Preparation process of fruit by ultrasonic permeation combined with hot air drying

Abstract

This invention provides a fruit preparation process using ultrasonic permeation combined with hot air drying. The process includes the following steps: S1: Pre-treatment stage, selecting fresh, undamaged apples free from pests and diseases and of uniform ripeness, rinsing them with running water to remove impurities, and drying them. The fruit preparation process using ultrasonic permeation combined with hot air drying provided by this invention can effectively shorten the overall drying cycle, reduce production energy consumption, improve fruit drying efficiency, better adapt to the needs of industrial-scale production, and reduce enterprise processing costs. The final post-treatment stages of manual screening and vacuum packaging further improve product storage stability, reduce product defect rates, and improve product texture and rehydration properties, making the taste after rehydration close to that of fresh fruit, significantly increasing product added value. This process has a wide range of applications and can be widely used in the drying and processing of various common fruits.

Description

Technical Field

[0001] This invention relates to the field of fruit processing technology, and in particular to a fruit preparation process combining ultrasonic permeation and hot air drying. Background Technology

[0002] Fruit hot air drying is a processing method that uses continuously flowing warm air to dehydrate fruit slices and chunks in a closed or semi-closed environment. Through the circulation of hot air at a suitable temperature, the internal and surface moisture of the fruit is removed. Without destroying the main nutrients and flavor, the water activity is reduced to inhibit the growth of microorganisms, resulting in dried fruit products that are resistant to storage and have a soft and chewy texture. The entire drying process relies on hot air convection heat exchange, without the addition of any additional ingredients, thus preserving the original flavor and shape of the fruit.

[0003] The preparation of fruit using ultrasonic permeation combined with hot air drying is a composite fruit drying technology. First, the fruit is placed in a sugar and salt solution, and ultrasonic cavitation and mechanical effects are used to enhance permeation and dehydration, quickly removing some water and optimizing the microstructure of the material. Then, it is dried by hot air circulation, where the warm air convection carries away the residual moisture. This technology can shorten the drying time, improve mass transfer efficiency, and better preserve the flavor, color and nutrition of the fruit, producing dried fruit products that are resistant to storage and have a soft and chewy texture.

[0004] Traditional ultrasonic permeation combined with hot air drying process has several drawbacks. Single ultrasonic permeation parameters can easily cause excessive permeation on the surface of the fruit and insufficient permeation inside, resulting in uneven taste. Direct hot air drying after permeation can cause drying stress due to mismatch in moisture migration, leading to product cracking, deformation, and hardness. Constant hot air parameters can easily cause a crust to form on the surface of the fruit, prolonging the drying time and damaging heat-sensitive nutrients, causing browning. At the same time, the lack of an intermediate buffering process makes it impossible to repair the minor cell damage caused by ultrasound, further deteriorating the product texture.

[0005] Therefore, it is necessary to provide a fruit preparation process that combines ultrasonic permeation with hot air drying to solve the above-mentioned technical problems. Summary of the Invention

[0006] This invention provides a fruit preparation process combining ultrasonic permeation and hot air drying, which solves the problems of unreasonable process parameters and lack of buffering, which easily lead to poor taste, cracking and browning, nutrient damage and deterioration of fruit.

[0007] To solve the above-mentioned technical problems, the fruit ultrasonic permeation combined with hot air drying preparation process provided by the present invention includes the following steps: S1: Pre-treatment stage. Select fresh, undamaged, disease-free, and uniformly ripe apples. Rinse them with running water to remove impurities, wipe them dry, remove the stems, peels, and cores, cut them into uniform slices while controlling the thickness error, soak them in citric acid solution to protect the color, stir, then take them out, rinse, and drain.

[0008] S2: Ultrasonic permeation stage. Prepare a permeation solution of sucrose and ascorbic acid, stir to dissolve, and keep at a constant temperature for later use. Soak apple slices in the permeation solution in proportion, put them into an ultrasonic device, set the parameters for treatment, stir intermittently, and then wipe off the permeation solution on the surface after the process is completed.

[0009] S3: In the segmented tempering stage, lay the apple slices flat on a tray with gaps between them. First, place them in a constant temperature and humidity chamber for low-temperature tempering, and then adjust to medium temperature tempering while maintaining the same humidity. After completion, the slices will be free of stains and stickiness, and the moisture will be evenly distributed.

