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

Abstract

The present application discloses a preparation method and application of a bamboo leaf flavonoids-chitosan edible coating film. The thickness of the target film obtained by the method in the present application is relatively large, which overcomes the problem of being unable to be prepared due to poor toughness of the thick film in the related art. The preparation method and application provided by the present application, by combining experiments with technical means, design the components in the mixed film-forming liquid, improve the content of bamboo leaf flavonoids in the target film, so that the target film can play an outstanding beneficial effect in terms of preserving the food materials that are easily contaminated by bacteria such as meat food. Further, the preparation method and application in this specification realize the protection of the chitosan liquid film to the mixed liquid film during the drying process by the hierarchical design of different film layers, and solve the problem of cracking and uneven yield reduction caused by the difficult dispersion of bamboo leaf flavonoids to a certain extent.

Description

Technical Field

[0001] The present application relates to the technical field of preparation of compositions based on organic polymer compounds, and in particular to a preparation method and application of an edible bamboo leaf flavonoid-chitosan coating. Background Art

[0002] Food storage and preservation are essential in daily life. While traditional freezing methods offer low cost and ease of use, their potential damage to the ingredients themselves cannot be ignored. Freezing dehydrates ingredients, affecting their texture and flavor. This impact is particularly significant for precious ingredients like bluefin tuna and Black Angus steak. While chitosan films have been used in food preservation, they primarily protect ingredients by physically isolating them from external bacteria and are difficult to inhibit naturally occurring bacteria. Furthermore, meat ingredients are often soft and prone to stretching and deformation during transportation and packaging. Chitosan films of conventional thickness (between 20 and 50 microns) are easily damaged, making them ineffective in providing effective protection.

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

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

[0005] The embodiments of this application adopt the following technical solutions:

[0006] In a first aspect, the present invention provides a method for preparing an edible bamboo leaf flavonoid-chitosan coating, the method comprising:

[0007] Under the condition that the thickness of the target film is detected to be between 200 microns and 300 microns, a mixed film-forming liquid is prepared; the mixed film-forming liquid is obtained by mixing a first chitosan solution, a bamboo leaf flavonoid solution, and glycerol; in the mixed film-forming liquid, the mass fraction 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 of glycerol is between 0.06% and 0.1%;

[0008] Placing the mixed film-forming liquid on a substrate and performing tape casting to obtain a mixed liquid film; the thickness of the mixed liquid film ranges from 1 cm to 1.5 cm;

[0009] The mixed liquid film is dried, and when the thickness of the mixed liquid film is between 30% and 40% of the original thickness, a second chitosan solution is sprayed onto the mixed liquid film to form a chitosan liquid film; the chitosan mass fraction in the second chitosan solution is between 2% and 3.6%, the mass fraction of glycerol is between 1.5% and 2.5%, and the thickness of the chitosan liquid film is between 2 mm and 4 mm;

[0010] The composite liquid membrane composed of the chitosan liquid membrane and the mixed liquid membrane is dried until the target membrane is obtained.

[0011] In an optional embodiment of this specification, the method further includes:

[0012] When it is detected that the target membrane is used for preserving fish, the mass fraction of glycerol in the second chitosan solution is in a range of 1.5% to 2.2%.

[0013] In an optional embodiment of this specification, the method further includes:

[0014] When it is detected that the target film is used for preserving fresh meat, the mass fraction of glycerol in the second chitosan solution is in a range of 2% to 2.5%.

[0015] In an optional embodiment of this specification, the method further includes:

[0016] When it is detected that the thickness of the target film exceeds 250 microns, the mixed liquid film is dried until the thickness of the mixed liquid film is between 35% and 40% of the original thickness, and then the second chitosan solution is sprayed onto the mixed liquid film.

[0017] In an optional embodiment of this specification, the method further includes:

[0018] When the mixed liquid film is dried, the temperature range is between 20°C and 25°C.

[0019] In an optional embodiment of this specification, the method further includes:

[0020] When the composite liquid film is dried, the temperature range is between 25°C and 30°C.

[0021] In an optional embodiment of this specification, the method further includes:

[0022] When the composite liquid film is dried, the temperature range is between 30°C and 40°C.

[0023] In an optional embodiment of this specification, the method further includes:

[0024] When the composite liquid membrane is dried, vacuum drying is adopted.

