferably, the fruit is selected from any one of apples, pears, citrus fruits, kiwifruit, strawberries, and bananas. Of course, the above are only some of the fruits listed in this invention; nicotinamide can also be used in the prevention and control of diseases in other fruits.

[0006] The present invention has the following advantages and effects compared with the prior art: (1) Nicotinamide has excellent control effects in the prevention and treatment of fruit diseases. Taking the control of blue mold in apples as an example, after 3 days, the incidence of blue mold in apples treated with 300mM nicotinamide was 0; after 2 days, the incidence of blue mold in apples treated with 200mM nicotinamide was about 30%; while in the control group (CK), the incidence of blue mold in apples reached about 96% after 3 days; as shown in the attached figure. Figure 1 As shown; (2) The inhibition experiment of nicotinamide on the growth of Penicillium expansum under in vitro conditions showed that the mycelial zone of Penicillium expansum was the largest in the CK group, while the mycelial zone was extremely small under the treatment with 100mM nicotinamide concentration; this indicates that nicotinamide has a significant inhibitory effect on Penicillium expansum. Similarly, in vitro experiments on Penicillium digitatum and Penicillium anthracis also proved that nicotinamide has excellent inhibitory effects on Penicillium digitatum and Penicillium anthracis; details are attached. Figure 2-4 As shown; (3) Nicotinamide itself is a food fortifier that is safe to ingest. Its application in the prevention and control of fruit diseases avoids the harm to human health caused by traditional pesticides. Attached Figure Description

[0007] Figure 1 The effect of nicotinamide treatment on the incidence of blue mold disease in apples (day 3 post-inoculation).

[0008] Figure 2 The effect of nicotinamide on the growth of Penicillium extended under in vitro conditions.

[0009] Figure 3 The effect of nicotinamide on the growth of Penicillium finger under in vitro conditions.

[0010] Figure 4 The effect of nicotinamide on the growth of anthrax bacteria under in vitro conditions. Detailed Implementation

[0011] To enable those skilled in the art to better understand the present invention, the present invention will now be further described in conjunction with specific embodiments.

[0012] Experimental materials Taking apples as an example, the apples selected are of the Fuji variety and purchased from Jiajiayue Supermarket in Changqing University Town, Jinan, Shandong. Penicillium extended, Penicillium fingerling, and anthracnose fungus were provided by the Institute of Botany, Chinese Academy of Sciences, and are preserved in our laboratory. Nicotinamide is a domestically produced food-grade industrial product, purchased from Hubei Jusheng Technology Co., Ltd., with product number CAS 98-92-0.

[0013] Example 1: Control effect of nicotinamide on postharvest blue mold in apples Experimental steps: 1. Selection: Select apples that are uniform in size, free from mechanical damage, pests and diseases, and similar in color as experimental materials.

[0014] 2. Soaking for sterilization and rinsing and air-drying: Soak the apples in a 2% NaClO solution for 2 minutes to remove pathogens from the surface of the apples. After rinsing the apples thoroughly with running water, let them air-dry naturally until there are no water stains on the surface of the apples.

[0015] 3. Wound preparation and pathogen inoculation: Using a sterilized steel nail, symmetrically puncture two 4 mm × 5 mm wounds at the equatorial region of the apple. Use a pipette to aspirate 20 μL of 1×10⁻⁶ mol / L of the solution. 5 A suspension of Penicillium spores per mL was applied dropwise to the wound on the apple fruit.

[0016] 4. After the Penicillium spore suspension has been absorbed, use a pipette to take 20 μL of nicotinamide solution of different concentrations (100 mM, 200 mM, 300 mM) and drip it onto the fruit wound again. The control group was treated with an equal volume of sterile distilled water.

[0017] 5. Storage: Place the processed apples in a plastic basket approximately 330 mm long, 250 mm wide, and 120 mm high, cover with a polyethylene preservation bag and seal. Place the plastic basket in a refrigerator and set the temperature to 25 ℃ and the relative humidity to 95%.

[0018] 6. Morbidity determination: Each inoculation treatment was divided into 3 parallel groups, with 10 apples used in each parallel group. Three days after inoculation, the morbidity rate of apples in each inoculation group was calculated and statistically analyzed according to the following formula. The calculation results are shown in Table 1, and the statistical results are as follows. Figure 1 As shown.

