Preparation method and application of bamboo leaf flavonoid-chitosan edible coating film

Abstract

The invention discloses a preparation method and application of a bamboo leaf flavonoid-chitosan edible coating film, the thickness of a target film obtained through the method is large, and the problem that in the related technology, due to the fact that a thick film is poor in toughness, preparation cannot be achieved is solved. According to the preparation method and the application provided by the invention, the components in the mixed film forming liquid are designed by combining a technical means with a test, and the content of the bamboo leaf flavone in the target film is increased, so that the target film can exert outstanding beneficial effects in the aspect of preservation of meat food materials which are easily polluted by bacteria. Furthermore, according to the preparation method and application in the specification, through hierarchical design of different film layers, a chitosan liquid film protects a mixed liquid film in the drying process, and the problem that the yield is reduced due to cracking and non-uniformity caused by the characteristic that bamboo leaf flavone is difficult to disperse is solved to a certain extent.

Description

Technical Field

[0001] This application relates to the technical field of the preparation of compositions based on organic polymers, and particularly relates to a preparation method and application of a bamboo leaf flavonoid-chitosan edible coating film. Background Art

[0002] In human daily life, the storage and preservation of food are essential links. Traditional freezing preservation has the characteristics of low cost and convenient operation, but its harm to the ingredients themselves cannot be ignored. Freezing will cause the ingredients to dehydrate, affecting the taste and flavor. For precious ingredients such as bluefin tuna and black Angus steak, this impact cannot be ignored. In the related art, although chitosan films are also applied in the field of food preservation, the chitosan films mainly protect the ingredients by physically isolating external bacteria, but it is difficult to inhibit the bacteria inherent in the ingredients. Moreover, most meat ingredients have a soft texture, and they may be extended and deformed during transportation and packaging. Chitosan films with a conventional thickness (between 20 microns and 50 microns) are easily damaged and difficult to achieve the protection effect.

[0003] It can be seen that how to provide an edible coating film for the preservation of meat ingredients has become an urgent problem to be solved. Summary of the Invention

[0004] The embodiments of this application provide a preparation method and application of a bamboo leaf flavonoid-chitosan edible coating film to at least partially solve the above technical problems.

[0005] The embodiments of this application adopt the following technical solutions: In a first aspect, the embodiments of this application provide a preparation method of a bamboo leaf flavonoid-chitosan edible coating film, and the method includes: Under the condition that the detected thickness range of the target film is between 200 microns and 300 microns, prepare a mixed film-forming solution; the mixed film-forming solution is obtained by mixing a first chitosan solution, a bamboo leaf flavonoid solution, and glycerol; in the mixed film-forming solution, the mass fraction range of chitosan is between 0.6% and 0.75%, the mass fraction of bamboo leaf flavonoid is between 0.003% and 0.007%, and the mass fraction range of glycerol is between 0.06% and 0.1%; Place the mixed film-forming solution on a substrate and cast it into shape to obtain a mixed liquid film; the thickness range of the mixed liquid film is between 1 cm and 1.5 cm; Dry the mixed liquid film. When the thickness of the mixed liquid film is between 30% and 40% of the original thickness, spray the second chitosan solution onto the mixed liquid film to form a chitosan liquid film. The mass fraction range of chitosan in the second chitosan solution is between 2% and 3.6%, and the mass fraction range of glycerol is between 1.5% and 2.5%. The thickness range of the chitosan liquid film is between 2 mm and 4 mm. Dry the composite liquid film composed of the chitosan liquid film and the mixed liquid film until the target film is obtained.

[0006] In an alternative embodiment of this specification, the method further includes: When it is detected that the target film is used for preserving fish, the mass fraction range of glycerol in the second chitosan solution is between 1.5% and 2.2%.

[0007] In an alternative embodiment of this specification, the method further includes: When it is detected that the target film is used for preserving meat, the mass fraction range of glycerol in the second chitosan solution is between 2% and 2.5%.