[0025] In an optional embodiment of this specification, the method further includes:

[0026] Drying the obtained composite liquid film within a preset temperature range, and when it is detected that the transmittance of the composite liquid film is less than a preset transmittance threshold, weighting the preset temperature range using a drying weight value, and continuing to dry the composite liquid film within the weighted temperature range until the target film is obtained;

[0027] The drying weight value is a numerical value between 0 and 1, which is positively correlated with the ratio of the thickness of the chitosan liquid film to the thickness of the mixed liquid film; is positively correlated with the transmittance when the thickness of the mixed liquid film is between 30% and 40% of the original thickness when the mixed liquid film is dried; and is negatively correlated with the area of ​​the substrate.

[0028] In a second aspect, an embodiment of the present application also provides an application of an edible bamboo leaf flavonoid-chitosan coating film, wherein the edible bamboo leaf flavonoid-chitosan coating film prepared by the method described in the first aspect is coated on the surface of food so that the side formed by the mixed liquid film is in contact with the food.

[0029] In a third aspect, an embodiment of the present application further provides an electronic device, including:

[0030] processor; and

[0031] A memory arranged to store computer executable instructions which, when executed, cause the processor to perform the method steps of the first aspect.

[0032] In a fourth aspect, an embodiment of the present application further provides a computer-readable storage medium, which stores one or more programs. When the one or more programs are executed by an electronic device including multiple applications, the electronic device executes the method steps described in the first aspect.

[0033] At least one of the above technical solutions adopted in the embodiments of the present application can achieve the following beneficial effects:

[0034] The present application provides a preparation method and application of a bamboo leaf flavonoid-chitosan edible coating, which combines bamboo leaf flavonoids and chitosan, and the obtained bamboo leaf flavonoid-chitosan edible coating can protect food both physically and in terms of antibacterial properties. Moreover, the target film obtained by the method in the present application is relatively thick, which overcomes the problem of being unable to be prepared in the related art due to poor toughness of the thick film. The preparation method and application provided by the present application, through technical means combined with experiments, designs the components in the mixed film-forming liquid, increases the content of bamboo leaf flavonoids in the target film, and enables the target film to play an outstanding beneficial effect in preserving meat food, which is easily contaminated by bacteria. Furthermore, 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 solves the problem of cracking and uneven yield reduction caused by the difficult dispersion of bamboo leaf flavonoids. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings described herein are used to provide a further understanding of the present application and constitute 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 on the present application. In the drawings:

[0036] Figure 1 A schematic diagram of a process for preparing a bamboo leaf flavonoid-chitosan edible coating provided in an embodiment of this specification;

[0037] Figure 2 This is a schematic diagram of the structure of an electronic device in an embodiment of this specification. DETAILED DESCRIPTION

[0038] The present invention will be further described in detail below with reference to the accompanying drawings by way of specific embodiments. Similar elements in different embodiments are numbered with associated similar elements. In the following embodiments, many detailed descriptions are provided to enable the present application to be better understood. However, those skilled in the art will readily appreciate that some of the features may be omitted under different circumstances, or may 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. This is to avoid overwhelm the core of the present application with excessive descriptions, and for those skilled in the art, it is not necessary to describe these related operations in detail. They will fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0039] In addition, the features, operations, or characteristics described in the specification may be combined in any appropriate manner to form various embodiments. Furthermore, the steps or actions in the method description may be reordered or adjusted in a manner readily apparent to those skilled in the art. Therefore, the various sequences in the specification and drawings are provided solely for the purpose of clearly describing a particular embodiment and are not intended to be mandatory, unless otherwise specified.

[0040] The serial numbers assigned to components herein, such as "first," "second," etc., are used solely to distinguish the objects being described and do not convey any sequential or technical meaning. References to "connection" and "coupling" herein, unless otherwise specified, include both direct and indirect connections (couplings).

[0041] The following describes in detail the technical solutions provided by various embodiments of the present application in conjunction with the accompanying drawings.

[0042] like Figure 1 As shown, the preparation method of the bamboo leaf flavonoids-chitosan edible coating in this specification comprises the following steps:

[0043] S100: preparing a mixed film-forming solution under the condition that the thickness of the target film is detected to be between 200 μm and 300 μm.

