Method for improving fatty acid components and increasing linoleic acid content of field muskmelon seeds by applying melatonin

Abstract

The invention discloses a method for improving fatty acid components and increasing linoleic acid content of field muskmelon seeds by melatonin application, and relates to the technical field of agricultural science, and the method comprises the following steps: preparing melatonin solutions of 0, 50, 100 and 200 [mu] mol / L; 7 days and 14 days after field muskmelon pollination, field muskmelon fruits are soaked in the melatonin solution at nightfall, and the fruits are wrapped with tin foil paper; measuring fatty acid components and content of the field muskmelon seeds in a mature period; carrying out fatty acid component comparative analysis on the field muskmelon seeds soaked in clear water; according to the method, the field muskmelon seed fatty acid component and the corresponding melatonin treatment concentration which are remarkably changed are screened out, and the experimental result shows that after exogenous melatonin treatment, the field muskmelon seed fatty acid component can be changed, the content of linoleic acid is increased, and the quality of the seed oil is improved.

Description

Technical Field

[0001] The present invention relates to the field of agricultural science and technology, and specifically to a method for improving the fatty acid composition of Momordica balsamina seeds and increasing the content of linoleic acid by applying melatonin. Background Art

[0002] At present, rapeseed and peanuts are mainly produced in China, and the planting concentration of other oil crops is much lower. Such a single planting structure is not conducive to coping with the increasingly severe international trade environment, nor is it conducive to modern agriculture's resistance to harsh environmental changes. Therefore, introducing new oil crops to diversify the planting structure can not only improve modern people's dietary habits, but also better ensure national grain and oil security and is conducive to the sustainable development of modern agriculture.

[0003] During the consumption or processing of melon fruits, a large amount of by-products will be generated. Most of these materials consist of seeds and are usually discarded, resulting in waste. The oil content of melon seeds is about 21%-32%, which can become an alternative source of vegetable oil and is one of the solutions for the industry to meet the current demand for new vegetable oils. Compared with soybeans, rapeseed, peanuts, etc., the melon seed oil contains a higher proportion of unsaturated fatty acid linoleic acid, about 60%-72%. Linoleic acid is an essential fatty acid for the human body, which cannot be synthesized in the body and needs to be ingested through diet. It is beneficial to reducing cholesterol, blood pressure, blood lipids, etc. and is healthier.

[0004] Momordica balsamina, a common wild plant of the Cucurbitaceae family and the genus Cucumis, is usually considered a wild melon. Its fruits are small, with many seeds and are inedible, mainly used for oil extraction. The content of unsaturated fatty acid linoleic acid in its seed oil is high, and it is a new type of oil crop. At present, the oil extraction value of Momordica balsamina seeds has been developed in the market, with a mature oil extraction process, and Momordica balsamina seed oil products have been launched, and the market response is very good. Although it has been planted in small amounts in some provinces, it has not been developed and utilized on a large scale. The cultivation system is not mature enough, the quality is uneven, the fruits are small, and the yield is low, resulting in an average oil yield and reduced benefits, which greatly affects its subsequent development.

[0005] Previous studies have found that in plants, melatonin is involved in many physiological processes of plant growth and development, including plant morphogenesis, seed germination, fruit ripening, etc. At the same time, melatonin is also involved in biological and abiotic stresses, such as salt stress, water stress, and cold stress. In terms of oil, melatonin also has a regulatory effect on oil metabolism. Exogenous melatonin treatment can significantly promote the growth and development of soybeans, improve the tolerance of soybeans to salt and drought stresses, and is beneficial to the increase of seed fatty acid content. Therefore, in the present invention, melatonin is applied to treat Momordica balsamina fruits to improve the fatty acid composition in Momordica balsamina seeds and further increase the content of linoleic acid, providing a theoretical basis for a complete Momordica balsamina cultivation system. Summary of the Invention

[0006] Aiming at the above-mentioned disadvantages of the existing technology, the purpose of the present invention is to provide a method for improving the fatty acid composition of Momordica balsamina seeds and increasing the linoleic acid content by melatonin application. The experimental results show that after exogenous melatonin treatment, the fatty acid composition of Momordica balsamina seeds can be changed and the linoleic acid content can be increased, improving the quality of seed oil.

