CN111567616A - Strawberry fruit preservation method - Google Patents

Abstract

The invention discloses a fresh-keeping method for post-harvest strawberry fruits. The method comprises the following steps: spraying benzyl isothiocyanate (BITC) solution on the surface of strawberry fruit. The concentration of BITC solution is 50-200μg/mL; its spray rate is 15-25mL per kilogram of strawberry fruit. The detection results of the natural incidence of strawberry fruit showed that the spray treatment of BITC could effectively inhibit the occurrence of strawberry fruit postharvest disease (strawberry gray mold).

Description

A kind of preservation method of strawberry fruit

technical field

The invention belongs to the field of storage and preservation of fruits and vegetables, and in particular relates to a fresh-keeping method for strawberry fruits.

Background technique

Strawberry (Fragaria ananassa) is a perennial herb of the genus Rosaceae. Strawberry fruit is bright in color and unique in flavor. It is rich in minerals, dietary fiber, vitamin C, vitamin A, vitamin E, vitamin PP, vitamin B1, vitamin B2, and carotene. , tannic acid, anthocyanins and flavonoids and other nutrients, especially vitamin C content is 7-10 times higher than apples, grapes. The carotene and vitamin A rich in strawberries can relieve night blindness, maintain the health of epithelial tissue, improve eyesight and liver, and promote growth and development. It is known as the "Queen of Fruits" and is welcomed by consumers. However, because strawberry fruit belongs to berries, the peel is fragile and the water content is high, and it is extremely vulnerable to mechanical damage during harvesting and transportation, resulting in infection by pathogenic fungi, resulting in rot and deterioration. Therefore, the short post-harvest preservation period has become a key factor restricting the development of the strawberry industry. Extending the shelf life of strawberry fruit and improving its commodity value is an urgent problem to be solved in the storage and preservation of strawberries, and it is also a research hotspot and difficulty in the field of fruit and vegetable storage and preservation.

Isothiocyanate (ITCs) is an organosulfur compound with anti-cancer and anti-cancer effects in cruciferous plants. ITCs mainly exist in the form of glucose isothiocyanate conjugates in cruciferous vegetables, such as broccoli, cabbage, kale, cauliflower, and Brussels sprouts. About 100 kinds of ITCs have been found, but the ITCs that are often exposed in the diet and have been proved to have anti-cancer effects through experiments mainly include benzyl isothiocyanate (BITC), allyl isothiocyanate (Allylisothiocyanate) , AITC), phenethyl isothiocyanate (phenethyl isothiocyanate, PEITC) and sulforaphane (Sulforaphane, SFN). BITC is a safe natural product of plant origin, and there is no report on its application in the field of strawberry preservation.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide new uses of benzyl isothiocyanate (BITC).

The new use of the benzyl isothiocyanate (BITC) provided by the present invention includes the following at least one aspect:

1) Application in the control of Botrytis cinerea;

2) application in the preparation of products for preventing and treating botrytis;

3) Application in inhibiting Botrytis cinerea.

The gray mold can be caused by Botrytis cinerea.

The gray mold can specifically be strawberry gray mold, grape gray mold, apple gray mold, etc.; furthermore, it can be strawberry gray mold that occurs after strawberry fruit is harvested.

The product can be a fungicide.

The said inhibition of Botrytis cinerea is embodied in the following a) and/b):

a) inhibit the spore germination and mycelial growth of Botrytis cinerea;

b) inhibiting the expansion rate of botrytis cinerea on strawberry fruit caused by Botrytis cinerea.

Another object of the present invention is to provide a method for preventing and treating Botrytis cinerea on fruits.

The method for preventing and treating Botrytis cinerea provided by the present invention comprises the following steps: spraying a benzyl isothiocyanate (BITC) solution on the surface of the fruit.

The fruit fruit can be strawberry fruit, grape fruit, apple fruit and the like.

The concentration of benzyl isothiocyanate in the benzyl isothiocyanate (BITC) solution is 50-200 μg/mL, specifically 100 μg/mL.

The benzyl isothiocyanate (BITC) solution is obtained by diluting the benzyl isothiocyanate (BITC) mother liquor with water. The concentration of the benzyl isothiocyanate (BITC) mother liquor is 0.1-0.2 g/mL, and the solvent thereof is absolute ethanol.

The fruit is a strawberry fruit, and the spraying amount of the benzyl isothiocyanate (BITC) solution is 15-25 mL per kilogram of the strawberry fruit, specifically 20 mL.

Another object of the present invention is to provide a fresh-keeping method for post-harvest strawberry fruits.

The fresh-keeping method for post-harvest strawberry fruit provided by the present invention comprises the following steps: spraying a benzyl isothiocyanate (BITC) solution on the surface of the strawberry fruit.

The concentration of benzyl isothiocyanate in the benzyl isothiocyanate (BITC) solution is 50-200 μg/mL, specifically 100 μg/mL.

The benzyl isothiocyanate (BITC) solution is obtained by diluting the benzyl isothiocyanate (BITC) mother liquor with water. The concentration of the benzyl isothiocyanate (BITC) mother liquor is 0.1-0.2 g/mL, and the solvent thereof is absolute ethanol.