[0044] The target film in this specification is the bamboo leaf flavonoids-chitosan edible coating film to be produced. In the related art, the thickness of the edible coating films used for food preservation is mostly in the range of 20 microns to 50 microns. Films of this thickness are suitable for preserving eggs and apples, but when used to preserve meat ingredients that are easily deformed, the edible coating film will crack due to deformation and stretching, and the barrier performance is also poor. If a thicker edible coating film is directly prepared, uneven shrinkage or even cracking will occur during the preparation process. The target film produced by the method described in this specification can achieve a higher thickness and can preserve food.

[0045] The mixed membrane-forming liquid described in this specification is obtained by mixing a first chitosan solution, a bamboo leaf flavonoid solution, and glycerol. The method described in this specification places restrictions on the composition of the mixed membrane-forming liquid. As for how to achieve this ratio, all technical means available in the relevant art for achieving this ratio are applicable to this specification, where conditions permit.

[0046] For example, chitosan can be dissolved in 1 wt% glacial acetic acid, magnetically stirred, and filtered to obtain a first chitosan solution. The solvent for the bamboo leaf flavonoid solution can be ethanol, which is then magnetically stirred to obtain a bamboo leaf flavonoid solution. The volume ratio of the two solutions is then adjusted to obtain a mixed solution. After the mixed solution is magnetically stirred for a certain period of time, glycerol is added and stirred continuously to obtain a mixed film-forming solution. The mixed film-forming solution is required to be fully mixed with the three solutes without precipitation.

[0047] In the mixed membrane-forming liquid of the present specification, the mass fraction of chitosan is in the range of 0.6% to 0.75%, the mass fraction of bamboo leaf flavonoids is in the range of 0.003% to 0.007%, and the mass fraction of glycerol is in the range of 0.06% to 0.1%.

[0048] The chitosan content in the mixed film-forming solution is significantly low, at least half the typical value. Compared to bamboo leaf flavonoids, chitosan is a highly polar molecule with a larger molecular weight, making them chemically incompatible. This leads to a high degree of segregation in the mixed solution, which negatively impacts the preparation of the target film. In particular, if bamboo leaf flavonoids segregate, the target film exhibits significantly weaker antibacterial properties, virtually eliminating its preservation properties for perishable protein ingredients like meat. As ethanol evaporates, significant segregation occurs during the drying process. Segregation not only weakens the antibacterial properties but also reduces the transmittance of the target film and produces uneven imaging, impacting its performance. Reducing the amount of chitosan can mitigate the instability of the molecular distribution in the mixed solution film caused by its strong molecular polarity, thereby reducing segregation. However, this composition ratio is problematic in conventional chitosan film preparation. The reduced chitosan content reduces the mechanical strength of the target film, making it difficult to remove from the substrate even after drying, resulting in substandard product.

[0049] The content of bamboo leaf flavonoids in the mixed film-forming liquid of this specification is significantly increased, about twice that of the related art. On the one hand, it can improve the antibacterial effect on food materials, and on the other hand, it can also improve the polarity uniformity of the mixed film-forming liquid, reduce segregation, and avoid the occurrence of unevenness. Increasing the content of bamboo leaf flavonoids is not harmless. Since bamboo leaf flavonoids are more prone to segregation, increasing its content is usually accompanied by the problem of unevenness in the prepared film.

[0050] However, even so, since the goal is to produce a thicker film, the thickness of the mixed liquid film will also be thicker. If the drying method in the conventional preparation means is adopted, it will lead to a long drying time and the segregation problem will still exist. Therefore, in the process of designing the distribution ratio, the inventors conducted a large number of experiments and analyzed the data to determine the mass fraction of glycerol in the mixed film-forming liquid to be between 0.06% and 0.1%, so as to improve the drying efficiency by reducing the use of glycerol. Moreover, this glycerol content can also make the mixed liquid film in a "semi-dry" state (thickness reduced to 30% to 40%) without cracking and other phenomena. However, the film in the "semi-dry" state is obviously not able to be used directly. Even due to the small amount of glycerol used, it cannot be completely removed from the substrate even if it is further dried. It is necessary to combine the subsequent steps to complete the preparation of the target film.

[0051] In addition, the inventors found through experimental data that under the ratio of chitosan and bamboo leaf flavonoids in the mixed film-forming liquid, if the mass fraction of glycerol reaches 0.2%, the drying time will be significantly increased, resulting in the segregation of bamboo leaf flavonoids.

