Coloring method for black grapes

Abstract

To provide a coloring method for black grapes that allows coloration of the fruit skin of the black grapes without the use of chemical agents.SOLUTION: In a coloring method for black grapes according to an embodiment, the black grapes are irradiated with at least one of ultraviolet light having a peak wavelength of 280 nm and ultraviolet light having a peak wavelength of 365 nm at some stage on and after the veraison phase of black grape cultivation.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to a method for coloring black grapes.

Background Art

[0002] In recent years, in grape cultivation, global warming has been affecting the coloring of grapes. In particular, the impact of global warming on the coloring of black grapes is significant, and due to global warming, it has become difficult for the peel of black grapes to be colored in a beautiful black color. Since the coloring state of black grapes affects the commercial value of black grapes including grades, it is required to ship black grapes with appropriately colored peels as products.

[0003] By spraying a drug containing abscisic acid (ABA) or the like on black grapes, it is possible to improve the coloring state of black grapes. However, when using a drug, the coloring state is locally improved only at the locations where the drug adheres to the black grapes, or the sprayed drug affects leaves or the like. Further, when black grapes are covered with a bag or the like as a measure against pests and birds and beasts, it is necessary to spray the drug after removing the bag. For this reason, it is required to ship black grapes with appropriately colored peels without using a drug.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The problem to be solved by the present invention is to provide a method for coloring black grapes that enables coloring of the peel without using a drug.

Means for Solving the Problems

[0006] In the method for coloring black grapes according to the embodiment, at any time after the veraison stage in the cultivation of black grapes, the black grapes are irradiated with at least one of ultraviolet light with a peak wavelength of 280 nm and ultraviolet light with a peak wavelength of 365 nm.

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a method for coloring black grapes that enables the coloring of the pericarp without using chemicals.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0009] In the method for coloring black grapes (5) according to the embodiment, at any time after the veraison stage in the cultivation of black grapes (5), the black grapes (5) are irradiated with ultraviolet light having a peak wavelength of 280 nm. As a result, the pericarp can be colored without using chemicals.

[0010] In the coloring method of the black grape (5) according to the embodiment, ultraviolet light with a peak wavelength of 365 nm is irradiated onto the black grape (5) during any period after the véraison stage in the cultivation of the black grape (5). As a result, the peel can be colored without using a chemical agent.

[0011] In the coloring method of the black grape (5) according to the embodiment, ultraviolet light irradiation is performed in a state where the black grape (5) is not irradiated with sunlight. As a result, anthocyanin is synthesized in the black grape (5) using sugars, energy, etc. obtained by photosynthesis during the day, etc., and the peel of the black grape (5) is colored. Therefore, the coloring of the peel of the black grape (5) can be actively promoted.

[0012] In the coloring method of the black grape (5) according to the embodiment, ultraviolet light irradiation is performed at least after harvesting the black grape (5). As a result, even after harvesting the black grape (5), the coloring state of the peel of the black grape (5) can be improved.

[0013] In the coloring method of the black grape (5) according to the embodiment, ultraviolet light irradiation is performed in a state where the cumulative irradiation time per day is within the range of 15 minutes or more and 240 minutes or less. When the black grape (5) is irradiated with ultraviolet light for 15 minutes or more per day, the coloring of the peel of the black grape (5) is appropriately promoted by the ultraviolet light irradiation. Also, by setting the cumulative irradiation time of ultraviolet light per day to 240 minutes or less, burning of the peel of the black grape (5) caused by ultraviolet light is effectively suppressed.

[0014] Hereinafter, the embodiment will be described with reference to the drawings.

[0015] FIG. 1 shows an example of a processing system 1 according to an embodiment. In the example of FIG. 1, the processing system 1 includes an ultraviolet light source 2 and a control device 3. The ultraviolet light source 2 can irradiate black grapes 5 with ultraviolet light. The control device 3 is composed of, for example, a computer such as a server, and includes one or more processors or integrated circuits, and a storage medium such as one or more memories. The processor or integrated circuit of the control device 3 includes any one of a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), a microcomputer, an FPGA (Field Programmable Gate Array), and a DSP (Digital Signal processor), etc. The control device 3 controls the operation of the ultraviolet light source 2 to control the irradiation of ultraviolet light from the ultraviolet light source 2. Note that the control described later performed by the control device 3 may be performed by a server in a cloud environment or the like.

