Banana fruit preservation and ripening LED box cover equipment and preservation and ripening method

Abstract

The present invention relates to the technical field of fruit and vegetable preservation, and provides a banana fruit preservation and ripening LED box cover device and a preservation and ripening method thereof, comprising: a box cover; an LED light group, arranged at the top of the box cover, the LED light group comprising four light color light strips of red, purple, blue and orange, the band range of red light is 660-675nm, the band range of purple light is 400-405nm, the band range of blue light is 450-460nm, and the band range of orange light is 610-615nm; a touch operation screen, arranged at the top of the box cover and connected to the LED light group, for controlling the opening and closing of light strips of different light colors; a control box, arranged in the box cover and connected to the touch operation screen, for selecting different single light colors or light color combinations for irradiation based on the maturity and storage and transportation time of banana fruits. The present invention is simple to operate and can meet the storage and transportation requirements of accurate preservation and ripening of bananas in one device at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of fruit and vegetable preservation, and in particular to a banana fruit preservation and ripening LED box cover device and a banana fruit preservation and ripening method. Background Art

[0002] Bananas are typical respiratory climacteric fruits. They are usually harvested at low maturity. After harvesting, they release a large amount of ethylene during the ripening process, resulting in a respiratory peak, which leads to a series of physiological and biochemical changes, causing great changes in the color, hardness and flavor of the fruit. In terms of appearance, the color of the peel is an intuitive indicator of maturity. Unripe bananas are green because the peel contains a large amount of chlorophyll. As the fruit matures, the chlorophyll gradually degrades, and the peel changes from green to golden yellow. At this time, it can be eaten. As the fruit matures further, the fruit begins to age, the peel turns brown, black spots grow, and gradually spread. The hardness of the fruit also gradually softens with the increase of maturity, which is related to the pectin, hemicellulose and starch contained in the fruit. In the process of fruit ripening, the biggest change is the starch content. The starch content of unripe fruits is about 20%, and when they are mature and softened, it is almost reduced to 1%. At the same time, the soluble sugar content increases rapidly to 15%-20%.

[0003] Unripe bananas cannot reach the level of consumer consumption, but they are very suitable for storage and transportation. In the actual application of post-harvest banana harvesting, storage and transportation, fruit farmers will judge the maturity of bananas based on color, and determine the storage and transportation conditions and sales conditions of the batch of samples. Specifically, there are three situations: 1) When harvesting in summer and autumn, the storage and transportation time is long, or transportation at room temperature, the harvest maturity should be relatively low, that is, the fruit with dark green color should be selected for harvesting; 2) When harvesting in autumn and winter, long distance and long storage and transportation, choose bananas with green to light green color, obvious edges and corners, and white to slightly yellowish flesh in the cross section; 3) The fruit color fades to yellow-green, basically without edges and corners, and most of the flesh in the cross section turns yellow. Bananas that are close to fully ripe are only suitable for short-distance and short-time storage and transportation, but the bananas harvested at this time are of better quality and more suitable for consumption. Therefore, in order to transport bananas to other regions for sale in South China, Southwest my country, Indonesia, Malaysia, the Philippines and other places, it is usually necessary to store and transport bananas for a long time. Therefore, bananas with very low maturity are usually picked, and ethylene is added exogenously during transportation to regulate the ripening of bananas.

[0004] As a plant hormone that regulates maturity and aging, ethylene is widely present in various tissues and organs of plants. It can regulate physiological processes such as respiration, enzyme activity and hormone levels, and induce fruit maturity and aging by directly or indirectly affecting metabolic levels. A large number of studies have shown that ethylene is closely related to the maturity and aging of respiratory climacteric fruits. It is believed that ethylene can initiate the ripening of fruits, and bananas are very sensitive to ethylene. However, in the actual production and application process, problems often occur in the sales process due to improper control of the amount of ethylene added, mainly including 1) excessive addition, causing bananas to mature and age quickly, spontaneously develop diseases or be infected by exogenous microorganisms, resulting in large-scale rot, causing losses, and excessive ethylene can easily affect human health; 2) too little addition, resulting in bananas failing to fully mature on the sales shelves, affecting sales and causing backlog rot. Therefore, in the actual production, storage and transportation of bananas, there is an urgent need for a device and method that can more accurately and conveniently control the maturity state of bananas. Summary of the invention

[0005] The invention provides a banana fruit preservation and ripening LED box cover device and a banana fruit preservation and ripening method. Red, blue, orange and purple LED light strips with different light colors are set to illuminate bananas, so as to meet the storage and transportation requirements of accurate preservation and ripening of bananas in one device at the same time. The operation is simple, and the economic losses caused by overripeness, rot and failure to mature due to improper manual operation are reduced. In addition, a full physical lighting method is adopted, which is safe, non-toxic and pollution-free, eliminates consumers' concerns about the safety of eating bananas preserved by LED lighting, reduces the pollution of chemical drugs to the environment, achieves the purpose of energy saving and emission reduction, and effectively promotes the rapid healing of damaged bananas.

[0006] The invention provides an LED box cover device for preserving and ripening banana fruits, comprising: a box cover; an LED light group, which is arranged at the top of the box cover, and comprises four light strips of red, purple, blue and orange, wherein the wavelength range of red light is 660-675nm, the wavelength range of purple light is 400-405nm, the wavelength range of blue light is 450-460nm, and the wavelength range of orange light is 610-615nm; a touch operation screen, which is arranged at the top of the box cover and connected to the LED light group, and is used for controlling the opening and closing of light strips of different colors; and a control box, which is arranged in the box cover and connected to the touch operation screen, and is used for selecting different single light colors or light color combinations for irradiation based on the maturity and storage and transportation time of banana fruits.

[0007] The banana fruit preservation and ripening LED box cover device provided by the present invention also includes an exhaust system, which is connected to the control box and is respectively arranged on both sides of the box cover for dissipating heat for banana fruits and the LED light group.

[0008] According to the banana fruit preservation and ripening LED box cover device provided by the present invention, the exhaust system includes a blower and an exhaust fan, which are respectively arranged on two sides of the box cover to form a heat dissipation channel.

[0009] According to the banana fruit preservation and ripening LED box cover device provided by the present invention, the blower and the exhaust fan are both provided with shutters, and the shutters are connected to the control box.

[0010] According to the banana fruit preservation and ripening LED box cover device provided by the present invention, the LED light groups are provided with four groups arranged in parallel.

[0011] According to the banana fruit preservation and ripening LED box cover device provided by the present invention, a plurality of retractable temperature and humidity sensors are arranged in the box cover, and the temperature and humidity sensors are connected to the control box and are respectively arranged at the four top corners of the box cover.

[0012] According to the LED box cover device for preserving and ripening banana fruits provided by the present invention, an adjustable buckle is provided at the bottom of the box cover for connecting with fruit and vegetable transport boxes of different specifications.

[0013] The present invention also provides a method for preserving and ripening banana fruits using the LED box cover device, comprising the following steps:

[0014] The ripeness of bananas is determined based on the color card; different single light colors or light color combinations are selected for irradiation according to the ripeness and storage and transportation time of the bananas.

[0015] According to the banana fruit preservation and ripening method of the LED box cover device provided by the present invention, the maturity of the bananas is divided into green ripe, commercial ripe and shelf ripe; the storage and transportation time is divided into: long-term, medium-term and short-term, wherein the long-term is more than 7 days, the medium-term is 4-6 days, and the short-term is 1-3 days.

[0016] The banana fruit preservation and ripening method provided by the present invention includes nine lighting modes, which respectively execute the following instructions:

[0017] When the bananas are green and ripe and have been stored for a long time, turn on the blue LED light for a while and then turn on the orange LED light.

[0018] When the bananas are ripe and in the middle of storage and transportation, turn on the orange LED light;

[0019] When the bananas are green and ripe and the storage and transportation time is short, turn on the red LED light;

[0020] When the bananas are commercially ripe and have been stored for a long time, turn on the blue LED light for a while and then turn on the orange LED light.

[0021] When the bananas are commercially ripe and the storage time is medium, turn on the purple LED light for a period of time, and then turn on the orange LED light;

[0022] When the bananas are commercially ripe and the storage and transportation time is short, turn on the orange LED light;

[0023] When the bananas are shelf-ripe and the storage time is long-term or medium-term, turn on the blue and purple LED lights at the same time;

[0024] When the bananas are shelf-ripe and the storage and transportation time is short, turn on the purple LED light.

[0025] The banana fruit preservation and ripening LED box cover device and the banana fruit preservation and ripening method provided by the present invention irradiate bananas by arranging LED lamp groups of different light colors, adopt a full physical illumination method, and are safe, non-toxic and pollution-free; during the storage and transportation of bananas, red light (band range of 660-675nm), blue light (band range of 450-460nm), purple light (band range of 400-405nm), orange light (band range of 610-615nm) and different combinations of the above four light colors are used for processing; different irradiation light combinations are used according to the maturity of the bananas and the storage and transportation time, so as to achieve the effects of accurate preservation and ripening; and the operation is simple through the touch operation screen.