[0052] S102: placing the mixed film-forming liquid on a substrate and performing tape casting to obtain a mixed liquid film.

[0053] Any material that can be used as a substrate in the related art, where conditions permit, is applicable to this specification. For example, the substrate can be made of glass. Any process that can achieve tape casting in the related art, where conditions permit, is applicable to this specification.

[0054] The thickness of the mixed liquid film described in this specification ranges from 1 cm to 1.5 cm. Because the glycerol content in the mixed liquid film is low, even a thicker mixed liquid film does not significantly increase the drying time. Furthermore, at this glycerol content, even a thicker mixed liquid film will not produce a film material of 200 to 300 microns after drying, but rather a thinner one, and its mechanical properties will not meet the required performance.

[0055] S104: Drying the mixed liquid film, and when the thickness of the mixed liquid film is between 30% and 40% of the original thickness, spraying a second chitosan solution onto the mixed liquid film to form a chitosan liquid film.

[0056] In the related art, technical means that can be used to achieve drying are applicable to this specification when conditions permit.

[0057] The inventors discovered through experiments that, under the composition ratio of the mixed film-forming liquid, when the thickness of the mixed liquid film was 20% of the original thickness, significant bamboo leaf flavonoid segregation occurred, and the resulting film also exhibited a certain degree of brittleness. If the mixed liquid film is thicker, the liquid phase content is high, which is not conducive to subsequent drying. A thickness of 30% to 40% is a more reasonable range for the composition ratio of the mixed film-forming liquid.

[0058] The method described herein sprays the second chitosan solution onto the mixed liquid film, rather than using a coating process. On the one hand, given that the mixed liquid film is in a "semi-dry" state, the coating process would disrupt the still somewhat fluid mixed liquid film, resulting in unevenness. On the other hand, chitosan (β-(1→4)-2-amino-2-deoxy-D-glucose) is a larger molecule than bamboo leaf flavonoids, resulting from the N-deacetylation of chitin and possessing a linear structure. Orienting these linear macromolecules would be beneficial for improving the mechanical properties of the resulting target film. The spraying process causes small droplets containing chitosan to be extruded from the nozzle. This process causes the chitosan molecules to extend somewhat toward the direction of the droplet's ejection, thereby achieving a certain degree of molecular orientation. At higher drying temperatures, this orientation can be retained to a certain extent, thereby improving the mechanical properties of the target model.

[0059] The chitosan mass fraction in the second chitosan solution is in the range of 2% to 3.6%, the mass fraction of glycerol is in the range of 1.5% to 2.5%, and the thickness of the chitosan liquid film is in the range of 2 mm to 4 mm. In the method of the present specification, the chitosan mass fraction in the second chitosan solution is higher than that in the related art method of preparing a film with only a single solute component of chitosan, which is harmful in the process of preparing a film with a single solute component, causing the film to be brittle and not having practical value. However, the inventors found through a large number of experiments and data analysis that when the mass fraction of glycerol in the second chitosan solution is in the range of 1.5% to 2.5%, the chitosan liquid film can not only achieve the mechanical strength (tensile strength not less than 12 MPa, elongation at break not less than 50%) that matches a thick film of 200 to 300 microns by mutual solubility with the glycerol in the mixed liquid film, but also ensure that the target film has good uniformity, and achieves good fusion between the mixed liquid film and the chitosan liquid film without delamination. After the chitosan liquid film is attached to the mixed liquid film, due to the high liquid phase content of the chitosan liquid film and the large and uniform surface tension of the liquid phase formed, this force will be transmitted from the lower mixed liquid film. Under the action of this force, the mixed liquid film is difficult to crack even if the glycerol content is low; even if the bamboo leaf flavonoids content is high, segregation is difficult to occur, which is conducive to achieving the uniformity of the target film.

[0060] In an optional embodiment of this specification, the temperature range for drying the mixed liquid film is between 20°C and 25°C. Because the mixed liquid film itself has a low glycerol content, its water absorption capacity is correspondingly weakened, and even drying at a lower temperature can achieve the desired effect. Furthermore, bamboo leaf flavonoids are unstable at high temperatures, so a lower drying temperature can also prevent inactivation.

