A method and apparatus for processing pepper or chinese pricklyash

Abstract

This invention discloses a processing method and equipment for pepper or litsea cubeba, relating to the field of pepper or litsea cubeba processing technology. The method includes: placing fresh pepper or litsea cubeba into a rotatable container; evacuating the container until the internal pressure drops to a negative pressure sufficient for the material to boil at 25°C or below, then stopping the vacuuming; adjusting the container temperature to 55°C and maintaining it; when the pressure inside the container rises back to -50 kPa to -20 kPa, evacuating again until the material boils at 25°C or below; repeating this cycle while keeping the container rotating for 8-12 hours to soften the pericarp and prepare it for peeling. This invention efficiently and gently softens the pericarp under medium-temperature conditions, ensuring seed integrity and product quality, while avoiding wastewater or chemical reagent contamination, providing an ideal pretreatment basis for subsequent peeling processes.

Description

Technical Field

[0001] This invention relates to the field of pepper or litsea cubeba processing technology, and particularly to a method and equipment for processing pepper or litsea cubeba. Background Technology

[0002] Pepper and Litsea cubeba are important specialty spice crops in southern my country. Processed pepper products mainly include black pepper, white pepper, and dried green pepper. Black pepper is made by drying immature, greenish-yellow fruits with their skins on. White pepper is made from fully ripe, red fruits; the outer, meso, and endocarps are removed, leaving only the seeds, which are then dried. Because the endocarp is a hard, woody shell tightly bound to the seeds, it is difficult to peel off when dry; therefore, the pericarp must be fully softened before peeling. The processing of Litsea cubeba fruits faces a similar softening requirement; dried green pepper is obtained by drying in an oxygen-free environment.

[0003] Currently, the main methods for softening the peel of fresh peppercorns are soaking and heating / cooking. Soaking involves immersing the fresh fruit in water for 7 to 20 days, allowing the peel to soften through natural fermentation or soaking, followed by rubbing or rinsing to separate the peel from the seeds. This method is time-consuming, highly susceptible to changes in ambient temperature and water quality, and prone to bacterial growth that can cause off-flavors in the seeds. Furthermore, the large amount of organic wastewater generated during soaking is costly to treat. Heating / cooking softens the peel by introducing steam or hot water into the fresh peppercorns. While this method significantly shortens the time compared to soaking, it is typically carried out at high temperatures. High temperatures can damage heat-sensitive volatile components in the material, directly resulting in a diluted flavor, loss of original characteristic aromas, and deterioration of the final product quality, affecting the flavor and quality of subsequent processing. Additionally, some methods use chemical reagents for soaking to accelerate softening, but these pose food safety risks, and the wastewater treatment also presents environmental challenges.

[0004] Patent CN104643267A discloses a mechanized comprehensive processing method for white pepper. Its specification describes that the traditional soaking process has a processing cycle of 7 to 20 days, and the soaking process is prone to producing odors and organic wastewater problems.

[0005] Patent CN101703308A discloses a method for peeling fresh peppercorns. The method involves soaking fresh peppercorn spikes in a pectinase solution with a volume concentration of 1-5‰ until the peel decomposes. The soaked peppercorns are then removed, and the peel and stems are removed to obtain peppercorns. This is an enzyme-assisted peeling process, but it has the potential for enzyme residue and high production costs.

[0006] The 2024 achievement announcement of the Hainan Provincial Department of Science and Technology recorded a chain-based industrial processing technology that improves processing efficiency by combining steam curing with mechanical peeling and hot air drying. However, both steam curing and 60℃ hot air drying are high-temperature treatments, which can easily lead to the loss of heat-sensitive volatile effective components. At the same time, the peeling and drying processes are independent of each other and require multiple sets of equipment to work together.

[0007] A 2024 achievement announcement from the Hainan Provincial Department of Science and Technology describes a chain-based processing technology for pepper, which relies on a continuous production line mode combining steam curing with mechanical peeling and hot air drying to improve overall processing efficiency. However, the process uses high-temperature steam curing and 60°C hot air drying, both of which are medium-high temperature heat treatments, which can easily cause a large amount of heat-sensitive volatile active ingredients in pepper to evaporate and be lost.

[0008] In summary, existing pepper pericarp softening processes either have low processing efficiency or suffer from heat-sensitive volatile components and deteriorate product flavor quality due to high-temperature treatment. Some processes also have environmental shortcomings. Therefore, there is an urgent need in this field to develop a new pepper or litsea cubeba pretreatment softening process that is fast, clean, can be operated at medium temperatures, and avoids high-temperature damage to the quality of raw materials. Summary of the Invention

[0009] To address the aforementioned shortcomings of existing softening pretreatment methods, this invention provides a processing method and equipment for pepper or litsea cubeba, aiming to solve the technical problems of existing pretreatment processes, such as long processing time, easy generation of off-odors, easy introduction of chemical reagents, and damage to the quality of finished products due to high-temperature treatment. The entire process requires no additional water addition and has no external water consumption, and can quickly and cleanly soften the peel of fresh fruit under medium-temperature conditions, avoiding damage to the quality of materials caused by high temperatures, and providing favorable process conditions for subsequent peeling and drying processes.

[0010] The specific technical solution is as follows: This invention discloses a method for processing pepper or litsea cubeba, comprising: Place the fresh peppercorns or fresh litsea cubeba into a rotatable container; Vacuum the container until the internal pressure drops to a negative pressure at which the material can boil at or below 25°C, then stop evacuating; adjust the temperature inside the container to 55°C and maintain it; when the pressure inside the container rises back to -50kPa to -20kPa, evacuate the container again until the material boils at or below 25°C. During this cyclical process, keep the container rotating for 8-12 hours to soften the peel and make it ready for peeling.