[0010] S4: Gradient hot air drying stage. First, dry at low temperature and high wind speed, then adjust to medium temperature and medium wind speed, and then high temperature and low wind speed according to the moisture content of the slices, until the moisture content of the slices reaches the specified standard.

[0011] S5: In the post-processing stage, the dried apple slices are cooled to room temperature in a clean environment at room temperature. Unqualified slices are manually screened to remove them. Qualified slices are vacuum-packed, labeled with information, and stored in a warehouse under specified conditions. In S1, the slice thickness is controlled at 2.5-3mm, with a thickness error not exceeding 0.2mm. The citric acid solution concentration is 0.4%. During soaking, it needs to be gently stirred regularly. After soaking, it is rinsed with deionized water. In S2, the permeation solution is 6%-7% sucrose solution + 0.2% ascorbic acid. The ultrasonic power is 160-180W and the frequency is 40kHz. The ultrasonic and permeation temperatures are both 28-30℃. The mass ratio of slices to permeation solution is 1:5. In S4, the drying temperatures and wind speeds for each gradient are 46-48℃ / 2.2-2.4m / s, 56-58℃ / 1.7-1.9m / s, and 66-68℃ / 1.2-1.4m / s, respectively. The corresponding moisture content nodes are 22%-25% and 15%, with a final moisture content of 12%. In S5, the packaging is a food-grade sealed bag. The storage temperature is 10-15℃ and the relative humidity is 60%. The shelf life can reach 6-8 months.

[0012] Preferably, in the S1 pretreatment stage, the total time for soaking in citric acid solution for color protection and rinsing with deionized water is controlled at 15-20 minutes, of which the soaking time for color protection accounts for no less than 60%, ensuring the color protection effect while avoiding excessive softening of the fruit slices.

[0013] Preferably, in the S2 ultrasonic permeation stage, the ultrasonic treatment and the stirring time of the permeation liquid are controlled in a coordinated manner, with stirring once every 10 minutes, and the duration of each stirring session being 30-60 seconds. The total stirring time does not exceed 15% of the total ultrasonic time, so as to avoid damaging the structure of the fruit slices.

[0014] Preferably, the total tempering time of the S3 segmented tempering stage is controlled at 40-45 minutes, wherein the ratio of low temperature tempering time to medium temperature tempering time is 1.1-1.3:1, to ensure the synergistic effect of uniform moisture distribution and cell damage repair.

[0015] Preferably, the total drying time of the S4 gradient hot air drying stage is controlled at 102-115 min, the drying time of the three stages decreases sequentially, and the difference between the drying times of two adjacent stages does not exceed 17 min, so as to achieve gradient evaporation of moisture and reduce drying stress.

[0016] The preparation equipment required in S1-S5 includes a mounting frame; A multi-segment preparation frame is mounted on top of a mounting base via a fixing bracket. From left to right, the top of the multi-segment preparation frame is equipped with a preheating mechanism, an ultrasonic generating mechanism, a humidity control device, a hot air generating mechanism, and a cooling structure. The top of the multi-segment preparation frame has multiple slots, and each slot is equipped with a partition component.

[0017] Preferably, both sides of the multi-segment preparation frame are provided with sealing covers, both sides of the multi-segment preparation frame are equipped with operating tables, and the other side of each operating table is equipped with a winding rack. The operating table includes a table surface and a support frame, and the support frame is installed at the bottom of the table surface. The tabletop is also equipped with slide rails. The opening on the tabletop is designed to facilitate placing the processed fruit slices into the perforated tray. After the sealing cover is opened, the moving component can be moved directly into the multi-segment preparation frame. A winding roller with a rope can be installed on the winding frame. By connecting one end of the rope to the connecting component, the moving component can be pulled to move inside the multi-segment preparation frame.

[0018] Preferably, the mounting base includes a base plate, a mounting structure, and an adjustment structure. The mounting structure is used to mount the adjustment structure on the bottom of the base plate. A control box with a door is mounted on the front of the mounting frame, and an operation panel is mounted on the front of the mounting frame.

[0019] Preferably, the bottom of the inner wall of the multi-segment preparation frame is provided with multiple slide rails, and a moving component is slidably connected inside the multi-segment preparation frame. The moving component includes two sealing plates, a connecting plate and multiple pulleys. The two sealing plates are installed on both sides of the connecting plate, and the pulleys are rotatably connected to the bottom of the sealing plates. Multiple perforated trays are installed between the two sealing plates. Connecting components are installed on both sides of the moving component. The connecting component includes an opening and a hanging ring, and the hanging ring is installed inside the opening. The connecting plate is located between the two sealing plates near the bottom. The pulley rolls inside the slide rail. The outer surface of the sealing plate fits against the inner surface of the multi-segment preparation frame. This ensures the sealing of the moving component in each segment without affecting its normal movement. The hanging ring is used to connect with the rope.