[0061] In an optional embodiment of the present invention, if the target film thickness is detected to be greater than 250 microns, indicating that a very thick target film is required, the second chitosan solution is sprayed onto the mixed liquid film when the mixed liquid film is dried until the thickness is between 35% and 40% of the original thickness. Since the mixed liquid film contains a low amount of glycerol, further drying may cause the mixed liquid film to be too thin. The method of the present invention 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, the thickness difference between the upper and lower layers will be large. In the initial stage of drying the composite liquid film, the liquid phase content of the two layers will also be large, which is not conducive to the diffusion of glycerol in the chitosan liquid film into the mixed liquid film. After experiments and analysis of experimental data, the inventors determined that spraying when the thickness of the mixed liquid film is between 35% and 40% of the original thickness can achieve a better fusion effect between the two layers.

[0062] S106: Drying the composite liquid membrane composed of the chitosan liquid membrane and the mixed liquid membrane until the target membrane is obtained.

[0063] The drying process at this stage is not just a process of removing liquid phase components. The inventors found through microscopic observation that glycerol penetrated from the chitosan liquid membrane into the mixed liquid membrane, increasing the material exchange between the two layers and achieving bonding.

[0064] Since the chitosan liquid film is formed by spraying, bubbles are likely to form therein. However, the chitosan liquid film thickness in this specification is only between 2 mm and 4 mm, which provides good conditions for degassing. Therefore, there is no need to degas the second chitosan solution separately. In an optional embodiment, degassing can be achieved by vacuum drying. In this way, even if spraying is used, bubbles will not be generated.

[0065] The present application provides a preparation method and application of a bamboo leaf flavonoid-chitosan edible coating, which combines bamboo leaf flavonoids and chitosan, and the obtained bamboo leaf flavonoid-chitosan edible coating can protect food both physically and in terms of antibacterial properties. Moreover, the target film obtained by the method in the present application is relatively thick, which overcomes the problem of being unable to be prepared in the related art due to poor toughness of the thick film. The preparation method and application provided by the present application, through technical means combined with experiments, designs the components in the mixed film-forming liquid, increases the content of bamboo leaf flavonoids in the target film, and enables the target film to play an outstanding beneficial effect in preserving meat food, which is easily contaminated by bacteria. Furthermore, 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 solves the problem of cracking and uneven yield reduction caused by the difficult dispersion of bamboo leaf flavonoids.

[0066] The target film produced by the method described in this specification has a higher thickness and has a better preservation effect on fish and meat ingredients that are easily deformed, or large ingredients. This preservation effect is not only reflected in the physical isolation, but also in the antibacterial effect.

[0067] Compared to eggs, fruits, and vegetables, since the process of obtaining the ingredients does not damage the surface of the ingredients, the possibility of bacteria invading their interior at a faster rate is smaller. However, this is not the case with fish and meat. The process of obtaining the ingredients is inevitably accompanied by damage to the surface of the ingredients, and the exposed protein is easily infected by bacteria, thus becoming spoiled. However, the spoilage characteristics of fish and meat are also different. Fish has a high content of unsaturated fatty acids, and corruption often starts from the decomposition of unsaturated fatty acids. Due to its polar molecular structure, glycerol will affect the dispersibility of bamboo leaf flavonoids to a certain extent, thereby reducing the universality of the antibacterial effect. In an optional embodiment of the present specification, when it is detected that the target membrane is used to preserve fish, the mass fraction of glycerol in the second chitosan solution ranges from 1.5% to 2.2%. This glycerol content can reduce the use of glycerol to a certain extent, improve the dispersibility of bamboo leaf flavonoids, and thus improve its universality of bacterial inhibition. Moreover, through analysis of experimental data, the inventors found that this degree of reduction in glycerol use will not have a significant impact on the mechanical barrier effect and mechanical strength of the target film, and there is no need to adjust other process parameters in the preparation process.

[0068] In another optional embodiment of the present specification, when the target membrane is detected for use in 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 cooking ingredients. The relatively high glycerol content enables the target membrane to maintain good barrier properties even when encapsulating large pieces of food.

[0069] Different designs are also made in the drying process for the two ingredients, fish and meat. When the mass fraction of glycerol in the second chitosan solution is between 1.5% and 2.2%, the temperature range is between 25°C and 30°C when the composite liquid film is dried. Under this condition, the glycerol content matches the temperature range used during drying. Since the glycerol content is not very high, the drying temperature is relatively low. The target film in this specification is thicker, and cracking due to component segregation is very likely to occur during drying. A lower drying temperature can avoid segregation caused by molecular movement.