[0008] In an alternative embodiment of this specification, the method further includes: When it is detected that the thickness of the target film exceeds 250 microns, dry the mixed liquid film until the thickness of the mixed liquid film is between 35% and 40% of the original thickness, and then spray the second chitosan solution onto the mixed liquid film.

[0009] In an alternative embodiment of this specification, the method further includes: When drying the mixed liquid film, the temperature range is between 20°C and 25°C.

[0010] In an alternative embodiment of this specification, the method further includes: When drying the composite liquid film, the temperature range is between 25°C and 30°C.

[0011] In an alternative embodiment of this specification, the method further includes: When drying the composite liquid film, the temperature range is between 30°C and 40°C.

[0012] In an alternative embodiment of this specification, the method further includes: When drying the composite liquid film, vacuum drying is adopted.

[0013] In an alternative embodiment of this specification, the method further includes: Dry the obtained composite liquid film within a preset temperature range. When it is detected that the light transmittance of the composite liquid film is less than a preset light transmittance threshold, weight the preset temperature range with a drying weight value, and continue to dry the composite liquid film with the weighted temperature range until the target film is obtained; The drying weight value is a numerical value ranging from 0 to 1, which is positively correlated with the ratio of the thickness of the chitosan liquid film to the mixed liquid film; it is positively correlated with the light transmittance when the thickness of the mixed liquid film is between 30% and 40% of the original thickness during drying of the mixed liquid film; and it is negatively correlated with the area of the substrate.

[0014] In a second aspect, an embodiment of the present application also provides an application of a bamboo leaf flavonoid-chitosan edible coating film. The bamboo leaf flavonoid-chitosan edible coating film prepared by the method described in the first aspect is coated on the surface of food, such that the side formed by the mixed liquid film is in contact with the food.

[0015] In a third aspect, an embodiment of the present application also provides an electronic device, including: A processor; and A memory arranged to store computer-executable instructions, and the executable instructions, when executed, cause the processor to execute the method steps described in the first aspect.

[0016] In a fourth aspect, an embodiment of the present application also provides a computer-readable storage medium. The computer-readable storage medium stores one or more programs, and when the one or more programs are executed by an electronic device including multiple application programs, the electronic device is caused to execute the method steps described in the first aspect.

[0017] The above at least one technical solution adopted in the embodiments of the present application can achieve the following beneficial effects: The present application provides a preparation method and application of a bamboo leaf flavonoid-chitosan edible coating film, which combines bamboo leaf flavonoids and chitosan. The obtained bamboo leaf flavonoid-chitosan edible coating film can protect food ingredients both physically and bacteriostatically. Moreover, the thickness of the target film obtained by the method in the present application is relatively large, overcoming the problem in related technologies that a thick film cannot be prepared due to poor toughness. The preparation method and application provided in the present application design the components in the mixed film-forming liquid through technical means combined with experiments, increasing the content of bamboo leaf flavonoids in the target film, so that the target film can play an outstanding beneficial effect in the preservation of food ingredients such as meat ingredients that are easily contaminated by bacteria. Further, the preparation method and application in this specification realize the protection of the mixed liquid film by the chitosan liquid film during the drying process through the hierarchical design of different film layers, and to a certain extent solve the problems of cracking and reduced yield caused by the difficult dispersion characteristics of bamboo leaf flavonoids and unevenness. Brief Description of the Drawings

[0018] The drawings described herein are provided to further understand the present application and form a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings: Figure 1 is a schematic process diagram of a method for preparing a bamboo leaf flavonoid-chitosan edible coating provided in an embodiment of this specification; Figure 2 is a schematic structural diagram of an electronic device in an embodiment of this specification. Detailed Description of the Embodiments

[0019] The present invention will be further described in detail below in conjunction with the drawings through specific embodiments. Similar elements in different embodiments are labeled with related similar element numbers. In the following embodiments, many details are described to enable a better understanding of the present application. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification to avoid the core part of the present application being overwhelmed by excessive description. For those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0020] In addition, the features, operations, or characteristics described in the specification can be combined in any appropriate manner to form various embodiments. At the same time, the steps or actions in the method description can also be reordered or adjusted in a manner obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for clearly describing a certain embodiment and do not mean that they are necessary sequences unless it is stated that a certain sequence must be followed.