[0020] Preferably, the separating component includes a connecting strip and a partition, the partition being mounted at the bottom of the connecting strip.

[0021] Compared with related technologies, the fruit ultrasonic permeation combined with hot air drying preparation process provided by the present invention has the following beneficial effects: This invention provides a fruit preparation process combining ultrasonic permeation and hot air drying. This process, through precise color-protecting treatment and slice thickness control in the pretreatment stage, combined with the uniform diffusion of the permeate during ultrasonic permeation, effectively solves the problem of uneven taste (sweet on the outside, bland on the inside) in traditional drying processes. It also inhibits oxidative browning of the fruit pulp during processing, maintaining a bright and natural color and significantly improving the product's taste and appearance. Furthermore, the segmented tempering stage effectively repairs minor damage to fruit cells caused by ultrasonic treatment, balances the moisture gradient inside and outside the pulp, and alleviates drying stress. Combined with gradient hot air drying, it achieves orderly dehydration, significantly reducing the cracking and deformation rate during drying, improving the product's appearance integrity, and facilitating subsequent storage and transportation. Simultaneously, the combination of ultrasonic permeation and gradient hot air drying... Optimizing and controlling key drying parameters can effectively prevent the destruction of heat-sensitive nutrients such as vitamin C and polyphenols by continuous high temperatures, significantly improving the retention rate of nutrients and effectively enhancing the nutritional value of the product. In addition, the synergistic optimization of various process links such as pretreatment, ultrasonic penetration, segmented tempering, gradient hot air drying, and post-treatment can effectively shorten the overall drying cycle, reduce production energy consumption, improve the efficiency of fruit drying and processing, better adapt to the needs of industrial-scale production, and reduce enterprise processing costs. Finally, the manual screening and vacuum packaging processes in the post-treatment stage can further improve the product's storage stability, reduce the product defect rate, and improve the product's texture and rehydration performance, making its taste close to that of fresh fruit after rehydration, significantly increasing the product's added value. This process has a wide range of applications and can be promoted and applied to the drying and processing of a variety of common fruits. Attached Figure Description

[0022] Figure 1 A schematic diagram of the first embodiment of the fruit ultrasonic permeation combined with hot air drying preparation process provided by the present invention; Figure 2 A schematic diagram of the structure of the second embodiment of the fruit ultrasonic permeation combined with hot air drying preparation process provided by the present invention; Figure 3 A schematic diagram of the perforated tray is provided for this invention; Figure 4 Provided for the present invention Figure 3An enlarged view of point A shown; Figure 5 Provided for the present invention Figure 3 An enlarged view of point B shown; Figure 6 Provided for the present invention Figure 3 A magnified view of point C shown.

[0023] The diagram is labeled as follows: 1. Mounting base frame; 101. Base plate; 102. Mounting structure; 103. Adjustment structure; 2. Fixing frame; 3. Multi-segment preparation frame; 4. Operating table; 401. Tabletop; 402. Support; 5. Rewinding frame; 6. Sealing cover; 7. Preheating mechanism; 8. Ultrasonic generating mechanism; 9. Humidity control equipment; 10. Hot air generating mechanism; 11. Separating component; 111. Connecting strip; 112. Partition; 12. Cooling structure; 13. Operating panel; 14. Control box; 15. Box door; 16. Moving component; 161. Sealing plate; 162. Connecting plate; 163. Pulley; 17. Perforated tray; 18. Connecting component; 181. Opening; 182. Hanging ring; 19. Slide rail; 20. Socket. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] First Embodiment Please refer to the following: Figure 1 ,in, Figure 1 This is a schematic diagram of a first embodiment of the fruit ultrasonic permeation combined with hot air drying preparation process provided by the present invention. The fruit ultrasonic permeation combined with hot air drying preparation process includes the following steps: S1: Pre-treatment stage. Select fresh, undamaged, disease-free, and uniformly ripe apples. Rinse them with running water to remove impurities, wipe them dry, remove the stems, peels, and cores, cut them into uniform slices while controlling the thickness error, soak them in citric acid solution to protect the color, stir, then take them out, rinse, and drain.