[0016] The processing system 1 in the example of FIG. 1 includes a user interface 6. The user interface 6 is provided with, for example, an operation member for inputting an operation by a user of the processing system 1 or the like, and a notification unit for notifying information to a user of the processing system 1 or the like. As the operation member, for example, a remote control, a keyboard, a touch panel, a button, etc. are used. The control device 3 controls the operation of the ultraviolet light source 2 based on an operation input by the operation member or the like, and controls the irradiation of ultraviolet light from the ultraviolet light source 2. Further, the notification unit notifies information by any one of screen display and voice, etc.

[0017] Also, in an example of FIG. 1, the control device 3 has a timer function 7. And the control device 3 controls the operation of the ultraviolet light source 2 and the irradiation of ultraviolet light from the ultraviolet light source 2 based on the time measured by the timer function 7. Further, the processing system 1 in the example of FIG. 1 is provided with a visible light sensor 8. The visible light sensor 8 detects sunlight from the sun. The control device 3 determines whether or not the sunlight is irradiating the black grape 5 based on the detection result of the visible light sensor 8. And the control device 3 controls the operation of the ultraviolet light source 2 and the irradiation of ultraviolet light from the ultraviolet light source 2 based on the determination result as to whether or not the sunlight is irradiating the black grape 5. Note that the control device 3 may determine whether or not the light irradiating the black grape 5 from the sun exceeds a predetermined light amount based on the detection result of the visible light sensor 8.

[0018] Also, in an example of FIG. 1, the black grape 5 is covered with a bag 11 for measures against pests, birds and beasts, etc. The bag 11 is, for example, a transparent bag, and visible light and ultraviolet light can pass through the bag 11. For this reason, sunlight from the sun and ultraviolet light from the ultraviolet light source 2 pass through the bag 11 and irradiate the black grape 5.

[0019] Here, grapes are classified into black grapes, red grapes and blue grapes according to the coloring system of the fruit skin. Blue grapes are also called white grapes and green grapes. Examples of black grape varieties include Kyoho, Pione and Fujiminori, etc. Examples of red grape varieties include Kwinina, Aki Queen and Ryubou, etc. Examples of blue grape varieties include Shine Muscat, Kattakurugan and Setouchi Giants, etc.

[0020] Also, the color of the skin of black grapes is derived from anthocyanin, and the coloring state of the skin of black grapes changes corresponding to the anthocyanin content in black grapes. And in black grapes, the higher the anthocyanin content, the higher the degree of skin coloring. The increase in the degree of skin coloring of black grapes means, for example, that the color of the grapes becomes darker or the color of the grapes approaches black. Also, anthocyanin has the property of absorbing ultraviolet light. And in black grapes, when irradiated with ultraviolet light, anthocyanin is synthesized and the resistance to ultraviolet light is improved. That is, in black grapes, anthocyanin is synthesized as a compound that improves the resistance to ultraviolet light by irradiation with ultraviolet light. Also, anthocyanin has an absorption maximum for ultraviolet light in the wavelength range of 270 nm or more and 280 nm or less.

[0021] In the embodiment, by irradiating the black grapes 5 with ultraviolet light from the ultraviolet light source 2, anthocyanin is actively synthesized in the black grapes 5. And by actively synthesizing anthocyanin in the black grapes, the degree of skin coloring of the black grapes is increased and the coloring state of the skin of the black grapes is improved.

[0022] In black grapes, when irradiated with ultraviolet light after the véraison stage, the irradiation with ultraviolet light affects the synthesis of anthocyanin. Therefore, by irradiating black grapes with ultraviolet light after the véraison stage, the coloring state of the skin of the black grapes is affected by the irradiation with ultraviolet light. Here, in the growth of grapes, after flowering, in the first stage, the fruits grow and enlarge significantly. And in the second stage after the first stage, the growth of the fruits once stagnates, and in the third stage after the second stage, the fruits grow and enlarge again. And in the growth of grapes, the period when it changes from the second stage to the third stage is called the véraison stage.

[0023] In an embodiment, during any period after the véraison stage, the black grape 5 is irradiated with ultraviolet light from the ultraviolet light source 2. Then, after the véraison stage and before the black grape 5 is shipped as a product, the black grape 5 is irradiated with ultraviolet light. In one example, after the véraison stage and before the black grape 5 is harvested, the black grape 5 is irradiated with ultraviolet light. In this case, during the growth process until the black grape 5 is harvested, the black grape 5 is irradiated with ultraviolet light at any time after the véraison stage, and the black grape 5 is irradiated with ultraviolet light at any time during the third stage including the véraison stage.