[0026] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 This is a front view of the LED box cover device for preserving and ripening banana fruits provided by the present invention;

[0029] Figure 2 It is a side view of the LED box cover device for preserving and ripening banana fruits provided by the present invention;

[0030] Figure 3 It is a partial cross-sectional view of the LED box cover device for preserving and ripening banana fruits provided by the present invention;

[0031] Figure 4 It is a flow chart of the fresh-keeping and ripening method provided by the present invention;

[0032] Figure 5 This is a diagram of the banana ripeness color chart;

[0033] Figure 6-Figure 9 These are experimental data comparison diagrams of the effects of different wavelengths of four LED light colors provided by the present invention on the change of the a value of banana color;

[0034] Figure 10-13 These are experimental data comparison diagrams of the effects of different wavelengths of four LED light colors provided by the present invention on the change of banana hardness;

[0035] Figure 14-17 These are experimental data comparison diagrams of the effects of different wavelengths of four LED light colors provided by the present invention on the changes in banana decay;

[0036] Figure 18-Figure 21 These are experimental data comparison diagrams of the effects of different wavelengths of four LED light colors provided by the present invention on the changes in the starch content of bananas;

[0037] Figure 22-Figure 25 These are experimental data comparison diagrams of the effects of different wavelength bands of four LED light colors provided by the present invention on the changes in the soluble sugar content of bananas;

[0038] Figure 26-Figure 29 These are experimental data comparison diagrams of the effects of different wavelengths of four LED light colors provided by the present invention on the changes in the total phenol content of bananas;

[0039] Figure 30-Figure 33 These are experimental data comparison diagrams of the effects of different wavelengths of four LED light colors provided by the present invention on the changes in hydrogen peroxide content in bananas;

[0040] Fig.34 It is a comparison chart of experimental data on the effects of different treatment methods provided by the present invention on the short, medium and long term color L values ​​of bananas of three maturity levels;

[0041] Fig.35 It is a comparison chart of experimental data on the effects of different treatment methods provided by the present invention on the short-, medium- and long-term color a values ​​of bananas of three maturity levels;

[0042] Fig.36 It is a comparison chart of experimental data on the effects of different treatment methods provided by the present invention on the short-, medium- and long-term hardness of bananas of three maturity levels;

[0043] Fig.37 It is a comparison chart of experimental data on the effects of different treatment methods provided by the present invention on the short-, medium- and long-term chewiness of bananas of three degrees of maturity;

[0044] Fig.38 It is a comparison chart of experimental data on the effects of different treatment methods provided by the present invention on the short, medium and long-term starch contents of bananas at three maturity levels;

[0045] Fig.39 It is a comparison chart of experimental data on the effects of different treatment methods provided by the present invention on the short-, medium- and long-term sucrose content of bananas at three maturity levels;

[0046] Fig.40 It is a comparison chart of experimental data on the effects of different treatment methods provided by the present invention on the short-, medium- and long-term fructose content of bananas of three maturity levels;

[0047] Fig.41 It is a comparison chart of experimental data on the effects of different treatment methods provided by the present invention on the short-, medium- and long-term glucose contents of bananas of three maturity levels;

[0048] Fig.42 It is a comparison chart of experimental data on the effects of different treatment methods provided by the present invention on the short-, medium- and long-term respiration intensities of bananas of three maturity levels;

[0049] Fig.43 It is a comparison chart of experimental data on the effects of different treatment methods provided by the present invention on the short-, medium- and long-term ethylene release of bananas at three maturity levels;

[0050] Fig.44 It is a comparison chart of experimental data on the effects of different treatment methods provided by the present invention on the short, medium and long term weight loss of bananas of three maturity levels;

[0051] Fig.45 It is a comparison chart of experimental data on the effects of different treatment methods provided by the present invention on the short-, medium- and long-term decay of bananas at three maturity levels;

[0052] Fig.46 It is a comparison chart of experimental data on the effects of different treatment methods provided by the present invention on the short-, medium- and long-term malondialdehyde contents of bananas at three maturity levels;

[0053] Fig.47 It is a comparison chart of experimental data on the effects of different treatment methods provided by the present invention on the short, medium and long-term hydrogen peroxide contents of bananas of three maturity levels;

[0054] Reference numerals:

[0055] 1: Box cover; 2: LED light group; 3: Light color light strip;

[0056] 4: Touch screen; 5: Blower; 6: Exhaust fan;

[0057] 7: Temperature and humidity sensor; 8: Buckle; 9: Power switch. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0059] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present invention.

[0060] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0061] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0062] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0063] Combine the following Figure 1-Figure 3 The banana fruit preservation and ripening LED box cover device of the present invention is described. The banana fruit preservation and ripening LED box cover device provided by the present invention mainly comprises: a box cover 1, an LED light group 2, a touch operation screen 4 and a control box. Among them, a power switch 9 is provided on the box cover 1. The box cover 1 is the main body of the whole device, and all other devices are integrated and installed on the box cover 1, and the structure is compact.

[0064] The LED light group 2 is arranged at the top of the box cover 1, and the LED light group 2 includes four light strips 3 of red, purple, blue and orange. The wavelength range of red light is 660-675nm, the wavelength range of purple light is 400-405nm, the wavelength range of blue light is 450-460nm, and the wavelength range of orange light is 610-615nm. The LED light group 2 of the present invention adopts four LED light colors with fixed wavelengths, which can better and more accurately avoid the deviation of the preservation effect caused by light color fluctuations, thereby achieving the functions of delaying storage time and preservation, catalyzing banana post-ripening color change and inhibiting microbial growth, and the present invention can effectively improve the preservation, ripening and antibacterial effects of bananas by selecting the above-mentioned wavelength ranges in red, purple, blue and orange light colors. For specific effects, please refer to the experiments described later.

[0065] The touch operation screen 4 is arranged on the top of the box cover 1 and is connected to the LED light group 2, and is used to control the opening and closing of the light strips 3 with different light colors, and the operation is simple.

[0066] The control box is arranged in the box cover 1 and connected to the touch operation screen 4, and is used to select different single light colors or light color combinations for irradiation based on the maturity and storage and transportation time of the banana fruit. It should be understood that the control box of the present invention is used to control the operation of the entire device. A plurality of preset lighting modes can be set in the control box of the present invention to respectively cope with the storage and transportation of bananas of different maturity at different storage and transportation times, and the manual mode can be adjusted to set any one of the light colors in the light color light strip 3 to irradiate alone or a combination of multiple light colors, and the irradiation time and the intermittent frequency of irradiation can be set.

[0067] In this embodiment of the present invention, two LED light groups are arranged to illuminate bananas, and red light (band range is 660-675nm), blue light (band range is 450-460nm), purple light (band range is 400-405nm), orange light (band range is 610-615nm) and the above four light color combinations are used for processing during the storage and transportation of bananas, integrating the functions of delaying storage time and preservation, catalyzing ripening and inhibiting biological substances during the storage and transportation of bananas, and achieving the purpose of multifunctional preservation through rapid ripening with red light, medium-slow ripening with orange light, delayed ripening with blue light and antibacterial with purple light; and different irradiation light combinations are used according to the maturity and storage and transportation time of the bananas to achieve the effect of precise preservation and ripening.

[0068] It can be understood that the present invention uses LED lamps to irradiate bananas, which is a fully physical method. It is safe, non-toxic and pollution-free, eliminates consumers' concerns about the safety of eating bananas preserved by LED light, reduces the pollution of chemicals to the environment, achieves the purpose of energy saving and emission reduction, and effectively promotes the rapid healing of damaged bananas.

[0069] In one example, the box cover device of the present invention also includes an exhaust system, which is connected to the control box and is respectively arranged on both sides of the box cover 1, automatically dehumidifying and dissipating heat from the box cover 1, that is, dissipating heat from the banana fruit and the LED light group 2, which can ensure operational stability and banana storage effect, and effectively ensure the service life of the LED light group 2.

[0070] Specifically, the exhaust system includes a blower 5 and an exhaust fan 6, which are respectively arranged on both sides of the box cover 1 to form a heat dissipation channel on the upper layer of the box cover 1, which can dissipate the heat of the LED light group 2 in the box cover 1 during the preservation process, ensure the temperature balance in the box cover, ensure that the heat generated by the equipment will not affect the stored banana materials, and reduce the impact of increased respiration intensity of bananas due to heat floating.