[0026] S2: Ultrasonic permeation stage. Prepare a permeation solution of sucrose and ascorbic acid, stir to dissolve, and keep at a constant temperature for later use. Soak apple slices in the permeation solution in proportion, put them into an ultrasonic device, set the parameters for treatment, stir intermittently, and then wipe off the permeation solution on the surface after the process is completed.

[0027] S3: In the segmented tempering stage, lay the apple slices flat on a tray with gaps between them. First, place them in a constant temperature and humidity chamber for low-temperature tempering, and then adjust to medium temperature tempering while maintaining the same humidity. After completion, the slices will be free of stains and stickiness, and the moisture will be evenly distributed.

[0028] S4: Gradient hot air drying stage. First, dry at low temperature and high wind speed, then adjust to medium temperature and medium wind speed, and then high temperature and low wind speed according to the moisture content of the slices, until the moisture content of the slices reaches the specified standard.

[0029] S5: In the post-processing stage, the dried apple slices are cooled to room temperature in a clean environment at room temperature. Unqualified slices are manually screened to remove them. Qualified slices are vacuum-packed, labeled with information, and stored in a warehouse under specified conditions. In S1, the slice thickness is controlled at 2.5-3mm, with a thickness error not exceeding 0.2mm. The citric acid solution concentration is 0.4%. During soaking, it needs to be gently stirred regularly. After soaking, it is rinsed with deionized water. In S2, the permeation solution is 6%-7% sucrose solution + 0.2% ascorbic acid. The ultrasonic power is 160-180W, the frequency is 40kHz, and the ultrasonic and permeation temperatures are both 28-30℃. The mass ratio of slices to permeation solution is 1:5. In S4, the drying temperatures and wind speeds at each gradient are 46-48℃ / 2.2-2.4m / s, 56-58℃ / 1.7-1.9m / s, and 66-68℃ / 1.2-1.4m / s, respectively. The corresponding moisture content nodes are 22%-25% and 15%, with a final moisture content of 12%. In S5, the packaging is a food-grade sealed bag. The storage temperature is 10-15℃, the relative humidity is 60%, and the shelf life can reach 6-8 months. When selecting fruits, strict screening is necessary to ensure that each fruit is fresh, undamaged, free from pests and diseases, and uniformly ripe to avoid affecting processing quality due to individual differences. Use running water for rinsing, paying particular attention to cleaning impurities from crevices on the fruit surface. Dry the fruit with a sterile soft cloth to prevent secondary contamination. Thoroughly disinfect knives before slicing. Precisely control the thickness of slices to avoid exceeding tolerances. During citric acid solution soaking, stir gently and periodically. After soaking, rinse thoroughly with deionized water and allow to drain naturally; do not squeeze. When preparing the mixed permeation solution, stir thoroughly to ensure complete dissolution of sucrose and ascorbic acid. Store at a constant temperature away from direct sunlight. Ensure slices are completely submerged during soaking. Strictly adhere to the set parameters during ultrasonic treatment, stirring gently at intervals. The drying time should not be too long. When absorbing surface liquid, use sterile absorbent paper to gently press to avoid damaging the slices. The tray should be sterilized in advance during the slow recovery process. Slices should be laid flat without overlap and with uniform spacing. The transition from low temperature to medium temperature should be slow to prevent sudden temperature changes that could cause the slices to crack. Abnormal slices should be checked and removed regularly throughout the process. Before gradient drying, check the equipment air ducts. Slices should be laid flat evenly. Each gradient should be switched only after the equipment parameters have stabilized. Moisture content should be sampled and tested throughout the process to ensure it meets the standards. Cooling should be carried out in a clean environment at room temperature. Unqualified slices should be carefully removed during screening. Food-grade sealed bags should be used for vacuum packaging, with all air removed and the information clearly labeled. Warehouse storage should maintain the specified temperature and humidity. Slices should be stored away from walls and the ground. Regular checks should be conducted to prevent moisture and mold growth.

[0030] In the S1 pretreatment stage, the total time for soaking in citric acid solution for color protection and rinsing with deionized water is controlled at 15-20 minutes, with the soaking time for color protection accounting for no less than 60%, ensuring the color protection effect while avoiding excessive softening of the fruit slices.

[0031] During the S2 ultrasonic permeation stage, the time for ultrasonic treatment and permeation liquid stirring is controlled in a coordinated manner. Stirring is performed once every 10 minutes, with each stirring session lasting 30-60 seconds. The total stirring time does not exceed 15% of the total ultrasonic time to avoid damaging the fruit slice structure.

