Method for regulating and controlling sweet potato moisture migration and inhibiting starch degradation through high-voltage alternating electric field

Abstract

The invention discloses a method for regulating and controlling sweet potato moisture migration and inhibiting starch degradation by a high-voltage alternating electric field. The method comprises the following steps: sorting and cleaning sweet potatoes; sweet potato callus; and applying a high-voltage alternating electric field: putting the callus sweet potato sample into a constant-temperature storage box connected with high-voltage alternating electric field equipment, flatly paving without overlapping, and starting the high-voltage alternating electric field equipment for storage. According to the method for regulating and controlling sweet potato moisture migration and inhibiting starch degradation through the high-voltage alternating electric field, dynamic moisture migration and redistribution between sweet potato tissues can be effectively regulated and controlled, the moisture content in sweet potatoes is maintained, the osmotic potential difference between different parts of sweet potatoes is reduced, and gene expression of aquaporin is regulated and controlled; meanwhile, the high-voltage alternating electric field effectively maintains the starch content of the sweet potatoes, inhibits soluble sugar accumulation and amylase activity, maintains the integrity of starch particle morphology, and regulates the expression level of sugar transporter protein in the sweet potatoes to inhibit starch degradation.

Description

Technical Field

[0001] The present invention relates to the technical field of sweet potato storage, and particularly to a method for regulating water migration and inhibiting starch degradation in sweet potatoes by high-voltage alternating electric fields. Background Art

[0002] Sweet potato (Ipomoea batatas L.) is a high-yielding and adaptable food crop, accounting for more than 50% of the global output. The tuberous roots of sweet potatoes are their main edible parts. Freshly harvested sweet potato tuberous roots are large in volume, tender in texture, and contain a large amount of water. However, the tuberous roots of sweet potatoes still maintain a high metabolic activity after harvest and have a strong respiration and metabolism during storage. In particular, post-harvest water migration easily leads to uneven water distribution in the internal tissues, resulting in epidermal shrinkage and hollowing, seriously affecting the edible quality and commercial value of sweet potatoes.

[0003] Starch is one of the main components of sweet potato tuberous roots. Sweet potato starch has a strong water absorption capacity and can be made into various products such as pastries, vermicelli, and sheets of bean jelly. The respiration and other metabolisms of sweet potatoes are still relatively vigorous after harvest. At this time, the life activities of sweet potatoes gradually change from mainly anabolic metabolism to mainly decomposing high-molecular compounds in the body, including decomposing polysaccharides such as starch into simple molecules such as disaccharides and monosaccharides, resulting in a decrease in starch content and an increase in soluble sugar content, and reducing the starch yield of sweet potatoes.

[0004] Therefore, it is of great significance to inhibit the internal water migration and redistribution in sweet potatoes, effectively maintain the starch content, and improve the quality of post-harvest sweet potatoes.

[0005] As an emerging fresh-keeping treatment technology, electric fields are green and residue-free. Some studies speculate that applying an external electric field will change the biofilm potential difference, thereby generating bioelectric currents and delaying cell metabolism; at the same time, applying a certain intensity of electric field strength will generate ozone due to discharge, killing the microorganisms attached to the surface of fruits and vegetables; the microwave effect it produces will interfere with the state of internal water, thereby changing the process of ice crystal formation. A high-voltage alternating electric field is an electric field with an alternating electric field intensity, and its current size and direction both change periodically. As a physical fresh-keeping technology, it has the advantages of environmental protection, no thermal effect, low energy consumption, high safety, easy disassembly and replacement, etc. Summary of the Invention

[0006] The object of the present invention is to provide a method for regulating water migration and inhibiting starch degradation in sweet potatoes by high-voltage alternating electric fields, which can effectively regulate the dynamic migration and redistribution of water between sweet potato tissues, maintain the internal water content of sweet potatoes, reduce the osmotic potential difference between different parts of sweet potatoes, and regulate the gene expression of aquaporins; at the same time, the high-voltage alternating electric field effectively maintains the starch content of sweet potatoes, inhibits the accumulation of soluble sugars and the activity of amylase, maintains the integrity of the starch granule morphology, and regulates the expression level of sugar transporters in sweet potatoes to inhibit starch degradation.