[0070] When the mass fraction of glycerol in the second chitosan solution is between 2% and 2.5%, the composite liquid film is dried at a temperature between 30°C and 40°C. Under these conditions, the glycerol content and the drying temperature range are well matched. Because a high glycerol content improves water absorption, higher temperatures can accelerate drying. Furthermore, a high glycerol content also reduces cracking.

[0071] 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 light transmittance, which allows users to observe the food through the coating. Generally, the thicker the film material, the lower its light transmittance. In addition, the segregation of macromolecules and crystallization of liquid will reduce the film's light transmittance.

[0072] In an optional embodiment of the present specification, the obtained composite liquid film is dried within a preset temperature range, and when it is detected that the transmittance of the composite liquid film is less than a preset transmittance threshold value (indicating that a certain degree of segregation and crystallization has occurred. In the case where the substrate is a glass substrate, the transmittance of the substrate can be combined for calculation and detection to obtain the transmittance of the composite liquid film. The transmittance threshold value is related to the user's requirements for the use of the target film), the preset temperature range is weighted using a drying weight value, and the composite liquid film is continued to be dried within the weighted temperature range until the target film is obtained (the thickness reaches the requirement, that is, the drying is stopped); the drying weight value is a value between 0 and 1 and is positively correlated with the ratio of the thickness of the chitosan liquid film and the mixed liquid film (the thickness used for the ratio calculation is the thickness detected when the liquid film is just formed). to a certain thickness. The thicker the chitosan film, the higher the drying temperature. As a macromolecule, the segregation of chitosan has a more obvious effect on transmittance. The thickness of the chitosan liquid film itself is relatively low. Although high-temperature drying will accelerate segregation, this segregation effect will stop quickly with rapid drying); it is positively correlated with the transmittance when the thickness of the mixed liquid film is between 30% and 40% of the original thickness when the mixed liquid film is dried (the segregation and crystallization of bamboo leaf flavonoids are very harmful to the antibacterial effect. Although the surface tension of the upper film inhibits crystallization, the crystallization problem cannot be ignored. The lower the transmittance at this time, the more it indicates that bamboo leaf flavonoids crystallize, 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 be uneven, and the unevenness will aggravate the segregation problem, so the temperature should be reduced as much as possible)

[0073] Furthermore, this specification also provides an application of an edible bamboo leaf flavonoids-chitosan coating. The edible bamboo leaf flavonoids-chitosan coating prepared by the aforementioned method is coated on the surface of food so that the side formed by the mixed liquid film is in contact with the food to better exert the antibacterial effect.

[0074] This application can execute the method in any of the aforementioned embodiments and can achieve the same or similar technical effects, which will not be described in detail here.

[0075] Figure 2 This is a schematic diagram of the structure of an electronic device according to an embodiment of the present application. Figure 2At the hardware level, the electronic device includes a processor and, optionally, an internal bus, a network interface, and memory. The memory may include internal memory, such as high-speed random-access memory (RAM), or non-volatile memory, such as at least one disk drive. Of course, the electronic device may also include other hardware required for its services.

[0076] The processor, network interface, and memory can be interconnected via an internal bus, which can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus. The bus can be divided into an address bus, a data bus, a control bus, and the like. For ease of representation, Figure 2 Only one bidirectional arrow is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0077] The memory is used to store programs. Specifically, the program may include program code, which includes computer operating instructions. The memory may include internal memory and non-volatile memory, and provides instructions and data to the processor.

[0078] The processor reads the corresponding computer program from the non-volatile memory into the internal memory and then runs it, logically forming an application for an edible bamboo leaf flavonoid-chitosan coating. The processor executes the program stored in the memory and is specifically configured to perform any of the aforementioned methods for preparing an edible bamboo leaf flavonoid-chitosan coating.

