JP2022118185A - Production method of leaf vegetables and production device of leaf vegetables - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method and a production device of leaf vegetables in which a temperature condition and a light quality condition are changed, for clarifying an environment control for increasing quantity of biosynthesis of folate salt, and leaf vegetables with high folate salt can be produced.

SOLUTION: There is provided a RGB independent modulation light source plant cultivation device 1 for vegetables using water culture under an artificial illumination in which lights of red color, blue color and green color are controlled comprising: a light radiation part 5 for radiating a light to vegetables 3; and a control part 7 for controlling at least one of a ratio of lights of red color, blue color and green color radiated by the light radiation part 5, a photosynthesis effective photon flux density (PPFD) and a growth environment temperature for increasing density of folate salt.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2022,JPO&INPIT

Description

Patent Law Article 30, Paragraph 2 Application Applied January 29, 2018, 15th Infrared Radiation Application-Related Conference, Tokyo University of Technology, Kamata Campus

TECHNICAL FIELD The present invention relates to a method for producing leafy vegetables and the like, and more particularly to a method for producing leafy vegetables by hydroponics under artificial lighting in which red, blue and green light is controlled.

Currently, the technology of hydroponic cultivation of leafy vegetables under artificial lighting is progressing. In particular, the inventors have also improved the technology for hydroponic cultivation under artificial lighting in which red, blue, and green lights are controlled. Many studies on such technology involve adjusting the ratio of red and blue.

By the way, foods such as leafy vegetables contain folate, specifically natural vitamin B. Intake of folate is said to be effective, for example, in the treatment of hyperhomocysteinemia and the risk of fetal neural tube defects. Therefore, the Ministry of Health, Labor and Welfare also calls on women who wish to conceive to take folate at around 400 μg/day, as a lack of folate in pregnant women may cause fetal disorders. Here, the biosynthesis of such folate has been elucidated as described in Non-Patent Document 1.

In recent years, the distinction between folate and folic acid has become clearer, and folic acid is said to be contained in artificially synthesized medicines and supplements that do not exist naturally.

John Scott, Fabrice Rebeille and John Fletcher, Review: Folic acid and folates: the feasibility for nutritional enhancement in plant foods, Journal of the Science of Food and Agriculture, 80:795-824 (2000).

However, at present, the environmental regulation that increases the amount of folate biosynthesis has not been sufficiently elucidated. Therefore, the inventor tried to clarify the problem by changing the temperature condition in addition to the light quality condition. As for the light quality conditions, an attempt was made to clarify by changing the R (red light), G (green light), and B (blue light) ratios and the photosynthetically effective photon flux density (PPFD).

Therefore, the present invention attempts to elucidate the environmental control that increases the amount of biosynthesis of folate by changing not only the light quality condition but also the temperature condition. An object of the present invention is to provide a production apparatus for leafy vegetables.

A first aspect of the present invention is an apparatus for producing leafy vegetables by hydroponic cultivation under artificial lighting in which red, blue and green light is controlled, comprising irradiation means for irradiating the leafy vegetables with light. , a control means for controlling at least one of the ratio of the red, blue and green light emitted by the irradiation means, the photosynthetically active photon flux density (PPFD), and the growth environment temperature, in order to increase the concentration of folate; It is prepared.

A second aspect of the present invention is a method for producing leafy vegetables by hydroponics under artificial lighting with controlled red, blue and green light, wherein the concentration of folate is increased in the leafy vegetables. Therefore, the ratio of the red, blue and green lights is controlled by light quality conditions including at least the green light.

In the third aspect of the present invention, in the second aspect, the photosynthetically active photon flux density ( PPFD) is controlled under the condition of increased light quality.

In the fourth aspect of the present invention, in the second or third aspect, in order to increase the folate concentration of the leafy vegetables, the growing environment temperature is set to the state before chip burn occurs as the upper limit. It is characterized in that the temperature is controlled under a high temperature condition.

A fifth aspect of the present invention is a method for producing leafy vegetables by hydroponics under light-controlled artificial lighting, wherein chip burn is added to the leafy vegetables in order to increase the concentration of folate. It is characterized in that control is performed under temperature conditions in which the temperature of the growing environment is increased while the upper limit is the state before the occurrence of .