[0024] Also, in the embodiment, if the black grape 5 is irradiated with ultraviolet light after the véraison stage, the timing of irradiating the black grape 5 with ultraviolet light is not limited to before the black grape 5 is harvested. In one example, after the black grape 5 is harvested and before the black grape 5 is shipped, the black grape 5 is irradiated with ultraviolet light. Even if the black grape 5 is irradiated with ultraviolet light after harvesting, anthocyanin can be synthesized in the black grape 5 using the sugar and energy obtained until harvesting. Therefore, even if the black grape 5 is irradiated with ultraviolet light after harvesting, the coloring state of the skin of the black grape 5 can change using the sugar and energy obtained until harvesting.

[0025] Also, when irradiating the black grape 5 with ultraviolet light after harvesting, if it is after the véraison stage, the black grape 5 may be irradiated with ultraviolet light during any period before harvesting. In this case, after the véraison stage, the black grape 5 is irradiated with ultraviolet light both before and after harvesting.

[0026] The ultraviolet light source 2 that irradiates the black grape 5 with ultraviolet light is provided with a light-emitting element such as an ultraviolet light LED. Then, the ultraviolet light source 2 irradiates the black grape 5 with the ultraviolet light from the light-emitting element. In one example, the black grape 5 is irradiated with ultraviolet light having a peak wavelength of 280 nm. In another example, the black grape 5 is irradiated with ultraviolet light having a peak wavelength of 365 nm. In still another example, the ultraviolet light source 2 irradiates the black grape 5 with both ultraviolet light having a peak wavelength of 280 nm and ultraviolet light having a peak wavelength of 365 nm. In this case, a light-emitting element that emits ultraviolet light having a peak wavelength of 280 nm and a light-emitting element that emits ultraviolet light having a peak wavelength of 365 nm are provided in the ultraviolet light source 2. In the present embodiment, the peak wavelength of the light irradiated by the light-emitting element does not have to be exactly 280 nm. For example, it may be any peak wavelength in the range of 270 nm to 290 nm. The peak wavelength is preferably in the range of 270 nm to 280 nm, and more preferably 280 nm. Similarly, in the present embodiment, the peak wavelength of the light irradiated by the light-emitting element does not have to be exactly 365 nm. For example, it may be any peak wavelength in the range of 355 nm to 375 nm. The peak wavelength is preferably 365 nm.

[0027] Here, as described above, anthocyanins derived from the coloring of the pericarp of black grapes have an absorption maximum for ultraviolet light in the wavelength range of 270 nm or more and 280 nm or less. For this reason, in embodiments and the like, it is preferable that at least ultraviolet light with a peak wavelength of 280 nm is irradiated onto the black grapes 5. However, since anthocyanins have the property of absorbing ultraviolet light, in embodiments and the like, only ultraviolet light with a peak wavelength of 365 nm may be irradiated onto the black grapes 5. Also, it may be configured such that the superiority of the intensity of the irradiated ultraviolet light changes according to the elapsed time since the start of irradiation. For example, for a certain period from the start of irradiation, since anthocyanins have not yet been completely synthesized (the anthocyanin content is low), irradiation is performed such that the intensity of ultraviolet light with a peak wavelength of 270 nm or more and 280 nm or less is higher than the intensity of ultraviolet light with a peak wavelength of 365 nm. Also, after a certain period of time has elapsed, since the anthocyanin content has been increasing, irradiation is performed such that the intensity of ultraviolet light with a peak wavelength of 365 nm is higher than the intensity of ultraviolet light with a peak wavelength of 270 nm or more and 280 nm or less.

[0028] Also, for black grapes 5, it is preferable that ultraviolet light from the ultraviolet light source 2 is irradiated over the entire bunch (entire fruits). And for black grapes 5, it is preferable that the illuminance of the ultraviolet light is uniform or substantially uniform over the entire bunch (entire fruits). In one example, the ultraviolet light source 2 is arranged near the black grapes 5 and at a position shifted vertically downward from the black grapes 5. Then, the ultraviolet light emitted vertically upward from the ultraviolet light source 2 is irradiated onto the black grapes 5. Also, in the configuration where the ultraviolet light emitted vertically upward from the ultraviolet light source 2 is irradiated onto the black grapes 5, the ultraviolet light source 2 may be arranged with a shift also in the horizontal direction with respect to the black grapes 5. In this case, the ultraviolet light from the ultraviolet light source 2 is irradiated onto the black grapes 5 from the diagonally lower side. In this way, in the configuration of irradiating ultraviolet light from the lower side of the black grapes 5, compared with the configuration of irradiating ultraviolet light from the upper side, since the light is irradiated from a place far from the position of the human eye, there is also an effect that strong ultraviolet light is difficult to reach the human eye. Also, generally, an ultraviolet light source also has the effect of attracting insects, but by irradiating ultraviolet light from the lower side, it becomes possible to attract insects that do not fly in the air. That is, it is possible to expect suppression of insect adhesion to the black grapes 5.