[0011] Preferably, after completing the cycle operation, the peeling process begins: the pressure inside the container is adjusted to a range of -50 kPa to -10 kPa, and the temperature inside the container is adjusted to a range of 25°C to 55°C. During the process, the container is kept rotating until the peeling of the material is completed.

[0012] Preferably, after the cycle operation is completed, the peeling and drying process begins: the container continues to rotate, the pressure inside the container is adjusted to maintain within the range of -98kPa to -94kPa, and the container temperature is adjusted to 25℃ to 37℃ for dehydration and drying until the material reaches the preset moisture content.

[0013] Preferably, the rotational speed of the container is 3 rpm to 10 rpm.

[0014] Preferably, the peeling structure is provided on the inner wall of the container, and the material is made to collide and rub against the peeling structure to remove the fruit peel when the container is rotated.

[0015] Preferably, the amount of material loaded does not exceed one-half of the container volume.

[0016] Preferably, a condensation recovery device is provided on the pipeline used for evacuating the container to condense and collect volatile oils and cell fluids volatilized from the material during the cyclic operation.

[0017] Preferably, a condensation recovery device is provided on the pipeline used for evacuating the container, for condensing and collecting volatile oils and cell fluids volatilized from the material during cyclic operation and / or vacuum drying.

[0018] Another aspect of the present invention discloses a processing apparatus for processing pepper or litsea cubeba, comprising: A drying drum is a sealed, rotatable container used to hold materials to be processed. A vacuum generator, connected to the drying cylinder, is used to create a vacuum inside the drying cylinder; A temperature control device is installed inside the drying drum to regulate the internal temperature of the drying drum. A drive device, connected to the drying cylinder, is used to drive the drying cylinder to rotate; The control system is used to control the vacuum generator to perform vacuuming and to regulate the temperature inside the drying drum by controlling the temperature control device.

[0019] Preferably, it further includes: A peeling device is installed on the inner wall of the drying drum and is used to remove the fruit peel by colliding and rubbing with the material when the drying drum rotates; the peeling device includes multiple strip-shaped components with edges or raised threads; A condensation recovery device is connected to the extraction pipeline between the drying cylinder and the vacuum generating device.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention involves evacuating a sealed container at room temperature, allowing the cell sap contained in the fresh fruit to vaporize and boil under low negative pressure and medium temperature conditions. The fruit peel is then quickly softened by the water vapor wetting effect. No long-term soaking in water or biological fermentation is required. The entire softening process can be completed in a short time under medium temperature conditions, significantly shortening the pretreatment time and facilitating the orderly implementation of subsequent peeling and drying operations.

[0021] This invention eliminates the need for any external additives such as acids, alkalis, or enzymes, thus avoiding chemical residue pollution and wastewater treatment costs. It utilizes the natural moisture of the raw materials for negative pressure boiling to soften the peel, requiring no additional water and eliminating external water consumption. This avoids the large wastewater discharge problems associated with conventional soaking processes, meeting green and environmentally friendly production standards. The entire process operates within a medium temperature range, abandoning the traditional high-temperature cooking process. This reduces energy consumption and completely prevents the loss of heat-sensitive volatile oils and active components in pepper and litsea cubeba caused by high temperatures, maximizing the preservation of the raw materials' natural aroma while maintaining the product's inherent quality. Attached Figure Description

[0022] Figure 1 This is a process flow diagram of the method of the present invention; Figure 2 This is a flowchart of the peeling process of the present invention; Figure 3 This is a process flow diagram of peeling and drying in another embodiment of the present invention; Figure 4 This is a system functional block diagram in another embodiment of the present invention; Figure 5 This is a structural diagram of the processing equipment of the present invention; Figure 6 This is a partial sectional view of the processing equipment of the present invention; Figure 7 yes Figure 6 A magnified view of a portion of the image.

[0023] In the diagram, 1-drying cylinder, 2-bearing support, 3-cylinder cover, 4-driven gear, 5-drive device, 6-support, 7-air collecting pipe, 8-peeling device, 9-air collecting hole, 10-heating pipe, 11-door telescopic rod. Detailed Implementation

[0024] The embodiments of the invention will be described in further detail below with reference to the accompanying drawings, so that the objectives, technical solutions and technical effects of the invention will be presented more clearly.

[0025] This invention abandons the traditional process of long-term soaking in external water and high-temperature cooking. Instead, it relies on a closed, rotatable container to construct a medium-temperature negative pressure circulating phase change system, which fully utilizes the cell sap contained in the fresh fruit to achieve additive-free fruit peel softening.