[0007] To achieve the above object, the present invention provides the following technical solution: A method for improving the fatty acid composition of Momordica balsamina seeds and increasing the linoleic acid content by melatonin application, comprising the following steps:

[0008] Step 1: Dissolve 0.232 g of melatonin in 2 mL of absolute ethanol, and then add water to make up to 10 mL to prepare a 100 μmol / L melatonin stock solution;

[0009] Step 2: At 7 and 14 days after pollination of Momordica balsamina, soak the Momordica balsamina fruits in the above melatonin solution in the evening, and wrap the fruits with tinfoil to further avoid light;

[0010] Step 3: Determine the fatty acid composition of Momordica balsamina seeds at the mature stage (28 days after pollination);

[0011] Step 4: Compare and analyze the fatty acid composition with Momordica balsamina seeds soaked in water;

[0012] Step 5: Screen out the significantly changed fatty acid components of Momordica balsamina and the corresponding melatonin treatment concentrations.

[0013] Preferably, when the melatonin solution is used, a surfactant with a volume ratio of 0.5% is added, and the surfactant is TritonX-100.

[0014] Preferably, the molecular formula of the melatonin preparation is C13H16N2O2, which is insoluble in water, easily soluble in organic solvents such as ethanol and DMSO, sensitive to light, and easily oxidized.

[0015] Preferably, in order to make Momordica balsamina fully absorb during the soaking process of melatonin, a certain proportion of surfactant (the addition ratio is 0.5%) is also added to the additive.

[0016] Preferably, the best soaking time in Step 2 is in the evening, and the soaked Momordica balsamina fruits are wrapped with tinfoil. Melatonin is sensitive to light and easily oxidized.

[0017] Preferably, the methods published in national standards / agricultural industry standards are used in Steps 3 and 4 to determine the fatty acid components in Momordica balsamina seeds. After spraying the melatonin solution, the analysis results show that the fatty acid composition of Momordica balsamina seeds is changed and the linoleic acid content is increased.

[0018] Compared with the existing technology, the beneficial effects of the present invention are:

[0019] The application method of the present invention is simple to operate, with low input cost and quick results. Through research, it is determined that the optimal soaking concentration of melatonin is 200 μmol / L, which can significantly improve the fatty acid composition of Melothria indica seeds and increase the content of linoleic acid. Through creative research, it is found that melatonin can be used to change the fatty acid composition of Melothria indica seeds and increase the content of linoleic acid, thus improving the quality of seed oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a morphological display diagram of Melothria indica fruit seeds at different development stages of the present invention;

[0021] Figure 2 It is a table showing the changes in oil content of Melothria indica seeds at different development stages of the present invention;

[0022] Figure 3 It is a table showing the changes in the content of fatty acid components in Melothria indica seeds after being treated with melatonin at different concentrations of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] Please refer to Figures 1-3 , the present invention provides a technical solution: a method for improving the fatty acid composition of Melothria indica seeds and increasing the content of linoleic acid by applying melatonin, including the following steps:

[0024] Step 1: Dissolve 0.232 g of melatonin in 2 mL of absolute ethanol, and then add water to make up the volume to 10 mL to prepare a 100 μmol / L melatonin stock solution;

[0025] Step 2: At 7 and 14 days after pollination of Melothria indica, soak the Melothria indica fruits in the above-mentioned melatonin solution in the evening, and wrap the fruits with tin foil to further avoid light;

[0026] Step 3: Determine the fatty acid composition of Melothria indica seeds at the mature stage (28 days after pollination);

[0027] Step 4: Conduct a comparative analysis of the fatty acid components with Melothria indica seeds soaked in water;

[0028] Step 5: Screen out the significantly changed fatty acid components of Melothria indica and the corresponding melatonin treatment concentration.