[0029] Also, when irradiating ultraviolet light on the black grapes 5 before harvesting, it is preferable that the parts other than the bunch (other than the fruits) on the vine of the black grapes 5 are not irradiated with ultraviolet light as much as possible. Thereby, in the vine of the black grapes 5, the stems, leaves, etc. are not irradiated with ultraviolet light as much as possible, and the influence of the ultraviolet light irradiated on the black grapes 5 on the stems, leaves, etc. is reduced.

[0030] Also, in one example of FIG. 1, the black grapes 5 are covered with a bag 11 that is permeable to visible light and ultraviolet light, but the bag 11 covering the black grapes 5 may not be provided. In particular, when pests, birds, beasts, etc. do not affect the growth of the black grapes 5, ultraviolet light may be irradiated on the black grapes 5 that are not covered with the bag 11 or the like. Also, when irradiating ultraviolet light on the black grapes 5 after harvesting, the ultraviolet light is irradiated on the black grapes 5 that are not covered with the bag 11 or the like.

[0031] Also, when irradiating black grapes 5 with ultraviolet light before harvesting, it is preferable to irradiate the black grapes 5 with ultraviolet light in a state where the black grapes 5 are not irradiated with sunlight. In this case, for example, ultraviolet light is irradiated to the black grapes 5 at night. In one example, the control device 3 controls the operation of the ultraviolet light source 2 to irradiate ultraviolet light in a time zone corresponding to night based on the time measured by the timer function 7. Also, in one example, the control device 3 controls the operation of the ultraviolet light source 2 to irradiate ultraviolet light in a time zone when dew is not attached (or a time zone with little dew attachment) to the surface of the black grapes 5 based on the time measured by the timer function 7. When water droplets such as dew adhere to the surface of the black grapes 5, it is difficult for ultraviolet light to reach the surface of the black grapes 5, so ultraviolet light is irradiated in a time zone when dew is not attached (or there is little attachment). The time zone when dew is not attached (or there is little attachment) is, for example, immediately after sunset or a day when it is not raining. At this time, the control device 3 may control the operation of the ultraviolet light source 2 in conjunction with a sensor different from the timer function 7 (for example, a temperature sensor, a humidity sensor, etc.) in addition to (or instead of) the timer function 7. In another example, the control device 3 enables the irradiation of ultraviolet light from the ultraviolet light source 2 only when it is determined based on the detection result by the visible light sensor 8 that the black grapes 5 are not irradiated with sunlight.

[0032] In one example, after the véraison stage and until harvesting, the irradiation of the black grapes 5 with ultraviolet light is performed every day. And the irradiation of the black grapes 5 with ultraviolet light is performed only in a state where the black grapes 5 are not irradiated with sunlight, for example, only at night. For this reason, the irradiation of the black grapes 5 with ultraviolet light is not performed during the time from sunrise to sunset.

[0033] In addition, in this example, a reference time range is set for the cumulative irradiation time of ultraviolet light per day on the black grape variety 5. Then, the time zone for irradiating ultraviolet light is adjusted so that the cumulative irradiation time of ultraviolet light per day on the black grape variety 5 falls within the reference time range. The reference time range for the cumulative irradiation time per day is set, for example, in the range of 15 minutes or more and 240 minutes or less. Note that the irradiation of ultraviolet light on the black grape variety 5 may be performed only once a day, or may be performed in multiple times with time intervals. However, in any case, ultraviolet light is irradiated on the black grape variety 5 only when sunlight is not irradiating the black grape variety 5 at night or the like, and the cumulative irradiation time of ultraviolet light per day on the black grape variety 5 falls within the reference time range.

[0034] In another example, after being harvested, the black grape variety 5 is irradiated with ultraviolet light. In this example, the black grape variety 5 is irradiated with ultraviolet light only on any one day from after being harvested until being shipped. Also in this example, on the day when the ultraviolet light is irradiated, the cumulative irradiation time of ultraviolet light per day on the black grape variety 5 falls within the above-mentioned reference time range. And the reference time range for the cumulative irradiation time per day is set, for example, in the range of 15 minutes or more and 240 minutes or less. Also, on the day when the ultraviolet light is irradiated, the irradiation of ultraviolet light on the black grape variety 5 may be performed only once, or may be performed in multiple times with time intervals.