[0071] According to an embodiment of the present invention, the blower 5 and the exhaust fan 6 are both provided with shutters, and the shutters are preferably electric shutters, and the shutters are connected to the control box to prevent the external light from affecting the LED lighting effect during the lighting process.

[0072] The specific number of the LED light groups 2 of the present invention is not particularly limited. In the present embodiment, four LED light groups 2 are arranged in parallel to cover the inner top of the box cover 1 so as to fully illuminate the bananas.

[0073] According to the embodiment of the present invention, a plurality of retractable temperature and humidity sensors 7 are provided in the box cover 1. The temperature and humidity sensors 7 are connected to the control box and are respectively provided at the four top corners of the box cover 1. The temperature and humidity sensors 7 can monitor the temperature and humidity of the LED light group 2 in the box cover and the surface of the banana to ensure that the box will not overheat during storage and transportation. In addition, the present invention can stretch the temperature and humidity sensors 7 to contact the surface of the banana fruit according to demand, monitor the data closer to the banana, thereby improving the detection accuracy and achieving precise control.

[0074] In addition, the bottom of the box cover 1 is provided with an adjustable buckle 8 for connecting with fruit and vegetable transport boxes of different specifications. In practical applications, the box cover 1 of the present invention can be directly used for two types of fruit and vegetable transport boxes that are currently used more on the market, namely polyethylene plastic boxes or iron boxes with a length, width and height of 48*34.5*60cm or 54*36*30cm. By providing an adjustable buckle, the present invention is applicable to a variety of commonly used fruit and vegetable storage and transportation boxes, effectively reducing manufacturing costs and saving equipment investment.

[0075] Refer to the following Figure 4 The banana fruit preservation and ripening LED box cover device provided by the present invention is described. The preservation and ripening method described below and the banana fruit preservation and ripening LED box cover device described above can correspond to each other.

[0076] The banana fruit preservation and ripening method provided by the present invention mainly comprises the following steps:

[0077] S1: Determine the ripeness of bananas based on the color chart.

[0078] like Figure 5 As shown, the determination standard of banana maturity of the present invention refers to the colorimetric card with more international standards for determination. In the colorimetric card, bananas are divided into 7 grades according to color. The present invention takes into account the actual application situation, therefore, the relatively close green colorimetric cards No. 1 and No. 2 are identified as green-ripe, the greenish and slightly yellowish colorimetric cards No. 3 and No. 4 are identified as commercially mature, and the yellowish and slightly greenish colorimetric card No. 5 is identified as shelf-ripe. It should be understood that the green-ripe state refers to a state that is completely unacceptable to consumers, and it is necessary to ripen for a long time before it can be eaten; the commercially mature state refers to a state that is partially acceptable to consumers, but it needs to be ripened in a short time before it can be used; the shelf-ripe state refers to a state that is fully accepted by consumers, and it is almost edible without ripening or very short-term ripening, while the yellow colorimetric card No. 6 and the yellow with black spots No. 7 are fully mature states, which fully meet the consumer edible standards, but the state has almost no storability. Therefore, the present invention divides the maturity of bananas into green-ripe, commercially mature and shelf-ripe, and the three maturity levels rise in sequence. The higher the maturity, the faster it rots and the shorter the storage period.

[0079] Before performing step S1, a pretreatment step is also included: cleaning soil impurities, dead leaves, insects and other foreign matter on the surface of the harvested fresh banana fruits, and removing banana fruits with diseases and insect pests.

[0080] S2: Select different single light colors or light color combinations for irradiation according to the maturity and storage and transportation time of the bananas. The present invention divides the storage and transportation time according to the domestic general logistics period. The storage and transportation time is mainly divided into: long-term, medium-term and short-term, among which the long-term is more than 7 days, the medium-term is 4-6 days, and the short-term is 1-3 days.

[0081] Before performing step S2, the method further includes a packing step: putting bananas into a box, the banana packing height is not higher than two-thirds of the box, and the bananas are not packed in a stacked manner, and are placed in a cool and ventilated place for processing, and then the box cover device of the present invention is installed on the box.

[0082] According to an embodiment of the present invention, the banana fruit preservation and ripening method provided by the present invention includes nine lighting modes, which respectively execute the following instructions:

[0083] When the bananas are green and ripe and have been stored for a long time, turn on the blue LED light for a while and then turn on the orange LED light.

[0084] When the bananas are ripe and in the middle of storage and transportation, turn on the orange LED light;

[0085] When the bananas are green and ripe and the storage and transportation time is short, turn on the red LED light;

[0086] When the bananas are commercially ripe and have been stored for a long time, turn on the blue LED light for a while and then turn on the orange LED light.

[0087] When the bananas are commercially ripe and the storage time is medium, turn on the purple LED light for a period of time, and then turn on the orange LED light;

[0088] When the bananas are commercially ripe and the storage and transportation time is short, turn on the orange LED light;

[0089] When the bananas are shelf-ripe and the storage time is long-term or medium-term, turn on the blue and purple LED lights at the same time;

[0090] When the bananas are shelf-ripe and the storage and transportation time is short, turn on the purple LED light.

[0091] To facilitate understanding of the technical solution of the present invention, the above nine lighting modes are listed below, which can be executed accordingly according to the maturity of bananas and the target storage and transportation period.

[0092] LED lighting method Banana ripeness Required storage period Blue light + orange light combination Green long Orange Light Green Mid-term Red light Green short term Blue light + orange light combination Commercial maturity long Purple light + orange light combination Commercial maturity Mid-term Orange Light Commercial maturity short term Blue light + purple light combination Shelf mature long Blue light + purple light combination Shelf mature Mid-term Purple light Shelf mature short term

[0093] As mentioned above, red light is used for rapid ripening, orange light is used for medium-slow ripening, blue light is used for delayed ripening, and purple light is used for antibacterial. Therefore, for green-ripe and commercially ripe bananas, when they are about to arrive at the storage and transportation destination, they need to be ripened before they can be sold, and they need to be irradiated with red or orange light; while for shelf-ripened bananas, they need to be preserved or inhibited from bacteria without ripening, and they need to be irradiated with blue or purple light.

[0094] Specifically, for green-ripe and commercially ripe bananas, they cannot be ripened quickly in the long term, and orange light is used. At the same time, they need to be prevented from ripening and rotting on their own during the long-term storage and transportation process. Therefore, blue light is used for preservation in the early period of the long term, and orange light is used for ripening later. Since the maturity of commercially ripe bananas is higher than that of green-ripe, in the medium term, commercially ripe bananas need to be irradiated with purple light first and then with orange light. Moreover, long-term preservation of commercially ripe bananas by blue light also has an antibacterial effect, and purple light is not needed. However, commercially ripe bananas need to be irradiated with purple light for antibacterial in the medium term. For shelf-ripe and long-term and medium-term bananas, freshness and antibacterial are required, so blue light and purple light are used. They can be sold in the short term, and freshness is not required but antibacterial is required, so purple light is used.

[0095] The method of the present invention achieves the effect of accurate preservation and ripening by setting nine short, medium and long-term irradiation times and combined light modes for green-ripe, commercial-ripe and shelf-ripe bananas, breaking the traditional extremely simple storage and transportation or high energy consumption mode of cold chain transportation, applying LED lighting technology to the transportation of bananas, significantly improving the applicable scope of banana storage and transportation, improving the efficiency of banana storage and transportation, reducing the decay of bananas during storage and transportation, and maintaining the quality. In addition, the method of the present invention is simple to operate, and the preservation and ripening effects are good during storage and transportation, which solves the problems of limited existing storage and transportation technology, large amount of human and material resources, and difficult control of human factors and conditions, and is easy to promote and apply on a large scale.

[0096] The following describes the wavelength ranges of the four light colors involved in the box cover device of the present invention, which are red light (wavelength range of 660-675nm), blue light (wavelength range of 450-460nm), purple light (wavelength range of 400-405nm) and orange light (wavelength range of 610-615nm), and each wavelength range of the four light colors has a different effect on the storage effect of bananas.

[0097] Specifically, in optical vision, the entire band of red light is 640-700nm, which is roughly divided into three bands according to classification. Among them, the visual sense of 640-660nm is Chinese red and pure red, the visual sense of 660-675nm is brick red, and the visual sense of 675-700nm is dark red.

[0098] The entire band of orange light is 605-640nm, which is roughly divided into four bands according to classification. Among them, the visual sense of 605-610nm is amber, the visual sense of 610-615nm is orange, the visual sense of 615-625nm is tangerine, and the visual sense of 625-640nm is sunset color.

[0099] The entire blue band is 440-505nm, which is roughly divided into five bands according to classification. Among them, the visual sense of 440-450nm is sea (deep) blue, the visual sense of 450-460nm is pure blue, the visual sense of 460-475nm is bright blue, the visual sense of 475-495nm is sky blue, and the visual sense of 495-505nm is light cyan.

