Method for reducing capsaicin content in pepper fruits

Abstract

The present invention provides a method for reducing the capsaicin content in pepper fruits, belonging to the field of agricultural technology. The method for reducing the capsaicin content in pepper fruits provided by the present invention comprises spraying the pepper plants with a hydrogen peroxide solution after the pepper plants enter the flowering period. By spraying the pepper plants with a hydrogen peroxide solution at an extreme concentration of 2 mmol / L to 4 mmol / L multiple times, the present invention achieves the purpose of reducing the capsaicin content in the pepper fruits. The method is simple to operate, has low preparation costs, is easy to control, and has a wide range of applications.

Description

Technical Field

[0001] The invention relates to the technical field of agriculture, and in particular to a method for reducing the content of capsaicin in pepper fruits. Background Art

[0002] Capsaicinoids are an alkaloid synthesized specifically in the placenta and pericarp of pepper fruits, responsible for their pungent flavor. Research has shown that capsaicinoid accumulation is primarily influenced by genetics, the environment, competing substances, and enzymes. Generally, the genotype of the pepper and the specific genes that determine capsaicinoid content play a decisive role in capsaicinoid accumulation. Furthermore, capsaicinoid accumulation is sensitive to environmental stresses. Stressors such as temperature, moisture, and light can significantly affect capsaicinoid metabolism, leading to changes in capsaicinoid content in pepper fruits. Furthermore, capsaicinoid accumulation competes with the production of lignin, tannins, and flavonoids. Capsaicinoid synthases and degraders also influence capsaicinoid content.

[0003] In recent years, due to the global warming effect, extreme climate conditions have frequently occurred in pepper-producing areas. High temperatures, drought, and other adverse conditions have caused peppers grown during the optimal harvest period to exceed the recommended spiciness, seriously impacting the quality of fresh, mildly spicy peppers. Among the various types of cultivated peppers, Hangzhou peppers are popular among consumers for their thin, slightly spicy, and excellent quality, harvested during the optimal harvest period (generally around 15 days after flowering). Currently, excessive accumulation of capsaicin in Hangzhou peppers due to adverse conditions such as high temperatures and drought, resulting in excessive spiciness, is a major constraint on the development of the industry.

[0004] Hydrogen peroxide (H2O2) is an inorganic compound with the chemical formula H2O2. Pure hydrogen peroxide is a light blue, viscous liquid that is miscible with water in any proportion and is a strong oxidant. Aqueous hydrogen peroxide solutions diluted with water to a certain concentration (less than 3%) are commonly known as hydrogen peroxide. They are colorless, transparent liquids widely used in medical wound disinfection and food sterilization. Hydrogen peroxide (H2O2), as a small molecule with a simple structure and easy diffusion, is widely present in plants at extremely low concentrations. As an endogenous signaling substance, it participates in the response and metabolic regulation of various biological processes in plant cells. Existing studies have shown that extremely low concentrations of hydrogen peroxide can act as a signaling substance to regulate the metabolism of endogenous substances in plants, while high concentrations of hydrogen peroxide can stimulate plant cells to cause oxidative stress and produce a stress response. Studies have shown that 0.5 mmol / L of hydrogen peroxide can deactivate SOD activity and produce plant toxicity.

[0005] Therefore, how to reasonably use hydrogen peroxide to reduce the content of capsaicin in pepper fruits to solve the technical problem of excessive accumulation of capsaicin in pepper fruits, which leads to excessive spicy peppers, is a problem that technicians in this field urgently need to solve. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for reducing the capsaicin content in pepper fruits, which is used to solve the problem that, under the current frequent extreme climate conditions, capsaicin accumulates in large quantities in pepper fruits during the production of fresh-eating slightly spicy peppers, resulting in excessive spiciness and reduced fruit quality and economic benefits.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0008] The invention provides a method for reducing the capsaicin content in pepper fruits. After the pepper plants enter the flowering period, hydrogen peroxide solution is sprayed on the pepper plants.

[0009] Preferably, the variety of the pepper plant is Hangzhou pepper.

[0010] Preferably, the pepper plants are cultivated under a light-dark alternating environment with a light-dark cycle of 11-13h / 11-13h, a light culture temperature of 24-25°C, and a light intensity of 180-220 μmol·m -2 ·S -1 , the temperature for dark culture is 18-22℃.

[0011] Preferably, the relative humidity of the air in the alternating light and dark environment is 40-60%.

[0012] Preferably, the spraying is performed 2 to 3 times, with the time interval between each spraying being 4 to 6 days.

[0013] Preferably, the first spraying of the hydrogen peroxide solution is on the day the pepper plants bloom.

[0014] Preferably, the spraying is performed 1 to 3 hours before the pepper plants enter dark culture.

[0015] Preferably, the spraying method is whole plant spraying, and the spraying parts include stems, leaves, flowers, and fruits.

[0016] Preferably, the concentration of the hydrogen peroxide solution is 2 mmol / L to 4 mmol / L; each time the solution is sprayed, it is sufficient to spray until water droplets fall off.