[0021] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the described objects and do not have any sequential or technical meaning. And the "connection" and "coupling" mentioned in the present application, unless otherwise specified, both include direct and indirect connection (coupling).

[0022] The technical solutions provided in each embodiment of the present application will be described in detail below in conjunction with the drawings.

[0023] As Figure 1 shown, the method for preparing the bamboo leaf flavonoid-chitosan edible coating in this specification includes the following steps: S100: Prepare a mixed film-forming solution under the condition that the thickness range of the target film is between 200 microns and 300 microns.

[0024] The target film in this specification is the edible film of bamboo leaf flavonoid-chitosan to be prepared. In the related art, the thickness of the edible film used for food preservation is mostly in the range of 20 microns to 50 microns. Such a thickness of the film is okay for preserving eggs and apples, but for preserving meat ingredients that are prone to deformation, cracks will occur in the edible film due to deformation and extension, and the barrier performance is also poor. If a thicker edible film is directly prepared, uneven shrinkage or even cracking will occur during the preparation process. However, the target film prepared by the method in this specification can reach a higher thickness and can achieve the preservation of food ingredients.

[0025] The mixed film-forming solution in this specification is obtained by mixing a first chitosan solution, a bamboo leaf flavonoid solution, and glycerol. The method in this specification places restrictions on the composition of the mixed film-forming solution. As for how to achieve such a ratio, all technical means that can be used to achieve this ratio in the related art are applicable to this specification under the condition of permission.

[0026] Exemplarily, chitosan can be dissolved in glacial acetic acid with a concentration of 1 wt% to obtain a first chitosan solution through magnetic stirring and filtration. The solvent of the bamboo leaf flavonoid solution can be selected as ethanol, and the bamboo leaf flavonoid solution can be obtained through magnetic stirring. Then, adjust the volume ratio of the two to obtain a mixed solution. After magnetic stirring the mixed solution for a certain period of time, add glycerol and continue stirring to obtain a mixed film-forming solution. The requirement for the mixed film-forming solution is that the three solutes are fully mixed and there is no precipitation.

[0027] In the mixed film-forming solution of this specification, the mass fraction range of chitosan is between 0.6% and 0.75%, the mass fraction of the bamboo leaf flavonoid is between 0.003% and 0.007%, and the mass fraction range of glycerol is between 0.06% and 0.1%.

[0028] Among them, the content of chitosan in the mixed film-forming solution is significantly low, at least half lower than the conventional value. Compared with bamboo leaf flavonoids, chitosan is a strongly polar molecule with a relatively large molecular weight, and it is very difficult for the two to be compatible at the chemical level, making it easy for segregation to occur in the mixed solution, which has a relatively negative impact on the preparation of the target film. Especially if bamboo leaf flavonoids segregate, then the target film will exhibit obvious weak antibacterial ability, and for ingredients such as meat whose protein is prone to spoilage, it will almost lose its freshness preservation effect. With the volatilization of ethanol, obvious segregation will occur during the drying process. In addition to weakening the antibacterial ability, segregation will also cause the light transmittance of the target film to decrease and the imaging to be uneven, affecting the use effect. Reducing the use of chitosan can weaken the instability of the molecular distribution of the mixed solution film caused by its strong molecular polarity, thereby weakening the segregation phenomenon. However, in the preparation of conventional chitosan films, this ingredient ratio has problems because the reduction of chitosan content will lead to a decrease in the mechanical strength of the target film, and even after drying, it is very difficult to remove it from the substrate, and thus good products cannot be obtained.

[0029] In this specification, the content of bamboo leaf flavonoids in the mixed film-forming solution is significantly increased, about twice that of the related technology. On the one hand, it can improve the antibacterial effect on food ingredients, and on the other hand, it can also improve the polarity uniformity of the mixed film-forming solution, weaken the segregation phenomenon, and avoid the appearance of unevenness. Increasing the content of bamboo leaf flavonoids is not without harm either. Since bamboo leaf flavonoids are more prone to segregation, the increase in its content usually comes with the problem of uneven films obtained.