[0100] The entire band of purple light is 400-440nm, which is roughly divided into three bands according to classification. Among them, the visual sense of 400-405nm is grape purple, the visual sense of 405-430nm is violet, and the visual sense of 430-440nm is blue-purple.

[0101] It can be seen from the above description that different light colors have multiple bands. Therefore, the following comparative experiment will be conducted on the effects of different bands of the four LED light colors provided by the present invention on bananas. This is to illustrate that the red and orange LED light bands of the present invention can stimulate the ripening, softening, and color change of bananas, and have the best ripening effect on bananas; at the same time, it is to illustrate that the blue and purple LED light bands of the present invention can delay the ripening of bananas, maintain color and hardness, and inhibit the growth of surface microorganisms to play a fresh-keeping and antibacterial effect, and have the best fresh-keeping and antibacterial effect on bananas.

[0102] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples are all commercially available unless otherwise specified. Specific embodiment 1

[0104] This embodiment provides a method for storing, transporting and ripening green and ripe bananas, comprising the following steps:

[0105] (1) Selection: Clean the soil, dead leaves, insects and other foreign matter on the surface of the harvested fresh green and ripe bananas, and remove the bananas with diseases and insect pests;

[0106] (2) Packing: Bananas weighing more than 40 kg are divided into three groups and placed in polyethylene plastic boxes or iron boxes. The bananas are packed no higher than two-thirds of the box and are not stacked. They are placed in a cool and ventilated place for processing;

[0107] (3) Light color adjustment: After closing the LED box cover, select red light and adjust the wavelength to 660-675nm;

[0108] (4) Simulated storage and transportation: bananas packed with LED box covers are loaded onto a conventional cold chain transport vehicle. To ensure temperature stability during transportation, the temperature of the cold storage in the transport vehicle is adjusted to 25±2°C for simulated storage and transportation. The storage and transportation period is until the bananas naturally ripen and rot until they lose their consumer quality, which is about 8 days at most.

[0109] (5) Sampling and testing: Bananas were observed and sampled every day. Each time, samples were taken from three groups of the same treatment. After sampling, color change and texture softening were measured. Microbial infection and decay phenomena were counted. The pulp was frozen at -20°C and reserved as samples for physical and chemical experiments. Among the physical and chemical indicators, banana starch content, soluble sugar content, ascorbic acid content, and total phenol content were selected to measure the ripening of the bananas. Specific embodiment 2

[0111] The present embodiment is different from the specific embodiment 1 in that orange light is selected in the light color adjustment step (3) and the wavelength band is modulated to 610-615 nm. Specific embodiment 3

[0113] The present embodiment is different from the specific embodiment 1 in that in step (3) of adjusting the light color, blue light is selected and the wavelength band is modulated to 450-460 nm. Specific embodiment 4

[0115] The present embodiment is different from the specific embodiment 1 in that in step (3) of adjusting the light color, purple light is selected and the wavelength band is modulated to 400-405 nm.

[0116] Control group 1

[0117] The present embodiment is different from the specific embodiment 1 in that in step (3) of adjusting the light color, red light is selected and the wavelength band is modulated to 640-660 nm.

[0118] Control group 2

[0119] The present embodiment is different from the specific embodiment 1 in that in step (3) of adjusting the light color, red light is selected and the wavelength band is modulated to 675-700 nm.

[0120] Control group 3

[0121] The present embodiment is different from the specific embodiment 1 in that orange light is selected in the light color adjustment step (3) and the wavelength band is modulated to 605-610 nm.

[0122] Control group 4

[0123] The present embodiment is different from the specific embodiment 1 in that orange light is selected in the light color adjustment step (3) and the wavelength band is modulated to 615-640 nm.

[0124] Control group 5

[0125] The present embodiment is different from the specific embodiment 1 in that in step (3) of adjusting the light color, blue light is selected and the wavelength band is modulated to 440-450 nm.

[0126] Control group 6

[0127] The present embodiment is different from the specific embodiment 1 in that in step (3) of adjusting the light color, blue light is selected and the wavelength band is modulated to 460-475 nm.

[0128] Control group 7

[0129] The difference between this embodiment and the specific embodiment 1 is that in step (3) of light color adjustment, blue light is selected and the wavelength band is modulated to 475-495 nm.

[0130] Control group 8

[0131] This embodiment is different from the specific embodiment 1 in that in step (3) of adjusting the light color, blue light is selected and the wavelength band is modulated to 495-505 nm.

[0132] Control group 9

[0133] The present embodiment is different from the specific embodiment 1 in that in step (3) of adjusting the light color, purple light is selected and the wavelength band is modulated to 405-430 nm.

[0134] Control group 10

[0135] The present embodiment is different from the specific embodiment 1 in that in step (3) of adjusting the light color, purple light is selected and the wavelength is modulated to 430-440 nm.

[0136] Control group 11

[0137] Different from the above-mentioned specific embodiments 1-4 and control groups 1-10, the control group was treated under dark conditions, referred to as CK group.

[0138] The experimental results are as follows:

[0139] Test 1. Banana color determination method: The banana skin color difference was determined using a 3nh spectrophotometer. The L*, a*, and b* values ​​were measured perpendicular to the banana skin head, middle, and tail tissues, and the data were recorded and averaged. 20 banana fingers were taken from each treatment group for determination.

[0140] The results are as follows Figure 6-Figure 9As shown, it shows the change of the color a value of banana under the irradiation of different bands of red, purple, blue and orange light. During the natural ripening process of banana, the peel changes from green to yellow, and the color a value changes from negative to positive and gradually increases. Compared with the control group, blue light and purple light can extend the shelf life by 2 days, and the a value after 8 days of irradiation with blue light 440-495nm is significantly lower than the a value of the CK group after 6 days, which effectively inhibits the yellowing of bananas; among them, the 450-460nm blue light of the present invention has the best effect in inhibiting the increase of a value. The results of purple light are similar to those of blue light, among which the 400-405nm purple light of the present invention has the best effect in inhibiting the increase of a value. The color a value changes of red light and orange light are not significantly different from those of the CK group, that is, the final color is close to the appearance color of bananas in the CK group.

[0141] Test 2: Banana hardness determination method: Banana pulp hardness is determined using a texture analyzer. During the determination, peel off the peel of one banana finger completely and evenly with a knife, then place the peeled surface of the banana finger horizontally on the stage of the texture analyzer, and puncture the texture index radially. Take a point every 2 cm, take 5 points on each banana finger, repeat 3 times, and calculate the average value.

[0142] The results are as follows Figure 10-13 As shown, it is shown that the hardness of bananas changes under the irradiation of different bands of red, purple, blue and orange light. All fruits and vegetables will soften naturally due to post-ripening and aging during the natural ripening process, and the hardness value is constantly decreasing. Blue light and purple light can effectively inhibit the decline in hardness. The hardness of bananas on the shelf for 8 days with blue light 440-450nm and 460-475nm is close to the hardness of the CK group for 6 days, while the hardness of the 450-460nm shelf for 8 days of the present invention is significantly higher than that of other groups, which is the best group for delaying the decline in hardness. The hardness of the three bands of purple light irradiation for 6 days is significantly higher than that of the CK group, and the hardness difference of the three bands after 8 days on the shelf is not significant. Orange light and red light have a ripening effect on bananas, so they can promote the decline in hardness. After being treated with orange light and red light, the hardness of bananas is significantly lower than that of the CK group, and the orange light 610-615nm and the red light 660-675nm can effectively avoid the excessive softening of the hardness of bananas during the shelf process relative to other bands of corresponding light colors, and prevent rot.

[0143] Test 3: Banana rot determination method: After simulated storage and transportation, bananas of different maturity and different treatment methods were counted as diseased and rotten fruits if the fruit stalk or banana finger showed obvious rot, and the percentage of rotten fruits in the total number of fruits was counted. At least 100 banana fruits were observed for each treatment group, and the test was repeated three times.

[0144] Rot is the most important phenomenon that affects the commercial quality and economic benefits of fruits and vegetables during storage and transportation. The main causes of banana rot are axis rot and fungal infection rot of banana fingers. Figure 14-17As shown in the figure, under natural conditions, bananas rot in large quantities after the second day. The rot rate of the CK group after 4 days of shelf storage exceeded 4%, and the rot rate after 6 days of storage was close to 7%. Purple light is the light color that most significantly inhibits the rot rate of bananas. The rot rate of bananas irradiated with the three bands is less than 2% after 8 days of shelf storage, among which purple light 400-405nm is the most significant group to inhibit rot. Although blue light can well preserve bananas and maintain the color and hardness of the fruit, the final rot rate is close to 2%, and blue light 450-460nm is the group with the least rot.