[0007] To achieve the above object, the present invention provides a method for regulating water migration and inhibiting starch degradation in sweet potatoes by high-voltage alternating electric fields, comprising the following steps: Step 1, sorting and cleaning of sweet potatoes: Sort sweet potato samples, and after washing and disinfecting the sorted sweet potatoes, air-dry them naturally. Step 2, wound healing of sweet potatoes: Place the naturally air-dried sweet potato samples in a room-temperature storage box for wound healing to perform self-repair, prevent water loss and pathogen invasion. Step 3, applying a high-voltage alternating electric field: Put the wound-healed sweet potato samples into a constant-temperature storage box connected to a high-voltage alternating electric field device, lay them flat without overlapping, and turn on the high-voltage alternating electric field device for storage.

[0008] Further, when sorting in Step 1, select fresh sweet potato tubers with uniform size, intact appearance, no pests, diseases and mechanical damage, and the weight is 300 g - 600 g.

[0009] Further, the wound healing time in Step 2 is 3 - 5 days.

[0010] Further, the field strength of the high-voltage alternating electric field in Step 3 is 2 - 8 kV·m -1 , and the frequency of the high-voltage alternating electric field is 50 Hz.

[0011] Further, the temperature of the constant-temperature storage box in Step 3 is 11 - 15 °C.

[0012] Further, the high-voltage alternating electric field device in Step 3 is an intelligent constant-temperature storage box with a high-voltage alternator connected to electrode plates.

[0013] Further, in Step 3, the sweet potatoes are stored in the high-voltage alternating electric field device for 8 weeks, and the sweet potato samples are sampled according to the spatial position every 2 weeks for detection.

[0014] Further, the detection indexes include the water content, osmotic potential and gene expression analysis of aquaporins in different parts of sweet potatoes; the starch content, soluble sugar content, amylase activity, starch granule morphology integrity and gene expression analysis of sugar transporters in sweet potatoes.

[0015] Further, during detection, the sweet potato is longitudinally divided into an upper layer Top, a middle layer Middle, and a lower layer Bottom, and transversely divided into an inner xylem IX, an outer xylem OX, and a phloem P; by applying a high-voltage alternating electric field, the water migration between different parts of the root system during the postharvest storage of sweet potatoes is regulated, and starch degradation is inhibited.

[0016] The present invention also provides a system for implementing the above method, including a high-voltage alternating electric field with an electric field strength of 2 - 8 kV·m -1 , and a frequency of 50 Hz.

[0017] The present invention also provides the application of the above system in regulating water migration in sweet potatoes.

[0018] The present invention also provides the application of the above system in inhibiting starch degradation.

[0019] The present invention also provides the application of the above system in regulating water migration and redistribution between cells by regulating the expression of PIP-pTOM75 and PIP2;7.

[0020] The present invention also provides the application of the above system in inhibiting the transport and distribution of soluble sugars by inhibiting the transport activity of INT1, thereby feedback inhibiting starch degradation.

[0021] The advantages and positive effects of the method for regulating water migration and inhibiting starch degradation in sweet potatoes by a high-voltage alternating electric field according to the present invention are as follows: 1. In the present invention, a high-voltage alternating electric field is used to regulate the water migration and redistribution in different parts of the sweet potato, and the internal water migration is inhibited to the greatest extent, enabling the sweet potato to maintain the best water state and uniform distribution within 8 weeks of storage.

[0022] 2. The present invention can effectively reduce the osmotic potential difference between different parts of the sweet potato and regulate the expression level of aquaporin in different parts of the sweet potato to control the water flow between cells.

[0023] 3. The present invention provides a method for inhibiting starch degradation in sweet potatoes by a high-voltage alternating electric field, enabling the sweet potato to maintain a high starch content within 8 weeks of storage.

