Application of brassinolide in improving volatile aroma substances of chilies

Abstract

The invention belongs to the technical field of agricultural planting, and particularly relates to application of brassinolide in improving volatile aroma substances of chilies. The invention further provides a planting method for improving the volatile aroma substances of the chilies. The planting method comprises the following steps: dissolving brassinolide in water to obtain a brassinolide solution; the brassinolide solution is used for spraying pepper seedlings in different growth periods until the leaves slightly drip water. According to the method, in the growth and development process of pepper fruits, the brassinolide aqueous solution is sprayed to pepper plants for treatment, the content of volatile aroma substances of the peppers can be greatly increased, the commodity of the peppers is increased, and economic benefits are increased for farmers. According to the method, the improvement effect can be achieved only through a foliage spraying method, operation is easy and convenient, the using amount is small, and the effect taking speed is high. As a plant regulator substance, brassinolide has the advantages of quick effect on plants, low dosage, quick metabolism, no plant regulator residue, safety, reliability and wide application prospect.

Description

Technical Field

[0001] This application belongs to the technical field of agricultural planting, and specifically relates to the application of brassinolide in improving the volatile aroma substances of peppers. Background Art

[0002] Pepper is the third largest vegetable crop in the world after legumes and tomatoes. It has become a popular vegetable variety because it is rich in bioactive compounds such as capsaicin, Vc, flavonoids, phenolic acids, and carotenoids. With the improvement of living standards, consumers not only evaluate the quality of peppers by nutritional and appearance qualities, but also put forward higher requirements for aroma quality, especially the aroma of green peppers. The content of volatile aroma substances in pepper fruits is the key factor affecting the aroma quality of peppers. Plant growth regulators are widely used in pepper planting and play a very good role in promoting plant growth, increasing yield and quality. However, no relevant research has been found on the relationship between the volatile components and characteristic aroma during the treatment of pepper products with plant regulators. Summary of the Invention

[0003] The purpose of the present invention is to solve the deficiencies of the prior art and provide the application of brassinolide in improving the volatile aroma substances of peppers. The specific technical solutions are as follows: In the first aspect, the present invention provides the application of brassinolide in improving the volatile aroma substances of peppers.

[0004] As a further preferred embodiment, the volatile aroma substances include at least one of aldehydes, esters, ketones, and terpenes.

[0005] In the second aspect, the present invention provides a planting method for improving the volatile aroma substances of peppers, comprising the following steps: Dissolve brassinolide in water to obtain a brassinolide solution; Spray the brassinolide solution on pepper seedlings at different growth stages until the leaves are slightly dripping with water; The spraying treatment of pepper seedlings at different growth stages includes spraying once during the flowering period and / or young fruit period of peppers or spraying once 7 days before pepper harvesting.

[0006] As a further preferred embodiment, spray the brassinolide solution once during the flowering period or young fruit period of peppers.

[0007] As a further preferred embodiment, spray the brassinolide solution once during both the flowering period and young fruit period of peppers.

[0008] As a further preferred embodiment, spray the brassinolide solution once 7 days before pepper harvesting.

[0009] As a further preferred embodiment, the concentration of the brassinolide solution is 0.03 mg / L - 0.05 mg / L.

[0010] As a further preferred embodiment, the concentration of the brassinolide solution is 0.04 mg / L.

[0011] As a further preferred embodiment, the spraying is carried out by a sprayer.

[0012] As a further preferred embodiment, the spraying is carried out on sunny days or cloudy days without rain.

[0013] The beneficial effects of the present invention are as follows: During the growth and development process of pepper fruits, by spraying an aqueous solution of brassinolide on pepper plants, the present invention can significantly increase the content of volatile aroma substances in peppers, improve the commercial quality of peppers, and increase the economic benefits for farmers. The method of the present invention can achieve the improvement effect only by foliar spraying, with simple operation, less dosage and quick effect. As a plant regulator substance, brassinolide has a quick effect, less dosage, fast metabolism, no residue of plant regulators on plants, is safe and reliable, and has broad application prospects. Description of the Drawings

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0015] Figure 1 Shown is the total ion chromatogram of volatile aroma substances in peppers; Figure 2 Shown is the species map of volatile aroma substances in peppers; Figure 3 Shown is the content map of volatile aroma substances in peppers; Figure 4 Shown is the heat map of volatile aroma substances in peppers; Figure 5 Shown is the PLS-DA map and hierarchical clustering map of volatile aroma substances in peppers. Detailed Embodiments

[0016] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0017] Example 1 A planting method for improving the volatile aroma substances of peppers, comprising the following steps: (1) First, dissolve brassinolide in a small amount of absolute ethanol, and then dilute it with water to 0.04 mg / L, and stir evenly to obtain an aqueous solution of brassinolide.