[0145] Although exogenous ripening can make bananas change color and soften quickly, it may also accelerate the ripening and aging process of bananas and increase the possibility of rotting. Fig.16 and Fig.17 It can be seen that the orange light 610-615nm and the red light 660-675nm of the present invention can effectively and to the greatest extent reduce the rot rate of bananas during 6 days on the shelf.

[0146] Test 4: Determination of starch content and sugar content in bananas: The starch content of bananas was determined using a starch content kit. Each group of samples was repeated 3 times and the average value was calculated.

[0147] The soluble sugar content of bananas was determined by HPLC. Weigh 1.0 g of banana pulp, place it in a pre-cooled mortar, add 5 mL of deionized water, grind it thoroughly into a slurry, and then transfer it to a 10 mL centrifuge tube. Ultrasonicate the mixture for 15 minutes and let it stand for 50 minutes. Centrifuge at 12000g for 30 minutes at 4°C. Repeat the extraction twice and combine the filtrates. Make up to 50 mL with deionized water, filter through a 0.22 μm water membrane to obtain the test solution, and store it in a refrigerator at 4°C. Using a 1260 HPLC-ELSD system, sucrose, glucose and fructose standards were prepared into a standard solution with a certain concentration gradient using deionized water. The sugar in banana pulp was qualitatively analyzed according to the retention time, and the sugar content was quantified by the external standard method against the standard curve, and the fructose, glucose and sucrose contents were added together to calculate the soluble sugar content of bananas. Repeat the operation three times.

[0148] During storage, bananas will experience normal post-ripening and aging. In order for the banana to undergo normal physiological metabolism, the starch in the body will gradually break down into sugars for respiration and energy supply. Therefore, after fully ripening, the starch content of bananas decreases, the astringent taste fades, and the sugar content and sweetness increase. However, after the ripening period, bananas will consume a large amount of the originally converted sugar due to the aging process and eventually rot.

[0149] Figure 18-Figure 21It shows the change of starch content of bananas under multiple wavelengths of red, orange, blue and purple LEDs. During the shelf process, with the ripening phenomenon, the starch content of bananas in the CK group showed a continuous downward trend, and the starch content of bananas in the CK group decreased by 37.68%. Among all the groups irradiated with blue light, after 8 days of shelf, the wavelengths of blue light 440-450nm, 450-460nm and 460-475nm can effectively reduce the loss of starch. Among them, the starch content of blue light 450-460nm wavelength after 8 days of shelf is 1.24 times that of the CK group after 6 days. The effect of purple light is similar to that of blue light. The starch content of the three bands of purple light after 8 days of irradiation is higher than that of the CK group. Among them, the purple light of 400-405nm and 405-430nm has a better effect on retaining starch content. Orange light and red light have a ripening effect on bananas. The three bands of orange light all promote the conversion of starch content, but there is no significant difference among the three bands. However, there is a significant difference in the starch content of bananas after red light irradiation. The conversion of starch content by red light 660-675nm is most significant. After 6 days on the shelf, the starch content is 72.5% of that in the CK group.

[0150] Figure 22-Figure 25 The changes in the soluble sugar content of bananas during shelf storage show that under natural ripening conditions, the sugar content of bananas shows a trend of increasing significantly first and then decreasing. This is because the sugar converted from starch gradually accumulates during ripening, and then consumes a large amount of its own sugar after reaching the respiratory peak. Therefore, delaying the starch-sugar conversion and maintaining the soluble content during the shelf preservation of bananas are of great significance to their commercial and storage characteristics.

[0151] Except for the 495-505nm band, blue light has an inhibitory effect on the loss of soluble sugar in bananas during shelf storage. The soluble sugar content of blue light 450-460nm changes the least, and no obvious peak appears. The results of 400-405nm in purple light irradiation are the same as those of blue light 450-460nm. Orange and red light irradiation can ripen bananas. Fig.24 It can be seen that the bananas under orange light 610-615nm irradiation had no obvious peak in 6 days, which proves that the orange light ripening in this band consumes sugar slowly for bananas, and it is easier to control its ripening rate than CK and other groups. Under red light irradiation, the soluble sugar peak of bananas at 660-675nm is significantly higher than all other groups, which proves that this band can promote the starch-sugar conversion of bananas and achieve the purpose of rapid ripening.

[0152] Test 5. Determination of total phenol content and hydrogen peroxide content in banana: The total phenol content is determined using the Folin-Ciocalteu reagent method. Take 0.5 mL of the above polyphenol extract in a test tube, replace the blank control test tube with a 70% ethanol solution, add 1.5 mL of 5-fold diluted Folin-Ciocalteu reagent to each test tube, shake and mix well, let stand for 5 minutes, add 1 mL of 6% NaCO3 solution, heat in a 75°C water bath for 15 minutes, and then immediately place in a -20°C refrigerator to cool to terminate the reaction. Pipette 150 μL of the liquid that terminated the reaction into an ELISA plate and measure the absorbance at 765 nm. Using gallic acid as the equivalent, calculate the total phenol content of banana fruit in units of: mg 100g -1 .

[0153] The H2O2 content was determined using a H2O2 test kit. Weigh 5.0 g of liquid nitrogen-ground banana fruit sample, add 5.0 mL of 100 mmol / L, pH = 7.4 sodium phosphate buffer that has been pre-cooled in the refrigerator overnight, mix and grind into a homogenate in an ice bath, and perform refrigerated centrifugation at 4 ° C and 10000 / min for 30 minutes. The collected supernatant is the H2O2 extract, which is frozen and stored waiting for determination. Try to extract and measure it now. Determine the H2O2 content according to the instructions, mix the gradient concentration reagents in each tube, adjust to zero with distilled water, measure the absorbance value of each tube at 405 nm, make a standard curve and determine the H2O2 content of the sample, and repeat the experiment three times. The H2O2 content is calculated as mmol / g. The total phenol extraction of banana fruit is carried out by ethanol extraction. Weigh 10 g of liquid nitrogen-ground banana fruit sample in a 50 mL centrifuge tube and add 20 mL of 70% ethanol solution. Shake and mix for 5 minutes, and ultrasonicate the mixture for 0.5 hours. Centrifuge at 10000r / min, 4°C for 30min, collect the supernatant, repeat the above steps to extract phenolic substances in the residue twice, and combine the three supernatants to obtain the polyphenol extract. Place the polyphenol extract in a rotary evaporator for rotary evaporation at 30°C, and then dilute it to 50mL with distilled water for later use.

[0154] The results are as follows Figure 26-Figure 29As shown in the figure, the total phenol content of all groups is on a downward trend during the shelf process. This is because the active oxygen metabolism of fruits and vegetables gradually increases during the post-ripening and aging process, and the phenolic substances of fruits and vegetables themselves are consumed to remove the free radicals produced by active oxygen metabolism. In addition, polyphenols cannot continue to be synthesized by themselves after harvesting, so they show a continuous downward trend. Therefore, the total phenol content is often used to judge the storage of fruits and vegetables. If the total phenol content decreases too much, it means that the fruits and vegetables have or are about to enter the process of aging and decay during storage and transportation. In blue light and purple light, since these two light colors can effectively delay the aging of fruits and vegetables, after 8 days of shelf, the total phenol content of all groups except blue light 495-505nm is higher than that of the CK group on the shelf for 6 days. Among them, the three bands of blue light 440-450nm, 450-460nm, 460-475nm and purple light are significantly higher than the CK group, which proves that the accumulation of active oxygen free radicals can be effectively reduced, thereby reducing the aging damage of fruits and vegetables. Blue light 450-460nm and purple light 400-405nm are the most effective groups. Red light and orange light accelerated the loss of polyphenols during the ripening process of bananas. Red light 660-675nm and orange light 610-615nm could avoid the loss of banana polyphenols, and the final total phenol content was significantly higher than that of the CK group.

[0155] During the storage, transportation and sales of fruits and vegetables, free radicals produced by their own active oxygen metabolism have been widely verified to attack fruit and vegetable cells and tissues, thereby accelerating the aging and decay of fruits and vegetables. Hydrogen peroxide is a typical representative product of active oxygen free radicals, so please refer to Figure 30-Figure 33 , which shows the production of hydrogen peroxide in bananas during LED lighting. During the natural ripening and aging process of bananas, the hydrogen peroxide content of bananas in the CK group increased by 21.8% within 6 days. Both blue light and purple light can significantly inhibit the accumulation of hydrogen peroxide during shelf storage, but the blue light effect is more significant. Among them, the blue light of 450-460nm has the best effect, and the hydrogen peroxide content only increased by 3.2% after 8 days of shelf storage; the irradiation of the 400-405nm band of purple light has the best inhibitory effect on the accumulation of hydrogen peroxide among the three bands.