[0024] 4. The present invention can effectively inhibit the accumulation of soluble sugars and the activity of amylase, effectively maintain the integrity of the starch granule morphology, and regulate the expression level of sugar transporters in sweet potatoes to control the sugar accumulation during storage.

[0025] 5. The present invention effectively regulates the water migration and redistribution during the postharvest storage of sweet potatoes by using a high-voltage alternating electric field, providing a safe and efficient technology for the postharvest storage of sweet potatoes, and improving the storage quality of postharvest sweet potatoes at the same time.

[0026] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Description of the Drawings

[0027] Figure 1 It is a spatio-temporal variation diagram of the water content of different parts during the post-harvest storage of sweet potatoes in the embodiment of the present invention; Figure 2 It is a spatio-temporal variation diagram of the osmotic potential of different parts before and after the post-harvest storage of sweet potatoes in the embodiment of the present invention; Figure 3 It is the expression of aquaporin genes in different parts during the post-harvest storage of sweet potatoes in the embodiment of the present invention. Among them, A is the expression level of PIP-pTOM75 and PIP2;7 genes in the horizontal space, B is the expression level of PIP-pTOM75 and PIP2 genes in the vertical space, C is the expression level of PIP2;7 gene during storage, and D is the expression level of PIP-pTOM75 gene during storage; Figure 4 It is a diagram of the change in starch content during the post-harvest storage of sweet potatoes in the embodiment of the present invention; Figure 5 It is a diagram of the morphological change of starch granules during the post-harvest storage of sweet potatoes in the embodiment of the present invention. Among them, A is the observation result under an optical microscope. ① is the observation result of freshly harvested sweet potatoes under an optical microscope, ② is the statistical result of the starch particle size of freshly harvested sweet potatoes, ③ is the observation result of sweet potatoes in the comparative example under an optical microscope, ④ is the statistical result of the starch particle size of sweet potatoes in the comparative example, ⑤ is the observation result of sweet potatoes in Example 2 under an optical microscope, ⑥ is the statistical result of the starch particle size of sweet potatoes in Example 2, and B is the observation result under a transmission electron microscope; ⑦ is the transmission electron microscope result of sweet potatoes in the comparative example at 4 weeks, ⑧ is the transmission electron microscope result of sweet potatoes in Example 2 at 4 weeks, ⑨ is the transmission electron microscope result of sweet potatoes in the comparative example at 8 weeks, and ⑩ is the transmission electron microscope result of sweet potatoes in Example 2 at 8 weeks; Figure 6 It is a diagram of the change in soluble sugar content during the post-harvest storage of sweet potatoes in the embodiment of the present invention; Figure 7 It is a diagram of the change in amylase activity during the post-harvest storage of sweet potatoes in the embodiment of the present invention; Figure 8 It is the expression of sugar transporter genes during the post-harvest storage of sweet potatoes in the embodiment of the present invention; Figure 9 It is a physical diagram of an intelligent constant-temperature storage box with a high-voltage alternating electric field device in the embodiment of the present invention. Detailed Embodiments

[0028] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the ordinary meanings as understood by those of ordinary skill in the art to which the present invention pertains.

[0030] Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present invention. For the experimental methods without specific conditions noted in the following embodiments, they are generally determined according to national standards. For the experimental instruments, equipment, and reagents without sources noted in the following embodiments, they are all commercially available raw materials.

[0031] Unless otherwise defined or stated, all professional and scientific terms used in the present invention have the same meanings as those familiar to persons skilled in the art. In addition, any methods and materials similar or equivalent to the described content can be applied to the methods of the present invention. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0032] Example 1 A method for regulating the water migration and inhibiting starch degradation of sweet potatoes based on a high-voltage alternating electric field, the specific steps are as follows: (1) Sorting, selecting fresh sweet potatoes with uniform size, no pests, diseases, and mechanical damage as experimental materials.

[0033] (2) After washing the sweet potatoes with sterile water and naturally air-drying them, place the sweet potatoes in a room-temperature incubator for three days of wound healing.