[0035] Here, as verifications related to the embodiments and the like, the following first verification and second verification were performed. In the first verification, under three conditions of Example 1, Example 2, and Comparative Example 1, a variety of black grape called Pione was grown, and the coloring state of the peel of the harvested Pione was compared. And in the first verification, in each of the three trees α1, α2, α3, Pione was grown under the three conditions of Example 1, Example 2, and Comparative Example 1, and the fruits grown under the conditions of Example 1, the fruits grown under the conditions of Example 2, and the fruits grown under the conditions of Comparative Example 1 were compared with each other.

[0036] Figure 2 schematically shows the conditions for growing peonies in Example 1, Example 2, and Comparative Example 1 in the first verification. As shown in Figure 2, in each of Example 1 and Example 2, after the Berezon period and until the peonies were harvested, ultraviolet light was irradiated on the peonies using the ultraviolet light source 2 every day for 24 days. At this time, the peonies irradiated with ultraviolet light were covered with a bag that was permeable to ultraviolet light and visible light, that is, a transparent bag. Also, the peonies were irradiated with ultraviolet light from an ultraviolet light source arranged diagonally downward. In each of Example 1 and Example 2, ultraviolet light was irradiated on the peonies using the ultraviolet light source 2 at night when sunlight was not irradiating the peonies.

[0037] In Example 1, ultraviolet light with a peak wavelength of 280 nm was irradiated on the peonies, and the illuminance of ultraviolet light on the peonies was about 10 μW / cm 2 This was the case. Also, in Example 1, the cumulative irradiation time of ultraviolet light per day was set to 15 minutes. Therefore, the cumulative irradiation amount of ultraviolet light per day in the peonies was about 9 mJ / cm 2 This was the case. Also, in Example 1, ultraviolet light was irradiated 3 times a day at intervals. That is, ultraviolet light was irradiated for 5 minutes 3 times a day at intervals.

[0038] In Example 2, ultraviolet light with a peak wavelength of 365 nm was irradiated on the peonies, and the illuminance of ultraviolet light on the peonies was about 50 μW / cm 2 This was the case. Also, in Example 2, the cumulative irradiation time of ultraviolet light per day was set to 240 minutes. Therefore, the cumulative irradiation amount of ultraviolet light per day in the peonies was about 720 mJ / cm 2 This was the case. Also, in Example 2, ultraviolet light was irradiated only once continuously for 240 minutes a day.

[0039] In Comparative Example 1, ultraviolet light was not irradiated on the peonies using the ultraviolet light source 2. Also, the peonies were covered with a white bag. Note that the white bag is less permeable to ultraviolet light and visible light than the transparent bag.

[0040] In the first verification, for each of the fruits grown under the conditions of Example 1, the fruits grown under the conditions of Example 2, and the fruits grown under the conditions of Comparative Example 1, the color of the fruit peel, the sugar content, and the tartaric acid content were calculated. Then, for the fruits grown under the conditions of Example 1 in trees α1 to α3, the average values of the color of the fruit peel, the sugar content, and the tartaric acid content were calculated, and for the fruits grown under the conditions of Example 2 in trees α1 to α3, the average values of the color of the fruit peel, the sugar content, and the tartaric acid content were calculated. Then, for the fruits grown under the conditions of Comparative Example 1 in trees α1 to α3, the average values of the color of the fruit peel, the sugar content, and the tartaric acid content were calculated.

[0041] The color of the fruit peel was calculated using the color chart value (C.C value), the sugar content was calculated using the Brix value, and the tartaric acid content was calculated as the mass per 100 ml in grams. In the first verification, for each of the average values of the color of the fruit peel, the sugar content, and the tartaric acid content, the increase or decrease rate of the value of the fruit grown under the conditions of Example 1 with respect to the value of the fruit grown under the conditions of Comparative Example 1 was calculated. Also, in the first verification, for each of the average values of the color of the fruit peel, the sugar content, and the tartaric acid content, the increase or decrease rate of the value of the fruit grown under the conditions of Example 2 with respect to the value of the fruit grown under the conditions of Comparative Example 1 was calculated.