[0030] However, even so, because the target is to prepare a relatively thick film, the thickness of the mixed solution film will also be relatively thick. If the drying method in the conventional preparation means is used, it will lead to a long drying time and the segregation problem still exists. Therefore, in the process of designing the ingredient ratio, the inventor conducted a large number of experiments and, through the analysis of data, determined the mass fraction of glycerol in the mixed film-forming solution to be between 0.06% and 0.1% to improve the drying efficiency by reducing the use of glycerol, and this content of glycerol can also ensure that when the mixed solution film is in a "semi-dry" state (the thickness is reduced to 30% to 40%), no cracking and other phenomena will occur. However, the film in the "semi-dry" state is obviously not directly usable, and even because the amount of glycerol used is small, even if it is further dried, it cannot be completely removed from the substrate. The preparation of the target film needs to be completed in combination with subsequent steps.

[0031] In addition, the invention found through experimental data that under the ingredient ratio of chitosan and bamboo leaf flavonoids in the mixed film-forming solution, if the mass fraction of glycerol reaches 0.2%, it will significantly increase the drying time and cause the segregation of bamboo leaf flavonoids.

[0032] S102: Place the mixed film-forming solution on a substrate and cast it into shape to obtain a mixed solution film.

[0033] In the related art, the materials that can be used as substrates are all applicable to this specification under allowable conditions. For example, the material of the substrate can be glass. In the related art, the process of tape casting can be realized, which is all applicable to this specification under allowable conditions.

[0034] The thickness range of the mixed liquid film in this specification is between 1 cm and 1.5 cm. Since the glycerol content in the mixed liquid film is low, even if the thickness of the mixed liquid film is relatively thick, it will not significantly increase the drying time. Moreover, at this glycerol content, even a relatively thick mixed liquid film cannot obtain a film material with a thickness of 200 to 300 microns after drying, but the thickness is on the low side, and its mechanical properties cannot meet the use requirements.

[0035] S104: Dry the mixed liquid film. When the thickness of the mixed liquid film is between 30% and 40% of the original thickness, spray the second chitosan solution onto the mixed liquid film to form a chitosan liquid film.

[0036] In the related art, the technical means that can be used to achieve drying are all applicable to this specification under allowable conditions.

[0037] The inventors found through experiments that under the component ratio of the mixed film-forming liquid, when the thickness of the mixed liquid film is 20% of the original thickness, obvious segregation of bamboo leaf flavonoids has occurred, and the obtained film will also show a certain degree of brittleness. If the thickness of the mixed liquid film is relatively thick, then the content of the liquid phase component in it is relatively high, which is also not conducive to subsequent further drying. A thickness of 30% to 40% is a relatively reasonable thickness range under the component ratio of the mixed film-forming liquid.

[0038] The method in this specification sprays the second chitosan solution onto the mixed liquid film instead of using a coating process. On the one hand, considering that the mixed liquid film is in a "semi-dry" state, the coating process will damage the still somewhat fluid mixed liquid film at this time, resulting in unevenness. On the other hand, considering that chitosan (β-(1→4)-2-amino-2-deoxy-D-glucose) is a relatively large molecule compared to bamboo leaf flavonoids and is a product obtained by N-deacetylation of chitin and has a linear structure. If this linear macromolecule can show an oriented state, it is beneficial to improve the mechanical properties of the obtained target film. The spraying process will cause small droplets containing chitosan to be extruded from the nozzle, and this process will cause the extension direction of chitosan molecules to extend to a certain extent in the direction of the small droplets being ejected, thereby achieving molecular orientation to a certain extent. Under the condition of adopting a relatively high drying temperature, this orientation can be retained to a certain extent, thereby improving the mechanical properties of the target model.