[0034] (3) Transfer the wound-healed sweet potato samples into an intelligent constant-temperature storage box equipped with a high-voltage alternating electric field, place them horizontally under the electrode plates without overlapping each other, the treatment field strength is 2 kV·m -1 , the frequency is 50 Hz; during the treatment process, keep it dark without light, the environmental temperature is 13 °C, and all sweet potato samples are stored in the storage box for 8 weeks.

[0035] Example 2 Compared with Example 1, change the field strength treatment intensity in Step 3, and the steps are as follows: (1) Sorting, selecting fresh sweet potatoes with uniform size, no pests, diseases, and mechanical damage as experimental materials.

[0036] (2) After washing the sweet potatoes with sterile water and naturally air-drying them, place the sweet potatoes in a room-temperature incubator for three days of wound healing.

[0037] (3) Transfer the wound-healed sweet potato samples into an intelligent constant-temperature storage box equipped with a high-voltage alternating electric field, place them horizontally under the electrode plates without overlapping each other, the treatment field strength is 4 kV·m -1 , the frequency is 50 Hz; during the treatment process, keep it dark without light, the environmental temperature is 13 °C, and all sweet potato samples are stored in the storage box for 8 weeks.

[0038] Example 3 Compared with Example 1, the field strength treatment intensity in Step 3 was changed, and the steps were as follows: (1)Sorting, selecting fresh sweet potatoes with uniform size, no pests, diseases or mechanical damage as experimental materials.

[0039] (2)After washing the sweet potatoes with sterile water, air-dry them naturally, and place the sweet potatoes in a room temperature incubator for three days of wound healing.

[0040] (3)Transfer the wounded sweet potato samples into an intelligent constant temperature storage box equipped with a high-voltage alternating electric field, place them horizontally under the electrode plates without overlapping each other, and the treatment field strength is 8 kV·m -1 , and the frequency is 50 Hz; keep it dark during the treatment process, the ambient temperature is 13 °C, and all sweet potato samples are stored in the storage box for 8 weeks.

[0041] Control Example Compared with Example 1, the intelligent constant temperature storage box equipped with an electric field treatment device in Example 1 was changed to an ordinary storage box without electric field treatment, and the steps were as follows: (1)Sorting, selecting fresh sweet potatoes with uniform size, no pests, diseases or mechanical damage as experimental materials.

[0042] (2)After washing the sweet potatoes with sterile water, air-dry them naturally, and place the sweet potatoes in a room temperature incubator for three days of wound healing.

[0043] (3)Transfer the wounded sweet potato samples into an ordinary intelligent constant temperature storage box, place them horizontally under the electrode plates without overlapping each other, keep it dark during the treatment process, the ambient temperature is 13 °C, and all sweet potato samples are stored in the storage box for 8 weeks.

[0044] For the above examples and control examples, the internal water migration change law of sweet potatoes and indexes such as starch and soluble sugar content were compared under different field strength intensities by a single electric field. There was not much difference in the influence of water migration and inhibition of starch degradation of sweet potatoes in the examples with field strength intensities of 2 and 8 kV·m -1 , while there was water migration between different parts of sweet potatoes at a field strength intensity of 4 kV·m -1 . There were obvious differences in the distribution and migration of water between tissues, and the sugar accumulation in sweet potatoes was significantly inhibited, and the expression level of sugar transporter genes was significantly different. Positive effects were shown at this treatment intensity, and thus the optimal electric field treatment intensity was determined to be 4 kV·m -1 .

[0045] Under the conditions of constant temperature and humidity storage, sweet potato samples were taken according to the spatial position every two weeks, and liquid nitrogen frozen samples were taken for the next experiment; the test indicators included the water content, osmotic potential and gene expression analysis of aquaporin in each part of the sweet potato; the starch content, soluble sugar content, amylase activity, morphological integrity of starch granules and gene expression analysis of sugar transporters in sweet potato. The data results of Example 2 and the comparative example are as Figures 1-8 shown.

