A processing system and method for daylily snack food

Abstract

This application relates to the field of food processing technology, and in particular to a processing method and system for daylily snack food. The method includes raw material grading, graded blanching and color protection, gradient dehydration, moisture balancing, directional shaping, vacuum impregnation and seasoning, and low-temperature vacuum drying steps, along with corresponding automated equipment. By dynamically matching process parameters with raw material quality characteristic vectors, combined with feedback control of moisture migration rate during dehydration, the method effectively maintains stable texture and color. Directional shaping imparts a standardized geometric shape to the product, improving its adaptability for packaging and transportation. Vacuum impregnation and low-temperature final drying ensure uniform flavor and safe water activity. This application effectively solves problems such as deterioration of texture, nutritional fluctuations, monotonous form, and unstable quality in traditional daylily processing.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, and more specifically, to a processing system and method for daylily snack food. Background Technology

[0002] Daylily, a common edible vegetable, is rich in dietary fiber, protein, various amino acids and minerals. In traditional diets, it is often consumed fresh, dried or simply cooked.

[0003] Currently, existing daylily processing methods mainly focus on sun-drying, oven-drying, or simple dehydration for preservation, aiming to meet long-term storage and consumption needs. However, these methods generally suffer from limited processing capabilities and low added value. Particularly during dehydration and rehydration, the daylily's tissue structure is prone to collapse or fibrosis, resulting in a rough texture and significant flavor loss, failing to meet modern consumers' demands for ready-to-eat and diverse flavor profiles in snack foods. Furthermore, existing technologies lack systematic control over key processing steps such as blanching, color protection, and seasoning, often relying on independent single-step processes. This easily leads to browning, nutrient loss, and flavor instability, making it difficult to guarantee product quality consistency and sensory experience. Simultaneously, traditional daylily products are mostly in loose or simple strip form, lacking the shaping design required for snack foods, resulting in poor product shape stability and hindering packaging, transportation, and long-term shelf life preservation.

[0004] Therefore, how to construct a stable structure and taste system suitable for snack foods by synergistically optimizing multiple processing techniques while preserving the original nutritional components and natural flavor of daylilies, and thus transform daylilies from a traditional ingredient into high-value-added ready-to-eat snack foods, has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] In view of this, the present invention proposes a processing system and method for daylily snack foods, aiming to solve the problem that the current processing technology of daylilies mainly focuses on simple dehydration and preservation, lacks systematic control over the moisture and tissue structure during the dehydration process, as well as key processes such as blanching, color protection and shaping, which leads to the product being prone to structural collapse or fibrosis, unstable taste and flavor quality, and difficulty in forming a stable form and high value-added product suitable for ready-to-eat snack foods.

[0006] This invention proposes a processing method for daylily snack food, comprising: After harvesting, the daylily raw materials are graded and screened according to the length, diameter and maturity of the flower buds, and raw materials of the same grade are sent to the corresponding pre-processing unit. In the preset processing unit, different combinations of heat medium temperature and action time are determined according to the tissue density of daylilies of different grades. Daylilies of different grades are blanched and then immersed in a composite color-protecting liquid containing metal chelating agents and antioxidants for protection treatment. The heat medium includes one or more of steam, hot water or microwave. After protection treatment, the daylilies were dehydrated in sequence through the first dehydration zone, the second dehydration zone, and the third dehydration zone. The environmental humidity, temperature, and airflow speed in the first dehydration zone, the second dehydration zone, and the third dehydration zone decreased in a stepwise manner. Real-time monitoring of the surface moisture evaporation rate and internal moisture diffusion coefficient of daylily; when the ratio of the two deviates from the preset equilibrium range, the temperature and humidity gradient between adjacent dehydration zones is dynamically adjusted. After dehydration, the daylily is transferred to the moisture balance regulating chamber, where the moisture inside and outside the material is redistributed under a constant relative humidity environment. The daylily after the moisture balance regulation in the moisture balance regulating chamber is sent to the orientation molding device, where the daylily is lightly pressed and shaped based on the replaceable mold group in the orientation molding device. The semi-finished product after shaping is vacuum impregnated and seasoned, and then the semi-finished product after vacuum impregnation and seasoning is dried at low temperature to complete the preparation.

[0007] Furthermore, based on the tissue density of different grades of daylilies, different combinations of heat medium temperature and treatment time were determined, including: collecting the initial chlorophyll content, reducing sugar concentration, and cell wall pectin methyl esterase activity of each batch of daylilies to construct a raw material quality characteristic vector. Based on the raw material quality characteristic vector, determine whether to add microwave treatment and compound color-protecting solution formulation to the blanching operation.

[0008] Furthermore, based on the raw material quality characteristic vector, when determining whether to add microwave treatment and compound color-protecting solution formulation during the blanching process, the following should be considered: Based on the chlorophyll content and pectin methyl esterase activity in the raw material quality characteristic vector; Obtain the mean value of chlorophyll content in each historical batch, and determine the mean value of chlorophyll content as the chlorophyll baseline value; The mean value of each pectin methyl esterase activity in each historical batch was obtained, and the mean value of each pectin methyl esterase activity was determined as the benchmark value of pectin methyl esterase activity. Based on the relationship between chlorophyll content and chlorophyll baseline value in the raw material quality characteristic vector, the compound color-protecting liquid formula is determined. When the chlorophyll content is lower than the chlorophyll baseline value, it is determined that ascorbic acid at a preset concentration level will be added to the compound color-protecting liquid. Based on the relationship between pectin methyl esterase activity and the benchmark value of pectin methyl esterase activity in the raw material quality characteristic vector, it is determined whether to add microwave treatment. Specifically, when the pectin methyl esterase activity is higher than the benchmark value of pectin methyl esterase activity, it is determined that microwave-assisted treatment should be added when blanching daylilies of different grades.

[0009] Furthermore, when the protected daylily is dehydrated sequentially through the first dehydration zone, the second dehydration zone, and the third dehydration zone, the process includes: The ambient humidity in the first dehydration zone is maintained at 85%–90% RH, and the wind speed is 0.3–0.5 m / s; The humidity in the second dehydration zone is 60%–70%RH, and the wind speed is 1.0–1.5 m / s; The humidity in the third dehydration zone is 30%–40% RH, the wind speed is 0.8–1.0 m / s, and the temperature is maintained at 35–40℃.