[0042] Figure 3 shows, as the verification results in the first verification, the calculation results of the color of the fruit peel, the sugar content, and the tartaric acid content respectively. In Figure 3, for each of the average values of the color of the fruit peel, the sugar content, and the tartaric acid content, the increase or decrease rate of the value of the fruit grown under the conditions of Example 1 with respect to the value of the fruit grown under the conditions of Comparative Example 1, and the increase or decrease rate of the value of the fruit grown under the conditions of Example 2 with respect to the value of the fruit grown under the conditions of Comparative Example 1 are shown.

[0043] Further, FIG. 4 shows images of fruits grown under the respective conditions of Example 1, Example 2, and Comparative Example 1 as verification results in the first verification. In FIG. 4, for each of the three trees α1 to α3, an image of a fruit grown under the conditions of Example 1, an image of a fruit grown under the conditions of Example 2, and an image of a fruit grown under the conditions of Comparative Example 1 are shown. Also, in FIG. 4, the images of the fruits are shown in grayscale. Therefore, in the images of the fruits in FIG. 4, the higher the degree of coloring of the fruit skin, the closer it is shown in a black color.

[0044] As shown in FIG. 3, in each of Example 1 and Example 2 where ultraviolet light was irradiated on the fruits after the véraison stage, the color chart values of the fruit skin increased compared to Comparative Example 1 where no ultraviolet light was irradiated on the fruits. Actually, in the fruits grown under the conditions of Example 1, the average value of the color chart values of the fruit skin increased by 34.1% compared to the fruits grown under the conditions of Comparative Example 1. And in the fruits grown under the conditions of Example 2, the average value of the color chart values of the fruit skin increased by 29.5% compared to the fruits grown under the conditions of Comparative Example 1.

[0045] Therefore, as shown in FIG. 4, in the fruits grown under the respective conditions of Example 1 and Example 2, the black grape variety, Piore, was colored in a beautiful black color compared to the fruits grown under the conditions of Comparative Example 1. In the first verification, in any of the trees α1 to α3, the coloring state of the fruits grown under the respective conditions of Example 1 and Example 2 was improved compared to the fruits grown under the conditions of Comparative Example 1. From the above, it was demonstrated that by irradiating ultraviolet light with a peak wavelength of 280 nm or 365 nm on the fruits after the véraison stage, the coloring state of the fruit skin is improved.

[0046] Also, as shown in Fig. 3, in each of Example 1 and Example 2, corresponding to the improved coloring state of the pericarp compared to Comparative Example 1, the sugar content increased compared to Comparative Example 1. Actually, in the fruits grown under the conditions of Example 1, the average value of the Brix value of the sugar content increased by 5.3% compared to the fruits grown under the conditions of Comparative Example 1. And in the fruits grown under the conditions of Example 2, the average value of the Brix value of the sugar content increased by 7.6% compared to the fruits grown under the conditions of Comparative Example 1.

[0047] Also, in each of Example 1 and Example 2, corresponding to the improved coloring state and the increased sugar content compared to Comparative Example 1, the tartaric acid content decreased compared to Comparative Example 1. Actually, in the fruits grown under the conditions of Example 1, the average value of the tartaric acid content value decreased by 12.1% compared to the fruits grown under the conditions of Comparative Example 1. And in the fruits grown under the conditions of Example 2, the average value of the tartaric acid content value decreased by 12.1% compared to the fruits grown under the conditions of Comparative Example 1.

[0048] From the above first verification, by irradiating the fruits with ultraviolet light having a peak wavelength of 280 nm or 365 nm after the véraison stage, the coloring state of the pericarp was improved. And by irradiating the fruits with ultraviolet light having a peak wavelength of 280 nm or 365 nm after the véraison stage, the sugar content of the fruits increased and the tartaric acid content of the fruits decreased. Therefore, by irradiating the fruits with ultraviolet light having a peak wavelength of 280 nm or 365 nm after the véraison stage, the grade of the pionné increased and the commercial value improved.

[0049] In the second verification, for pionné, a kind of black grape, ultraviolet light was irradiated using an ultraviolet light source after harvesting. In the second verification, the verification was carried out under two conditions of Example 3 and Example 4. In each of Example 3 and Example 4, the harvested pionné was irradiated with ultraviolet light having a peak wavelength of 280 nm. Also, in each of Example 3 and Example 4, the irradiation of ultraviolet light to the pionné was carried out only once continuously for 240 minutes. In each of Example 3 and Example 4, the cumulative irradiation amount of ultraviolet light to the pionné was 72 J / cm 2 and became.