A sixth aspect of the present invention is a method for producing leafy vegetables by hydroponics under light-controlled artificial lighting, wherein chip burn is added to the leafy vegetables in order to increase the concentration of folate. It is characterized in that control is performed under light quality conditions in which the photosynthetically effective photon flux density (PPFD) is increased while the upper limit is the state before the occurrence of .

According to the first aspect of the present invention, the concentration of folate is controlled by controlling at least one of the ratio of red, blue and green light irradiated to leafy vegetables, the photosynthetically active photon flux density (PPFD), and the growth environment temperature. can be increased. This makes it possible to provide high-folate leafy vegetables to pregnant women and the like.

According to the second aspect of the present invention, by controlling the ratio of red, blue and green light with light quality conditions including at least green light, leafy vegetables can be produced more effectively than when green light is not included. Conversely, the concentration of folate can be increased. This makes it possible to provide high-folate leafy vegetables to pregnant women and the like.

According to the third and sixth aspects of the present invention, by increasing the photosynthetically active photon flux density (PPFD) and controlling the light quality condition while setting the state before chip burn as the upper limit, can be used to increase folate levels. This makes it possible to provide high-folate leafy vegetables to pregnant women and the like.

According to the fourth and fifth aspects of the present invention, the concentration of folate in leafy vegetables is increased by controlling the temperature conditions in which the growth environment temperature is increased while the state before chip burn occurs is the upper limit. can be increased. This makes it possible to provide high-folate leafy vegetables to pregnant women and the like.

1 is a block diagram of an RGB independent dimming light source plant cultivation apparatus according to an embodiment of the present invention; FIG. Fig. 2 is a graph showing the results of folate content under each light quality condition in a 20°C cultivation plot of green leaf lettuce (fancy green). It is a graph which showed the result about folate content in each light quality condition in the 25 degreeC cultivation division of green leaf lettuce (fancy green). FIG. 4 is a graph for facilitating comparison of the graphs shown in FIGS. 2 and 3 at 20° C. and 25° C. FIG. It is a graph showing the correlation (RB) between cultivation temperature and folate biosynthesis. It is the graph which showed the correlation (RGB) in cultivation temperature and folate biosynthesis.

Embodiments of the present invention will be described in detail below with reference to the drawings, but the present invention is not limited thereto.

FIG. 1 is a block diagram of an RGB independent dimming light source plant cultivation apparatus according to an embodiment of the present invention.

The RGB independent dimming light source plant cultivation apparatus 1 is provided with a light irradiation section 5 which is an LED light source for irradiating the vegetables 3 with light. Here, for example, red is set to 660 nm, green to 525 nm, and blue to 460 nm. The RGB independent dimming light source plant cultivation apparatus 1 includes a control section 7 , and the control section 7 has a light quality condition control section 9 and a temperature condition control section 11 . The light quality condition control unit 9 controls the RGB ratio and the photosynthetically active photon flux density (PPFD) with respect to the light quality condition of the light emitted from the light irradiation unit 5 to the vegetables 3 . The temperature condition control unit 11 controls the growing environment temperature of the vegetables 3 . That is, the control unit 7 can control at least one (or a combination) of the RGB ratio, the photosynthetically active photon flux density (PPFD), and the growth environment temperature condition of the light quality condition.

In the following, it is shown that folate content can be increased by controlling the RGB ratio, photosynthetically active photon flux density (PPFD), and growth environment temperature conditions, based on the clarification of the mechanism of folate biosynthesis, which is the findings of this study. I will explain the experiments that were conducted.

[Test plants and cultivation light source settings]
In the experiments, green leaf lettuce (fancy green) was used as a test plant. Two types of growth temperature, 20°C and 25°C, were set for the growth environment temperature conditions. As for the light quality conditions, RB and RGB sections with different RGB ratios were provided, and the respective sections were provided with different photosynthetically effective photon flux densities (PPFD) of 150 ppfd and 200 ppfd.

Here, LED light sources were used, and red (red) of RGB used light of 660 nm, green (green) used light of 525 nm, and blue (blue) used light of 460 nm. Regarding 150 ppfd in the RB section, 112.0 ppfd for Red and 38 ppfd for Blue, and 200 ppfd for 150.0 ppfd for Red and 50.0 ppfd for Blue. Regarding 150 ppfd for RGB, 98.0 ppfd for Red, 22.0 ppfd for Green, 30 ppfd for Blue, and 200 ppfd for 139.0 ppfd for Red, 21.0 ppfd for Green, and 40.0 ppfd for Blue.