[0079] The above application Figure 1The method for preparing an edible bamboo leaf flavonoid-chitosan coating disclosed in the illustrated embodiment can be applied to or implemented by a processor. The processor may be an integrated circuit chip with signal processing capabilities. During implementation, the steps of the method described above can be performed by hardware integrated logic circuits within the processor or by software instructions. The processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can 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, or discrete hardware components. The methods, steps, and logic block diagrams disclosed in the embodiments of this application can be implemented or executed. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in the embodiments of this application can be directly executed by a hardware decoding processor or by a combination of hardware and software modules within the decoding processor. The software module can be located in a storage medium well-known in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, etc. The storage medium is located in the memory, and the processor reads the information in the memory and, in conjunction with its hardware, completes the steps of the above method.

[0080] The electronic device may also perform Figure 1 A preparation method of bamboo leaf flavonoids-chitosan edible coating, and realizes Figure 1 The functions of the illustrated embodiment will not be described in detail in the embodiments of the present application.

[0081] An embodiment of the present application also proposes a computer-readable storage medium, which stores one or more programs, and the one or more programs include instructions. When the instructions are executed by an electronic device including multiple application programs, any one of the aforementioned methods for preparing the bamboo leaf flavonoids-chitosan edible coating is executed.

[0082] 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 an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, 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 magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0083] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes 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 a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 The application of the functions specified in the box or boxes.

[0084] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture including the application of the instructions, which is implemented in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0085] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The steps for the function specified in one or more boxes.

[0086] In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0087] Memory may include non-permanent storage in a computer-readable medium, in the form of random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of a computer-readable medium.

[0088] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can be implemented using 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 RAM (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 technologies, compact disc read-only memory (CD-ROM), digital versatile disc (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 transitory computer-readable media such as modulated data signals and carrier waves.

[0089] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0090] 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 an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, 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 magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0091] The foregoing is merely 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 modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. A method for preparing an edible bamboo leaf flavonoid-chitosan coating, characterized in that: The method comprises: Under the condition that the thickness of the target film is detected to be between 200 microns and 300 microns, a mixed film-forming liquid is prepared; the mixed film-forming liquid is obtained by mixing a first chitosan solution, a bamboo leaf flavonoid solution, and glycerol; in the mixed film-forming liquid, the mass fraction 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 of glycerol is between 0.06% and 0.1%; Placing the mixed film-forming liquid on a substrate and performing tape casting to obtain a mixed liquid film; the thickness of the mixed liquid film ranges from 1 cm to 1.5 cm; The mixed liquid film is dried, and when the thickness of the mixed liquid film is between 30% and 40% of the original thickness, a second chitosan solution is sprayed onto the mixed liquid film to form a chitosan liquid film; the chitosan mass fraction of the second chitosan solution is between 2% and 3.6%, the mass fraction of glycerol is between 1.5% and 2.5%, and the thickness of the chitosan liquid film is between 2 mm and 4 mm; the temperature range during the drying of the mixed liquid film is between 20° C. and 25° C.; The composite liquid membrane composed of the chitosan liquid membrane and the mixed liquid membrane is dried until the target membrane is obtained.

2. The method according to claim 1, wherein: The method further comprises: 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%; when the composite liquid film is dried, the temperature ranges from 25° C. to 30° C.

3. The method according to claim 1, wherein: The method further comprises: When it is detected that the target film is used for preserving meat, the mass fraction of glycerol in the second chitosan solution is between 2% and 2.5%; when the composite liquid film is dried, the temperature range is between 30° C. and 40° C.

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

5. The method according to claim 1, wherein: The method further comprises: When the composite liquid membrane is dried, vacuum drying is adopted.

6. The method according to claim 4, wherein: The method further comprises: Drying the obtained composite liquid film within a preset temperature range, and when it is detected that the transmittance of the composite liquid film is less than a preset transmittance threshold, weighting the preset temperature range using a drying weight value, and continuing to dry the composite liquid film within the weighted temperature range until the target film is obtained; The drying weight value is a numerical value between 0 and 1, which is positively correlated with the ratio of the thickness of the chitosan liquid film to the thickness of the mixed liquid film; is positively correlated with the transmittance when the thickness of the mixed liquid film is between 30% and 40% of the original thickness when the mixed liquid film is dried; and is negatively correlated with the area of ​​the substrate.

7. An application of an edible bamboo leaf flavonoid-chitosan coating, characterized in that: The bamboo leaf flavonoids-chitosan edible coating film prepared by the method according to claim 1 is coated on the surface of food so that the side formed by the mixed liquid film is in contact with the food.

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