[0017] The present invention achieves the purpose of reducing the capsaicin content in pepper fruits by repeatedly spraying pepper plants with a hydrogen peroxide solution with a concentration of 2mM to 4mM. The method is simple to operate, low in preparation cost, easy to control, and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0019] Figure 1 This is a graph showing the capsaicin content in pepper fruits after spraying different concentrations of hydrogen peroxide solution for different times in Example 1;

[0020] Figure 2 This is a graph showing the detection results of the net photosynthetic rate Pn in pepper plant leaves after spraying different concentrations of hydrogen peroxide solution for different times in Example 2. DETAILED DESCRIPTION

[0021] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0022] Example 1

[0023] Pepper seedling cultivation: Hangzhou pepper seedlings were selected and cultured under a light-dark cycle of 12 h / 12 h, a light culture temperature of 25 °C, and a light intensity of 200 μmol·m -2 ·S -1 The pepper plants were cultured for 3 months under the conditions of dark culture temperature of 20°C and relative humidity of 50%. The Hangzhou peppers tested in this example were pollinated on the day of flowering. The petals fell off 3-4 days later and small fruits began to form. They expanded over time and were picked 10-20 days after flowering.

[0024] Continue to cultivate under the above cultivation environment, and when the cultivated pepper plants enter the flowering period, perform the following treatments:

[0025] Treatment 1: Spray the pepper plants with a 2 mM hydrogen peroxide solution on the day they flower, 3 hours before they enter dark cultivation. Spray the entire pepper plant until water droplets fall off. Repeat the spraying every 5 days for a total of 4 times.

[0026] Treatment 2: Spray the pepper plants with a 4 mM hydrogen peroxide solution on the day they flower, 3 hours before they enter dark cultivation. Spray the entire pepper plant until water droplets fall off. Repeat the spraying every 5 days for a total of 4 times.

[0027] Treatment 3: Spray the pepper plants with an 8 mM hydrogen peroxide solution on the day they flower, 3 hours before they enter dark cultivation. Spray the entire pepper plant until water droplets fall off. Repeat the spraying every 5 days for a total of 4 times.

[0028] Control group: Spray water on the day the pepper plants bloom, 3 hours before the pepper plants enter dark culture, and spray the entire pepper plant until water droplets fall off; then repeat the spraying every 5 days, for a total of 4 times.

[0029] Determination of capsaicin content in pepper fruits: Pick and measure the capsaicin content in pepper fruits on the third day after spraying hydrogen peroxide solution or water for 2, 3, or 4 times. The method for determining the content of capsaicinoids shall refer to the national standard GB / T21266-2007.

[0030] The results are as follows Figure 1 As shown in Table 1, it can be seen that: compared with the control (water, 0 mM), the capsaicin content in the pepper fruits was significantly reduced after spraying 2 mM, 4 mM or 8 mM hydrogen peroxide solution for 2, 3 or 4 times; among them, the capsaicin content in the pepper fruits sprayed with 2 mM hydrogen peroxide solution decreased most significantly, and the capsaicin content in the pepper fruits sprayed for 2, 3 and 4 times decreased by 72.4%, 82.8% and 85.2% respectively.

[0031] Table 1 Capsaicin content in peppers after spraying hydrogen peroxide solution at different concentrations and times

[0032]

[0033] Example 2

[0034] The net photosynthetic rate Pn of leaves is an important indicator to measure whether leaves are poisoned. Therefore, in order to further study the effects of spraying different concentrations of hydrogen peroxide solution and different spraying times on pepper plant leaves, the net photosynthetic rate Pn of pepper plant leaves in the above treatment groups after spraying hydrogen peroxide solution or water 2, 3, and 4 times was measured using a LI-6400 photosynthetic meter (LI-Cor, USA) on the third day. Figure 2 shown.

[0035] Depend on Figure 2It can be seen that compared with the control (water, 0mM), different treatment times of 2mM and 4mM hydrogen peroxide solutions had no significant effect on the net photosynthetic rate of leaves, while 8mM hydrogen peroxide treatment reduced the net photosynthetic rate Pn of pepper leaves. This indicates that spraying pepper plants with 2mM and 4mM hydrogen peroxide solutions had no effect on the growth of pepper plants, while spraying with 8mM hydrogen peroxide solution had a certain toxic effect on pepper leaves, which was not conducive to the growth of pepper plants.

[0036] As shown in the above examples, spraying a trace amount of hydrogen peroxide solution on pepper plants can significantly reduce the capsaicin content in pepper fruits, achieving the effect of controlling capsaicin levels. In addition, 2-4 mM hydrogen peroxide solution does not have a toxic effect on pepper plants.

[0037] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for reducing the capsaicin content in pepper fruits, characterized in that: After the pepper plants enter the flowering period, spray the pepper plants with hydrogen peroxide solution; The variety of the pepper plant is Hangzhou pepper; the number of spraying is 2 to 3 times, and the time interval between each spraying is 4 to 6 days; the concentration of the hydrogen peroxide solution is 2 mmol / L to 4 mmol / L.

2. The method according to claim 1, wherein The pepper plants were cultivated under a light-dark alternation environment with a light-dark cycle of 11-13 h / 11-13 h, a light culture temperature of 24-25° C., and a light intensity of 180-220 μmol·m -2 ·S -1 , the temperature for dark culture is 18~22℃.

3. The method according to claim 2, wherein The relative humidity of the air in the light-dark alternating environment is 40-60%.

4. The method according to claim 3, wherein The first spraying of hydrogen peroxide solution is on the day the pepper plants bloom.

5. The method according to claim 4, wherein The spraying time is 1 to 3 hours before the pepper plants enter dark culture.

6. The method according to claim 5, wherein The spraying method is whole plant spraying, and the spraying parts include stems, leaves, flowers and fruits.

7. The method according to any one of claims 1 to 6, wherein Each time you spray, spray until water droplets fall off.

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