[0156] Red light and orange light have a good effect on the yellowing of bananas, softening of hardness, and starch-sugar conversion. Therefore, in the process of ripening bananas, they may cause bananas to mature too quickly and enter the aging and decay process too early. Among them, orange light 605-610nm and red light 675-700nm make the hydrogen peroxide accumulation of bananas higher than the control CK group; however, orange light 610-615nm and red light 660-675nm are the groups with more obvious inhibitory effects on the rise of hydrogen peroxide in the two light colors, proving that under the irradiation of this band, although bananas show ripe characteristics, their own active oxygen metabolism balance is maintained well, and they also have good external resistance.

[0157] Therefore, based on all the data results above, blue light has a significant effect in delaying the ripening of bananas, reducing color changes and hardness loss, retaining starch content, inhibiting sugar conversion and consumption, and maintaining the balance of active oxygen metabolism, thereby reducing decay on the shelves. 450-460nm is the best band for the above phenomena in blue light.

[0158] Purple light has a certain effect on the preservation of bananas, but it is obviously not as effective as blue light. However, it has a significant inhibitory effect on banana axis rot and exogenous microbial infection, among which the 400-405nm band is the best band.

[0159] Orange light and red light have a good effect on the yellowing of bananas, softening of hardness, and starch-sugar conversion, so they can be used to ripen bananas. However, some bands of these two light colors will excessively stimulate the ripening of bananas, thereby accelerating the aging process, leading to premature rot and loss of edible quality. Among them, orange light 610-615nm and red light 660-675nm are bands that can not only promote the ripening of bananas, but also ensure the balance of active oxygen metabolism to maintain good quality of bananas after ripening.

[0160] Next, different treatment methods are used to conduct experiments on bananas of three maturity levels during short, medium and long term storage and transportation to illustrate the technical effects of the nine illumination modes of the present invention.

[0161] Example 1

[0162] This embodiment provides a method for storing and transporting green and ripe bananas in a long-term (10-day) mode, comprising the following steps:

[0163] (1) Selection: Clean the soil, dead leaves, insects and other foreign matter on the surface of the harvested fresh banana fruits, and remove the banana fruits with diseases and insect pests;

[0164] (2) Maturity determination: Determine the maturity of bananas according to the standard banana color card or the ripening rules of bananas of corresponding varieties;

[0165] (3) Packing: Put bananas of different sizes into polyethylene plastic boxes or iron boxes. The bananas should not be packed higher than two-thirds of the box. Bananas should not be stacked and should be placed in a cool and ventilated place for processing.

[0166] (4) Light color adjustment: After closing the LED box cover, select maturity and storage time on the touch screen: green ripe + long-term storage and transportation, set the storage and transportation time to 10 days, confirm that the blue LED light is turned on for the first 8 days and the orange LED light is turned on for the next 2 days, and then wait for transportation;

[0167] (5) Simulated storage and transportation: The bananas were packed and the LED box cover was turned on, and loaded onto a conventional cold chain transport vehicle. In order to ensure the temperature stability during transportation, the temperature of the cold storage in the transport vehicle was adjusted to 25±2℃, and a 10-day simulated storage and transportation was carried out.

[0168] Example 2

[0169] The present embodiment provides a method for storage and transportation of green-ripe bananas in a mid-term (6-day) mode, comprising the following steps: after performing steps (1), (2), and (3) of embodiment 1, selecting green-ripe + mid-term storage and transportation in light color adjustment in step (4), and setting the storage and transportation time to 6 days, and after confirming that the 6-day mode of orange light LED lighting is turned on, proceeding to step (5).

[0170] Example 3

[0171] The present embodiment provides a method for storing and transporting green and ripe bananas in a short-term (3-day) mode, comprising the following steps: after performing steps (1), (2), and (3) of embodiment 1, selecting green and ripe + short-term storage and transportation in light color adjustment in step (4), confirming that the 3-day mode of red light LED illumination is turned on, and then performing step (5).

[0172] Example 4

[0173] The present embodiment provides a method for storing and transporting commercially ripe bananas in a long-term (10-day) mode, comprising the following steps: after performing steps (1), (2), and (3) of embodiment 1, in step (4) light color adjustment, commercial ripening + long-term storage and transportation is selected, and after confirming that the mode of turning on the blue light LED lamp for 8 days and the orange light for 2 days is turned on, step (5) is performed.

[0174] Example 5

[0175] The present embodiment provides a method for storage and transportation of commercially ripe bananas in a mid-term (6-day) mode, comprising the following steps: after performing steps (1), (2), and (3) of embodiment 1, in step (4) light color adjustment, commercial ripening + mid-term storage and transportation is selected, and after confirming that the mode of turning on the purple LED light for 4 days and the orange light for 2 days is turned on, step (5) is performed.

[0176] Example 6

[0177] The present embodiment provides a method for storing and transporting commercially ripe bananas in a short-term (3-day) mode, comprising the following steps: after performing steps (1), (2), and (3) of embodiment 1, in step (4) light color adjustment, select commercial ripening + short-term storage and transportation and set the storage and transportation time to 3 days, and after confirming that the 3-day irradiation mode of the orange light LED is turned on, proceed to step (5).

[0178] Example 7

[0179] The present embodiment provides a method for storing and transporting shelf-ripe bananas in a long-term (10-day) mode, comprising the following steps: after performing steps (1), (2), and (3) of embodiment 1, in step (4) light color adjustment, select shelf-ripe + long-term storage and transportation, confirm that the mode of turning on blue light and purple light and simultaneously turning on LED lights for 10 days, and then perform step (5).

[0180] Example 8

[0181] This embodiment provides a method for storage and transportation of shelf-ripening bananas in a mid-term (6-day) mode. The method of this embodiment is the same as that of Example 7.

[0182] Example 9

[0183] The present embodiment provides a method for storing and transporting shelf-ripe bananas in a short-term (3-day) mode, comprising the following steps: after performing steps (1), (2), and (3) of embodiment 1, in step (4) light color adjustment, select shelf-ripe + short-term storage and transportation, and after confirming that the 3-day irradiation mode of the purple LED lamp is turned on, proceed to step (5).

[0184] Comparative Example 1

[0185] This comparative example is a blank control in which ripe green bananas are not subjected to any pretreatment: after performing steps (1) and (2), no wound healing treatment is performed and step (5) is performed directly, i.e., the bananas are selected, packed in baskets and directly placed in an environment with a temperature of 25±2°C and a relative humidity of 80-90% and stored in a constant temperature artificial climate chamber.

[0186] Comparative Example 2

[0187] This comparative example is a blank control in which commercially mature bananas are not subjected to any pretreatment: after performing steps (1) and (2), no wound healing treatment is performed and step (5) is performed directly, i.e., the bananas are selected, packed in baskets and directly placed in an environment with a temperature of 25±2° C. and a relative humidity of 80-90% and stored in a constant temperature artificial climate chamber.

[0188] Comparative Example 3

[0189] This comparative example is a blank control in which shelf-ripened bananas are not subjected to any pretreatment: after performing steps (1) and (2), no wound healing treatment is performed and step (5) is performed directly, i.e., the bananas are selected, packed in baskets and directly placed in an environment with a temperature of 25±2° C. and a relative humidity of 80-90% and stored in a constant temperature artificial climate chamber.

[0190] The following experiment was conducted on the above-mentioned Examples 1-9 and Comparative Examples 1-3: This experiment was conducted by using LED lighting to preserve bananas of different maturity and different storage and transportation expectations, and testing the parameters related to ripening and decay, to illustrate that the device and specific lighting method process of the present invention have good applicability for preservation, ripening and antibacterial in the simulated banana storage and transportation process.

[0191] The specific method is as follows:

[0192] (1) Selection and packing: fresh banana fruits with regular appearance, uniform size, no damage and no pests and diseases were selected from the experimental base, processed at the Guangxi experimental base, and packed according to the method of Example 1;

[0193] (2) Precooling: The harvested bananas were precooled in a precooling warehouse with the ambient temperature set at 18 ± 2 °C for 10 h.

[0194] (3) Simulated storage and transportation: Bananas for different storage and transportation purposes were subjected to the selection of LED box cover light color, illumination and time according to the requirements in Examples 1-9, and loaded into vehicles according to Example 1. They were uniformly shipped from Guangxi to Beijing. The actual delivery time was 3 days (defined as short-term storage and transportation). Bananas with a storage period exceeding 3 days continued to be simulated in the vehicle after arriving in Beijing. The medium-term simulated storage and transportation time was 6 days, and the long-term simulated storage and transportation time was 10 days.

[0195] (4) Real-time data sampling and sample retention: In Experimental Examples 1-9, after the bananas in each experimental group reached the simulated storage period, sampling and sample retention were performed.