The following conditions were selected as environmental setting conditions for the cultivation apparatus. Cultivation equipment uses a plant cellar (TAPS-6T) as part of the incubator, uses Keystone Technology's original plant growth LED lights and controllers (independent control of each stage), fertilization management pH = 6, EC = 2 dS/m, and the temperature and humidity were 20°C, 25°C, and 60±5%.

Next, the process from seeding to harvesting will be described. Seeds were sown directly on urethane. After cotyledon development, the plants were transferred to a black tray and fertilized with a culture solution. Planting was performed 21 days after sowing. Harvesting was carried out 21 days after planting.

Next, the test plots will be explained. In this experiment, two patterns of cultivation temperature of 20°C and 25°C were set for 21 days from fixed planting to harvest. Under each cultivation temperature condition, the four cultivation plots described above were established, and three repetitions of cultivation to harvesting were carried out in each.

Next, the measurement of folate content will be described. Plants grown for 21 days from fixed planting were harvested, and folate was analyzed using the edible part (above-ground part) from which the root (underground part) was removed. The analysis was entrusted to the Kanagawa Prefectural Industrial Technology Center and was carried out according to the microbiological test method.

FIG. 2 is a graph showing the results of folate content under various light quality conditions in a 20° C. cultivation plot for green leaf lettuce (fancy green). FIG. 3 is a graph showing the results of folate content under various light quality conditions in a 25° C. cultivation plot for green leaf lettuce (fancy green). FIG. 4 is a graph for facilitating comparison of the results shown in FIGS. 2 and 3 at 20.degree. C. and 25.degree. The vertical axis is folate content (μg) per 100 g fresh weight of edible portion.

As shown in FIGS. 2 and 3, at each temperature, the content also differs depending on the difference in the photosynthetically effective photon flux density (PPFD). There was a difference. Specifically, at 150 ppfd, the folate content was significantly higher in the RGB section than in the RB section. Even at 200 ppfd, the folate content was slightly higher in the RGB section than in the RB section. Also, as shown in FIG. 4, there was a difference in the content even at temperatures of 20.degree. C. and 25.degree. In particular, in the 200 ppfd RB and RGB plots, when cultivated at 25°C, the folate content increased about twice as much as when cultivated at 20°C.

Below is a summary. From the results of this experiment, it was clarified that in order to increase the folate content of the edible portion of leaf lettuce, it is better to grow at a cultivation temperature of 25°C after planting. It was also suggested that the folate content can be increased more under the condition that the photosynthetically effective photon flux density is 200 ppfd than under the condition of 150 ppfd. There is an opinion that it is effective to promote photorespiration to increase the folate content. It is considered effective as a method of producing crops with high salt content. Furthermore, since folate biosynthesis is regulated by methionine, it is expected that DNA is required at sites where cell division is active, methionine is consumed, and folate is produced vigorously at the same time. Therefore, folate concentrations are thought to be higher when lettuce live weight growth rate is high. From this, only when the live weight of lettuce increases significantly (especially about 14 to 21 days after planting), by setting the cultivation temperature to 25 ° C, it is possible to save electricity costs and other crops cultivated at the same time. It is thought that it will be possible to cultivate lettuce with an increased folate content while suppressing the influence of Furthermore, when comparing the light conditions, the photosynthetic photon flux density was increased, and the folate content in the test plot using a light source containing green light increased. Further increases in folate content are expected by finding optimum conditions using elevated light sources.

It should be noted that the upper limit of photosynthetically effective photon flux density (PPFD) and the upper limit of growth environment temperature are preferably in a state before chip burn occurs. Here, tip burn refers to a state in which the tips of leaves wither and turn brown.

In the above description, the experimental data is for green leaf lettuce (fancy green), but green and yellow vegetables that contain folate, especially "leafy vegetables," are also within the scope of the present invention. . This is because photosynthesis takes place in "leaf vegetables" and biosynthesis of folate is important, and the experimental results presented in this application are based on the elucidation of the principle of the mechanism of folate biosynthesis. Because it can be inferred. Here, "leafy vegetables" refer to vegetables whose leaves and stems are mainly edible. Examples include herbs (arugula, basil, etc.), but are not limited to these.