[0026] like Figure 1 As shown, fresh peppercorns or fresh Litsea cubeba are first placed in a sealed rotating container, and then the container is driven to rotate. Simultaneously, the temperature inside the container is controlled to rise to a constant 55°C, while a vacuum is applied. The vacuum creates a low negative pressure environment within the sealed rotating container to significantly lower the boiling point of water. Specifically, this low negative pressure is sufficient to allow the cell sap inside the fresh fruit to boil and vaporize at temperatures of 25°C or lower. In practice, reducing the absolute pressure inside the container to approximately -100.1 kPa to -98.2 kPa (gauge pressure) is sufficient to meet the boiling requirements at temperatures between 10°C and 25°C. The water vapor generated during this process fully penetrates and wets the fruit peel fiber tissue, achieving initial swelling and softening. Specifically, it is preferable to adjust the vacuum level to match the gauge pressure range corresponding to the boiling point of the cell sap at 10°C to 25°C; alternatively, the range can be expanded to match the boiling point of 1°C to 10°C, corresponding to gauge pressures of -100.71 kPa to -100.1 kPa. To reliably achieve the aforementioned low negative pressure conditions, the vacuum pumping equipment preferentially adopts a two-stage unit consisting of a water ring pump and a rotary vane pump connected in series. The water ring pump completes the rough pumping and withstands the vaporization of water vapor, while the rotary vane pump is responsible for further fine pumping and pressure reduction. Other single vacuum pumps or pump group combinations that can achieve the target low negative pressure are also applicable. The supporting structure of this type of vacuum unit is a conventional setting in this field and will not be elaborated here.

[0027] Once the material reaches a boiling state, vacuuming is stopped, and the container is sealed and pressurized. The chamber maintains a constant temperature of 55°C throughout the process. Under initial conditions, the boiling point of water is far below 55°C. The fresh fruit cell sap continuously boils and vaporizes, causing water vapor to accumulate within the chamber and the absolute pressure to gradually increase. The boiling point temperature corresponding to this pressure rises synchronously. When the boiling point temperature exceeds 55°C and the chamber pressure rises back to above -50 kPa, vigorous boiling ceases. However, at a constant temperature of 55°C, the water continues to evaporate slowly, allowing the pressure to continue rising. Once the set pressure threshold is reached, vacuuming is restarted to reset the negative pressure. This pressure recovery range can be selected within the range of -50 kPa to -20 kPa according to process requirements.

[0028] During the cyclic operation, the container rotates continuously, and the material tumbles and scatters within the cylinder, causing gas disturbance and mixing, resulting in a uniform distribution of water vapor concentration. When vacuuming is restarted, water vapor is extracted first from the evacuation port area, causing a rapid decrease in the total system pressure. Thanks to the thorough gas-phase mixing caused by the cylinder rotation, the difference in water vapor partial pressure throughout the cylinder is minimal, and the rate of decrease in water vapor partial pressure lags only slightly behind the rate of decrease in total pressure. During the brief period when the total pressure decreases rapidly but the water vapor partial pressure has not yet decreased synchronously, the water vapor partial pressure in the gas phase is higher than the saturated vapor pressure corresponding to 55°C, indicating a supersaturated state. Water vapor condenses on the material surface, cylinder wall, and in the gas phase space, precipitating liquid water that adheres to and wets the fruit peel surface.

[0029] The condensation process releases latent heat, which, combined with the forced convection heat transfer caused by rotation, rapidly homogenizes local temperature fluctuations. As the vacuum continues, the total system pressure further decreases. When the pressure drops to below 55°C (the boiling point of water), the condensed liquid water and the cell sap inside the fresh fruit regain boiling conditions and vaporize again to replenish water vapor. Throughout the vacuum process, the cylinder undergoes a dynamic phase transition of "rapid pressure reduction → saturated condensation → continued pressure reduction → reboiling".

[0030] During the vacuuming process in a single cycle, a portion of the condensate is discharged through the suction port, while the remaining portion remains on the material surface as condensate. By repeatedly performing the cycle of "negative pressure boiling to generate steam—stopping vacuum, increasing pressure and storing steam—re-vacuuming, decreasing pressure and condensing," the amount of condensate remaining in the container increases. During the continuous treatment process of 8–12 hours, the above cycle is repeated multiple times, and the liquid in the fresh fruit cells continuously undergoes a phase change cycle of vaporization, partial discharge, and in-situ condensation. The net effect of each cycle causes the condensed free water on the fruit peel surface to continuously accumulate and gradually thicken, ultimately forming a stable and uniform in-situ immersion environment in the container.

[0031] This invention relies on the spontaneous phase change of the material's own water vapor circulation to achieve a water immersion softening effect. The entire process requires no additional water, no external water consumption, and no chemical additives such as acids, alkalis, or enzymes, thus fundamentally eliminating the problems of large amounts of wastewater and chemical residue pollution. Simultaneously, the overall softening is completed through medium-temperature water vapor immersion, avoiding the damage to heat-sensitive volatile aromas and active ingredients caused by traditional high-temperature cooking. While ensuring efficient softening of the peel and shortening the processing cycle, it maximizes the preservation of the natural quality and characteristic flavor of fresh pepper and litsea cubeba fruit, achieving efficient, clean, and medium-temperature aroma-preserving pretreatment processing.

[0032] Example 1

[0033] This embodiment uses mature fresh peppercorns as raw material and elaborates in detail the complete method and process of softening the pericarp by utilizing the phase change of pepper cell liquid. (This can be combined with...) Figure 1 As shown.

[0034] 799 kg of fresh peppercorns were loaded into a horizontal, rotatable, sealed drying drum with a volume of 6000 L, with the loading amount controlled at approximately 30% of the drum's volume. The drum lid was closed and the sealing structure was tightened, creating a completely sealed negative pressure reaction chamber within the drying drum.