[0029] When using melatonin solution, a surfactant with a volume ratio of 0.5% is added. The surfactant is TritonX-100. The molecular formula of the melatonin preparation is C13H16N2O2. It is insoluble in water and easily soluble in organic solvents such as ethanol and DMSO. It is sensitive to light and easily oxidized. In order to enable the melothria indica to fully absorb melatonin during the soaking process, a certain proportion of surfactant (the addition ratio is 0.5%) is also added to the additive. The best soaking time in step two is in the evening, and the soaked melothria indica fruits are wrapped with tin foil. Melatonin is sensitive to light and easily oxidized. In steps three and four, the methods announced by national standards / agricultural industry standards are used to determine the fatty acid components in the melothria indica seeds. After spraying the melatonin solution, the analysis results show that the fatty acid components of the melothria indica seeds are changed and the content of linoleic acid is increased.

[0030] Example 1: Observation of the morphology of melothria indica seeds and determination of oil content

[0031] The collected and preserved melothria indica seeds are used. First, the melothria indica seeds are disinfected and sterilized, soaked in warm water at 50°C for 30 minutes, and then the melothria indica seeds are soaked in a petri dish lined with filter paper and placed in a seed incubator at 28°C. The water is changed once in the morning and once in the evening for germination. After germination, they are planted in a seedling tray with nutrient soil and cultivated in a greenhouse until they have four leaves and one heart, and then transplanted. The melothria indica seedlings grow rapidly, and fertilizer and water management should be strengthened. Every 5-7 days, the seedlings are watered with compound fertilizer water. The melothria indica fruits are mainly borne on the secondary vines and tertiary vines, and the tips of the vines must be pinched and the vines trimmed to promote fruiting. Generally, the six-vine method is adopted. When the melothria indica vines have 5-6 leaves, the tips are pinched after leaving 4 leaves, and 2 secondary vines are left. Then, each secondary vine leaves 3 tertiary vines. During the full-bloom period, the male flowers that will bloom the next day and the hermaphrodite flowers with normal development and the ovaries vertically upward are respectively isolated by putting paper caps on them every afternoon. From 8 to 9 o'clock in the morning on the day of flowering, artificial self-pollination is carried out and the pollination time is marked with a sign.

[0032] Seeds are taken 10 days after pollination, and then seeds are taken at 14, 18, 21, and 28 days after pollination respectively for morphological observation and oil content determination.

[0033] From 0 to 10 days after pollination, it is in the initial stage. The fruit grows rapidly, the fruit color is dark green, and at the same time the seeds swell rapidly.

[0034] From 10 to 14 days after pollination, it is in the acceleration stage. As the fruit grows, the seeds also grow, and the seed color turns slightly yellow. At this stage, the seeds are basically shaped.

[0035] From 18 to 28 days after pollination, it is in the stable stage. The fruit gradually turns into a yellow fruit, and the seeds turn yellowish-white.

[0036] Collect Melothria indica fruits at 10, 14, 18, 21, and 28 days after pollination, take out the seeds and dry them outdoors, and determine the oil content of Melothria indica seeds by the methods published in national standards / agricultural industry standards. Conduct three repeated experiments. The results show that the total oil content of Melothria indica seeds is about 25%; the oil content of Melothria indica seeds increases rapidly from 10 to 18 days after pollination and tends to be stable after 18 days, with the highest growth rate during the period of 10 - 14 days.

[0037] Example 2: Determination of fatty acid components in Melothria indica seeds

[0038] Further, determine the fatty acid content of Melothria indica seeds collected at 10, 14, 18, 21, and 28 days after pollination. As shown in Table 1, at the mature stage (28 days after pollination), the content of linoleic acid in Melothria indica seed oil is the highest, about 68.56%, followed by oleic acid (15.89%), palmitic acid (8.68%), and stearic acid (5.74%). The remaining fatty acid components are all less than 1%. This indicates that linoleic acid is the main component in Melothria indica seed oil.