[0050] In Example 3, ultraviolet light was irradiated on peonies with a color chart value of the pericarp color of 5.5 or more and 6.0 or less at the time of harvest. On the other hand, in Example 4, ultraviolet light was irradiated on peonies with a color chart value of the pericarp color of 3.5 or more and 4.0 or less at the time of harvest. Therefore, in Example 3 and Example 4, the coloring states of the pericarp before the ultraviolet light irradiation were made different from each other.

[0051] In each of Example 3 and Example 4, the coloring state of the pericarp of the peony was observed before the irradiation of ultraviolet light, immediately after the end of the irradiation of ultraviolet light, 1 day after the end of the irradiation of ultraviolet light, 2 days after the end of the irradiation of ultraviolet light, and 3 days after the end of the irradiation of ultraviolet light. And in each of Example 3 and Example 4, before the irradiation of ultraviolet light, immediately after the end of the irradiation of ultraviolet light, 1 day after the end of the irradiation of ultraviolet light, 2 days after the end of the irradiation of ultraviolet light, and 3 days after the end of the irradiation of ultraviolet light, the color of the pericarp was expressed in L * a * b * The color system was used for analysis.

[0052] At this time, for the color of the pericarp before the irradiation of ultraviolet light, immediately after the end of the irradiation of ultraviolet light, 1 day after the end of the irradiation of ultraviolet light, 2 days after the end of the irradiation of ultraviolet light, and 3 days after the end of the irradiation of ultraviolet light, the a * value and the b * value were calculated. The calculation of the a * value and the b * value was performed using a 200 - pix image, and for each of the a * value and the b * value, the average value of the values at three points in the image was calculated.

[0053] FIG. 5 shows the change in coloration state of the fruit skin in each of Examples 3 and 4 as the verification result of the second verification using images of the fruit. In FIG. 5, images of the fruit are shown for each of Examples 3 and 4 before UV irradiation, immediately after the end of UV irradiation, one day after the end of UV irradiation, two days after the end of UV irradiation, and three days after the end of UV irradiation. In FIG. 5, the fruit images are shown in grayscale. Therefore, in the fruit images in FIG. 5, the higher the degree of coloration of the skin, the closer to black it is shown.

[0054] In Example 3, in which UV light was irradiated to Pione grapes with a skin color color chart value of 5.5 or more and 6.0 or less at the time of harvest, the UV light irradiation reduced the skin color by * The value of a decreased compared to before UV irradiation. In fact, 3 days after the end of UV irradiation, a * In Example 3, the value of the skin color was reduced by about 10. * The values ​​hardly changed.

[0055] As described above, in Example 3, by irradiating ultraviolet light to Pione grapes whose skin color had a color chart value of 5.5 or more and 6.0 or less at the time of harvest, * With almost no change in value, * The value tended to decrease by about 10. Therefore, in Example 3, the color chart value of the skin color tended to increase by irradiation with ultraviolet light having a peak wavelength of 280 nm compared to before irradiation with ultraviolet light, and the grade of Pione tended to increase. In fact, as shown in FIG. 5, in Example 3, three days after the end of ultraviolet light irradiation, the Pione, which is a black grape, was colored a beautiful black color and the degree of coloring of the skin was increased compared to before irradiation with ultraviolet light.

[0056] In Example 4, in which UV light was irradiated to Pione grapes with a skin color color chart value of 3.5 or more and 4.0 or less at the time of harvest, the UV light irradiation also reduced the skin color a *The value decreased compared to before the ultraviolet light irradiation. Actually, three days after the end of the ultraviolet light irradiation, the value of a decreased by about 10 compared to before the ultraviolet light irradiation. * However, in Example 4, by irradiating the ultraviolet light, the value of b of the color of the fruit skin increased. * The value increased.

[0057] As described above, in Example 4, by irradiating the ultraviolet light to the Pioneer with the color chart value of the fruit skin color being 3.5 or more and 4.0 or less when harvested, the value of b increased, and the value of a * showed a tendency to decrease by about 10. For this reason, in Example 4, due to the irradiation of the ultraviolet light with a peak wavelength of 280 nm, the color chart value of the fruit skin color tended to decrease compared to before the ultraviolet light irradiation, and the grade of the Pioneer tended to decrease. Actually, as shown in FIG. 5, in Example 4, three days after the end of the ultraviolet light irradiation, the degree of coloring of the fruit skin of the Pioneer, which is a black grape, became lower compared to before the ultraviolet light irradiation. * From the above second verification, if the Pioneer has a color chart value of the fruit skin color of 5.5 or more when harvested, by irradiating the ultraviolet light with a peak wavelength of 280 nm after harvesting, the coloring state of the fruit skin was improved. That is, if the Pioneer has a color chart value of the fruit skin color of 5.5 or more when harvested, by irradiating the ultraviolet light after harvesting, the grade of the Pioneer increased and the commercial value improved. For this reason, it was demonstrated that depending on the coloring state of the black grape, the coloring state of the fruit skin can be improved by irradiating the ultraviolet light after harvesting.