[0035] The vacuum generator is activated to create a vacuum inside the drying drum, rapidly reducing the pressure to -99 kPa (gauge pressure). At this pressure, the saturated boiling point of water is approximately 22°C, far below the set temperature of 55°C inside the drum. Under this negative pressure, the cell sap inside the fresh fruit violently absorbs heat and boils, generating a large amount of water vapor. After the vacuum process stops, the water vapor continues to accumulate in the sealed space, creating a high-temperature, high-humidity environment that continuously and evenly wets the fruit peel, causing the pectin and cellulose in the peel to swell and soften rapidly.

[0036] As moisture continues to vaporize, the partial pressure of water vapor accumulates, and the total pressure inside the cylinder gradually rises. When the pressure sensor detects that the pressure inside the cylinder has risen to -35 kPa, the vacuum generator is restarted to adjust the pressure to -99 kPa. Since the material loading is only 30% of the cylinder volume, sufficient gas phase space is retained inside the cylinder; at the same time, the drying cylinder rotates continuously at a speed of 5 rpm, and the material is constantly tumbling and scattering, driving the gas inside the cylinder to continuously turbulent and mix, and the overall distribution of water vapor tends to be uniform.

[0037] When the vacuum is evacuated again, the gas near the suction port is preferentially extracted, and the total system pressure drops rapidly. Because the container rotation ensures thorough mixing of water vapor inside the cylinder, the rate of decrease in water vapor partial pressure lags slightly behind the rate of decrease in total pressure, but the spatial difference is small. During the brief window when the total pressure drops rapidly but the water vapor partial pressure has not yet decreased synchronously, the water vapor inside the cylinder reaches a supersaturated state, condensing extensively on the micro-layer of the material surface and the cylinder wall, precipitating liquid water that adheres to the fruit peel surface. The latent heat released during condensation is rapidly homogenized by the forced convection heat transfer caused by the rotation, eliminating localized temperature fluctuations.

[0038] As the vacuum continues, the total system pressure drops to -99 kPa, and the condensed liquid water and the cell sap inside the fresh fruit regain boiling conditions, vaporizing again to replenish water vapor. In a single cycle, some water vapor is discharged from the cylinder through the suction port, while the other part remains on the surface of the material as condensate.

[0039] The above-described process of "vacuuming to -99 kPa → cell sap boiling and vaporization → stopping vacuuming → pressure rising back to -35 kPa → vacuuming again" constitutes a complete cycle. Throughout this cycle, the drying drum rotates continuously at 5 rpm, causing the material to churn and condensate to distribute evenly on the fruit peel surface. This cycle continues for 10 hours, repeatedly cycling through "negative pressure boiling and steam generation – stopping vacuuming, increasing pressure and storing steam – re-vacuuming and decreasing pressure." The fresh fruit cell sap continuously undergoes a phase change cycle of vaporization, partial discharge, and partial in-situ condensation. The condensed free water on the peel surface accumulates and gradually thickens, ultimately forming a stable and uniform in-situ immersion environment around each fruit. After treatment, the fresh fruit peel is fully softened, and its binding force with the internal seeds is significantly reduced, making it easy to peel.

[0040] Example 2

[0041] This embodiment further verifies the softening effect of fresh peppercorns under different cycling parameters, demonstrating that the method of the present invention still possesses stable softening efficacy even when parameters fluctuate, and can be combined with... Figure 1 As shown.

[0042] 657 kg of fresh peppercorns were loaded into a 6000 L drying drum, filling it to approximately 26% of its volume. The drum lid was then closed to ensure a tight seal.

[0043] The vacuum generator is activated, drawing the pressure inside the cylinder to -98.3 kPa. At this pressure, the saturated boiling point of water is approximately 25°C. The cell sap inside the fresh fruit boils and vaporizes under negative pressure, at which point the vacuum process is stopped. Simultaneously, the temperature control device is activated to maintain the temperature inside the cylinder at 55°C. The boiling and vaporization of the fresh fruit cell sap under negative pressure and medium temperature conditions creates a high-temperature, high-humidity environment within the sealed space, continuously wetting the fruit peel tissue.

[0044] As moisture continues to vaporize, the pressure inside the cylinder gradually rises. When the pressure inside the cylinder reaches -25 kPa, the vacuum generator is restarted to reset the negative pressure, adjusting the pressure to -98.3 kPa. Since the loading volume is only 26% of the cylinder volume, sufficient gas phase space is retained inside the cylinder; at the same time, the drying cylinder rotates continuously at a speed of 8 rpm, and the material is constantly tumbling and scattering, driving continuous agitation and mixing of the gas inside the cylinder, resulting in a more uniform overall distribution of water vapor.

[0045] Upon re-evacuation, the total system pressure drops rapidly. Due to the rotation of the container, the water vapor inside the cylinder mixes thoroughly, and the rate of decrease in water vapor partial pressure lags slightly behind the rate of decrease in total pressure, but the spatial difference is small. During the brief window when the total pressure drops rapidly but the water vapor partial pressure has not yet decreased synchronously, the water vapor inside the cylinder reaches a supersaturated state, condensing extensively on the micro-layer of the material surface and the cylinder wall, and precipitating liquid water that adheres to the fruit peel surface. As the vacuum continues, the total system pressure drops to -98.3 kPa, and the condensed liquid water and the cell sap inside the fresh fruit regain boiling conditions, vaporizing again to replenish the water vapor. In a single cycle, some water vapor is discharged from the cylinder through the suction port, while the other part remains on the material surface as condensate.