[0010] Furthermore, the surface moisture evaporation rate and internal moisture diffusion coefficient of daylilies are monitored in real time. When the ratio of the two deviates from the preset equilibrium range, the temperature and humidity gradient between adjacent dehydration zones is dynamically adjusted, including: The ratio of surface moisture evaporation rate to internal moisture diffusion coefficient is obtained in real time. And based on the ratio, adjust the temperature and humidity gradient between adjacent dehydration zones, where: When the ratio is greater than 1.8, the temperature difference between the first dehydration zone and the second dehydration zone is reduced by 3℃, and the wind speed in the second dehydration zone is reduced by 0.2 m / s. When the ratio is less than 1.2, the relative humidity of the second dehydration zone is increased by 5%RH, and the residence time of the material in the zone is extended by 20 seconds.

[0011] Furthermore, when transferring the daylily buds to a moisture balance regulating chamber, and redistributing the moisture inside and outside the material under a constant relative humidity environment, the process includes: The moisture balance regulating chamber is equipped with multiple temperature and humidity sensors. When the relative humidity difference between any two points exceeds 5%RH, the circulating fan is activated and the angle of the air duct guide plate is adjusted so that the airflow covers all material stacking areas. When redistributing moisture inside and outside a material under constant relative humidity, the equilibrium termination condition is that within three consecutive sampling periods, the difference in moisture content between the material center and the surface is less than 0.8%, and the overall moisture content standard deviation is less than 1.5%.

[0012] Furthermore, the mold mounting surface is provided with a pressure feedback pad, wherein, When the contact pressure between the mold and the pressure plate is detected to be lower than 0.4 MPa, the secondary locking mechanism is triggered to perform the clamping action.

[0013] Furthermore, the vacuum impregnation seasoning process includes: The flavoring liquid is a mixture of flavoring agents, natural preservatives, and water activity regulators in a specific ratio. The impregnation pressure and time are set according to the thickness of the product. Evacuate to an absolute pressure of 5 kPa and maintain for 120 seconds; After injecting the seasoning liquid, apply a positive pressure of 80 kPa and maintain it for 180 seconds; Start the centrifuge at 800 rpm for 90 seconds to remove liquid adhering to the surface of the semi-finished product.

[0014] Furthermore, the low-temperature vacuum drying process includes: When the weight loss per unit time is less than 0.05 g / min, the near-infrared moisture probe is activated to detect water activity. If the water activity is detected in the range of 0.45–0.55 aw, the drying process is terminated.

[0015] Compared with existing technologies, the beneficial effects of this invention are as follows: By grading and screening daylily raw materials and matching blanching parameters according to the different grades of daylily tissue density, the processing parameters are precisely matched with the physiological structural characteristics of the raw materials. This effectively avoids tissue damage caused by over- or under-processing under traditional uniform process conditions, providing a stable and controllable initial structural foundation for subsequent dehydration and shaping processes. Secondly, by introducing a composite color-protecting treatment containing metal chelating agents and antioxidants, enzymatic browning and oxidation reactions are promptly inhibited after blanching. This not only improves the color stability of daylily products but also slows down the loss of nutrients caused by heat treatment to a certain extent, thereby improving the appearance quality and flavor retention of the finished product. Simultaneously, in the dehydration stage, a stepped decreasing temperature, humidity, and airflow speed configuration in multiple dehydration zones is adopted. Combined with real-time monitoring and dynamic adjustment of the surface moisture evaporation rate and internal moisture diffusion coefficient, the dehydration process is always in a moisture migration state conducive to tissue structure stability. This significantly reduces the risk of cell collapse or fibrosis caused by excessive moisture gradients, thus ensuring the fluffiness and good taste of the dehydrated daylilies. Furthermore, a moisture balance regulating chamber is installed after dehydration to redistribute moisture between the interior and surface of the material, eliminating structural stress caused by uneven residual moisture and providing a stable physical state for subsequent directional molding. Combined with a light-pressure shaping method using replaceable mold sets, this not only gives the product a uniform and stable snack food shape but also avoids structural damage caused by excessive compression, improving product molding consistency and structural integrity. Finally, the synergistic application of vacuum impregnation seasoning and low-temperature vacuum drying allows the seasoning components to penetrate evenly while maintaining a stable tissue structure, further reducing moisture content and extending shelf life. This results in daylily snack foods that are ready to eat, have a good taste, stable shape, and high added value.

[0016] On the other hand, this application also provides a processing system for daylily snack food, comprising: The grading module is configured to grade and screen the harvested daylily raw materials according to the length, diameter and maturity of the flower buds, and send the raw materials of the same grade to the corresponding pretreatment unit. The pretreatment unit is connected to the grading module. The pretreatment unit is configured to determine different combinations of heat medium temperature and action time according to the tissue density of different grades of daylily, to blanch the daylily of different grades, and to immerse the blanched daylily in a composite color-protecting solution containing metal chelating agents and antioxidants for protective treatment. The heat medium includes one or more of steam, hot water or microwave. The dehydration module, connected to the pretreatment module, is configured to sequentially pass the protected daylily through the first, second, and third dehydration zones for dehydration. The ambient humidity, temperature, and airflow velocity in the first, second, and third dehydration zones decrease in a stepwise manner. The dehydration module is also configured to monitor the surface moisture evaporation rate and internal moisture diffusion coefficient of the daylily in real time. When the ratio of the two deviates from the preset equilibrium range, the temperature and humidity gradient between adjacent dehydration zones is dynamically adjusted. The preparation module, connected to the dehydration module, is configured to transfer daylily buds to a moisture balance regulating chamber after dehydration, redistribute moisture inside and outside the material under constant relative humidity, and then send the daylily buds in the moisture balance regulating chamber to a directional molding device. The daylily buds are then lightly pressed and shaped using replaceable molds in the directional molding device. The preparation module is also configured to vacuum impregnate and season the shaped semi-finished product, and then perform low-temperature vacuum drying on the vacuum-impregnated and seasoned semi-finished product to complete the preparation.

