Production method and nutrient solution for cruciferous bud seedlings capable of enriching beneficial thioglycosides and reducing useless thioglycosides

Abstract

The invention discloses a cruciferous bud seedling production method capable of enriching beneficial thioglycoside and reducing useless thioglycoside and a nutrient solution. The nutrient solution for the cruciferous bud seedlings is a mixed aqueous solution of chitosan oligosaccharide and nano-selenium, the concentration of the chitosan oligosaccharide is 10-100 mg / L, and the concentration of the nano-selenium is 2-50 mg / L. By applying the nutrient solution provided by the invention and regulating and controlling the uptake and utilization of the plants on the sulfur element, the composition and content of the thioglycoside component in the cruciferous bud seedlings are changed, a more scientific and efficient solution is provided for the production of the cruciferous bud seedlings, green vegetables and functional food raw materials with higher quality and outstanding nutritional characteristics are provided for the market, and the economic benefits of the cruciferous bud seedlings are improved. And consumers can obtain high-quality sprouts which are rich in beneficial thioglycoside and contain few unfavorable thioglycoside.

Description

Technical Field

[0001] The invention relates to a cruciferous sprout production method and nutrient solution for enriching beneficial glucosinolates and reducing useless glucosinolates, belonging to the technical field of deep processing of agricultural products. Background Art

[0002] Cruciferous vegetables are considered an indispensable part of a healthy diet due to their rich nutrients and multiple health benefits. Common cruciferous vegetables include broccoli, cauliflower, radish, kale, cabbage, kale, rapeseed, etc. Cruciferous vegetables are rich in vitamin C, beta-carotene, chlorophyll and various mineral elements such as calcium, potassium, zinc, magnesium, etc. Glucosinolates (glucosinolates for short) in cruciferous vegetables are a class of plant compounds that have multiple effects such as anti-cancer and anti-inflammatory.

[0003] Cruciferous sprouts have some significant advantages in nutritional value compared to mature cruciferous vegetables, mainly due to the fact that the nutrients of sprouts are mainly converted from seeds in the early stage of growth. Although mature cruciferous vegetables are a good source of nutrition, the tender green, crisp taste and nutritional value of sprouts make them outstanding in some aspects. Sprouts have higher antioxidant content, lower energy density and richer phytochemicals in nutrition. In particular, the glucosinolates in cruciferous sprouts are several times or even dozens of times that of mature vegetables.

[0004] There are many types of glucosinolates. The main glucosinolates in cruciferous vegetables include 3-methylthiooxyallyl glucosinolate (Glucoiberin, IBE), 2-hydroxy-3-butenyl glucosinolate (Progoitrin, PRO), 2-propenyl glucosinolate (Sinigrin, SIN), 4-methylthiooxybutyl glucosinolate (Glucoraphanin, RAA), 3-butenyl glucosinolate (Gluconapin, NAP); 4-hydroxyindolyl-3-methyl glucosinolate (4-Hydroxyglucobrassicin, 4OH), 4-methylthiobutenyl glucosinolate Glucoerucin, ERU), 3-methylindolyl glucosinolate (Glucobrassicin, GBC), 4-methoxyindolyl-3-methyl glucosinolate (4-Methoxyglucobrassicin, 4ME), 1-methoxyindolyl-3-methyl glucosinolate (Neoglucobrassicin, NEO) and other glucosinolate components. Currently, it is known that the glucosinolates that are beneficial to the human body include RAA, GBC, etc. Some biologically active substances produced by hydrolysis have antioxidant, anti-inflammatory, anti-cancer and other effects, and play an important role in human health. There are also glucosinolates that are harmful to human health, such as PRO, which is a precursor of the goitrogens 5-vinyloxazolidine-2-thione.