[0046] Through multiple cycles of "negative pressure boiling steam generation—stopping extraction, increasing pressure and storing steam—re-extraction and decreasing pressure," condensate continuously accumulates on the surface of the material. Combined with the continuously replenished vapor, this gradually creates an in-situ immersion environment around the fresh fruit. During this cycle, the drying drum rotates continuously at 8 rpm for 8 hours. After this treatment, the fruit peel is fully softened, and its binding force with the internal seeds is significantly reduced, making it easy to peel.

[0047] Example 3

[0048] This embodiment uses fresh, ripe Litsea cubeba fruit as raw material.

[0049] Pack 800 kg of fresh Litsea cubeba into a 6000 L drying drum, filling it to approximately 40% of its volume. Close the drum lid to ensure a tight seal.

[0050] The vacuum generator is activated, drawing the pressure inside the cylinder to -99.5 kPa. At this pressure, the saturated boiling point of water is approximately 16°C. The cell sap inside the fresh fruit boils and vaporizes under negative pressure, at which point the vacuum process is stopped. Simultaneously, the temperature control device is activated to maintain the temperature inside the cylinder at 55°C. Under these negative pressure and medium-temperature conditions, the cell sap inside the Litsea cubeba fruit undergoes vigorous boiling and vaporization. The resulting water vapor creates a high-temperature, high-humidity environment within the sealed space, deeply wetting and softening the fruit peel.

[0051] As moisture continues to vaporize, the pressure inside the drum gradually rises. When the pressure inside the drum reaches -40 kPa, the vacuum generator is restarted to reset the negative pressure, adjusting the pressure to -99.5 kPa. The drying drum rotates continuously at 5 rpm, causing the material to tumble and the gas inside the drum to mix thoroughly. During the vacuuming process, some water vapor is discharged, while some condenses and remains on the surface of the material. Through multiple cycles, this gradually creates an in-situ immersion environment around the fresh fruit. This cycle continues for 12 hours, fully softening the pericarp of the Litsea cubeba and significantly reducing the binding force between the pericarp and the seeds.

[0052] After softening, maintain a vacuum state, adjust the temperature to 30℃, and start the drive device to continue rotating the drying drum. The peeling device on the inner wall of the drum applies gentle friction and kneading action to the softened material, causing the peel, pulp, and seeds to separate simultaneously. Vacuum drying continues, and the moisture in the separated peel and pulp continues to boil and evaporate under negative pressure and medium temperature conditions. The water vapor, carrying volatile oils and other components, enters the condensation and recovery device, where it is condensed at 0~10℃ and then separated and collected.

[0053] The material moisture content is monitored in real time by the control system. When the moisture content drops to ≤12%, the processing is complete. The vacuum generator and heating device are turned off, and the product is unloaded after the drying drum is depressurized.

[0054] The main technical specifications of this embodiment are shown in the table below:

[0055] The above data shows that the method of the present invention has a high peeling rate, retains sufficient key components of volatile oil, and simultaneously recovers by-products such as cell sap and fruit powder.

[0056] Example 4

[0057] This embodiment corresponds to the fresh peppercorns after the cyclic softening treatment described in Example 1, specifically verifying the peeling effect under normal pressure conditions. This can be combined with... Figures 1-2 As shown.

[0058] After the cycle operation in Example 1 is completed, the pressure inside the drying drum is adjusted to atmospheric pressure, and the temperature control device is adjusted to set the temperature inside the drum to 30°C. The drive device continues to drive the drying drum to rotate at a speed of 10 rpm.

[0059] During the rotation, the material tumbles and falls continuously inside the cylinder, colliding and rubbing against the peeling structure set on the inner wall of the cylinder. When the softened fresh fruit comes into repeated contact with the peeling structure, the soft peel is effectively rubbed off, while the internal pit is completely preserved because the peel has not yet been removed and the structure is dense.

[0060] The entire peeling process lasted approximately 6 hours, until visual inspection confirmed that the peel removal rate exceeded 98%.

[0061] Example 5

[0062] This embodiment, based on the cyclic softening process of Embodiment 2, further verifies the peeling treatment under a micro-negative pressure environment, which can be combined with... Figures 1-2 As shown.

[0063] After the cyclic softening operation is completed, a large amount of liquid condensed free water accumulates inside the drying cylinder due to the continuous precipitation of cell fluid during the repeated phase transition process of "negative pressure accelerated evaporation - pressure increase and condensation after pumping stop - pressure decrease and re-evaporation after pumping stop". The control system adjusts the vacuum generator to maintain the pressure inside the drying cylinder at -30 kPa, while the temperature inside the cylinder is set to 40°C through the temperature control device. The drive device maintains the continuous rotation of the drying cylinder at a speed of 8 rpm.

[0064] Under these conditions of slight negative pressure and medium temperature, the evaporation rate of water inside the cylinder is higher than that under normal pressure. However, the large amount of liquid condensed free water accumulated during the softening stage continuously coats and wets the surface of the fruit peel, providing sufficient interfacial lubrication medium and effectively reducing the binding force between the peel and the seeds, keeping the peel flexible and moist. During the tumbling process, the material continuously collides and shears against the peeling structure on the inner wall, gently peeling off the softened peel while keeping the seeds intact. The slight negative pressure also helps to remove evaporated water vapor in a timely manner, maintaining a suitable humidity inside the cylinder.

[0065] The peeling process lasts approximately 8 hours. Through program control and manual sampling, the peel removal rate remains stable at around 98.5%, and the seed damage rate is kept at a low level.