[0017] It is understood that the processing system and method for daylily snack food in the above embodiments of the present invention have the same beneficial effects, and will not be described again. Attached Figure Description

[0018] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A functional diagram of a daylily processing system provided in an embodiment of the present invention; Figure 2 A flowchart illustrating a processing method for daylily snack food provided in an embodiment of the present invention; Figure 3A schematic flowchart illustrating a processing method for a daylily snack food provided in an embodiment of the present invention; Figure 4 This is a functional block diagram of a processing system for daylily snack food provided in an embodiment of the present invention. Detailed Implementation

[0019] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] like Figure 1 The diagram shows a functional diagram of a daylily processing system: The raw material grading unit may include a vision recognition camera, an image processing module, and a mechanical sorting arm. The vision recognition camera is positioned above the raw material conveyor belt to capture geometric contour images of daylily buds; the image processing module receives the images, extracts parameters such as bud length, diameter, and color saturation, and generates grading instructions; the mechanical sorting arm drives a pneumatic actuator according to the grading instructions to push daylilies of the corresponding grade to the designated pre-processing channel entrance.

[0021] It is understood that the structures illustrated in the embodiments of the present invention do not constitute a specific limitation on the raw material grading unit. In other embodiments of this application, the raw material grading unit may include more or fewer components than illustrated, or combine some components, or split some components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0022] The graded blanching and color-protecting module can include multiple blanching chambers arranged in parallel, a composite color-protecting liquid tank, an online monitoring subsystem, and a central control unit. Each blanching chamber is independently equipped with a steam generator, a hot water circulation pump, or a microwave generator. Its heat medium output end is connected to the nozzles inside the chamber through a three-way solenoid valve to achieve rapid switching and precise supply of different heat medium forms. The composite color-protecting liquid tank contains an aqueous solution containing metal chelating agents and antioxidants. A circulation pump is installed at the bottom of the tank, and its outlet is connected to the spray head at the top of the tank through a pipeline, forming a closed circulation loop for the color-protecting liquid to ensure the stability and consistency of the color-protecting process.

[0023] The online monitoring subsystem includes a pH electrode and a conductivity probe, the sensing end of which is immersed in the composite color-protecting solution to monitor the chemical state parameters of the solution in real time. The monitoring signal is then conditioned and input to the analog input interface of the central control unit. The central control unit has a built-in process parameter library for storing blanching temperature curves, action times, and color-protecting control thresholds corresponding to different raw material grades.

[0024] During module operation, the central control unit first receives grade identification information from the raw material grading unit, and retrieves the corresponding blanching process parameters from the process parameter library based on the grade identification. It then sends temperature and time setpoints to the matching blanching chamber, thereby achieving differentiated blanching treatment for daylilies with varying degrees of tissue density. After blanching, the daylilies enter the composite color-protecting liquid tank via a conveyor mechanism. The soaking time is controlled by a photoelectric switch-triggered timing module at the tank outlet to prevent flavor loss due to over-soaking.

[0025] When the online monitoring subsystem detects that the pH value of the color-protecting solution deviates from the preset reference value of ±0.3, or the conductivity exceeds the preset threshold, the central control unit automatically outputs a control signal to drive the drain solenoid valve to open and start the new solution injection pump to update or replenish the color-protecting solution, thereby maintaining the stability of the color-protecting environment. Through the above structure and control method, the graded blanching and color-protecting module realizes the coordinated control of the blanching process and the color-protecting treatment, providing a raw material foundation with stable color and controlled structure for subsequent gradient dehydration and molding processes.

[0026] A gradient dehydration tower may include a first dehydration zone, a second dehydration zone, and a third dehydration zone stacked vertically. These zones are continuously connected by a material elevator or conveyor to form a multi-stage gradient dehydration channel. The first dehydration zone is equipped with a humidifier and a low-speed centrifugal fan, maintaining a relative humidity of 85%–90% RH and an air velocity of 0.3–0.5 m / s. This is used to slowly remove free water from the surface of the material under high humidity and low air velocity conditions, inhibiting rapid surface drying. The second dehydration zone is equipped with a dehumidifying impeller and a medium-speed axial flow fan, reducing the ambient humidity to 60%–70% RH and increasing the air velocity to 1.0–1.5 m / s. This promotes the diffusion of internal moisture to the surface while ensuring structural support. The third dehydration zone is equipped with a refrigeration and dehumidification unit and a low-temperature air supply system to control the ambient humidity at 30%–40% RH, the wind speed at 0.8–1.0 m / s, and the ambient temperature at 35–40℃, so as to achieve stable removal of moisture in the later stage of dehydration.

[0027] Each dehydration zone is equipped with an infrared moisture sensor array at its bottom to detect the surface moisture content of the material in real time. The output signal is processed by moving average filtering and then input to the main controller. At the same time, a near-infrared spectral probe is installed at the entrance of each dehydration zone and connected to a spectral analyzer via optical fiber to invert the internal moisture diffusion coefficient of the material in real time, thereby achieving synchronous perception of surface evaporation behavior and internal moisture migration status.

[0028] The main controller periodically calculates the ratio R of the surface moisture evaporation rate to the internal moisture diffusion coefficient based on the collected data, and uses this ratio as an evaluation index of the stability of the dehydration process. When R is greater than the preset upper limit, the main controller reduces the heating power of the first dehydration zone and simultaneously reduces the frequency conversion output frequency of the fan in the second dehydration zone to slow down the surface water loss rate. When R is less than the preset lower limit, the main controller increases the opening of the humidification solenoid valve in the second dehydration zone and prolongs the residence time of the material in the dehydration zone. The conveyor belt speed is driven by a servo motor, and its encoder feedback signal is connected to the motion control card to form a closed-loop regulation.

[0029] The moisture balance regulating chamber may include a sealed chamber body, a multi-point temperature and humidity sensor network, a circulating fan, an air duct guide plate, and an airtight sealing mechanism. The chamber body is a sealed structure, with multiple temperature and humidity composite sensors evenly distributed on its inner wall; in some specific embodiments, this number is eight. The data lines of the temperature and humidity sensors are connected to a data acquisition module to construct a three-dimensional temperature and humidity environmental field model inside the chamber. The circulating fan is installed at the top of the chamber body, and its air outlet is connected to an adjustable-angle air duct guide plate. The guide plate is driven by a stepper motor, and its position is fed back by a limit switch to achieve precise adjustment of the airflow direction and coverage area.

[0030] The airtight locking mechanism is located at the edge of the door and includes a silicone sealing strip, a cylinder, and a wedge-shaped locking tongue structure. When the door is closed, the cylinder pushes the wedge-shaped locking tongue to engage with the corresponding locking groove, so that the compartment forms an airtight environment, thereby preventing external humidity fluctuations from interfering with the moisture balance process.