[0039] The mass fraction range of chitosan in the second chitosan solution is between 2% and 3.6%, the mass fraction range of glycerol is between 1.5% and 2.5%, and the thickness range of the chitosan liquid film is between 2 mm and 4 mm. In the method of this specification, the mass fraction of chitosan in the second chitosan solution is higher than that in the related art where only a film with a single solute component of chitosan is prepared. This is harmful in the process of preparing a film with a single solute component and will cause the film to be brittle and of no use value. However, through a large number of experiments and data analysis, the inventors found that when the mass fraction of glycerol in the second chitosan solution is in the range of 1.5% to 2.5%, through the mutual solubility with glycerol in the mixed liquid film, the chitosan liquid film can not only match the mechanical strength (tensile strength not less than 12 MPa, elongation at break not less than 50%) matching that of a thick film with a thickness of 200 to 300 microns, but also ensure that the obtained target film has good uniformity, achieving good fusion between the mixed liquid film and the chitosan liquid film without delamination. After the chitosan liquid film adheres to the mixed liquid film, due to the relatively high liquid phase content of the chitosan liquid film, the liquid surface tension formed thereby is also large and uniform. This force will be transmitted to the underlying mixed liquid film. Under the action of this force, even if the glycerol content is low, it is difficult for the mixed liquid film to crack; even if the content of bamboo leaf flavonoids is high, it is difficult for segregation to occur, which is conducive to achieving the uniformity of the target film.

[0040] In an alternative embodiment of this specification, when drying the mixed liquid film, the temperature range is between 20°C and 25°C. Since the glycerol content in the mixed liquid film itself is low, its water absorption performance will also be correspondingly weakened, and the expected effect can be achieved even when drying at a relatively low temperature. Moreover, bamboo leaf flavonoids exhibit unstable characteristics at high temperatures, and a lower drying temperature can also avoid inactivation.

[0041] In an alternative implementation of this specification, when it is detected that the thickness of the target film exceeds 250 microns, indicating that the requirement for the target film is a very thick film, then when drying the mixed liquid film, when the thickness of the mixed liquid film reaches between 35% and 40% of the original thickness, the second chitosan solution is sprayed onto the mixed liquid film. Since the glycerol content in the mixed liquid film is small, further drying may cause the mixed liquid film to be too thin. However, the method in this specification can adjust the thickness of the target film by adjusting the thickness of the chitosan liquid film. If the chitosan liquid film is also thick, it will result in a large thickness difference between the upper and lower layers of the film, and in the initial stage of drying the composite liquid film, the liquid phase contents of the two will also differ greatly, which is not conducive to the diffusion of glycerol in the chitosan liquid film into the mixed liquid film. Through experiments and analysis of the experimental data, the inventors determined that spraying should be performed when the thickness of the mixed liquid film is between 35% and 40% of the original thickness to obtain a better fusion effect between the two layers.

[0042] S106: Dry the composite liquid film composed of the chitosan liquid film and the mixed liquid film until the target film is obtained.

[0043] The drying process in this stage is not only a process of removing the liquid-phase components. Through microscopic observation, the inventor found that glycerol penetrated from the chitosan liquid film to the mixed liquid film, increasing the mass exchange between the two layers and achieving binding.

[0044] Since the chitosan liquid film is formed by spraying, there are likely to be bubbles in it. However, with the thickness of the chitosan liquid film in this specification being only between 2 mm and 4 mm, it provides good conditions for exhausting air. Therefore, there is no need to exhaust air separately for the second chitosan solution. In an alternative embodiment, vacuum drying can be used to achieve air exhaust. In this way, even if the spraying method is used, no bubbles will be caused.