[0019] Measurement results and conclusions: like Figure 1 As shown, after apples were inoculated with Penicillium expansum at room temperature and stored for 3 days, the incidence rate in the control group (CK) was 100%, while the incidence rates in the 100 mM, 200 mM, and 300 mM nicotinamide treatments were significantly lower than those in the control group, with the incidence rate in the 300 mM nicotinamide treatment being 0%.

[0020] Based on the provided experimental data, the following conclusions can be drawn: (1) Expanding the infectivity of Penicillium to apples Under normal temperature conditions, untreated apples (control group) showed a 100% disease rate within 3 days of inoculation with Penicillium expansum, indicating that Penicillium expansum has a strong infectivity for apples and can cause disease in apples in a short period of time.

[0021] (2) Inhibitory effect of nicotinamide on Penicillium expansum Compared with the control group, apples treated with 100 mM, 200 mM, and 300 mM nicotinamide solutions showed a significant reduction in the incidence of disease. This result indicates that nicotinamide has a significant inhibitory effect on Penicillium expansum infection.

[0022] (3) Relationship between nicotinamide concentration and inhibitory effect In the experiment, among the three nicotinamide concentrations, the incidence of disease in apples gradually decreased with increasing concentration (from 100 mM to 300 mM). In particular, the 300 mM nicotinamide treatment resulted in 0% incidence, indicating that higher concentrations of nicotinamide have a stronger ability to inhibit Penicillium flocculation.

[0023] Regarding apple diseases, nicotinamide is used for prevention and control. CN104920367A discloses that it can be applied to the prevention and control of apple ring rot fungus, rot fungus and pear rot fungus.

[0024] Example 2: Effects of nicotinamide on the growth of Penicillium expansum, Penicillium fingernail, and Penicillium anthracis under in vitro conditions This study used the plate dilution method to evaluate the inhibitory effect of nicotinamide on the growth of Penicillium expansum, Penicillium fingerlingum, and Penicillium anthracis colonies, and to explore the inhibitory mechanism.

[0025] The specific steps are as follows: 1. Preparation: PDA (potato dextrose agar) was used as the basal culture medium, and different concentrations of nicotinamide were added to prepare drug-containing PDA plates and spore suspensions.

[0026] 2. Inoculation: Accurately pipette 50 µL of spore suspension and spread it evenly on a drug-containing PDA plate. Use a sterilized glass spreader or disposable spreader to ensure even inoculation.

[0027] 3. Preliminary culture: Place the inoculated plates in a biochemical incubator, set the temperature to 28 ℃, and let them culture statically for 1-2 days to ensure that the mycelium differentiates but has not yet produced sporulation.

[0028] 4. Secondary inoculation: Using a sterile punch, take a mycelial cake with a diameter of about 0.8 cm from the initial culture plate, with the mycelial side down, and inoculate it in the center of the drug-containing PDA plate. Seal the plate with sealing film to prevent contamination by other microorganisms.

[0029] 5. Final incubation: The plates were statically incubated at 28 ℃ for 7 days.

[0030] Experimental results showed that nicotinamide had a significant inhibitory effect on the growth of Penicillium expansum, Penicillium fingernail, and anthracnose. In particular, when the concentration of nicotinamide was 100 mM, the growth of Penicillium fingernail and anthracnose was completely inhibited, while Penicillium expansum showed a small amount of growth.

[0031] In summary, the results of this invention demonstrate the potential application value of nicotinamide in areas such as agricultural product preservation and disease control. Future research can further investigate the mechanism of action, optimal concentration, and safety of nicotinamide to provide a scientific basis for its application in practical production.

[0032] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. All equivalent changes and modifications made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. The application of nicotinamide in the prevention and control of postharvest diseases in fruits, characterized in that, When using nicotinamide to control postharvest diseases of fruit, the concentration is 100-300 mM; the diseases referred to are any of the pathogens that infect the fruit, such as blue mold, Penicillium expansum, Penicillium digitatum, and anthracnose.

2. The application as described in claim 1, characterized in that, The concentration of nicotinamide used to control postharvest diseases in fruits is 300 mM.

3. The application as described in claim 1, characterized in that, The applications include products for the preparation of postharvest disease control for fruits, and the products are used in any of the following forms: direct spraying of solutions, soaking treatment, preparation of coatings, slow-release formulations, or compounding with other fungicides.

4. The application as described in claim 1, characterized in that, The fruit can be selected from any one of the following: apple, pear, citrus, kiwi, strawberry, or banana.

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