[0031] During the moisture balance regulation process, the main controller receives data collected in real time from a multi-point temperature and humidity sensor network. When the relative humidity difference measured by any two sensors exceeds a preset threshold (e.g., 5% RH), the main controller starts the circulating fan and adjusts the angle of the guide vane according to the environmental field model, so that the circulating airflow covers all material stacking areas and promotes the uniform migration of moisture inside and on the surface of the material.

[0032] The criteria for determining whether moisture balance adjustment is complete are: within multiple consecutive sampling cycles, the difference in moisture content between the center and surface of the material is less than a preset threshold, and the standard deviation of the overall moisture content is lower than a set range. In some specific embodiments, within three consecutive sampling cycles (30 seconds per cycle), the difference in moisture content between the center and surface is less than 0.8%, and the standard deviation of the overall moisture content is lower than 1.5%. Through the above structure and control method, the moisture balance adjustment chamber can effectively eliminate the problem of uneven moisture after dehydration, stabilize the tissue structure of daylilies, and significantly reduce the risk of cracking or deformation during subsequent molding processes.

[0033] The orientation forming device may include a lifting platform, a mold storage turntable, a servo rotating support, a Hall position sensor, a pressure feedback pad, and a secondary locking mechanism. The lifting platform is driven by a hydraulic cylinder, and a pressure plate for applying pressure is installed on its top. The mold storage turntable is located below the lifting platform, and multiple sets of replaceable molds are evenly distributed around the turntable. In some specific embodiments, there are 4–6 sets, and each mold cavity corresponds to different finished product shapes such as strips, sheets, curls, or cubes.

[0034] The servo rotary support is connected to the central axis of the mold storage turntable, and its rotation angle is fed back in real time by an encoder; the Hall position sensor is fixedly set at the base of the rotary support, and the corresponding magnet is installed on the positioning pin of the target mold to detect whether the mold has rotated into place, thereby realizing precise positioning and confirmation in the mold selection process.

[0035] The pressure feedback pad is embedded on the lower surface of the pressure plate and integrates a piezoresistive sensor array to detect the contact pressure between the material and the mold in real time during the molding process. The secondary locking mechanism consists of a miniature cylinder and a wedge-shaped clamping block. Its action trigger condition is determined by the output signal of the pressure feedback pad to compensate for insufficient initial contact pressure and ensure molding stability.

[0036] During the operation of the orientation molding device, the central controller receives the product shape identifier from the production order, queries the mapping table between the product shape and the mold code, and outputs pulse signals to the servo driver to drive the servo rotary support to rotate. When the Hall position sensor outputs a high-level signal, it is determined that the target mold has rotated into position. Subsequently, the lifting platform rises to push the pressure plate into contact with the material and apply a preset light pressure. If the contact pressure detected by the pressure feedback pad is lower than the set threshold (e.g., 0.4 MPa), the secondary locking mechanism is triggered to perform a clamping action, providing stable constraint on the mold and the material.

[0037] A vacuum impregnation and seasoning station may include a vacuum tank, a vacuum pump, a positive pressure gas source, a liquid circulation pump, a centrifugal dehydrator, and a control valve assembly. The vacuum tank has a double-layered jacketed structure, and its internal volume can be set to 50–200 L. The tank lid is equipped with a quick-opening locking mechanism for easy loading and unloading of materials. The vacuum pump is connected to the air extraction port on the top of the tank through a pipeline, and a vacuum solenoid valve is installed on the pipeline to achieve precise control of the vacuuming process.

[0038] The positive pressure gas source uses food-grade inert gas, which in some specific embodiments is a nitrogen storage tank. Its output end passes through a pressure reducing valve and a proportional regulating valve in sequence before being connected to the tank body. This is used to apply controllable positive pressure to the inside of the tank body after the vacuum stage is completed. The liquid circulation pump draws seasoning liquid from the seasoning liquid storage tank, filters it through a filter, and then injects it into the bottom of the tank body to ensure the cleanliness of the seasoning liquid and the stability of the injection.

[0039] The centrifugal dehydrator is installed below the vacuum tank, with its drum connected to the tank's discharge port. Driven by a variable frequency motor, it is used to remove excess liquid adhering to the surface of the material after seasoning, thus avoiding affecting subsequent drying efficiency and the taste of the finished product.

[0040] During the seasoning process, after the material is placed into the vacuum tank and the lid is closed, the vacuum solenoid valve is first opened to drive the vacuum pump to draw the pressure inside the tank to a preset vacuum level, which is 5 kPa absolute pressure in some specific embodiments, and is maintained for a certain period of time to expel air from the pores of the material. Then the vacuum valve is closed, the seasoning liquid injection valve is opened to submerge the material in the seasoning liquid, and the positive pressure valve is opened to pressurize the tank to a preset pressure value, which is 80 kPa in some specific embodiments, and is maintained for a set pressure holding time to promote the penetration of the seasoning liquid into the material.

[0041] After seasoning is completed, open the discharge valve and start the centrifugal dehydrator. By setting the speed and running time, remove excess seasoning liquid from the surface to obtain a semi-finished product with uniform seasoning and a clean surface.

[0042] A low-temperature vacuum drying oven may include a drying chamber, a cold trap, a vacuum unit, weighing trays, a near-infrared moisture probe, and a temperature control module. The drying chamber contains multiple layers of stainless steel trays, with high-precision weighing sensors installed at the bottom of each tray. The signal lines of these sensors are connected to a data acquisition card to acquire real-time data on material weight changes during the drying process. Near-infrared moisture probes are installed on the side walls of the drying chamber, with their beams aimed at the center of the trays for non-contact detection of the material's moisture content.

[0043] A cold trap is located at the front end of the vacuum unit, filled with liquid nitrogen or ethylene glycol as a cooling medium. This trap condenses and captures water vapor generated during the drying process, reducing the load on the vacuum unit and improving system stability. The vacuum unit consists of a Roots pump and a rotary vane pump connected in series, achieving a stable and controllable low-pressure environment within the drying chamber through multi-stage pumping. The temperature control module is connected to the heating element and temperature sensor for precise temperature regulation of the drying chamber under low-temperature conditions.