The spraying amount of the benzyl isothiocyanate (BITC) solution is 15-25 mL per kilogram of strawberry fruit, specifically 20 mL.

The method further includes placing the strawberry fruit sprayed with the benzyl isothiocyanate (BITC) solution in a sterilized plastic basket, covered with a polyethylene fresh-keeping bag, and stored at 15-25°C.

BITC had a significant inhibitory effect on the spore germination and mycelial growth of Botrytis cinerea. In liquid medium PDB, 50 μg/mL BITC could completely inhibit the germination of Botrytis cinerea spores (Fig. 1A,B), 50 μg/mL on PDA plates inhibited colony growth by 42%, and 100 μg/mL BITC could Colony growth was completely inhibited (Fig. 1C). This indicated that BITC had a significant inhibitory effect on the germination and growth of Botrytis cinerea.

Description of drawings

Figure 1 shows the inhibitory effect of BITC on Botrytis cinerea; A. Observation of Botrytis cinerea spore germination after BITC treatment; B. Statistics of Botrytis cinerea spore germination rate after BITC treatment; C. Statistics of Botrytis cinerea colony diameter after BITC treatment.

Figure 2 shows the inhibitory effect of BITC on gray mold of strawberry fruit; A. The incidence of gray mold on strawberry fruit after BITC treatment (3 days post inoculation); B. Statistics on the diameter of gray mold on strawberry fruit after BITC treatment.

Figure 3 shows the inhibitory effect of BITC on the natural incidence of strawberry fruit; A. The natural incidence of strawberry fruit after BITC treatment; B. Statistics of natural incidence of strawberry fruit after BITC treatment.

Detailed ways

The present invention will be described below through specific embodiments, but the present invention is not limited thereto, and any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention. within.

The experimental methods used in the following examples are conventional methods unless otherwise specified.

The materials, reagents, etc. used in the following examples can be obtained from commercial sources unless otherwise specified.

Quantitative experiments in the following examples are all set up to repeat the experiments three times, and the results are averaged.

The BITC used in the examples was purchased from Sigma-Aldrich (article number: 252492)

The strain number of the pathogen Botrytis cinerea is B05.10, which was donated by Professor Paul Tudzynski of the University of Münster, Germany. Documented in: Segmüller N, Kokkelink L, Giesbert S, Odinius D, van Kan JAL, Tudzynski P. 2008. NADPH oxidases are involved in differentiation and pathogenicity in Botrytis cinerea. Mol Plant Microbe Interact, 21, 808-819.

Embodiment 1, the fresh-keeping method of strawberry postharvest based on BITC

1 method:

1.1 BITC solution preparation: firstly prepare BITC into 0.1g/mL mother solution with absolute ethanol, and then dilute the mother solution with distilled water to 10μg/mL, 50μg/mL and 100μg/mL working solutions respectively.

1.2 Detection of antibacterial effect of BITC:

Botrytis cinerea is one of the most important diseases that cause strawberry fruit rot loss. We took Botrytis cinerea (Botrytis cinerea for short), the pathogen of strawberry gray mold, as an example to test the inhibitory effect of BITC on the pathogen.

1.2.1 Detection of spore germination rate:

PDA (Potato Dextrose Agar) medium with concentrations of 10 μg/mL and 50 μg/mL was prepared with BITC stock solution, and a layer of sterile cellophane was spread on the medium. Then, 200 μL of B. cinerea spore suspension at a concentration of 5×10 ⁶ cells/mL was evenly spread on the cellophane of each medium. Then, the germination rate of conidia was detected under a light microscope at 7 hours and 9 hours after inoculation, and 3 visual fields were detected for each treatment concentration, and the inhibition rate of BITC on spore germination was calculated.

1.2.2 Detection of colony growth rate:

As above, PDA medium plates with concentrations of 10 μg/mL and 50 μg/mL were prepared with BITC stock solution, and PDA plates without BITC were used as controls. On the PDA plate of Botrytis cinerea that has been cultured for 4 days, a bacterial cake with a diameter of 5 mm is taken out with a hole punch and inoculated in the center of the PDA plate added with BITC. After that, the colony diameter is measured by the cross method every day, and the inhibition of BITC on the colony growth is calculated. Rate.

1.3 Strawberry fruit gray mold disease spot expansion detection:

The inhibition rate of BITC against gray mold of strawberry fruit was detected by stab wound inoculation. A B. cinerea spore suspension was prepared with a concentration of 10 ⁴ /mL in PDB (Potato Dextrose Broth) liquid medium. The waist of the strawberry fruit was stabbed (5 mm deep) with an inoculating needle, and then 5 μL of the prepared Botrytis spore suspension was inoculated into the wound. After 1 hour, BITC solutions of different concentrations were injected into the wound, and sterilized distilled water was used as a control. Put the inoculated strawberry fruits into sterilized plastic baskets, coat with polyethylene fresh-keeping bags, and store at 25°C. After that, the diameter of gray mold lesions was measured every day, and the inhibition rate of BITC against gray mold was calculated by the following formula.