[0045] The present application provides a preparation method and application of a bamboo leaf flavonoid-chitosan edible coating film, which combines bamboo leaf flavonoids and chitosan. The obtained bamboo leaf flavonoid-chitosan edible coating film can protect the food ingredients both physically and bacteriostatically. Moreover, the target film obtained by the method in the present application has a larger thickness, overcoming the problem in the related art that a thick film cannot be prepared due to poor toughness. The preparation method and application provided by the present application design the components in the mixed film-forming liquid through technical means combined with experiments, increasing the content of bamboo leaf flavonoids in the target film, so that the target film can play a prominent beneficial effect in the preservation of food ingredients such as meat that are easily contaminated by bacteria. Further, the preparation method and application in this specification realize the protection of the mixed liquid film by the chitosan liquid film during the drying process through the hierarchical design of different film layers, and to a certain extent solve the problems of cracking and unevenness caused by the difficult dispersion of bamboo leaf flavonoids, resulting in a reduction in the yield.

[0046] The target film prepared by the method in this specification has a higher thickness and has a better preservation effect on easily deformed fish and meat food ingredients or food ingredients with a larger volume. This preservation effect is not only reflected in the physical isolation but also in the bacteriostatic aspect.

[0047] Compared with eggs, fruits and vegetables are less likely to have bacteria invade their interior at a faster rate because the process of obtaining these ingredients does not damage their surfaces. However, this is not the case for fish and meat. The process of obtaining these ingredients is bound to be accompanied by damage to their surfaces, and the exposed proteins are easily infected by bacteria, leading to spoilage. However, the spoilage characteristics of fish and meat are also different. Fish has a relatively high content of unsaturated fatty acids, and spoilage often starts from the decomposition of unsaturated fatty acids. Glycerol, due to its polar molecular structure, will to a certain extent affect the dispersibility of bamboo leaf flavonoids, thereby reducing the universality of the antibacterial effect. In an alternative embodiment of this specification, when it is detected that the target film is used for preserving fish, the mass fraction of glycerol in the second chitosan solution ranges from 1.5% to 2.2%. This content of glycerol can reduce the use of glycerol to a certain extent, improve the dispersibility of bamboo leaf flavonoids, and thereby improve the universality of its antibacterial effect. Moreover, the inventor found through analysis of experimental data that reducing the use of glycerol to this extent will not significantly affect the mechanical barrier effect and mechanical strength of the target film, nor is it necessary to adjust other process parameters in the preparation process.

[0048] In another alternative embodiment of this specification, when it is detected that the target film is used for preserving meat, the mass fraction of glycerol in the second chitosan solution ranges from 2% to 2.5%. In some culinary cultures, large pieces of meat are often used as ingredients for cooking. A relatively high content of glycerol can enable the target film to maintain good barrier ability when covering large pieces of ingredients.

[0049] For the two ingredients of fish and meat, a differential design is also carried out in the drying process. When the mass fraction of glycerol in the second chitosan solution ranges from 1.5% to 2.2%, when drying the composite liquid film, the temperature range is between 25°C and 30°C. Under these conditions, the content of glycerol matches the temperature range used during drying. Since the content of glycerol is not very high, the drying temperature is also relatively low. The target film in this specification is relatively thick, and cracking due to component segregation is likely to occur during drying. The lower drying temperature can avoid segregation caused by molecular movement.

[0050] When the mass fraction of glycerol in the second chitosan solution ranges from 2% to 2.5%, when drying the composite liquid film, the temperature range is between 30°C and 40°C. Under these conditions, the content of glycerol matches the temperature range used during drying. Since the glycerol content is relatively high and its water absorption ability is also good, a higher temperature can accelerate the drying speed, and it is also less likely to crack under the action of a higher glycerol content.

[0051] The advantages of bamboo leaf flavonoid-chitosan edible coating for food preservation lie not only in its antibacterial and physical isolation properties, but also in its certain light transmittance, which enables users to observe the condition of the food itself through the bamboo leaf flavonoid-chitosan edible coating. Generally, the thicker the film material, the poorer its light transmittance. In addition, the segregation and crystallization of macromolecules will reduce the light transmittance of the film.