[0044] During the drying process, the main controller collects the change in material weight per unit time in real time and calculates the rate of weight change ΔW / Δt. When the rate is lower than the preset threshold, the near-infrared moisture probe is triggered to detect the water activity of the material. If the detection result is within the target water activity range, the main controller shuts down the heater and vacuum unit, and determines that the drying process is complete. If the target range is not reached, the drying time is extended and the detection process is repeated.

[0045] By combining a dual judgment mechanism of weight change rate monitoring and near-infrared water activity detection, the low-temperature vacuum drying oven can avoid the problems of over-drying or under-drying, and achieve precise control of the final moisture content, so that the daylily snack food produced has both good taste, flavor stability and long shelf life.

[0046] based on Figure 1 A functional diagram of a daylily processing system, combined with Figure 2 and Figure 3 This invention provides a method for processing daylily snack food, comprising: Step S100: The harvested daylily raw materials are graded and screened according to the length, diameter and maturity of the flower buds, and the raw materials of the same grade are sent to the corresponding pretreatment unit.

[0047] Understandably, based on the objective law that there is a significant correlation between the length, diameter, and maturity of daylily buds during their growth and development and their internal tissue density, moisture content distribution, and heat and dehydration resistance, grading and screening the harvested raw materials by size and maturity ensures that the daylilies entering the same pretreatment unit have a high degree of consistency in tissue structure and physiological state. This provides a stable basis for the precise matching of subsequent process parameters such as blanching, color protection, and dehydration, avoiding the problem of local over-processing or under-processing due to excessive differences in raw materials.

[0048] For example, in actual production, harvested daylilies can be divided into three categories according to the length of the buds: short buds, medium buds, and long buds. The maturity level can be further subdivided based on the diameter and degree of bud opening. Buds with denser tissue and higher maturity are sent to a high-temperature, short-time pretreatment unit, while buds with relatively loose tissue and lower maturity are sent to a low-temperature, slow-release pretreatment unit. This graded feeding method ensures that each batch of raw materials is heated and dehydrated more evenly during subsequent processing, thereby improving the consistency of the finished product's taste and quality.

[0049] Step S200: In the preset processing unit, according to the density of the tissue of daylilies of different grades, different combinations of heat medium temperature and action time are determined to blanch the daylilies of different grades, and the blanched daylilies are immersed in a composite color-protecting liquid containing metal chelating agents and antioxidants for protective treatment. The heat medium includes one or more of steam, hot water or microwave.

[0050] Specifically, based on the tissue density of different grades of daylilies, different combinations of heat medium temperature and treatment time are determined, including: collecting the initial chlorophyll content, reducing sugar concentration and cell wall pectin methyl esterase activity of each batch of daylilies, constructing a raw material quality feature vector, and determining whether to add microwave treatment and compound color-protecting solution formulation during the blanching operation based on the raw material quality feature vector.

[0051] Specifically, when determining whether to add microwave treatment and compound color-protecting solution formulation during the blanching process based on the raw material quality characteristic vector, the process includes: 1) Based on the chlorophyll content and pectin methyl esterase activity in the raw material quality characteristic vector; 2) Obtaining the average chlorophyll content of each historical batch and setting the average chlorophyll content as the chlorophyll baseline value; 3) Obtaining the average pectin methyl esterase activity of each historical batch and setting the average pectin methyl esterase activity as the pectin methyl esterase activity baseline value; 4) Determining the compound color-protecting solution formulation based on the relationship between the chlorophyll content and the chlorophyll baseline value in the raw material quality characteristic vector, wherein when the chlorophyll content is lower than the chlorophyll baseline value, a preset concentration of ascorbic acid is added to the compound color-protecting solution; 5) Determining whether to add microwave treatment based on the relationship between the pectin methyl esterase activity and the pectin methyl esterase activity baseline value in the raw material quality characteristic vector, wherein when the pectin methyl esterase activity is higher than the pectin methyl esterase activity baseline value, microwave-assisted treatment is added when blanching daylilies of different grades.

[0052] It is understandable that the differences in physiological maturity and tissue structure of daylily raw materials directly affect the blanching effect, color retention stability, and subsequent dehydration quality. By collecting key biochemical indicators such as chlorophyll content, reducing sugar concentration, and cell wall pectin methyl esterase activity, a raw material quality characteristic vector is constructed to characterize the tissue density and enzyme activity levels of different grades of daylilies. This vector is then compared with benchmark values ​​obtained from historical batch statistics to achieve adaptive adjustments to the type of blanching heat medium, temperature-time combination, and color retention solution formulation. Specifically, by controlling the amount of antioxidants to inhibit chlorophyll degradation and by introducing microwave-assisted blanching to rapidly inactivate highly active pectin methyl esterase, the mechanism simultaneously controls color retention and cell wall structure stability, avoiding browning or tissue softening caused by uniform processing.

[0053] For example, in an actual production batch, if the chlorophyll content of a certain grade of daylily is found to be lower than the historical average baseline value, while the pectin methyl esterase activity is significantly higher than the baseline level, the system will automatically introduce short-term microwave-assisted treatment on the basis of conventional steam blanching to accelerate enzyme inactivation and increase the concentration of ascorbic acid in the compound color-protecting solution. Conversely, for raw materials with high chlorophyll content and pectin methyl esterase activity close to or lower than the baseline value, only hot water or steam blanching is used and a standard color-protecting solution formula is used, thereby achieving graded blanching and color-protecting treatment effects with stable color, intact texture, and controllable processing risks under different raw material conditions.

[0054] Step S300: The protected daylily is dehydrated sequentially through the first dehydration zone, the second dehydration zone and the third dehydration zone. The ambient humidity, temperature and airflow speed of the first dehydration zone, the second dehydration zone and the third dehydration zone decrease in a stepwise manner. Specifically, the evaporation rate of surface moisture and the internal moisture diffusion coefficient of daylily are monitored in real time. When the ratio of the two deviates from the preset equilibrium range, the temperature and humidity gradient between adjacent dehydration zones is dynamically adjusted.

[0055] Specifically, when the protected daylily is dehydrated sequentially through the first dehydration zone, the second dehydration zone, and the third dehydration zone, the following conditions are met: the ambient humidity in the first dehydration zone is maintained at 85%–90% RH, and the wind speed is 0.3–0.5 m / s; the humidity in the second dehydration zone is 60%–70% RH, and the wind speed is 1.0–1.5 m / s; the humidity in the third dehydration zone is 30%–40% RH, the wind speed is 0.8–1.0 m / s, and the temperature is maintained at 35–40℃.