[0039]

[0040] Example 3: Treatment of Melothria indica fruits with melatonin solutions of different concentrations

[0041] To further increase the content of linoleic acid in Melothria indica seed oil, we conducted an experiment on treating Melothria indica fruits with exogenous melatonin. The specific experimental steps are as follows:

[0042] (1) Prepare melatonin solutions with concentrations of 0 (CK), 50 (T1), 100 (T2), and 200 (T3) μmol / L;

[0043] (2) At 7 and 14 days after pollination of Melothria indica, soak the fruits in the above melatonin solutions in the evening and wrap the fruits with tin foil;

[0044] (3) Determine the fatty acid composition of Melothria indica seeds at the mature stage (28 days after pollination);

[0045] (4) Conduct a comparative analysis of the fatty acid composition with Melothria indica seeds soaked in clear water (CK);

[0046] (5) Screen out the fatty acid components in Melothria indica seed oil with significant changes and the corresponding melatonin treatment concentrations.

[0047] When using the melatonin solution, add a surfactant with a volume ratio of 0.5%. The surfactant is TritonX - 100.

[0048] After melatonin treatment, the fatty acid component content in the seeds oil of Cucumis melo var. agrestis changed. Compared with the control group, for the seeds of Cucumis melo var. agrestis treated with melatonin, lauric acid, myristic acid, oleic acid and linoleic acid all changed significantly. The contents of lauric acid, myristic acid and oleic acid decreased significantly, while the linoleic acid increased significantly after T2 and T3 treatments, and the effect of T3 was the best. It is recommended to apply 200 μmol / L.

Claims

1. A method for improving the fatty acid composition of melothria indica seeds applied with melatonin and increasing the linoleic acid content, characterized in that, It includes the following steps: Step 1: Dissolve 0.232 g of melatonin in 2 mL of absolute ethanol, and then add water to make up the volume to 10 mL to prepare a 100 μmol / L melatonin stock solution. Step 2: At 7 days and 14 days after pollination of the melothria scabra, soak the melothria scabra fruits in the above melatonin solution in the evening, and wrap the fruits with tin foil to further avoid light. Step 3: Determine the fatty acid composition of the melothria scabra seeds at the mature stage (28 days after pollination). Step 4: Conduct a comparative analysis of the fatty acid components with the melothria scabra seeds soaked in water. Step 5: Screen out the significantly changed fatty acid components of the melothria scabra and the corresponding melatonin treatment concentrations.

2. A method for improving the fatty acid composition of melothria indica seeds and increasing the linoleic acid content by melatonin application according to claim 1, characterized in that: When the melatonin solution is used, a surfactant with a volume ratio of 0.5% is added, and the surfactant is TritonX-100.

3. A method for improving the fatty acid composition of melon seeds by melatonin application and increasing the linoleic acid content, as claimed in claim 1, wherein: The molecular formula of the melatonin preparation is C13H16N2O2, which is insoluble in water, easily soluble in organic solvents such as ethanol and DMSO, sensitive to light, and easily oxidized.

4. A method for improving the fatty acid composition of Momordica balsamina seeds and increasing the linoleic acid content by melatonin application according to claim 1, characterized in that: In order to enable the melothria scabra to fully absorb during the soaking process of melatonin, a certain proportion of surfactant (the addition ratio is 0.5%) is also added to the additive.

5. A method for improving the fatty acid composition of melatonin-applied Sicyos angulatus seeds and increasing the linoleic acid content according to claim 1, characterized in that: The best soaking time in Step 2 is in the evening, and the soaked melothria scabra fruits are wrapped with tin foil. Melatonin is sensitive to light and easily oxidized.

6. A method for improving the fatty acid composition of Momordica balsamina seeds and increasing the linoleic acid content by melatonin application according to claim 1, characterized in that: In Steps 3 and 4, the methods published in national standards / agricultural industry standards are used to determine the fatty acid components in the melothria scabra seeds. After spraying the melatonin solution, the analysis results show that the fatty acid components of the melothria scabra seeds are changed and the content of linoleic acid is increased.

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