[0005] At present, the enrichment and regulation technology of glucosinolates in cruciferous sprouts is mainly concentrated in the following three aspects: a. Variety selection: Through breeding means, cruciferous sprouts rich in glucosinolates can be selected to increase the content of glucosinolates at the genetic level. Chinese patent application (CN114287339B, a method for cultivating green cauliflower rich in beneficial glucosinolates and low in non-beneficial glucosinolates) provides a method for cultivating healthy functional broccoli with increased beneficial glucosinolates and reduced non-beneficial glucosinolates. This method is used to select a new broccoli variety with high content of beneficial glucosinolates RAA and GBC in seeds and low content of non-beneficial glucosinolate PRO. B. Seed pretreatment: Chinese patent application (CN114009327B, a method for cultivating broccoli sprouts enriched with selenium and sulforaphane and its application), after broccoli seeds are pretreated with plasma, the content of glucosinolate, a degradation product of glucosinolates in broccoli sprouts, is increased. c. Regulation of sprout growth environment: Adjust the growth environment sound speed such as temperature, light, humidity, and nutrient solution application to affect the synthesis and accumulation of glucosinolates. A Chinese patent application (CN109392354B, a method for efficiently enriching functional substances in broccoli sprouts) describes a method for obtaining broccoli sprouts enriched with glucosinolates by heat-shocking the sprouts and spraying them with a mixed aqueous solution of sodium selenite and zinc sulfate during the growth of the sprouts. At present, the existing technologies are all limited to the focus on the total amount of glucosinolates or the beneficial glucosinolates RAA, and there is no targeted enrichment of beneficial glucosinolates and reduction of useless glucosinolates through certain regulatory means during the growth of sprouts. At the same time, the existing technologies are also limited to increasing the RAA content in broccoli sprouts, and there are no reports on the targeted enrichment of beneficial glucosinolates and reduction of useless glucosinolates in different cruciferous sprouts. Summary of the invention

[0006] The purpose of the present invention is to provide a cruciferous sprout production method which is enriched with beneficial glucosinolates and reduced with unbeneficial glucosinolates. By applying a specific nutrient solution, the content of beneficial glucosinolates in the sprouts is increased, the content of unfavorable glucosinolates is reduced, and the yield of the sprouts is also increased to varying degrees.

[0007] The nutrient solution for cruciferous sprouts provided by the invention is a mixed aqueous solution of chitosan oligosaccharide and nano-selenium.

[0008] In the mixed aqueous solution, the concentration of the chitosan oligosaccharide is 10-100 mg / L, preferably 25-75 mg / L, and the concentration of the nano-selenium is 2-50 mg / L, preferably 10 mg / L.

[0009] The molecular weight of the chitosan oligosaccharide used in the invention is 340.33, and the particle size range of the nano-selenium is 10nm-100nm.

[0010] Based on the nutrient solution, the present invention also provides a method for cultivating cruciferous seedlings, comprising the following steps: The seeds with full grains, no defects, no diseases or insect pests and high germination rate are selected as raw materials; the seeds are subjected to germination treatment after being treated, and then the nutrient solution is sprayed for cultivation to obtain cruciferous sprouts.

[0011] During the cultivation process, the nutrient solution is sprayed once a day, and the spraying amount is based on ensuring that the seeds are moist and not short of water.

[0012] The culture conditions are as follows: a 24-hour light cycle with 12 hours of light and 12 hours of total darkness; The culture time is 3 to 7 days; The illumination conditions are: the light flux density is 30-250 μmol / (m 2 s), the temperature is 25℃~32℃; The completely dark condition is: the temperature is 15°C to 25°C.

[0013] The treatment steps are as follows: soaking in water at 25°C to 30°C for 2 to 5 hours.

[0014] The steps of the germination treatment are as follows: sowing the seeds in a seedling tray, controlling the ambient temperature to 28-35° C. in total darkness, and spraying with distilled water every day; The time of the germination treatment is 1 to 2 days.

[0015] The cruciferous sprouts involved in the present invention include kale and broccoli.

[0016] In the cruciferous sprouts cultivated by the method of the present invention, the content of the beneficial glucosinolate RAA is increased, the content of the harmful glucosinolate PRO is reduced, and the yield of the sprouts is guaranteed. Therefore, in the cruciferous sprouts obtained by the cultivation method of the present invention, the enrichment of glucosinolates is not only an increase in quantity, but also an optimization in quality.