[0046] Figure 1 Figure 6 shows the test results of the water content in each part of the sweet potato. The water content of fresh sweet potatoes is generally relatively high, up to about 60%. In the vertical space, the water content in the middle and upper parts is relatively high, which may be the main part of water storage ( Figure 1 ). In the horizontal space, the water content of the xylem (X) in the top and bottom parts of the sweet potato is higher than that of the phloem (P). In Example 2, the water content of the phloem in each part of the sweet potato remained above 60% in the first 4 weeks of storage, while the water content of most of the xylem remained above 60% in the first 6 weeks of storage ( Figure 1 ). By the 8th week of storage, the water content of the outer xylem in the top and middle parts of the sweet potato treated with a 4 kV·m -1 electric field strength still remained above 60% ( Figure 1 ). It can be inferred from this that the high-voltage alternating electric field mainly acts on the xylem (X) of the sweet potato preferentially, followed by the phloem (P). In the longitudinal space, the top part of the sweet potato retains more water; in the horizontal space, the xylem (X) of the sweet potato retains more water, effectively reducing the water content difference in different tissue parts of the sweet potato, indicating that the high-voltage alternating electric field plays a positive role in maintaining the uniformity of the internal water distribution of the sweet potato. Under the treatment of two different electric field strengths in Example 1 and Example 3, the water content difference in each part of the sweet potato is not significant, and the effect is not obvious.

[0047] Figure 2 Figure 7 shows the test results of the osmotic potential in each part of the sweet potato. Generally, the osmotic potential in mature fruits can be approximately considered as a dynamic and changing steady-state system. The osmotic potential of the xylem in fresh sweet potatoes is lower than that of the phloem, indicating that the xylem is the main part of water storage; the overall osmotic potential increases with the increase of storage time, indicating that water migration occurs from the inside to the outside of the sweet potato during storage. The osmotic potential in the upper part of the sweet potato is lower than that in the middle and lower parts, indicating that the water potential in the upper part is higher, and there is a dynamic migration of water from top to bottom in the vertical space. In Example 2, the treatment with high-voltage alternating electric field reduced the osmotic potential difference between different tissue parts of the sweet potato. Among them, the osmotic potential of the xylem in the sweet potato is higher than that of the phloem, and the internal water migrates from the outside to the inside according to the water potential gradient, promoting water redistribution to effectively maintain the optimal internal water distribution state of the sweet potato. Under the treatment of two different electric field strengths in Example 1 and Example 3, the osmotic potential difference in each part of the sweet potato is not significant, and the positive effect of the high-voltage alternating electric field on the dynamic migration of internal water in the sweet potato cannot be observed.

[0048] Figure 3 These are the test results of the expression of aquaporin (AQP) genes in various parts of sweet potato. Aquaporins are involved in the gene regulation of water molecule movement and are one of the key targets for regulating water activity during post-harvest treatment of fruits. In the horizontal space, the expressions of PIP-pTOM75 and PIP2;7 genes in the inner xylem of the middle part of sweet potato are the highest among different tissues, followed by the outer xylem and phloem ( Figure 3 in A). In the vertical space, the expression level of PIP-pTOM75 in the upper part of sweet potato is significantly higher than that in the middle and bottom parts ( Figure 3 in B). In contrast, the expression level of PIP2;7 in the middle part of sweet potato is higher ( Figure 3 in B). This indicates that the changes in the expression patterns of aquaporins in different tissues may lead to different water migration rates, thereby resulting in changes in water migration between tissues during post-harvest storage of sweet potato. At the 6th week of storage, the expression level of PIP-pTOM75 in Example 2 increased by more than twice compared with the control example ( Figure 3 in D). This shows that the high-voltage alternating electric field treatment controls the water migration and redistribution between cells by regulating the expressions of PIP-pTOM75 and PIP2;7. Under the treatments with two different field strengths in Example 1 and Example 3, there are no differences in the gene expression levels of aquaporins in various parts of sweet potato.