[0018] (2) The experiment of this example was carried out in the vegetable greenhouse planting base in Ruichang City, Jiujiang City, Jiangxi Province. The field management conditions such as fertilization and irrigation were kept consistent. The test time was from June to July 2024. Randomly select 150 pepper seedlings, 30 for each group. The spraying design of brassinolide is shown in Table 1: Table 1 The spraying concentrations of the experimental groups T1 - T4 were aqueous solutions of brassinolide, and the control group T0 was not sprayed. Other production management was carried out according to the daily management of the vegetable base. After the peppers were mature, collect fresh green peppers with uniform maturity, no pests and diseases, and no damage. Homogenize them with a homogenizer, accurately weigh 1.00 g of the sample into a 20 mL headspace vial, and add 100 μL of the internal standard 2 - octanol (10 mg / L). Equilibrate at 60 °C for 20 min, and extract with a 100 / 75 μm SPME solid - phase microextraction fiber at 60 °C for 30 min. After the extraction, desorb in the injection port for 2 min, and age the solid - phase microextraction fiber at 270 °C for 5 min before the next injection to prevent cross - contamination between samples. Analyze using a Shimadzu triple - quadrupole gas chromatography - mass spectrometry instrument. The total ion chromatograms of the four treatments are as Figure 1 shown.

[0019] Gas chromatography (GC) conditions: Separate compounds using a DB - WAX capillary column, use helium as the carrier gas with a flow rate of 1.0 mL / min. Inject with a split ratio of 50:1. The temperature - rising program: The initial column temperature of the chromatographic column is 50 °C, hold for 5 min, then rise to 250 °C at a rate of 10 °C / min, and hold for 10 min.

[0020] Mass spectrometry (MS) conditions: The acquisition mode is simultaneous data acquisition of Scan / MRM, the acquisition mass range is 30 - 500 m / z; the ionization mode is electron impact (EI); the emission energy is 70 eV; the detection voltage is +0.3 kV, the ion source temperature is 200 °C; the injection port temperature is 250 °C.

[0021] Qualitative and quantitative: The identification of volatile aroma compounds is based on the retention index calculated from n-alkanes. A mixed standard sample of n-alkanes (C9-C31) was analyzed by liquid injection according to the heating program of pepper aroma compounds. 2-Octanol standard sample was used as the internal standard. The volatile flavor of the samples was qualitatively and quantitatively analyzed by mass spectrometry using the NIST database. Only compounds with a mass spectrometry match degree greater than 80% were considered. The content of volatile aroma compounds was calculated according to formula (1).

[0022] (1) In the formula: Ci represents the content of volatile compound i, ng / g; C 0 represents the mass concentration of the internal standard, mg / L; V 0 represents the volume of the internal standard, mL; Si represents the peak area of volatile compound i; S 0 represents the peak area of the internal standard; M represents the sample mass, g.

[0023] Figure 2 is a diagram of the types of volatile aroma substances detected in pepper fruits. A total of 95 volatile aroma substances were detected from T0 to T4, mainly including five major types of volatile aroma substances such as esters, alcohols, aldehydes, ketones, and pyrazines. There were differences in the types and quantities of volatile aroma compounds detected in the T1-T4 treatments and the T0 treatment. The common volatile substances from T0 to T4 were 66, there was 1 unique volatile substance in T0, 2 unique ones in T1 and T3, and 7 unique ones in T4.

[0024] Figure 3 and Table 2 are diagrams of the contents of volatile aroma substances detected in pepper fruits, among which the concentrations of ester, alcohol, and aldehyde volatile substances are relatively high. Spraying brassinolide aqueous solution during different growth periods of pepper can increase the content of volatile aroma substances in the fruits of pepper plants. Compared with the control group (without spraying brassinolide aqueous solution), the total volatile aroma contents in the T1-T4 groups increased by 27.93%, 16.20%, 6.98%, and 11.55% respectively; Spraying brassinolide aqueous solution during different growth periods of pepper, the contents of alcohols and esters in the aroma substances increased significantly compared with the control group, and the alcohol content increased by 28.23% - 90.78%; The ester content increased by 67.94% - 107.5%. T1 and T2 can also increase the content of ketone substances.