[0056] Specifically, the surface moisture evaporation rate and internal moisture diffusion coefficient of daylilies are monitored in real time. When the ratio of the two deviates from the preset equilibrium range, the temperature and humidity gradient between adjacent dehydration zones is dynamically adjusted. This includes: acquiring the ratio of surface moisture evaporation rate to internal moisture diffusion coefficient in real time; and adjusting the temperature and humidity gradient between adjacent dehydration zones according to the ratio. Specifically, when the ratio is greater than 1.8, the temperature difference between the first and second dehydration zones is reduced by 3°C, and the wind speed in the second dehydration zone is reduced by 0.2 m / s. When the ratio is less than 1.2, the relative humidity in the second dehydration zone is increased by 5%RH, and the residence time of the material in the zone is extended by 20 seconds.

[0057] Understandably, based on the controlled mass transfer mechanism of "surface moisture evaporation - internal moisture diffusion" during the dehydration process of daylilies, the dehydration process is divided into multiple dehydration zones with progressively decreasing humidity, temperature, and airflow velocity. This guides moisture to migrate stably from the inside out, avoiding problems such as surface hardening due to excessively rapid initial evaporation and subsequent diffusion obstruction. By real-time monitoring of the ratio of surface moisture evaporation rate to internal moisture diffusion coefficient, and using this ratio as the core characterization parameter of dehydration uniformity, the temperature and humidity gradients and airflow conditions between adjacent dehydration zones are dynamically adjusted when the ratio deviates from the preset equilibrium range. This ensures that the external heat and mass transfer intensity matches the internal diffusion capacity, achieving adaptive balance control of the dehydration rate from a mechanistic perspective. This ensures stable daylily tissue structure, uniform color, and a controllable drying process.

[0058] For example, during the continuous dehydration process of a batch of daylilies, the system detected that the surface moisture evaporation rate was significantly higher than the internal moisture diffusion capacity during the transition from the first dehydration zone to the second dehydration zone, with the ratio rising to 1.9. This indicated a risk of excessive surface water loss. The system then automatically reduced the temperature difference between the first and second dehydration zones by 3°C and simultaneously reduced the wind speed in the second dehydration zone by 0.2 m / s to slow down surface evaporation and promote the migration of internal moisture to the surface. Conversely, in another batch, when the ratio was detected to drop to 1.1, indicating relatively limited internal diffusion and insufficient dehydration driving force, the system increased the relative humidity in the second dehydration zone by 5%RH and extended the material residence time by 20 seconds. This provided a buffer for the uniform migration of internal moisture, ultimately achieving uniform dehydration and stable quality of daylilies under different raw material conditions.

[0059] Step S400: After dehydration, the daylily is transferred to a moisture balance regulating chamber. Under constant relative humidity, the moisture inside and outside the material is redistributed. The daylily after moisture balance regulation in the moisture balance regulating chamber is sent to a directional molding device. The daylily is lightly pressed and shaped using replaceable molds in the directional molding device. The shaped semi-finished product is then vacuum impregnated and seasoned, and then vacuum-dried at low temperature to complete the preparation.

[0060] Specifically, when transferring daylily buds to a moisture balance regulating chamber to redistribute moisture inside and outside the material under constant relative humidity, the process includes: installing multiple temperature and humidity sensors in the moisture balance regulating chamber; when the relative humidity difference between any two points exceeds 5%RH, starting the circulating fan and adjusting the angle of the air duct guide plate to ensure that the airflow covers all material stacking areas; and when redistributing moisture inside and outside the material under constant relative humidity, the balance termination condition is that within three consecutive sampling periods, the difference in moisture content between the material center and the surface is less than 0.8%, and the overall moisture content standard deviation is less than 1.5%.

[0061] Specifically, the mold mounting surface is provided with a pressure feedback pad, wherein when the contact pressure between the mold and the pressure plate is detected to be lower than 0.4MPa, the secondary locking mechanism is triggered to perform a clamping action.

[0062] Specifically, the vacuum impregnation seasoning process includes: the seasoning liquid is a mixture of flavoring substances, natural preservatives and water activity regulators in proportion; the impregnation pressure and time are set according to the product thickness; vacuum is drawn to an absolute pressure of 5 kPa and maintained for 120 seconds; after injecting the seasoning liquid, a positive pressure of 80 kPa is applied and maintained for 180 seconds; a centrifugal dehydrator is started and rotated at 800 rpm for 90 seconds to remove the liquid adhering to the surface of the semi-finished product.

[0063] Understandably, after gradient dehydration, the moisture inside and outside the daylily is slowly released and balanced under constant relative humidity conditions through a moisture balance regulating chamber. This eliminates the moisture gradient formed during dehydration and prevents tissue collapse or stress concentration caused by local moisture content differences during subsequent shaping and seasoning stages. Through multi-point temperature and humidity sensing and adaptive adjustment of circulating airflow, the microenvironment within the material stacking area is made consistent. When the difference in moisture content between the center and the surface and the overall dispersion both meet the threshold conditions, it is determined that the moisture has reached a stable equilibrium state. Subsequently, in the directional shaping device, the daylily is shaped under light pressure conditions below the tissue damage threshold using a closed-loop pressure control mechanism composed of replaceable molds and pressure feedback pads, ensuring consistent morphology and preventing fibrosis. Then, the pressure difference formed by alternating vacuum and pressurization drives the seasoning liquid to quickly and evenly penetrate the tissue capillary structure, and the surface free water is controlled by centrifugal dehydration. Finally, moisture removal and flavor solidification are completed under low-temperature vacuum drying conditions, achieving synergistic stability of morphology, texture, and flavor from a mechanistic perspective.