[0196] Test 1. Banana color determination method: The banana skin color difference was determined using a 3nh spectrophotometer. The L*, a*, and b* values ​​were measured perpendicular to the banana skin head, middle, and tail tissues, and the data were recorded and averaged. 20 banana fingers were taken for each treatment for determination.

[0197] The results are as follows Fig.34 As shown, it shows the change of color L value of green ripe, commercial ripe and shelf ripe bananas after long-term, medium-term and short-term simulated storage and transportation. The test results show that the L value of bananas in the nine modes of the present invention can normally change from green to yellow and increase to more than 80 compared with the control example, and meet the demand for commercial sale of bananas when reaching the end of storage and transportation.

[0198] The phenomenon of bananas turning from green to yellow during ripening is very obvious. Fig.35The a value in the middle represents the change of red-green color. The greener the color, the smaller the a value is. In the simulated storage and transportation process, the nine setting modes can effectively turn the banana color from green to meet the commercial sales requirements; in the comparative example, the green-ripe bananas and commercial-ripe bananas cannot turn yellow under natural conditions due to their relatively low maturity, and need to be ripened later to meet the sales requirements.

[0199] Test 2: Method for determining banana hardness and chewing properties: banana pulp texture index is determined by texture analyzer. During the determination, peel the peel of one banana finger completely and evenly with a knife, then place the peeled surface of the banana finger horizontally on the stage of the texture analyzer, and measure the texture index by radial puncture, taking a point every 2 cm, taking 5 points for each banana finger, repeating 3 times, and calculating the average value.

[0200] As bananas ripen, not only will their color change from green to yellow, but their flesh will also soften significantly. Fig.36 It shows the change of banana pulp hardness. As can be seen from the figure, the hardness of bananas during the ripening process is significantly lower than the hardness of green and ripe bananas at the original point. The maturity of green and ripe bananas is low, and storage and transportation often end during storage and transportation, but exogenous reagents are still needed to make the green and ripe bananas mature and soften, so as to reach the sales state. The hardness of Examples 1-3 is significantly lower than that of Comparative Example 1, indicating that the green and ripe bananas treated by the present invention can reach a state that can be sold and eaten after the simulated storage and transportation ends. Commercially ripe and shelf-ripened bananas have a higher maturity, and long-term storage and transportation will cause bananas to rot quickly, causing losses. Therefore, the commercially ripe and shelf-ripened bananas treated by Examples 4-6 and Examples 7-9 have a higher hardness after simulated storage and transportation than Comparative Examples 2 and Comparative Example 3, indicating that the treatment method of the present invention can effectively delay the softening phenomenon of commercial and shelf-ripened bananas, so that when the bananas arrive at the storage and transportation point, the freshness of the bananas can be effectively maintained, and the aging process of the bananas can be delayed.

[0201] The chewiness reflects the state of the banana pulp being chewed after entering the mouth. Fig.37 It can be seen that the chewiness value is different from the hardness. The chewiness of green-ripe bananas will increase significantly after ripening, and the bananas treated with Examples 1-3 are significantly higher than the untreated group in Comparative Example 1, indicating that this treatment method can achieve a good chewing state after the simulated storage and transportation, and increase edibility. Commercially ripe and shelf-ripened bananas have a higher chewiness at the origin than after storage and transportation due to their higher maturity, but the chewiness of bananas treated with Examples 4-6 and Examples 7-9 is correspondingly higher than that of Comparative Examples 2 and 3. This shows that this treatment can effectively delay the ripening and aging of bananas with a higher degree of maturity.

[0202] Test 3: Determination of starch content in bananas: The starch content was determined using a starch content kit. Each group of samples was repeated 3 times and the average value was calculated.

[0203] During the ripening process, bananas usually accumulate carbohydrates in the form of starch, sucrose and monosaccharides. Starch is a transitional form of carbon assimilates during the development of banana fruits. The ripening of bananas is inevitably accompanied by a decrease in starch hydrolysis and an increase in sugar content. Therefore, starch content is also a key indicator of banana ripening.

[0204] Fig.38 It shows the change of starch content in banana fruit under nine different treatment conditions. Examples 1-6 can effectively reduce the starch content of green and commercial ripe bananas to 35 mg / g, which is lower than that of Comparative Examples 1 and 2. It shows that the treatment technology of the present invention can effectively catalyze the ripening of bananas and the hydrolysis of starch after completing simulated storage and transportation, and increase the taste and edible characteristics. Shelf-ripe bananas are more mature. After 4 days of storage without treatment, Comparative Example 3 shows extremely low starch content. This is because bananas enter the process of aging and decay in the late stage of ripening, consuming a large amount of starch as a respiratory metabolic substrate; bananas treated with Examples 7-9 can significantly alleviate this phenomenon and effectively extend the storage period of bananas.

[0205] Test 4, HPLC-ELSD method for determining the reducing sugar components of banana: Weigh 1.0g of banana pulp, place it in a pre-cooled mortar, add 5mL of deionized water, grind it thoroughly into a slurry, and then transfer it to a 10mL centrifuge tube. Ultrasonicate the mixed solution for 15min and let it stand for 50min. Centrifuge at 12000g for 30min at 4℃. Repeat the extraction twice and combine the filtrate. Make up to 50mL with deionized water, filter through a 0.22μm water membrane to obtain the test solution, and store it in a refrigerator at 4℃. Use 1260HPLC-ELSD system, and the chromatographic column is Innova! Durashell NH2column (250mm×4.60mm, 5μm). Elution conditions: mobile phase acetonitrile: water = 80:20 (v / v). Sample volume: 10μL; flow rate: 1mL / min; column temperature: 30℃; drift tube temperature 60℃; nitrogen flow rate: 2L / min. Use deionized water to prepare a standard solution of sucrose, glucose and fructose into a certain concentration gradient. Qualitative analysis of sugar in banana pulp is performed based on retention time, and the sugar content is quantified by external standard method and reference to the standard curve. Repeat the operation three times.

[0206] Experiments show that the soluble sugars in banana fruits are mainly sucrose, fructose and glucose. Figure 39-Figure 41The results of liquid chromatography-mass spectrometry for measuring the contents of three sugars in bananas of the present invention and the comparative example are shown in FIG. It can be seen that the change trends of the three sugars are similar, because as bananas mature, the hydrolysis of starch in banana fruits is accompanied by the accumulation of sucrose, fructose and glucose.

[0207] The treatments of Examples 1-6 can effectively increase and accumulate the three sugars of green and commercially ripe bananas. The sucrose, fructose and glucose contents of Examples 1-3, Examples 4-6 and Examples 7-9 are significantly higher than those of Comparative Examples 1, 2 and 3 respectively; and since the shelf-ripe bananas of Comparative Example 3 are at the end of post-ripening and are about to enter the process of decay and aging, the three sugar contents of the bananas of Comparative Example 3 are significantly lower than the three sugar contents of the bananas at the origin of shelf-ripening. This shows that the equipment of the present invention and the corresponding nine treatment methods can not only effectively extend the storage period of bananas during storage and transportation, but also properly ripen bananas so that they can reach the edible quality for sale at the end of storage and transportation.

[0208] Test 5. Method for determination of banana ethylene release and respiration intensity: Take 6 fruits from each treatment group, 2 fruits per group, determine their mass, place them in a 1.9L air-balanced sealed box, seal for 2 hours, use a 10mL syringe to balance the gas in the box from the rubber stopper or rubber tube at the top of the sealed box several times, then extract 1.0mL of gas, and determine the ethylene release and respiration intensity of the fruit by gas chromatography, repeat three times. Ethylene release is expressed in μL·kg -1 ·h -1 The respiratory intensity is expressed as the amount of CO2 released, and the unit is mL·kg -1 ·h -1 .

[0209] Gas chromatography detection conditions: The gas chromatograph used in the experiment was equipped with a CO2 converter, a flame ionization detector (FID), a CH-300A high-purity hydrogen generator, a stainless steel filling column (Porapak-100), a column length of 2m, carrier gas N2, an injection temperature of 120°C, a column temperature of 60°C, an ethylene detection temperature of 150°C, and a CO2 detection temperature of 360°C.

[0210]

[0211]

[0212] Banana fruit is a typical respiratory climacteric fruit. During the post-harvest storage process, the ethylene release and respiration intensity will gradually increase, and then decrease when reaching a certain peak after maturity. Figure 42-Figure 43It can be seen that as the bananas mature, the two indicators of the bananas at the green-ripe origin, the commercial-ripe origin, and the shelf-ripe origin continue to increase. Examples 1-3 and Comparative Example 1 can effectively improve the respiration intensity and ethylene release of green-ripe bananas, but the values ​​of the two indicators of Examples 1-3 are significantly higher than those of Comparative Example 1, indicating that the equipment of the present invention and the treatment method adopted can effectively improve the maturity of green-ripe bananas during the simulated freight storage period. Examples 4-6 and Comparative Example 2 are significantly higher than the commercial-ripe origin, but there is no significant difference in respiration intensity and ethylene release. It can be seen from Comparative Example 3 and the shelf-ripe origin that the respiration and ethylene intensity of shelf-ripe bananas decrease significantly during the simulated freight storage process, indicating that the maturity of the bananas has fully matured and begun to show signs of aging. Examples 7-9 can effectively maintain and slightly increase the respiration intensity and ethylene release of bananas.