[0066] Example 6

[0067] This embodiment, based on the cyclic softening process of mature fresh pepper in Example 1, specifically verifies the integrated peeling and drying process under the combined conditions of high vacuum and medium temperature. It can be combined with... Figure 1 and Figure 3 As shown.

[0068] After the cyclic softening operation is completed, a suitable amount of condensed free water remains inside the drum. In this embodiment, this water is not discharged separately, but is directly used as a lubricating medium for the subsequent peeling stage. The drive unit maintains the drying drum at a continuous rotation speed of 10 rpm, and the control system activates the vacuum generator to draw the pressure inside the drum to and stabilize it at -96 kPa. At the same time, the temperature control device adjusts the temperature inside the drum to 33°C.

[0069] Within this high vacuum and medium temperature range, the saturated boiling point of water drops to approximately 29°C. Moisture inside and on the surface of the material continuously and steadily vaporizes at 33°C. The continuous escape of water vapor creates a slight negative pressure suction effect at the interface between the pericarp and seed, which, combined with the tumbling of the material and the frictional shearing of the peeling structure, promotes the gradual peeling of the softened pericarp. Because the operating temperature is strictly controlled below 37°C, far lower than the temperature of traditional hot air drying or steam ripening, the oxidative degradation of heat-sensitive volatile oils and active ingredients is effectively avoided. Simultaneously, the moisture carried away by continuous vaporization gradually reduces the moisture content of the material, achieving simultaneous peeling and drying.

[0070] The control system monitors the material's moisture content in real time using a moisture sensor or estimates the moisture content by weighing the condensed cell sap. When the moisture content drops to a preset dryness level of 12%, the endpoint is reached. At this point, vacuuming and heating are stopped, and the product is slowly released to atmospheric pressure before being unloaded. This process lowers the boiling point through high vacuum, allowing moisture to evaporate continuously at medium temperatures. This utilizes residual moisture for lubrication, achieving gentle peeling while avoiding damage to quality from high temperatures.

[0071] The main technical specifications of this embodiment are shown in the table below:

[0072] The above data shows that the method of the present invention has a high peeling rate, retains sufficient key components of volatile oil, and simultaneously recovers by-products such as cell sap and fruit powder.

[0073] Example 7

[0074] This embodiment, based on the cyclic softening process of mature fresh pepper in Example 2, further verifies the integrated peeling and drying effect under the drying endpoint determination strategy and process parameter conditions. It can be combined with... Figure 1 and Figure 3 As shown.

[0075] After the softening cycle is complete, the drive unit maintains the drying drum at a speed of 6 rpm. The control system activates the vacuum generator to regulate and stabilize the pressure inside the drum at -94 kPa. Simultaneously, the temperature control device sets the temperature inside the drum to 37°C.

[0076] Under these conditions of high vacuum and medium temperature, the chamber pressure of -94 kPa lowers the saturated boiling point of water to approximately 31°C. Moisture inside and on the surface of the material continuously and steadily vaporizes at 37°C. The continuous escape of water vapor creates a slight negative pressure suction effect at the interface between the pericarp and the seed, which, combined with the tumbling of the material and the frictional shearing of the peeling structure, promotes the gradual peeling of the softened pericarp. Because the operating temperature is set at 37°C, the vaporization partial pressure of the volatile oil increases simultaneously, and the water vapor carries the volatile oil into the condensation and recovery unit, achieving efficient enrichment of byproducts. At the same time, the moisture carried away by continuous vaporization gradually reduces the moisture content of the material, achieving simultaneous peeling and drying.

[0077] The material moisture content can be monitored in real time using online weighing or a moisture sensor. The endpoint is reached when the moisture content drops below the preset drying level of 12%. At this point, vacuuming and heating are stopped, and the material is discharged after pressure is released.

[0078] The main technical specifications of this embodiment are shown in the table below:

[0079] The above data shows that the method of the present invention has a high peeling rate, retains sufficient key components of volatile oil, and simultaneously recovers by-products such as cell sap and fruit powder.

[0080] Example 8

[0081] The embodiments elaborate in detail the specific structure of the special equipment used to implement the above processing method, the connection relationship of its components, and its physical support for the process principle, such as... Figures 4-7 As shown.

[0082] The processing equipment is integrated from a drying cylinder 1, a condensation recovery device, a volatile oil recovery device, a cell sap collection device, a vacuum generator, and a control system. The condensation recovery device, volatile oil recovery device, and cell sap collection device are three independent functional units, arranged sequentially. The gas phase interface of the vacuum generator is connected to the gas phase space of the condensation recovery device and / or the gas phase space of the cell sap collection device to form a complete gas extraction path.

[0083] The drying cylinder 1 is a horizontal cylindrical structure with a volume of 6000 L, made of food-grade stainless steel. The two ends of the drying cylinder 1 are supported on the bracket 6 via bearing supports 2, allowing it to rotate around its central axis. One end of the cylinder is equipped with an openable and closable cover 3. An elastic sealing ring ensures airtightness between the cover 3 and the cylinder body, used for feeding, unloading, and maintaining a negative pressure environment during processing. The opening and closing of the cover 3 is driven by a telescopic rod 11, one end of which is connected to the drying cylinder 1, and the other end to the cover 3, achieving automatic opening and closing via hydraulic or pneumatic means.

[0084] A driven gear 4 is fixed around the outer circumference of the drying cylinder 1. The driven gear 4 meshes with the driving gear at the output end of the drive device 5. The drive device 5 consists of a variable frequency motor and a reducer. By adjusting the frequency of the variable frequency motor, the drying cylinder 1 can be steplessly adjusted within the range of 0~10 r / min, ensuring that the material obtains a uniform tumbling and friction effect during processing.