[0017] The present invention mainly regulates the uptake and utilization of sulfur by plants by applying the nutrient solution of the present invention during the growth and cultivation stage, thereby changing the composition and content of glucosinolate components in cruciferous sprouts, providing a more scientific and efficient solution for the production of cruciferous sprouts, providing the market with green vegetables and functional food raw materials with better quality and outstanding nutritional characteristics, and enabling consumers to obtain high-quality sprouts rich in beneficial glucosinolates and less in harmful glucosinolates. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 and Figure 2 These are photos showing the growth of kale sprouts under different treatments.

[0019] Figure 3 and Figure 4 These are photos of broccoli sprout growth under different treatments. DETAILED DESCRIPTION

[0020] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0021] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0022] The particle size of the nano-selenium used in the following examples is 10-100 nm, and the molecular weight of chitosan oligosaccharide is 340.33.

[0023] Example 1, Nutrient solution for cruciferous sprouts Nano-selenium (Nano-Se) and chitosan oligosaccharide (COS) were dissolved in water in a certain ratio to obtain nutrient solutions T2 and T3, respectively, with the following concentrations: T2: 10mg / L Nano-Se+25 mg / L COS.

[0024] T3: 10mg / L Nano-Se+75 mg / L COS.

[0025] Application Example 1: Cultivation of kale sprouts 1. Seed treatment: Select seeds with full grains, no defects, diseases and insect pests, and high germination rate as raw materials. Soak the qualified seeds in distilled water at 25℃~30℃ for 3 hours.

[0026] 2. Germination treatment: Evenly sow the soaked seeds in the seedling tray. Control the ambient temperature at 28-35°C in total darkness. Spray with distilled water every day. The spraying amount should be based on ensuring that the seeds are moist and not lacking in water. After 2 days, switch to routine growth management.

[0027] 3. Growth management: Spray the seeds with exogenous nutrient solution once a day to ensure that the seeds are moist and not lacking water; the 24-hour light environment cycle is 12 hours of light and 12 hours of complete darkness; under the 12-hour light condition, the light intensity is controlled at a light flux density of 90μmol / (m 2 s), the temperature was maintained at 25℃~32℃; under 12 hours of total darkness, the temperature was maintained at 15℃~25℃.

[0028] 4. Harvest: Harvest the whole sprout after 7 days of growth.

[0029] Among them, the exogenous nutrient solutions were chitosan oligosaccharide solutions with concentrations of 25 mg / L, 50 mg / L, 75 mg / L, and 100 mg / L, nano-selenium solutions with concentrations of 5 mg / L, 10 mg / L, 20 mg / L, and 40 mg / L, control treatment CK (distilled water), and the two nutrient solutions (T2 and T3) prepared in Example 1.

[0030] The growth of kale sprouts under CK, T2 and T3 treatment conditions are shown in the following photos. Figure 1 and Figure 2 shown.

[0031] The contents of RAA and PRO in the kale obtained by spraying the nutrient solution of the present invention are shown in Table 1.

[0032] The kale sprout yield (plant weight) obtained from different treatments is shown in Table 2.

[0033] Table 1 RAA and PRO contents in kale sprouts obtained using different nutrient solutions

[0034] It can be seen from the data in Table 1 that the RAA content in the kale obtained by spraying the nutrient solution of the present invention (T2 and T3) was significantly increased, while the PRO content was significantly reduced.

[0035] Table 2 The yield of kale sprouts obtained using different nutrient solutions

[0036] It can be seen from the data in Table 2 that the kale sprouts obtained by spraying the nutrient solution of the present invention have a significantly increased plant weight compared with CK.

[0037] Application Example 2: Cultivation of broccoli sprouts 1. Seed treatment: Select seeds with full grains, no defects, diseases and insect pests, and high germination rate as raw materials. Soak the qualified seeds in distilled water at 25℃~30℃ for 3 hours.

[0038] 2. Germination treatment: Evenly sow the soaked seeds in the seedling tray. Control the ambient temperature at 28-35°C in total darkness. Spray with distilled water every day. The spraying amount should be based on ensuring that the seeds are moist and not lacking in water. After 2 days, switch to routine growth management.