[0213] Test 6: Method for determining the weight loss rate of bananas: Three replicate groups were set up for each treatment of banana fruit, and 20 single fruits were used in each group. The weight of each single fruit was measured using a precision electronic analytical balance (1 / 10,000 level) and the data was recorded.

[0214] Weight loss rate (%) = (initial weight of marked fruit - weight of marked fruit after storage) / initial weight of marked fruit × 100;

[0215] Weight loss is the most common phenomenon during the storage and transportation of fruits and vegetables, which is usually caused by the fruits and vegetables consuming their own substrates and losing water during respiration. Fig.44 It is the weight loss rate of bananas during the simulated storage and transportation process. It can be seen from the figure that as the maturity of bananas increases, the average weight loss rate also increases accordingly. The weight loss rate of green ripe bananas is generally the lowest (less than 2%), while the weight loss rate of shelf ripe bananas is generally higher (greater than 2.5%). However, the weight loss rates of all treatment groups in Examples 1-9 are correspondingly lower than those of Comparative Examples 1-3 where bananas of the same maturity are not treated. This shows that the equipment and treatment method of the present invention can effectively reduce the weight loss phenomenon of green ripe, commercial ripe and shelf ripe bananas during the simulated storage and transportation process, greatly reduce losses and improve the economic value of actual production.

[0216] Test 7. Method for determining banana rot rate: After simulated storage and transportation, bananas of different maturity and different treatment methods were counted as diseased and rotten fruits if the fruit stalk or banana finger showed obvious rot, and the percentage of rotten fruits in the total number of fruits was counted. At least 100 banana fruits were observed for each treatment group, and the test was repeated three times;

[0217] Rot rate (%) = (rotten fruit number / total fruit number) × 100

[0218] In addition to weight loss, rot is a more obvious and widespread loss of fruits and vegetables during storage and transportation. As shown in the weight loss test, the more mature the fruit is, the more likely it is to rot during storage and transportation. Fig.45 As shown, Examples 1-9 can significantly inhibit the decay of bananas of different maturity during the simulated storage and transportation process, and reduce the decay rate to below 2.2%. This shows that the equipment and corresponding treatment method of the present invention can significantly inhibit the decay of bananas during storage and transportation, and reduce the economic losses caused by decay.

[0219] Test 8: Method for determining the content of malondialdehyde and hydrogen peroxide in banana: The extraction method of MDA is as follows: weigh 5.0g of banana pulp ground with liquid nitrogen, add 8mL of 10% TCA reagent, mix and grind to homogenate under ice bath conditions, centrifuge at 4℃, 10000r / min for 20min, and take the supernatant for use. The method for determining the content of MDA is as follows: take 5mL of the prepared supernatant (the control group uses 5mL of 10% TCA solution instead), add 2mL of 0.67% TBA solution, heat in a boiling water bath at 100℃ for 20min, cool to room temperature, centrifuge at 4℃ and 10000r / min for 30min, take the supernatant, and measure the absorbance value at 450nm, 532nm and 600nm wavelengths, and repeat the experiment three times.

[0220] The H2O2 content is determined using a H2O2 test kit. Weigh 5.0g of liquid nitrogen-ground banana fruit sample, add 5.0mL of 100mmol / L, pH=7.4 sodium phosphate buffer that has been pre-cooled in the refrigerator overnight, mix and grind into a homogenate in an ice bath, perform refrigerated centrifugation at 4°C and 10000 / min for 30min, and the collected supernatant is the H2O2 extract. Store frozen and wait for determination, and try to extract and measure immediately. Determine the H2O2 content according to the instructions, mix the gradient concentration reagents in each tube, adjust to zero with distilled water, measure the absorbance value of each tube at 405nm, make a standard curve and determine the H2O2 content of the sample, and repeat the experiment three times. The H2O2 content is calculated as mmol / g.

[0221] During the long-term storage and transportation of fruits, when they turn from ripe to senescent and corrupt, reactive oxygen metabolism disorder and accumulation of reactive oxygen will occur, which will damage the fruit body, induce peroxidation of unsaturated fatty acids on cell membrane lipids, increase cell membrane permeability, and gradually accumulate H2O2 and malondialdehyde content. Figure 46-Figure 47The two indicators reflect the aging degree of banana fruit. With the increase of maturity, the malondialdehyde and hydrogen peroxide contents of the three maturity banana origins and comparative examples 1-3 gradually increase. Compared with the comparison of their respective maturity, the different treatment methods in Examples 1-9 can significantly reduce the malondialdehyde content and hydrogen peroxide content of bananas. Among them, Examples 7-9 have the most obvious inhibitory effect on the malondialdehyde content of shelf-ripe bananas with higher maturity, and the malondialdehyde content of the banana samples in Comparative Example 3 is reduced by more than 50%. This shows that the equipment and corresponding treatment methods of the present invention can effectively reduce the degree of cell membrane damage during the storage and transportation of bananas, reduce the accumulation of active oxygen, and improve the stress resistance of bananas, thereby reducing the respiratory metabolism and weightlessness of bananas, delaying maturity, and ultimately reducing their decay.

[0222] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A banana fruit preservation and ripening method using an LED box cover device, characterized in that: The banana fruit preservation and ripening LED box cover equipment comprises: Box cover; An LED light group is arranged on the top of the box cover, and the LED light group includes four light strips of red, purple, blue and orange, wherein the wavelength range of red light is 660-675 nm, the wavelength range of purple light is 400-405 nm, the wavelength range of blue light is 450-460 nm, and the wavelength range of orange light is 610-615 nm; A touch screen is arranged on the top of the box cover and connected to the LED light group, and is used to control the opening and closing of light strips with different light colors; A control box is arranged in the box cover and connected to the touch operation screen, and is used to select different single light colors or light color combinations for irradiation based on the maturity of banana fruits and storage and transportation time; A plurality of retractable temperature and humidity sensors are arranged in the box cover, and the temperature and humidity sensors are connected to the control box and are arranged at the four top corners of the box cover respectively; The banana fruit preservation and ripening method of the LED box cover device comprises the following steps: Determine the ripeness of bananas based on a color chart; Choose different single light colors or light color combinations for irradiation according to the maturity and storage and transportation time of bananas; The maturity of the bananas is divided into green ripe, commercial ripe and shelf ripe; the storage and transportation time is divided into: long-term, medium-term and short-term, wherein the long-term is more than 7 days, the medium-term is 4-6 days, and the short-term is 1-3 days; There are nine lighting modes, which execute the following instructions respectively: When the bananas are green and ripe and have been stored for a long time, turn on the blue LED light for a while and then turn on the orange LED light. When the bananas are ripe and in the middle of storage and transportation, turn on the orange LED light; When the bananas are green and ripe and the storage and transportation time is short, turn on the red LED light; When the bananas are commercially ripe and have been stored for a long time, turn on the blue LED light for a while and then turn on the orange LED light. When the bananas are commercially ripe and the storage time is medium, turn on the purple LED light for a period of time, and then turn on the orange LED light; When the bananas are commercially ripe and the storage and transportation time is short, turn on the orange LED light; When the bananas are shelf-ripe and the storage time is long-term or medium-term, turn on the blue and purple LED lights at the same time; When the bananas are shelf-ripe and the storage and transportation time is short, turn on the purple LED light.

2. The method for preserving and ripening banana fruits by using LED box cover equipment according to claim 1, characterized in that: It also includes an exhaust system, which is connected to the control box and is respectively arranged on both sides of the box cover to dissipate heat for banana fruits and the LED light group.

3. The method for preserving and ripening banana fruits by using LED box cover equipment according to claim 2, characterized in that: The exhaust system includes a blower and an exhaust fan, which are respectively arranged on two sides of the box cover to form a heat dissipation channel.

4. The method for preserving and ripening banana fruits by using LED box cover equipment according to claim 3, characterized in that: The blower and the exhaust fan are both provided with shutters, and the shutters are connected to the control box.

5. The method for preserving and ripening banana fruits by using LED box cover equipment according to claim 1, characterized in that: The LED light groups are provided with four groups arranged in parallel.

6. The method for preserving and ripening banana fruits according to any one of claims 2 to 5, characterized in that: An adjustable buckle is provided at the bottom of the box cover for connecting with fruit and vegetable transport boxes of different specifications.

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