[0085] The gas collecting pipe 7 is installed along the central axis of the drying cylinder 1, and one end of it is sealed to the vacuum generating device. Several gas collecting holes 9 are evenly distributed on the pipe section of the gas collecting pipe 7. The air, water vapor and volatile oil mixture in the drying cylinder 1 can be collected through each gas collecting hole 9 and enter the gas collecting pipe 7, and then discharged from the gas collecting pipe 7 towards the subsequent condensation and recovery device.

[0086] The heating device consists of stainless steel heating tubes 10 installed inside the drying cylinder 1. Multiple heating tubes 10 are arranged along the inner circumference of the drying cylinder 1 and close to its inner wall. Both ends of the heating tubes 10 are connected to the end plates of the drying cylinder 1, allowing external heat to be input into the tubes. The internal temperature of the drying cylinder 1 is adjusted by circulating hot water into the heating tubes 10. The heating device, in conjunction with a temperature sensor, performs closed-loop feedback control to regulate the internal temperature within the range of 25℃ to 55℃.

[0087] The peeling device 8 is installed inside the drying cylinder 1, and multiple sets are arranged around the circumference of the drying cylinder 1. Each set consists of multiple food-grade stainless steel strips arranged sequentially and welded along the axial direction of the drying cylinder 1. Each stainless steel strip is a strip-shaped component with ridge protrusions on its surface to increase collision friction; these ridge protrusions can be structures such as raised spiral threads. The peeling device 8 is fixedly installed near the heating tube 10 of the heating device. When the drying cylinder 1 rotates, the material inside the cylinder continuously collides and rubs against the ridge protrusions on the surface of the stainless steel strips during tumbling, causing the softened peel and pulp to separate from the seeds. The peeling device 8 can also adopt other structural forms that can improve the collision friction intensity between materials and between materials and the cylinder wall, such as raised ridges, protrusions, spiral ribs, friction teeth, and other friction protrusion structures evenly distributed along the circumference of the inner wall of the cylinder.

[0088] The condensation recovery unit is a coil condenser that can be circulated with a cooling medium. Water vapor and volatile oil vapor mixed from the gas collecting pipe 7 first enter the condensation recovery unit via a vacuum pipeline, where they condense into a liquid mixture. The outlet of the condensation recovery unit is connected to the volatile oil recovery unit via a pipeline.

[0089] The volatile oil recovery unit is an oil-water separator that receives liquid mixtures from the condensation recovery unit. The liquid mixture automatically separates into layers based on density difference within the volatile oil recovery unit, with volatile oil on top and cell sap on the bottom. The upper part of the volatile oil recovery unit has a volatile oil collection port for discharging the separated volatile oil; the lower part is connected to a cell sap collection unit via pipeline to guide the separated cell sap into the cell sap collection unit.

[0090] The cell sap collection device is an independent, sealed collection container used for temporary storage of cell sap, with a cell sap drain port at the bottom for periodic discharge. A gas phase interface is located at the top of the cell sap collection device, and a vacuum generator is connected to this gas phase interface via a vacuum pipe to extract uncondensed gases from the drying cylinder 1, the condensation recovery device, the volatile oil recovery device, and the cell sap collection device, maintaining a negative pressure environment throughout the system.

[0091] The aforementioned drying cylinder 1, gas collecting pipe 7, condensation recovery device, volatile oil recovery device, cell fluid collection device, and vacuum generator are connected by a vacuum pipeline to form a closed gas flow path, ensuring that water vapor and volatiles can be effectively extracted and recovered step by step.

[0092] It should be noted that in this embodiment, the condensation recovery device, the volatile oil recovery device, and the cell sap collection device are configured as three independent devices. Depending on actual process requirements and equipment integration requirements, the volatile oil recovery device and the cell sap collection device can also be defined as sub-functional areas within the condensation recovery device assembly, i.e., volatile oil recovery and cell sap collection are built-in functional units of the condensation recovery device assembly. The corresponding combination should still be considered as a technical solution covered by this invention.

[0093] Here, the control system uses a programmable logic controller (PLC) as its core and a touchscreen as its human-machine interface. The control system is electrically connected to the start / stop valve of the vacuum generator, the temperature controller of the heating device, and the frequency converter of the drive unit 5. The control system is also equipped with a detection unit, including a moisture sensor for detecting the moisture content of the material inside the drying drum 1, and a weight sensor for detecting the dosage of volatile oil or cell sap collected in the volatile oil recovery device and cell sap collection device. Operators can set parameters such as the vacuuming pressure threshold, temperature value, rotation speed, number of cycles, or total running time on the touchscreen. The control system automatically executes vacuuming, heating, and rotation actions according to a preset program, and monitors the temperature, pressure, and material moisture content inside the drum in real time based on feedback signals from each sensor. It automatically stops vacuuming and heating when the preset processing endpoint conditions are met, thus achieving automated operation of the processes described in Examples 1-7, which will not be elaborated further here.

[0094] Example 9

[0095] To further verify the effects of the present invention, a combination of process parameters from Examples 1 and 6 was used for actual experiments, and actual experimental data was obtained. This data was then compared with existing data obtained from publicly available literature or industry technical manuals based on conventional soaking methods, chain processing methods, and enzyme-assisted peeling and low-temperature drying methods to verify the technical effects of the present invention.

[0096] The method of this invention uses the process parameters of Examples 1 and 6.