[0049] Figure 4 These are the test results of the starch content of sweet potato. The starch content of the sweet potato in the comparative example shows a fluctuating downward trend with the storage time and reaches the lowest point at 8 weeks; the starch content of the sweet potato treated with high-voltage alternating electric field shows a fluctuating trend during storage, but overall remains at a relatively high starch content level compared with the control group, significantly delaying the decrease in starch content during the storage of sweet potato. The high-voltage alternating electric field treatment significantly inhibits starch degradation during the storage of sweet potato.

[0050] Figure 5Observation results of the morphological changes of sweet potato starch granules. The optical microscope observation results show that there are no obvious morphological differences in freshly harvested sweet potatoes, and the peak shape corresponding to their particle size distribution is relatively narrow, indicating that the starch granules of fresh sweet potatoes are relatively uniform in size. During storage, the peak value of the particle size distribution of the starch granules in the comparative example decreased significantly, the size and shape were non-uniform, and the difference in particle size distribution was large. Among them, the average particle size of the comparative example (11.73 μm) was significantly smaller than the average particle size of the fresh sweet potato starch granules (21.37 μm), and the complete morphology of the starch granules was damaged during storage. The average value of the starch granules in Example 2 (15.63 μm) was significantly larger than that of the comparative example (11.73 μm), the range of particle size distribution was reduced compared with the comparative example, and the peak shape became narrower than that of the comparative example. The starch structure maintained a certain complete morphology, and the high-voltage alternating electric field treatment during the storage of sweet potatoes delayed the degradation of starch granules. In the transmission electron microscope observation results, in the middle and late stages of sweet potato storage, the integrity of the starch granules in the comparative example was damaged, cracks and deformations appeared, and they degraded into several irregular particles, and the edges were rough and wrinkled. Among them, in the 8th week of storage, relatively serious cracking occurred in the sweet potato starch granules, and irregular depressions appeared on the surface; while the surface of the sweet potato starch granules in the treatment group of Example 2 was smooth and intact, and they all maintained a good starch granule shape.

[0051] Starch degradation will lead to an increase in the content of soluble sugars. Figure 6 Test results of the soluble sugar content of sweet potatoes. During storage, the soluble sugar content of the comparative example and Example 2 generally showed a fluctuating upward trend, and the soluble sugar content continued to increase. However, the high-voltage alternating electric field treatment significantly inhibited the increase in the soluble sugar content in the middle stage of sweet potato storage. Basically, starting from the 2nd week of storage, the soluble sugar content of Example 2 was significantly lower than that of the comparative example, indicating that the high-voltage alternating electric field treatment effectively inhibited the decomposition of starch in sweet potatoes.

[0052] Figure 7 Test results of the amylase activity of sweet potatoes. The inhibitory effect of the high-voltage alternating electric field treatment on enzyme activity started from the 2nd week of storage. As the storage time extended to the 8th week, the amylase activity of Example 2 was significantly lower than that of the comparative example, and reached the lowest value in the 8th week of storage, significantly delaying the degradation of starch. The trends of amylase activity in the comparative example and Example 2 were generally the same, and the inhibitory effect of the high-voltage alternating electric field treatment on enzyme activity was mainly concentrated in the middle and late stages of storage.

[0053] Figure 8This is the test result of the expression of the sweet potato sugar transporter gene. Sugar transporters play a key role in regulating the post-harvest starch degradation of sweet potatoes. By regulating the transport and metabolism of sugars, they affect the starch accumulation in sweet potatoes. Research shows that when the activity of sugar transporters is inhibited, starch degradation will be inhibited. In this invention, the gene expression level of INT1 in the comparative example showed a trend of first increasing and then decreasing, reaching the highest point in the second week of storage and then decreasing in the middle and late stages of storage; while the gene expression level of INT1 in Example 2 decreased in the second week of storage, was significantly lower than that in the comparative example, and remained at a low level in the middle and late stages of storage, and its expression level was all lower than 1. It is speculated that the high-voltage alternating electric field treatment inhibits the transport and distribution of soluble sugars by inhibiting the transport activity of INT1, thereby feedback inhibiting starch degradation.