In addition to the above, further considerations are described. The starting material for folate biosynthesis is 6-hydroxymethyl-dihydropterin, which is synthesized from GTP (guanosine triphosphate). GTP is synthesized from guanine, one of the bases that make up nucleic acids such as DNA. Pterin and 6-hydroxymethyl-dihydropterin are synthesized from GTP. After this, biosynthesis proceeds further and finally tetrahydrofolate is synthesized. Tetrahydrofolate is the starting point of folate metabolism and changes into various folates to play a role. The enzymes used in this biosynthesis, HPPK, DHPS and DHFR/TS, are ubiquitous in mitochondria. Therefore, folate biosynthesis is thought to occur mainly in mitochondria.

Glycine-serine conversion takes place in mitochondria during photorespiration, which requires the folates tetrahydrofolate and 5,10-methylene-tetrahydrofolate. In other words, folate is photosynthesised during the process of photorespiration.

Tetrahydrofolate is the starting point and key folate for folic acid metabolism. A site containing a large amount of Tetrahydrofolate is a tissue in which cell division is active. For example, there are cotyledons at the time of germination. Folate is considered to be required during cell division because it is a substance involved in DNA synthesis.

As shown in FIGS. 5 and 6, under conditions of a cultivation environment temperature of 25° C. and 200 ppfd, both RB and RGB light qualities showed a strong correlation with a correlation coefficient of 0.9 or more.

Here, in the RGB section with light quality including green light, the concentration of folate at a cultivation temperature of 25°C and 150 ppfd is 40% or more higher than that at a cultivation environment temperature of 20°C. It is characteristic. It is speculated that the mechanism by which the RGB group relatively increased the folate concentration was that the stomata closed due to green light irradiation, resulting in a decrease in the intracellular carbon dioxide concentration, resulting in active photorespiration. For the biosynthesis of folate, which is a secondary metabolite, it is important that the primary metabolite is biosynthesized in a necessary and sufficient amount. For this purpose, it is important to make the intracellular photosynthetic pigments and antenna pigments work efficiently.

Some have pointed out that the absorption spectra of chlorophyll or pigments extracted from green leaves show that green light is only weakly absorbed, arguing that green light is insufficient for photosynthesis in green leaves. There are also papers that However, many spectra of absorptance (absolute light absorption) measured with an integrating sphere reveal that leaves on land absorb a significant portion of green light. Green light absorbed by leaves is also known to promote photosynthesis with high efficiency.

Based on the above considerations, as shown in FIGS. 5 and 6, in order to increase the folate content of the edible part of leaf lettuce, the cultivation environment temperature after planting is set to 25 ° C. In addition, it was suggested that 200 ppfd of light quality increased folate more than 150 ppfd of PPFD.

DESCRIPTION OF SYMBOLS 1... RGB independent light control light source plant cultivation apparatus, 5... Light irradiation part, 7... Control part, 9... Light quality condition control part, 11... Temperature condition control part

Claims (4)

An apparatus for producing leafy vegetables by hydroponics under artificial lighting, each having a peak wavelength and controlling the ratio of combinations of light with only three peak wavelengths of red, blue, and green,
irradiating means for irradiating the leafy vegetables with light;
A production apparatus for leafy vegetables, comprising control means for controlling a cultivation temperature, which is a growth environment temperature, under temperature conditions of 25° C. in order to promote photorespiration of the leafy vegetables in order to increase the concentration of folate. 2. The apparatus for producing leafy vegetables according to claim 1, wherein said control means controls the ratio of said red, blue and green light emitted by said irradiation means according to light quality conditions including at least said green light. A method for producing leafy vegetables by hydroponics under artificial illumination in which each has a peak wavelength and the ratio of combinations of light with only three peak wavelengths of red, blue, and green is controlled,
The control means controls the leafy vegetables under a temperature condition in which the cultivation temperature, which is the growth environment temperature, is set to 25° C. in order to promote the photorespiration of the leafy vegetables in order to increase the concentration of folate. A method for producing leafy green vegetables, characterized by: 4. The method for producing leafy vegetables according to claim 3, wherein said control means controls the ratio of said red, blue and green lights according to light quality conditions including at least said green light.

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