[0064] For example, after a batch of daylilies that have undergone gradient dehydration enters the moisture balance regulating chamber, the system detects that the relative humidity difference between different locations in the chamber reaches 6%RH. The system then starts the circulating fan and adjusts the angle of the guide vanes to ensure airflow covers the bottom and central stacked areas. After multiple sampling cycles, the system monitors that the moisture content difference between the center and surface of the daylilies has decreased to 0.6%, and the overall moisture content standard deviation is 1.2%, meeting the conditions for balancing. Subsequently, the material enters the directional molding device. When the initial contact pressure between the mold and the pressure plate is detected as 0.35MPa, the system triggers a secondary locking mechanism to compensate for clamping, ensuring the molding pressure remains stable within the set range. The semi-finished product undergoes vacuum impregnation and seasoning. First, a vacuum is applied to 5kPa for 120 seconds to expel residual gas from the tissue. Then, seasoning liquid is injected and a positive pressure of 80kPa is applied for 180 seconds to ensure full penetration of flavor substances. Finally, the liquid adhering to the surface is removed by centrifugation at 800rpm, and after low-temperature vacuum drying, a finished daylily snack food product with intact shape, uniform texture, and consistent flavor is obtained.

[0065] In the above embodiments, by grading and screening the daylily raw materials and matching the blanching parameters according to the different grades of daylily tissue density, the processing parameters and the physiological structural characteristics of the raw materials were precisely matched. This effectively avoided tissue damage caused by over- or under-processing under traditional uniform process conditions, providing a stable and controllable initial structural foundation for subsequent dehydration and shaping processes. Secondly, by introducing a composite color-protecting treatment containing metal chelators and antioxidants, enzymatic browning and oxidation reactions were promptly inhibited after blanching. This not only improved the color stability of the daylily products but also mitigated the loss of nutrients caused by heat treatment to a certain extent, thereby improving the appearance quality and flavor retention of the finished product. At the same time, in the dehydration stage, a stepped decreasing temperature, humidity, and airflow speed configuration in multiple dehydration zones was adopted. Combined with real-time monitoring and dynamic adjustment of the surface moisture evaporation rate and internal moisture diffusion coefficient, the dehydration process was always in a state of moisture migration conducive to tissue structure stability. This significantly reduced the risk of cell collapse or fibrosis caused by excessive moisture gradients, thus ensuring the fluffiness and good taste of the daylily after dehydration. Furthermore, a moisture balance regulating chamber is installed after dehydration to redistribute moisture between the interior and surface of the material, eliminating structural stress caused by uneven residual moisture and providing a stable physical state for subsequent directional molding. Combined with a light-pressure shaping method using replaceable mold sets, this not only gives the product a uniform and stable snack food shape but also avoids structural damage caused by excessive compression, improving product molding consistency and structural integrity. Finally, the synergistic application of vacuum impregnation seasoning and low-temperature vacuum drying allows the seasoning components to penetrate evenly while maintaining a stable tissue structure, further reducing moisture content and extending shelf life. This results in daylily snack foods that are ready to eat, have a good taste, stable shape, and high added value.

[0066] In another preferred embodiment based on the above embodiments, such as Figure 4 As shown, this embodiment also provides a processing system for daylily snack food, including: a grading module, a pretreatment unit, a dehydration module, and a preparation module, including: Specifically, the grading module is configured to grade and screen harvested daylily raw materials according to bud length, diameter, and maturity, and send raw materials of the same grade to the corresponding pretreatment unit. The pretreatment unit is connected to the grading module and is configured to determine different combinations of heat medium temperature and treatment time based on the tissue density of different grades of daylilies, to blanch the daylilies of different grades, and then immerse the blanched daylilies in a composite color-protecting solution containing metal chelating agents and antioxidants for protective treatment. The heat medium includes one or more of steam, hot water, or microwave. The dehydration module is connected to the pretreatment module and is configured to pass the protected daylilies through the first dehydration zone, the second dehydration zone, and the third dehydration zone in sequence for dehydration treatment. The ambient humidity, temperature, and airflow velocity in the water zone and the third dehydration zone decrease in a stepwise manner. The dehydration module is also configured to monitor the surface moisture evaporation rate and internal moisture diffusion coefficient of the daylily in real time. When the ratio of the two deviates from the preset equilibrium range, the temperature and humidity gradient between adjacent dehydration zones is dynamically adjusted. The preparation module is connected to the dehydration module. After dehydration, the preparation module is configured to transfer the daylily to the moisture balance regulating chamber, redistribute the moisture inside and outside the material under a constant relative humidity environment, and send the daylily after the moisture balance regulation in the moisture balance regulating chamber into the orientation molding device. The daylily is then lightly pressed and shaped based on the replaceable mold group in the orientation molding device. The preparation module is also configured to vacuum impregnate and season the shaped semi-finished product, and then perform low-temperature vacuum drying on the vacuum impregnated and seasoned semi-finished product to complete the preparation.

[0067] It is understood that the processing system and method for daylily snack food in the above embodiments of the present invention have the same beneficial effects, and will not be described again.

[0068] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program goods. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program goods embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0069] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program goods according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0070] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0071] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A processing method for daylily snack food, characterized in that, include: After harvesting, the daylily raw materials are graded and screened according to the length, diameter and maturity of the flower buds, and raw materials of the same grade are sent to the corresponding pre-processing unit. In the preset processing unit, different combinations of heat medium temperature and action time are determined according to the tissue density of daylilies of different grades. Daylilies of different grades are blanched and then immersed in a composite color-protecting liquid containing metal chelating agents and antioxidants for protection treatment. The heat medium includes one or more of steam, hot water or microwave. After protection treatment, the daylilies were dehydrated in sequence through the first dehydration zone, the second dehydration zone, and the third dehydration zone. The environmental humidity, temperature, and airflow speed in the first dehydration zone, the second dehydration zone, and the third dehydration zone decreased in a stepwise manner. Real-time monitoring of the surface moisture evaporation rate and internal moisture diffusion coefficient of daylily; when the ratio of the two deviates from the preset equilibrium range, the temperature and humidity gradient between adjacent dehydration zones is dynamically adjusted. After dehydration, the daylily is transferred to the moisture balance regulating chamber, where the moisture inside and outside the material is redistributed under a constant relative humidity environment. The daylily after the moisture balance regulation in the moisture balance regulating chamber is sent to the orientation molding device, where the daylily is lightly pressed and shaped based on the replaceable mold group in the orientation molding device. The semi-finished product after shaping is vacuum impregnated and seasoned, and then the semi-finished product after vacuum impregnation and seasoning is dried at low temperature to complete the preparation.

2. The processing method of daylily snack food according to claim 1, characterized in that, Based on the tissue density of different grades of daylilies, different combinations of heat medium temperature and treatment time were determined, including: collecting the initial chlorophyll content, reducing sugar concentration and cell wall pectin methyl esterase activity of each batch of daylilies, and constructing a raw material quality feature vector. Based on the raw material quality characteristic vector, determine whether to add microwave treatment and compound color-protecting solution formulation to the blanching operation.