[0032] The total tempering time of the S3 segmented tempering stage is controlled at 40-45 minutes, with the ratio of low temperature tempering time to medium temperature tempering time being 1.1-1.3:1, to ensure the synergistic effect of uniform moisture distribution and cell damage repair.

[0033] The total drying time of the S4 gradient hot air drying stage is controlled at 102-115 min. The drying time of the three stages decreases sequentially, and the difference between the drying times of two adjacent stages does not exceed 17 min, so as to achieve gradient evaporation of moisture and reduce drying stress.

[0034] The working principle of the fruit ultrasonic permeation combined with hot air drying preparation process provided by this invention is as follows: This process achieves a harmonious balance between efficient drying and quality protection through the coordinated operation of multiple stages, including pretreatment, ultrasonic permeation, segmented tempering, gradient hot air drying, and post-treatment. The overall process is tightly integrated and parameters are precisely controlled, significantly improving the overall quality of dried fruit products. In the pretreatment stage, target fruits with 8-9% maturity, sufficient flavor compound accumulation, and suitable flesh firmness are selected and sequentially washed, peeled, cut, and color-protected. This thoroughly removes surface dirt, residual impurities, and harmful microorganisms, ensuring strict uniformity in slice thickness and shape to guarantee uniform heat and mass transfer during subsequent processing. Simultaneously, appropriate... Soaking the fruit pieces in a suitable concentration of citric acid solution for color protection effectively inhibits the activity of polyphenol oxidase in the pulp, preventing oxidative browning during subsequent processing and maintaining the original color of the product. This lays a good foundation for the stable operation of subsequent process steps. The ultrasonic penetration stage uses ultrasound at a set frequency and power for assisted treatment. Utilizing the cavitation effect and mechanical vibration generated by ultrasound, the dense cuticle and wax layer of the fruit peel are gently broken down, clearing the internal channels for water and solute migration. This promotes the rapid and even diffusion of the penetrant containing sucrose and ascorbic acid into the pulp. Simultaneously, the penetration environment is strictly controlled. Under constant temperature conditions, while ensuring sufficient penetration, the integrity of the fruit pulp cells is maintained to the greatest extent, avoiding problems such as cell structure rupture and juice loss caused by excessively high parameters. The segmented tempering stage utilizes a constant temperature and humidity environment, with two temperature gradients (low and medium) to promote the smooth migration of moisture from the inside to the outside of the fruit pulp, balancing the internal and external moisture gradients. This effectively repairs minor cell damage caused by ultrasonic treatment and alleviates drying stress caused by differences in moisture evaporation rates during subsequent drying. This fundamentally prevents defects such as cracking, deformation, and uneven texture in the product. The gradient hot air drying process is based on the fruit pulp's condition... By adjusting the hot air temperature and airflow speed according to the moisture content and migration characteristics at different drying stages, the moisture can be evaporated in an orderly and gradual manner. This prevents the surface of the fruit pulp from rapidly forming a crust due to high temperature, which would hinder the escape of internal moisture. At the same time, it reduces the damage of heat-sensitive nutrients such as vitamins and polyphenols caused by continuous high temperature, thereby reducing nutrient loss and flavor deterioration. In the post-processing stage, the dried products are naturally cooled, manually graded and screened, and vacuum-packed in sequence. Products that do not meet the requirements in terms of appearance, color, and texture are removed, stabilizing the final quality of the product and isolating it from external air, moisture, and microorganisms, effectively extending the product's storage period and shelf life.

[0035] Compared with related technologies, the fruit ultrasonic permeation combined with hot air drying preparation process provided by the present invention has the following beneficial effects: This process, through precise color-protecting treatment and slice thickness control in the pretreatment stage, combined with the uniform diffusion of the penetrant during ultrasonic penetration, effectively solves the problem of uneven taste (sweet on the outside, bland on the inside) in traditional drying processes. It also inhibits oxidative browning of the fruit pulp during processing, maintaining a bright and natural color and significantly improving the product's taste and appearance. Furthermore, the segmented tempering stage effectively repairs minor damage to fruit cells caused by ultrasonic treatment, balances the moisture gradient inside and outside the pulp, and alleviates drying stress. Combined with gradient hot air drying, it achieves orderly dehydration, significantly reducing cracking and deformation rates during drying, improving product appearance integrity, and facilitating subsequent storage and transportation. Additionally, through optimized control of key parameters in ultrasonic penetration and gradient hot air drying, it can... This process effectively avoids the damage to heat-sensitive nutrients such as vitamin C and polyphenols caused by continuous high temperatures, significantly improving the retention rate of nutrients and enhancing the nutritional value of the product. Furthermore, the synergistic optimization of various processes, including pretreatment, ultrasonic penetration, segmented tempering, gradient hot air drying, and post-treatment, effectively shortens the overall drying cycle, reduces production energy consumption, and improves fruit drying efficiency. It better meets the needs of industrial-scale production, reduces enterprise processing costs, and the final manual sorting and vacuum packaging processes further enhance product storage stability, reduce product defect rates, and improve product texture and rehydration properties, making the taste of rehydrated fruit closer to that of fresh fruit, significantly increasing the added value of the product. This process has a wide range of applications and can be widely used in the drying and processing of various common fruits.