[0039] 3. Growth management: Spray the seeds with exogenous nutrient solution once a day to ensure that the seeds are moist and not lacking water; the 24-hour light environment cycle is 12 hours of light and 12 hours of complete darkness; under the 12-hour light condition, the light intensity is controlled at a light flux density of 60 μmol / (m 2 s), the temperature was maintained at 25℃~32℃; under 12 hours of total darkness, the temperature was maintained at 15℃~25℃.

[0040] 4. Harvest: Harvest the whole sprout after 7 days of growth.

[0041] Among them, the exogenous nutrient solutions were chitosan oligosaccharide solutions with concentrations of 25 mg / L, 50 mg / L, 75 mg / L, and 100 mg / L, nano-selenium solutions with concentrations of 5 mg / L, 10 mg / L, 20 mg / L, and 40 mg / L, control treatment CK (distilled water), and the two nutrient solutions (T2 and T3) prepared in Example 1.

[0042] The growth of broccoli sprouts under CK, T1 and T2 treatments is shown in the following figure. Figure 3 and Figure 4 shown.

[0043] Table 3 shows the contents of RAA and PRO in broccoli obtained by spraying the nutrient solution of the present invention (T2 and T3).

[0044] The broccoli sprout yield (plant weight) obtained from different treatments is shown in Table 4.

[0045] Table 3 RAA and PRO contents in broccoli sprouts obtained using different nutrient solutions

[0046] It can be seen from the data in Table 3 that the content of RAA in the broccoli obtained by spraying the nutrient solution of the present invention (T2 and T3) is significantly increased, and the content of PRO is significantly reduced.

[0047] Table 4 Broccoli sprout yields obtained using different nutrient solutions

[0048] Note: Different lowercase letters indicate significant differences among treatments (P<0.05).

[0049] Note: The data in the same table are derived from the same batch of sprout samples.

[0050] Note: FW stands for sprout fresh weight.

[0051] It can be seen from the data in Table 4 that the broccoli sprout plant weight obtained by spraying the nutrient solution of the present invention is most significantly increased.

Claims

1. A nutrient solution for cruciferous sprouts, which is a mixed aqueous solution of chitosan oligosaccharide and nano-selenium.

2. The nutrient solution according to claim 1, characterized in that: In the mixed aqueous solution, the concentration of the chitosan oligosaccharide is 10-100 mg / L, and the concentration of the nano-selenium is 2-50 mg / L.

3. Use of the nutrient solution according to claim 1 or 2 in cultivating cruciferous seedlings; The nutrient solution increases the content of 4-methylthiooxybutyl glucosinolate and reduces the content of 2-hydroxy-3-butenyl glucosinolate in the cruciferous sprouts.

4. The use according to claim 3, characterized in that: The cruciferous sprouts include kale and broccoli.

5. A method for cultivating cruciferous seedlings, comprising the following steps: The seeds are subjected to germination treatment after being treated, and then sprayed with the nutrient solution described in claim 1 or 2 for cultivation to obtain cruciferous seedlings.

6. The cultivation method according to claim 5, characterized in that: During the cultivation process, the nutrient solution is sprayed once a day.

7. The cultivation method according to claim 5 or 6, characterized in that: The culture conditions are as follows: a 24-hour light cycle with 12 hours of light and 12 hours of total darkness; The illumination conditions are: the light flux density is 30-250 μmol / (m 2 s), the temperature is 25℃~32℃; The completely dark condition is: the temperature is 15°C to 25°C.

8. The cultivation method according to any one of claims 5 to 7, characterized in that: The treatment steps are as follows: soaking in water at 25°C to 30°C for 2 to 5 hours.

9. The cultivation method according to any one of claims 5 to 8, characterized in that: The steps of the germination treatment are as follows: sowing the seeds in a seedling tray, controlling the ambient temperature to 28-35° C. in total darkness, and spraying with distilled water every day; The time of the germination treatment is 1 to 2 days.

10. The cultivation method according to any one of claims 5 to 8, characterized in that: The culture time is 3 to 7 days; The cruciferous sprouts include kale and broccoli.

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