_R : inhibition rate, _D0 : diameter of control lesions, DB: diameter of lesions after BITC treatment

1.4 Detection of natural incidence of strawberry fruit:

The inhibitory effect of BITC on the natural incidence of strawberry fruit was detected by spraying. Dilute the BITC stock solution to a working solution of 100 μg/mL with sterile distilled water. The BITC solution was evenly sprayed on the surface of strawberry fruit with a sprayer, and the spraying amount was about 20 mL per kilogram of strawberry fruit. After that, the strawberry fruit was placed in a sterilized plastic basket, covered with a polyethylene fresh-keeping bag, and stored at 25 °C. After that, the incidence of strawberry fruit was observed and counted every day, and the strawberry fruit with obvious mildew on the surface was defined as the diseased fruit.

2 Results:

BITC had a significant inhibitory effect on the spore germination and mycelial growth of Botrytis cinerea. In liquid medium PDB, 50 μg/mL BITC could completely inhibit the germination of Botrytis cinerea spores (Fig. 1A,B), 50 μg/mL on PDA plates inhibited colony growth by 42%, and 100 μg/mL BITC could Colony growth was completely inhibited (Fig. 1C). This indicated that BITC had a significant inhibitory effect on the germination and growth of Botrytis cinerea.

The results of stab wound inoculation experiments showed that BITC treatment could effectively inhibit the expansion rate of botrytis cinerea on strawberry fruit. On the 3rd and 4th day after strawberry fruit inoculation with Botrytis cinerea, the inhibition rates of 10 μg/mL BITC treatment on strawberry botrytis cinerea were 43% and 35%, respectively, and the inhibition rate of 50 μg/mL BITC treatment on strawberry botrytis cinerea reached 43% and 35%, respectively. 74% and 55% (Figure 2).

The control effect of BITC treatment on postharvest natural morbidity of strawberry fruit was further tested by spraying treatment, and the application concentration was 100μg/mL. The results showed that after 2 and 3 days of storage, the natural incidence rates of the control group were 55.3% and 82.3%, respectively, and the natural incidence rates of the BITC-treated group were 13.3% and 46.7% (Fig. 3). The inhibition rate of natural onset of strawberry fruit by BITC treatment was 75% and 43% after 2 and 3 days of storage, respectively (Fig. 3). This indicated that the spray treatment of BITC could effectively inhibit the occurrence of postharvest diseases of strawberry fruit.

Claims (10)

1. the application of benzyl isothiocyanate in following at least one aspect: 1) Application in the control of Botrytis cinerea; 2) application in the preparation of products for preventing and treating botrytis; 3) Application in inhibiting Botrytis cinerea. 2. application according to claim 1, is characterized in that: described botrytis cinerea is caused by botrytis cinerea; Described gray mold is strawberry gray mold; preferably strawberry gray mold occurs after strawberry fruit is harvested; The product is a fungicide. 3. application according to claim 1 is characterized in that: described inhibition of Botrytis cinerea is embodied in the following a) and/b): a) inhibition of spore germination and mycelial growth of Botrytis cinerea; b) Inhibits the expansion rate of botrytis cinerea on strawberry fruit caused by Botrytis cinerea. 4. A method for preventing and treating botrytis cinerea on fruit, comprising the steps of: spraying a benzyl isothiocyanate solution on the surface of the fruit. 5. method according to claim 4 is characterized in that: described fruit is strawberry fruit, grape fruit, apple fruit; The concentration of benzyl isothiocyanate in the benzyl isothiocyanate solution is 50-200 μg/mL. The benzyl isothiocyanate solution is obtained by diluting the benzyl isothiocyanate mother liquor with water; the concentration of the benzyl isothiocyanate mother liquor is 0.1-0.2 g/mL, and the solvent is Anhydrous ethanol. 6 . The method according to claim 5 , wherein the fruit is a strawberry fruit, and the spray amount of the benzyl isothiocyanate solution is 15-25 mL per kilogram of the strawberry fruit. 7 . 7. A fresh-keeping method for postharvest strawberry fruit, comprising the steps of: spraying a benzyl isothiocyanate solution on the surface of the strawberry fruit. 8 . The method according to claim 7 , wherein the concentration of benzyl isothiocyanate in the benzyl isothiocyanate solution is 50-200 μg/mL. 9 . The benzyl isothiocyanate solution is obtained by diluting the benzyl isothiocyanate mother liquor with water; the concentration of the benzyl isothiocyanate mother liquor is 0.1-0.2 g/mL, and the solvent is Anhydrous ethanol. 9 . The method according to claim 8 , wherein the spraying amount of the benzyl isothiocyanate solution is 15-25 mL per kilogram of strawberry fruit. 10 . 10. The method according to any one of claims 7-9, wherein the method further comprises placing the strawberry fruit after spraying the benzyl isothiocyanate solution in a sterilized plastic basket, Cover with polyethylene fresh-keeping bag and store at 15-25 ℃.

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