[0052] In an optional embodiment of this specification, the obtained composite liquid film is dried within a preset temperature range. When it is detected that the light transmittance of the composite liquid film is less than a preset light transmittance threshold (indicating a certain degree of segregation and crystallization. In the case where the substrate is a glass substrate, the light transmittance of the composite liquid film can be calculated and detected in combination with the light transmittance of the substrate. The light transmittance threshold is related to the user's requirements for the target film), the preset temperature range is weighted with a drying weight value, and the composite liquid film is continuously dried with the weighted temperature range until the target film is obtained (when the thickness reaches the requirement, the drying stops); the drying weight value is positively correlated with the ratio of a value between 0 and 1 to the thickness of the chitosan liquid film and the mixed liquid film (the thickness used for ratio calculation is the thickness detected when the liquid film is just formed. The thicker the chitosan film, the higher the drying temperature. As a macromolecule, the segregation of chitosan has a more obvious impact on the light transmittance. The thickness of the chitosan liquid film itself is relatively low. Although high-temperature drying will accelerate segregation, this segregation effect will stop relatively quickly with rapid drying); it is positively correlated with the light transmittance when the thickness of the mixed liquid film is between 30% and 40% of the original thickness (the segregation and crystallization of bamboo leaf flavonoids are very harmful to the antibacterial effect. Although the surface tension of the upper layer film inhibits crystallization, the crystallization problem cannot be ignored. The lower the light transmittance at this time, the more it indicates the appearance of bamboo leaf flavonoid crystallization, and the temperature should be reduced as much as possible to avoid further crystallization); and it is negatively correlated with the area of the substrate (the larger the area of the substrate, the more likely it is to appear uneven, and the uneven phenomenon will exacerbate the segregation problem, so the temperature should be reduced as much as possible). Furthermore, this specification also provides an application of the bamboo leaf flavonoid-chitosan edible coating. The bamboo leaf flavonoid-chitosan edible coating prepared by the aforementioned method is coated on the surface of the food, making the side formed by the mixed liquid film in contact with the food to better exert the antibacterial effect.

[0053] This application can execute the method in any of the foregoing embodiments and can obtain the same or similar technical effects, which will not be elaborated here.

[0054] Figure 2 It is a schematic structural diagram of an electronic device in an embodiment of this application. Please refer to Figure 2, at the hardware level, the electronic device includes a processor, and optionally also includes an internal bus, a network interface, and a memory. Among them, the memory may include a memory, such as a high-speed random access memory (RAM), and may also include a non-volatile memory, such as at least one disk memory, etc. Of course, the electronic device may also include other hardware required for other services.

[0055] The processor, network interface, and memory can be interconnected through an internal bus, and the internal bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For the sake of representation, Figure 2 only a bidirectional arrow is used in the figure, but it does not mean that there is only one bus or one type of bus.

[0056] The memory is used to store programs. Specifically, the program may include program code, and the program code includes computer operation instructions. The memory may include a memory and a non-volatile memory, and provide instructions and data to the processor.

[0057] The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it, forming an application of bamboo leaf flavonoid-chitosan edible coating at the logical level. The processor executes the program stored in the memory and is specifically used to execute any one of the aforementioned preparation methods of bamboo leaf flavonoid-chitosan edible coating.

[0058] The above is as described in this application Figure 1The preparation method of a bamboo leaf flavonoid-chitosan edible coating disclosed in the illustrated embodiment can be applied to a processor or implemented by a processor. The processor may be an integrated circuit chip with signal processing capabilities. During implementation, the steps of the above method can be completed by the integrated logic circuit of the hardware in the processor or instructions in the form of software. The above-mentioned processor may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. It can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as being executed and completed by a hardware decoding processor, or executed and completed by a combination of the hardware and software modules in the decoding processor. The software module may be located in a mature storage medium in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. This storage medium is located in the memory, and the processor reads the information in the memory and combines its hardware to complete the steps of the above method.

[0059] The electronic device can also execute Figure 1 the preparation method of a bamboo leaf flavonoid-chitosan edible coating in Figure 1 and implement the functions of the illustrated embodiment. The embodiments of the present application will not be elaborated here.