[0036] Second Embodiment Please refer to the following: Figures 2-3 - Figures 4-5 - Figure 6 , Figure 2 A schematic diagram of the structure of the second embodiment of the fruit ultrasonic permeation combined with hot air drying preparation process provided by the present invention; Figure 3 A schematic diagram of the perforated tray is provided for this invention; Figure 4 Provided for the present invention Figure 3 An enlarged view of point A shown; Figure 5 Provided for the present invention Figure 3 An enlarged view of point B shown; Figure 6 Provided for the present invention Figure 3 The enlarged view at point C shows a different fruit preparation process based on the ultrasonic permeation combined with hot air drying provided in the first embodiment of this application. The second embodiment of this application proposes another ultrasonic permeation combined with hot air drying process for fruit preparation. The second embodiment is merely a preferred embodiment of the first embodiment, and its implementation will not affect the individual implementation of the first embodiment.

[0037] Specifically, the difference in the fruit ultrasonic permeation combined with hot air drying preparation process provided in the second embodiment of this application is that the preparation equipment required in S1-S5 includes the mounting frame 1; The multi-segment preparation frame 3 is mounted on the top of the mounting base 1 via a fixing frame 2. From left to right, the top of the multi-segment preparation frame 3 is equipped with a preheating mechanism 7, an ultrasonic generating mechanism 8, a humidity control device 9, a hot air generating mechanism 10, and a cooling structure 12. The top of the multi-segment preparation frame 3 has multiple slots 21, and each slot 21 is equipped with a partition component 11. The preheating mechanism 7 consists of a constant-temperature heating wire, a rock wool insulation layer, and a mercury thermometer. The heating power is manually adjusted, and the temperature is stabilized with the insulation layer to provide a suitable constant-temperature environment for processing. The ultrasonic generating mechanism 8 contains four ultrasonic transducers, a manual power adjustment knob, and a power switch to generate 40kHz ultrasonic waves. The cavitation and vibration effects are used to break the cuticle layer of the fruit peel. The humidity control device 9 consists of a manual water-adding humidity adjustment box, a vent, and a hygrometer. Distilled water is manually added, and the adjustment range is 60%-70% to maintain the humidity required for slow drying. The hot air generating mechanism 10 contains an electric heating wire and a manually adjustable fan. The temperature is manually controlled at 40-70℃ and the wind speed is 1.2-2.4m / s to generate hot air for gradient drying of the fruit slices. The cooling structure 12 consists of a manually controlled exhaust fan and an exhaust port. The exhaust fan is manually turned on, and heat is drawn away through the exhaust port to quickly cool the dried fruit slices to room temperature. The separating component 11 can manually divide the multi-segment preparation frame 3 into multiple segments.

[0038] Please refer to Figure 2 Both sides of the multi-segment preparation frame 3 are provided with sealing covers 6, and both sides of the multi-segment preparation frame 3 are provided with operating tables 4. Each operating table 4 is provided with a winding rack 5 on the other side. The operating table 4 includes a table surface 401 and a support frame 402. The support frame 402 is installed at the bottom of the table surface 401. The tabletop 401 is also equipped with a slide rail 19. The opening on the tabletop 401 is designed to facilitate placing the processed fruit slices into the perforated tray 17. After the sealing cover 6 is opened, the moving component 16 can be moved directly into the multi-segment preparation frame 3. A winding roller with a rope can be installed on the winding frame 5. By connecting one end of the rope to the connecting component 18, the moving component 16 can be pulled to move inside the multi-segment preparation frame 3.