[0025] Table 2 Figure 4It is a heatmap of the content of volatile aroma substances detected in chili fruits. Heatmaps are usually used to visualize matrix data, representing the magnitude of values through the depth or different hues of colors. In the figure, the redder the color, the higher the content of the volatile substance, and the bluer the color, the lower the content of the volatile substance. There are significant differences in the content of volatile flavor compounds among the T0 - T4 groups. The content of volatile aroma substances in the T4 group is significantly higher than that in the T0 group.

[0026] Figure 5 It is the PLS - DA graph and hierarchical clustering graph of volatile aroma substances detected in chili fruits. The variance contribution rates of the two principal components in the PLS - DA graph are 30.3% and 22.9% respectively, reflecting most of the information. The T0 - T4 groups are effectively distinguished, indicating that brassinolide has the effect of changing the volatile aroma substances in chili. The hierarchical clustering graph divides the 5 treatment groups into 2 major categories. T0 is the first category, and T1 - T4 is the second category. The second category can be further divided into 2 sub - categories. T1 and T4 are one sub - category, and T2 and T3 are one sub - category, indicating that the aroma improvement mechanisms of T1 and T4 are similar, and the effects of T2 and T3 are similar.

[0027] Table 3 shows the content of capsaicinoids in chili fruits. Capsaicin is composed of a series of homologues. So far, 19 analogues have been discovered. They all have a common part of the structure and are all spicy. Among them, the content of capsaicin and dihydrocapsaicin accounts for more than 90% of the total capsaicin content. Compared with T0, there is no obvious difference in the content of dihydrocapsaicin in the T1 - T4 groups, while the content of capsaicin has increased by 87.88%, 31.41%, 38.40%, and 58.21% respectively; the total capsaicin (capsaicin + dihydrocapsaicin) has increased by 66.6%, 20.12%, 27.21%, and 43.06% respectively. In terms of the effect of increasing the total capsaicin (capsaicin + dihydrocapsaicin) content, T1 > T4 > T3 > T2.

[0028] Table 3 In summary, spraying brassinolide at different growth stages of chili can increase the aroma components and capsaicin content of chili. Spraying brassinolide during the flowering stage and before harvest of chili results in better flavor quality of the fruits.

[0029] The embodiments of the present application have been described above in conjunction with the accompanying drawings. Specific examples have been used herein to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the core idea of the present application. However, the present application is not limited to the above - mentioned specific implementation manners. The above - mentioned specific implementation manners are only illustrative and not restrictive. Under the inspiration of the present application, those of ordinary skill in the art can also make many forms without departing from the purpose of the present application and the scope protected by the claims, and all belong to the protection scope of the present application.

Claims

1. Application of brassinolide in improving the volatile aroma substances of pepper.

2. The use according to claim 1, characterized in that: The volatile aroma substances include at least one of aldehydes, esters, ketones and terpenes.

3. A method for increasing the volatile aroma substances of pepper, characterized in that: The following steps are involved: dissolving brassinolide in water to obtain a brassinolide solution; The brassinolide solution is used to spray pepper seedlings at different growth stages until water is slightly dripping from the leaves; The spraying treatment of pepper seedlings at different growth stages includes spraying once during the pepper flowering stage and / or young fruit stage or spraying once 7 days before the pepper is harvested.

4. The planting method according to claim 3, characterized in that: The brassinolide solution is used to spray pepper once during the flowering stage or the young fruit stage.

5. The planting method according to claim 3, characterized in that: The brassinolide solution is used to spray pepper once during the flowering stage and the young fruit stage.

6. The planting method according to claim 3, characterized in that: The brassinolide solution is used to spray the hot peppers once 7 days before harvesting.

7. The planting method according to claim 3, characterized in that: The concentration of the brassinolide solution is 0.03 mg / L-0.05 mg / L.

8. The planting method according to claim 4, characterized in that: The concentration of the brassinolide solution was 0.04 mg / L.

9. The planting method according to claim 3, characterized in that: The spraying is carried out using a sprayer.

10. The planting method according to claim 3, characterized in that: The spraying is carried out on a sunny or rainless cloudy day.

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