[0058]

[0059] ​In embodiments and the like, ultraviolet light with a peak wavelength of 280 nm or 365 nm is irradiated onto black grapes 5 during any period after the véraison stage and before shipping as a product. As a result, as shown in the above verification and the like, the coloring state of the peel of the shipped black grapes 5 can be improved compared to the case where the black grapes 5 are not irradiated with ultraviolet light. Therefore, black grapes 5 with appropriately colored peels can be shipped. Also, in embodiments and the like, the coloring state of the peel of black grapes 5 is improved without using a chemical. For this reason, black grapes 5 with appropriately colored peels can be shipped without using a chemical.

[0060] Also, in an example of embodiments and the like, when irradiating black grapes 5 with ultraviolet light before harvesting, the ultraviolet light is irradiated in a state where the black grapes 5 are not irradiated with sunlight. In the tree of black grapes 5, sugar and energy are obtained by photosynthesis in a state where sunlight such as during the day is irradiated. In this example, since the black grapes 5 are irradiated with ultraviolet light in a state where sunlight is not irradiated such as at night, anthocyanin is synthesized in the black grapes 5 using the sugar and energy obtained by photosynthesis during the day and the like, and the peel of the black grapes 5 is colored. For this reason, the coloring of the peel of the black grapes 5 can be actively promoted.

[0061] Also, in an example of embodiments and the like, ultraviolet light is irradiated after harvesting the black grapes 5. As shown in the above verification and the like, depending on the coloring state of the black grapes 5, even if the black grapes 5 are irradiated with ultraviolet light after harvesting, the coloring state of the peel of the black grapes 5 can be improved. For this reason, in this example, even after harvesting the black grapes 5, the coloring state of the peel of the black grapes 5 can be improved.

[0062] In addition, in one example of the embodiment or the like, ultraviolet light is irradiated onto black grapes 5 in a state where the cumulative irradiation time per day is within a range of 15 minutes or more and 240 minutes or less. By irradiating ultraviolet light for 15 minutes or more per day, the coloring of the skin of black grapes 5 is appropriately promoted by the irradiation of ultraviolet light. Further, by setting the cumulative irradiation time of ultraviolet light per day to 240 minutes or less, burning of the skin of black grapes 5 caused by ultraviolet light is effectively suppressed.

[0063] In the above-described embodiment or the like, the improvement of the coloring state of the skin of black grapes has been described. However, if the grape skin color is derived from anthocyanin, the above-described embodiment or the like can be applied. That is, if the grape skin color is derived from anthocyanin, even for red grapes and blue grapes, the coloring state of the skin can be improved according to the embodiment or the like described above.

[0064] According to at least one of these embodiments, in any period after the véraison stage in the cultivation of black grapes, at least one of ultraviolet light with a peak wavelength of 280 nm and ultraviolet light with a peak wavelength of 365 nm is irradiated onto the black grapes. Thereby, it is possible to provide a method for coloring black grapes that enables the skin to be colored without using a chemical agent.

[0065] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and its equivalent scope.

Explanation of Reference Numerals

[0066] 1... Processing system, 2... Ultraviolet light source, 3... Control device, 5... Black grapes.

Claims

Claim 1 A method for coloring black grapes, comprising irradiating black grapes with ultraviolet light having a peak wavelength of 280 nm during any period after the véraison stage in the cultivation of black grapes. A method for coloring black grapes. Claim 2 A method for coloring black grapes, comprising irradiating black grapes with ultraviolet light having a peak wavelength of 365 nm during any period after the véraison stage in the cultivation of black grapes. A method for coloring black grapes. Claim 3 The coloring method according to claim 1 or 2, wherein the ultraviolet light irradiation is performed in a state where the black grapes are not irradiated with sunlight. Claim 4 The coloring method according to claim 1 or 2, wherein the ultraviolet light irradiation is performed at least after harvesting the black grapes. Claim 5 The coloring method according to claim 1 or 2, wherein the ultraviolet light irradiation is performed in a state where the cumulative irradiation time per day is within a range of 15 minutes or more and 240 minutes or less.

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