[0039] Please refer to Figure 2 and Figure 3 The mounting base 1 includes a base plate 101, a mounting structure 102 and an adjustment structure 103. The mounting structure 102 is used to mount the adjustment structure 103 on the bottom of the base plate 101. A control box 14 with a door 15 is mounted on the front of the mounting frame 2. An operation panel 13 is mounted on the front of the mounting frame 2. The threaded connection between the mounting structure 102 and the adjustment structure 103 can adjust the stability of the base plate 101 as needed. The operation panel 13 can set the equipment operating parameters. The control box 14 is equipped with a power switch and a controller for the operation of auxiliary equipment.

[0040] Please refer to Figure 3 and Figure 5 The bottom of the inner wall of the multi-segment preparation frame 3 is provided with multiple slide rails 19. The interior of the multi-segment preparation frame 3 is slidably connected with a moving component 16. The moving component 16 includes two sealing plates 161, a connecting plate 162 and multiple pulleys 163. The two sealing plates 161 are installed on both sides of the connecting plate 162, and the pulleys 163 are rotatably connected to the bottom of the sealing plates 161. Multiple perforated trays 17 are installed between the two sealing plates 161. The moving component 16 is equipped with a connecting component 18 on both sides. The connecting component 18 includes an opening 181 and a hanging ring 182. The hanging ring 182 is installed inside the opening 181. The connecting plate 162 is located between the two sealing plates 161 near the bottom. The pulley 163 rolls inside the slide rail 19. The outer surface of the sealing plate 161 is in contact with the inner surface of the multi-segment preparation frame 3. This ensures the sealing of the moving component 16 in each segment without affecting the normal movement of the moving component 16. The hanging ring 182 is used to connect with the rope.

[0041] Please refer to Figure 3 and Figure 6 The partition assembly 11 includes a connecting strip 111 and a partition 112, with the partition 112 mounted on the bottom of the connecting strip 111; The partition 112 is inserted into the socket 20.

[0042] Compared with related technologies, the fruit ultrasonic permeation combined with hot air drying preparation process provided by the present invention has the following beneficial effects: To achieve seamless integration of processing steps in the hot air drying of fruits, and to precisely control key parameters such as ultrasound, temperature, humidity, and wind speed, ensuring coordinated operation of each process while reducing material transfer losses and contamination, improving processing efficiency, and lowering labor costs, a base frame 1 is installed to fix the overall structure. A multi-segment preparation frame 3 is divided into functional sections. Combined with a preheating mechanism 7, an ultrasonic generator 8, a humidity control device 9, a hot air generator 10, and a cooling structure 12, precise temperature, humidity, and speed control are achieved, ensuring uniform penetration and consistent drying of the fruit slices, reducing cracking and browning, and preserving nutrients. A perforated tray 17 carries the fruit slices, and with the help of ropes and a winding rack 5, certain components 16 can move along the slide rail 19. Furthermore, a separating component 11 achieves sealed separation of each section. After the fruit slices enter, the preheating mechanism 7 preheats and controls the temperature. The ultrasonic generator 8 produces ultrasonic waves to promote penetration, the humidity control device 9 maintains a gentle humidity level, the hot air generator 10 achieves gradient drying, the cooling structure 12 removes heat and cools the product, and the operation panel 13 allows for manual control of each mechanism. This design adopts an integrated structure to reduce material loss, and the various mechanisms work together to solve problems such as uneven penetration and high drying stress. The separating component 11 ensures stable parameters in each section, and the preheating mechanism 7 and humidity control device 9 provide precise temperature and humidity control to improve product quality. The perforated tray 17 and slide rail 19 ensure smooth conveying, the cooling structure 12 accelerates cooling and improves processing efficiency, the overall structure is stable, the mounting base 1 and fixed frame 2 enhance stability, the movable component 16 facilitates flexible placement, manual operation is convenient, it is suitable for large-scale processing, reduces costs, and minimizes loss and contamination during material handling.