[0054] Figure 9 This is a physical diagram of an intelligent constant-temperature storage box with a high-voltage alternating electric field device.

[0055] Therefore, the method for regulating water migration and inhibiting starch degradation in sweet potatoes using the above-mentioned high-voltage alternating electric field in this invention can effectively regulate the dynamic migration and redistribution of water between sweet potato tissues, maintain the internal water content of sweet potatoes, reduce the osmotic potential difference between different parts of sweet potatoes, and regulate the gene expression of aquaporins; at the same time, the high-voltage alternating electric field effectively maintains the starch content of sweet potatoes, inhibits the accumulation of soluble sugars and the activity of amylase, maintains the integrity of the starch granule morphology, and regulates the expression level of sugar transporters in sweet potatoes to inhibit starch degradation.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for regulating sweet potato moisture migration and inhibiting starch degradation by a high voltage alternating electric field, characterized in that: The following steps are involved: Step 1, sweet potato sorting and cleaning: sorting the sweet potato samples, cleaning and disinfecting the sorted sweet potatoes, and naturally air-drying them; Step 2, sweet potato healing: the naturally air-dried sweet potato samples are placed in a room temperature storage box for healing for 3-5 days to perform self-repair and prevent water loss and pathogen invasion; Step 3, applying a high-voltage alternating electric field: placing the wounded sweet potato samples into a constant temperature storage box connected to a high-voltage alternating electric field device, laying them flat without overlapping, and turning on the high-voltage alternating electric field device for storage.

2. The method for regulating sweet potato moisture migration and inhibiting starch degradation by a high voltage alternating electric field according to claim 1, characterized in that: When sorting in step 1, select fresh sweet potato tubers with uniform size, intact appearance, no pests or mechanical damage, and weighing 300g-600g.

3. The method for regulating sweet potato moisture migration and inhibiting starch degradation by a high voltage alternating electric field according to claim 1, characterized in that: The field strength of the high voltage alternating electric field in step 3 is 2-8 kV·m -1 The frequency of the high-voltage alternating electric field is 50Hz; the temperature of the constant temperature storage box is 11-15℃; the high-voltage alternating electric field equipment is an intelligent constant temperature storage box in which a high-voltage alternator is connected to an electrode plate; the sweet potatoes are stored in the high-voltage alternating electric field equipment for 8 weeks, and the sweet potato samples are taken according to the spatial position every 2 weeks for testing.

4. The method for regulating sweet potato moisture migration and inhibiting starch degradation by a high voltage alternating electric field according to claim 3, characterized in that: The detection indicators include water content, osmotic potential and gene expression analysis of water channel proteins in various parts of sweet potato; starch content, soluble sugar content, amylase activity, starch granule morphological integrity and gene expression analysis of sugar transporters in sweet potato.

5. The method for regulating sweet potato moisture migration and inhibiting starch degradation by a high voltage alternating electric field according to claim 3, characterized in that: During the test, the sweet potatoes were divided into the upper layer Top, the middle layer Middle and the lower layer Bottom vertically, and into the inner xylem IX, the outer xylem OX and the phloem P horizontally; high-voltage alternating electric field treatment was used to regulate the water migration between different parts of the root system and inhibit starch degradation during the post-harvest storage of sweet potatoes.

6. A system for implementing the method according to any one of claims 1 to 5, characterized in that: Including field strength of 2-8 kV·m -1 , high voltage alternating electric field with a frequency of 50Hz.

7. Use of the system as claimed in claim 6 in regulating water migration in sweet potatoes.

8. Use of the system as claimed in claim 6 in inhibiting starch degradation.

9. Use of the system as claimed in claim 6 in regulating water migration and redistribution between cells by regulating the expression of PIP-pTOM75 and PIP2;7.

10. Use of the system according to claim 6 for inhibiting the transport and distribution of soluble sugars by inhibiting the transport activity of INT1, thereby feedback inhibiting starch degradation.

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