[0060] The embodiments of the present application also propose a computer-readable storage medium that stores one or more programs. The one or more programs include instructions that, when executed by an electronic device including multiple application programs, execute any of the foregoing preparation methods of a bamboo leaf flavonoid-chitosan edible coating.

[0061] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memory, CD-ROM, optical memory, etc.) that contain computer-usable program code.

[0062] The present application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate an application for implementing the functions specified in Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0063] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including an instruction application that implements the functions specified in Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0064] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0065] In a typical configuration, a computing device includes one or more processors (CPUs), an input / output interface, a network interface, and memory.

[0066] The memory may include non-permanent memory in the computer-readable medium, random access memory (RAM), and / or non-volatile memory in the form of, for example, read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0067] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0068] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0069] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems or computer program products. Therefore, the present application may take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware. Moreover, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0070] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A preparation method of a bamboo leaf flavonoid-chitosan edible coating, characterized in that, The method includes: Under the condition that the detected thickness range of the target film is between 200 microns and 300 microns, prepare a mixed film-forming solution; the mixed film-forming solution is obtained by mixing a first chitosan solution, a bamboo leaf flavonoid solution, and glycerol; in the mixed film-forming solution, the mass fraction range of chitosan is between 0.6% and 0.75%, the mass fraction of bamboo leaf flavonoid is between 0.003% and 0.007%, and the mass fraction range of glycerol is between 0.06% and 0.1%; Place the mixed film-forming solution on a substrate and cast it into shape to obtain a mixed liquid film; the thickness range of the mixed liquid film is between 1 cm and 1.5 cm; Dry the mixed liquid film. When the thickness of the mixed liquid film is between 30% and 40% of the original thickness, spray a second chitosan solution onto the mixed liquid film to form a chitosan liquid film; in the second chitosan solution, the mass fraction range of chitosan is between 2% and 3.6%, the mass fraction range of glycerol is between 1.5% and 2.5%, and the thickness range of the chitosan liquid film is between 2 mm and 4 mm; Dry the composite liquid film composed of the chitosan liquid film and the mixed liquid film until the target film is obtained.

2. The method according to claim 1, wherein The method further includes: When it is detected that the target film is used for preserving fish, the mass fraction range of glycerol in the second chitosan solution is between 1.5% and 2.2%.

3. The method according to claim 1, characterized in that, The method further includes: When it is detected that the target film is used for preserving meat, the mass fraction range of glycerol in the second chitosan solution is between 2% and 2.5%.

4. The method according to claim 1, wherein The method further includes: When it is detected that the thickness of the target film exceeds 250 microns, dry the mixed liquid film. When the thickness of the mixed liquid film is between 35% and 40% of the original thickness, spray the second chitosan solution onto the mixed liquid film.

5. The method according to claim 1, wherein The method further includes: When drying the mixed liquid film, the temperature range is between 20°C and 25°C.

6. The method according to claim 2, wherein The method further includes: When drying the composite liquid film, the temperature range is between 25°C and 30°C.

7. The method according to claim 3, characterized in that The method further includes: When drying the composite liquid film, the temperature range is between 30°C and 40°C.

8. The method according to claim 1, wherein The method further includes: When drying the composite liquid film, vacuum drying is adopted.

9. The method according to claim 4, wherein The method further includes: Dry the obtained composite liquid film within a preset temperature range. When it is detected that the light transmittance of the composite liquid film is less than a preset light transmittance threshold, weight the preset temperature range with a drying weight value, and continue to dry the composite liquid film with the weighted temperature range until the target film is obtained; The drying weight value is a numerical value ranging from 0 to 1, which is positively correlated with the ratio of the thickness of the chitosan liquid film to the mixed liquid film; positively correlated with the light transmittance when the thickness of the mixed liquid film is between 30% and 40% of the original thickness during drying of the mixed liquid film; and negatively correlated with the area of the substrate.

10. Application of a bamboo leaf flavonoid-chitosan edible coating, characterized in that, The bamboo leaf flavonoid-chitosan edible coating prepared by the method described in claim 1 is coated on the surface of the food, such that one side formed by the mixed liquid film contacts the food.

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