[0043] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A fruit preparation process combining ultrasonic permeation and hot air drying, characterized in that, Includes the following steps: S1: Pre-treatment stage: Select fresh, undamaged, disease-free, and uniformly ripe apples, rinse them with running water to remove impurities, wipe them dry, remove the stems, peels and cores, cut them into uniform slices and control the thickness error, soak them in citric acid solution to protect the color, stir, take them out, rinse and drain. S2: Ultrasonic permeation stage, prepare a mixed permeation solution of sucrose and ascorbic acid, stir to dissolve and keep at a constant temperature for later use; soak apple slices in the permeation solution in proportion, put them into the ultrasonic equipment and set the parameters for treatment, stir intermittently, and after the end, wipe off the surface permeation solution; S3: Segmented tempering stage. Lay apple slices flat on a tray with gaps between them. First, place them in a constant temperature and humidity chamber for low-temperature tempering, then keep the humidity constant and adjust to medium temperature tempering. After completion, the slices will be free of stains and stickiness, and the moisture will be evenly distributed. S4: Gradient hot air drying stage, first dry at low temperature and high wind speed, then adjust to medium temperature and medium wind speed, then high temperature and low wind speed according to the moisture content of the slices, until the moisture content of the slices reaches the specified standard. S5: In the post-processing stage, the dried apple slices are cooled to room temperature in a clean environment. Unqualified slices are manually screened to remove them. Qualified slices are vacuum-packed, labeled with information, and stored in a warehouse under specified conditions.

2. The fruit ultrasonic permeation combined with hot air drying preparation process according to claim 1, characterized in that, In the S1 pretreatment stage, the total time for soaking in citric acid solution for color protection and rinsing with deionized water is controlled at 15-20 minutes, with the soaking time for color protection accounting for no less than 60%, ensuring the color protection effect while avoiding excessive softening of the fruit slices.

3. The fruit ultrasonic permeation combined with hot air drying preparation process according to claim 1, characterized in that, In the S2 ultrasonic permeation stage, the ultrasonic treatment and permeation liquid stirring time are controlled in a coordinated manner. Stirring is performed once every 10 minutes, with each stirring session lasting 30-60 seconds. The total stirring time does not exceed 15% of the total ultrasonic time to avoid damaging the fruit slice structure.

4. The fruit ultrasonic permeation combined with hot air drying preparation process according to claim 1, characterized in that, The total tempering time of the S3 segmented tempering stage is controlled at 40-45 minutes, with the ratio of low temperature tempering time to medium temperature tempering time being 1.1-1.3:1, to ensure the synergistic effect of uniform moisture distribution and cell damage repair.

5. The fruit ultrasonic permeation combined with hot air drying preparation process according to claim 1, characterized in that, The total drying time of the S4 gradient hot air drying stage is controlled at 102-115 min, with the drying time of the three stages decreasing sequentially, and the difference between the drying times of two adjacent stages not exceeding 17 min, so as to achieve gradient evaporation of moisture and reduce drying stress.

6. The fruit ultrasonic permeation combined with hot air drying preparation process according to claim 1, wherein the preparation equipment used in steps S1-S5 is characterized in that, Includes mounting base; A multi-segment preparation frame is mounted on top of a mounting base via a fixing bracket. From left to right, a preheating mechanism, an ultrasonic generating mechanism, a humidity control device, a hot air generating mechanism, and a cooling structure are sequentially installed on the top of the multi-segment preparation frame. An insertion port is provided on the top of the multi-segment preparation frame, and a partition component is provided inside each insertion port.

7. The fruit ultrasonic permeation combined with hot air drying preparation process according to claim 6, characterized in that, Both sides of the multi-segment preparation frame are provided with sealing covers, and both sides of the multi-segment preparation frame are equipped with operating tables. The other side of each operating table is equipped with a winding rack. The operating table includes a tabletop and a support frame, and the support frame is installed at the bottom of the tabletop.

8. The fruit ultrasonic permeation combined with hot air drying preparation process according to claim 6, characterized in that, The mounting base includes a base plate, a mounting structure, and an adjustment structure. The mounting structure is used to install the adjustment structure at the bottom of the base plate. A control box with a door is mounted on the front of the mounting frame, and an operation panel is mounted on the front of the mounting frame.

9. The fruit ultrasonic permeation combined with hot air drying preparation process according to claim 6, characterized in that, The bottom of the inner wall of the multi-segment preparation frame has multiple slide rails. A moving component is slidably connected inside the multi-segment preparation frame. The moving component includes a sealing plate, a connecting plate, and pulleys. The sealing plate is installed on both sides of the connecting plate. The pulleys are rotatably connected to the bottom of the sealing plate. A perforated tray is installed between the sealing plates. A connecting component is installed on both sides of the moving component. The connecting component includes an opening and a hanging ring. The hanging ring is installed inside the opening.

10. The fruit ultrasonic permeation combined with hot air drying preparation process according to claim 6, characterized in that, The separator assembly includes a connecting strip and a partition, the partition being mounted at the bottom of the connecting strip.

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