3. The processing method of daylily snack food according to claim 2, characterized in that, When determining whether to add microwave treatment and compound color-protecting solution formulation during the blanching process based on the raw material quality characteristic vector, the following should be included: Based on the chlorophyll content and pectin methyl esterase activity in the raw material quality characteristic vector; Obtain the mean value of chlorophyll content in each historical batch, and determine the mean value of chlorophyll content as the chlorophyll baseline value; The mean value of each pectin methyl esterase activity in each historical batch was obtained, and the mean value of each pectin methyl esterase activity was determined as the benchmark value of pectin methyl esterase activity. Based on the relationship between chlorophyll content and chlorophyll baseline value in the raw material quality characteristic vector, the compound color-protecting liquid formula is determined. When the chlorophyll content is lower than the chlorophyll baseline value, it is determined that ascorbic acid at a preset concentration level will be added to the compound color-protecting liquid. Based on the relationship between pectin methyl esterase activity and the benchmark value of pectin methyl esterase activity in the raw material quality characteristic vector, it is determined whether to add microwave treatment. Specifically, when the pectin methyl esterase activity is higher than the benchmark value of pectin methyl esterase activity, it is determined that microwave-assisted treatment should be added when blanching daylilies of different grades.

4. The processing method of daylily snack food according to claim 1, characterized in that, When the protected daylily is dehydrated sequentially through the first dehydration zone, the second dehydration zone, and the third dehydration zone, the process includes: The ambient humidity in the first dehydration zone is maintained at 85%–90% RH, and the wind speed is 0.3–0.5 m / s; The humidity in the second dehydration zone is 60%–70%RH, and the wind speed is 1.0–1.5 m / s; The humidity in the third dehydration zone is 30%–40% RH, the wind speed is 0.8–1.0 m / s, and the temperature is maintained at 35–40℃.

5. The processing method of daylily snack food according to claim 4, characterized in that: Real-time monitoring of the surface moisture evaporation rate and internal moisture diffusion coefficient of daylilies; when the ratio of the two deviates from the preset equilibrium range, dynamic adjustment of the temperature and humidity gradient between adjacent dehydration zones, including: The ratio of surface moisture evaporation rate to internal moisture diffusion coefficient is obtained in real time. And based on the ratio, adjust the temperature and humidity gradient between adjacent dehydration zones, where: When the ratio is greater than 1.8, the temperature difference between the first dehydration zone and the second dehydration zone is reduced by 3℃, and the wind speed in the second dehydration zone is reduced by 0.2 m / s. When the ratio is less than 1.2, the relative humidity of the second dehydration zone is increased by 5%RH, and the residence time of the material in the zone is extended by 20 seconds.

6. The processing method of daylily snack food according to claim 1, characterized in that, When transferring daylily buds to a moisture balance regulating chamber, and redistributing the moisture inside and outside the material under a constant relative humidity environment, the process includes: The moisture balance regulating chamber is equipped with multiple temperature and humidity sensors. When the relative humidity difference between any two points exceeds 5%RH, the circulating fan is activated and the angle of the air duct guide plate is adjusted so that the airflow covers all material stacking areas. When redistributing moisture inside and outside a material under constant relative humidity, the equilibrium termination condition is that within three consecutive sampling periods, the difference in moisture content between the material center and the surface is less than 0.8%, and the overall moisture content standard deviation is less than 1.5%.

7. The processing method of daylily snack food according to claim 2, characterized in that, The mold mounting surface is provided with a pressure feedback pad, wherein... When the contact pressure between the mold and the pressure plate is detected to be lower than 0.4 MPa, the secondary locking mechanism is triggered to perform the clamping action.

8. The processing method of daylily snack food according to claim 1, characterized in that, The vacuum impregnation seasoning process includes: The flavoring liquid is a mixture of flavoring substances, natural preservatives and water activity regulators in a certain proportion. The impregnation pressure and time are set according to the thickness of the product. Evacuate to an absolute pressure of 5 kPa and maintain for 120 seconds; After injecting the seasoning liquid, apply a positive pressure of 80 kPa and maintain it for 180 seconds; Start the centrifuge at 800 rpm for 90 seconds to remove liquid adhering to the surface of the semi-finished product.

9. The processing method of daylily snack food according to claim 8, characterized in that, The low-temperature vacuum drying process includes: When the weight loss per unit time is less than 0.05 g / min, the near-infrared moisture probe is activated to detect water activity. If the water activity is detected in the range of 0.45–0.55 aw, the drying process is terminated.

10. A processing system for daylily snack food, employing the processing method for daylily snack food as described in any one of claims 1-9, characterized in that, include: The grading module is configured to grade and screen the harvested daylily raw materials according to the length, diameter and maturity of the flower buds, and send the raw materials of the same grade to the corresponding pretreatment unit. The pretreatment unit is connected to the grading module. The pretreatment unit is configured to determine different combinations of heat medium temperature and action time according to the tissue density of different grades of daylily, to blanch the daylily of different grades, and to immerse the blanched daylily in a composite color-protecting solution containing metal chelating agents and antioxidants for protective treatment. The heat medium includes one or more of steam, hot water or microwave. The dehydration module, connected to the pretreatment module, is configured to sequentially pass the protected daylily through the first, second, and third dehydration zones for dehydration. The ambient humidity, temperature, and airflow velocity in the first, second, and third dehydration zones decrease in a stepwise manner. The dehydration module is also configured to monitor the surface moisture evaporation rate and internal moisture diffusion coefficient of the daylily in real time. When the ratio of the two deviates from the preset equilibrium range, the temperature and humidity gradient between adjacent dehydration zones is dynamically adjusted. The preparation module, connected to the dehydration module, is configured to transfer daylily buds to a moisture balance regulating chamber after dehydration, redistribute moisture inside and outside the material under constant relative humidity, and then send the daylily buds in the moisture balance regulating chamber to a directional molding device. The daylily buds are then lightly pressed and shaped using replaceable molds in the directional molding device. The preparation module is also configured to vacuum impregnate and season the shaped semi-finished product, and then perform low-temperature vacuum drying on the vacuum-impregnated and seasoned semi-finished product to complete the preparation.

Images