[0097] Traditional soaking method: Soak at room temperature for 7-15 days, changing the water 2-3 times during this period; after soaking until the fruit peel is rotten and soft, take it out and rub off the fruit peel by manually stepping on it or mechanically stirring it; after peeling, rinse the seeds with clean water to remove the remaining fruit peel and pulp; finally, spread them out in the drying yard to dry naturally in the sun for 2-3 days until the moisture content reaches the standard, with a total processing cycle of 9-23 days.

[0098] Chain-processing method: Fresh peppers are put into a steam ripening equipment, and steam is introduced to soften the peel. After ripening, they are transferred to a mechanical peeling machine for peeling. The peeled seeds are sent to a hot air drying equipment and dried at 60℃ for 8 hours until the moisture content reaches the standard. The total processing cycle is 14~17 hours.

[0099] Enzyme-assisted peeling and low-temperature drying method: Fresh peppers are put into an enzymatic hydrolysis tank, and an appropriate amount of water and pectinase preparation are added. The enzymatic hydrolysis is carried out at 35~55℃ for 4~16 hours to degrade the pectin in the peel and make it soft. After the enzymatic hydrolysis is completed, the peel is removed by a mechanical peeling machine. The peeled seeds are sent to a low-temperature drying equipment and dried at 40~55℃ until the moisture content meets the standard. The total processing cycle is 2~3 days.

[0100] The comparison results of key parameters are shown in the table below:

[0101] The comparative data above show that the total processing cycle of this invention is approximately 1-2 days, significantly shorter than the 9-23 days of the traditional soaking method. This is attributed to the rapid softening of the peel through negative pressure boiling phase change of the pepper fruit cell sap. Furthermore, the maximum heating temperature is 55℃, lower than the 60℃ of the chain-based industrial technology, thus avoiding the damage to heat-sensitive volatile components caused by high temperatures as described in the background technology. This invention does not add water, acids, alkalis, enzymes, or other external media throughout the entire process, solving the problems of organic wastewater discharge and odor associated with traditional soaking methods at the source, while simultaneously recovering byproducts such as cell sap and volatile oils.

[0102] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the patent application of the present invention. All equivalent changes, substitutions or modifications made within the technical spirit and principles indicated by the present invention should be included within the scope of patent protection covered by the present invention.

Claims

1. A method for processing pepper or Chinese prickly ash, characterized in that, include: Place the fresh peppercorns or fresh litsea cubeba into a rotatable container; Vacuum the container until the internal pressure drops to a negative pressure at which the material can boil at or below 25°C, then stop evacuating; adjust the temperature inside the container to 55°C and maintain it; when the pressure inside the container rises back to -50kPa to -20kPa, evacuate the container again until the material boils at or below 25°C. During this cyclical process, keep the container rotating for 8 to 12 hours to soften the fruit peel and make it ready for peeling.

2. The method of processing pepper or Chinese prickly ash according to claim 1, characterized in that: After completing the cycle, the peeling process begins: the pressure inside the container is adjusted to a range of -50 kPa to -10 kPa, and the temperature inside the container is adjusted to a range of 25°C to 55°C. During the process, the container is kept rotating until the peeling of the material is completed.

3. The method of processing pepper or Chinese prickly ash according to claim 1, characterized in that: After the cycle is completed, the peeling and drying process begins: the container continues to rotate, the pressure inside the container is adjusted to maintain within the range of -98kPa to -94kPa, and the container temperature is adjusted to 25℃ to 37℃ for dehydration and drying until the material reaches the preset moisture content.

4. The method of processing pepper or Chinese prickly ash according to claim 1, characterized in that: The container rotates at a speed of 3 to 10 rpm.

5. The method of processing pepper or Chinese prickly ash according to claim 1, characterized in that: The peeling structure installed on the inner wall of the container removes the fruit peel by causing the material to collide and rub against the peeling structure when the container rotates.

6. The method of processing pepper or Chinese prickly ash according to claim 1, characterized in that: The amount of material loaded does not exceed one-half of the container volume.

7. The method of processing pepper or Chinese prickly ash according to claim 1, characterized in that: A condensation recovery device is installed on the pipeline used for evacuating the container to condense and collect volatile oils and cell fluids volatilized from the material during the cyclic operation.

8. The method of processing of pepper or litsea according to claim 3, wherein: A condensation recovery device is provided on the pipeline used for evacuating the container, for condensing and collecting volatile oils and cell fluids volatilized from the material during cyclic operation and / or vacuum drying.

9. A pepper or litsea processing apparatus, characterized by, For implementing the processing method according to any one of claims 1 to 8, comprising: A drying drum is a sealed, rotatable container used to hold materials to be processed. A vacuum generator, connected to the drying cylinder, is used to create a vacuum inside the drying cylinder; A temperature control device is installed inside the drying drum to regulate the internal temperature of the drying drum. A drive device, connected to the drying cylinder, is used to drive the drying cylinder to rotate; The control system is used to control the vacuum generator to perform vacuuming and to regulate the temperature inside the drying drum by controlling the temperature control device.

10. The pepper or litsea processing apparatus according to claim 9, characterized by: Also includes: A peeling device is installed on the inner wall of the drying drum and is used to remove the fruit peel by colliding and rubbing with the material when the drying drum rotates; the peeling device includes multiple strip-shaped components with edges or raised threads; A condensation recovery device is connected to the extraction pipeline between the drying cylinder and the vacuum generating device.

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