Pretreatment process and pretreatment equipment for antioxidant storage of hickory nuts

Abstract

The invention belongs to the technical field of hickory nut storage, and discloses a hickory nut anti-oxidation storage pretreatment process and pretreatment equipment, and the process comprises the following steps: S1, sorting freshly picked and cleaned hickory nuts through the pretreatment equipment, and removing empty and shriveled seeds, bad seeds and the like; s2, screening the hickory nuts without empty and shriveled seeds, bad seeds and the like through pretreatment equipment in a unified manner to distinguish small, medium and large hickory nuts, and respectively feeding the hickory nuts into different assembly lines for spraying antioxidant and edible coating liquid; s3, the small, medium and large carya cathayensis fruits sprayed with the coating liquid enter different intelligent controlled atmosphere all-in-one machines to be subjected to controlled atmosphere treatment, and low-temperature storage is combined, so that the storage period of the carya cathayensis fruits with shells is prolonged to 6-8 months, and the storage period of the shelled carya cathayensis kernels is prolonged to 3-4 months; wherein during the controlled atmosphere treatment, the concentration of oxygen is 2-5%, the concentration of carbon dioxide is 3-5%, and the balance is nitrogen. According to the low-oxygen environment, moisture evaporation and nutrient consumption of the nuts are reduced, the freshness of the nuts can be kept, and peculiar smells caused by oxidation are avoided.

Description

Technical Field

[0001] This invention relates to the field of pecan storage technology, and in particular to a pretreatment process and equipment for antioxidant storage of pecans. Background Technology

[0002] Pecans, a unique nut with both high nutritional and economic value, are rich in unsaturated fatty acids, protein, and minerals, making them a popular health food among consumers. However, pecans face severe quality deterioration challenges during post-harvest storage, particularly due to the negative effects of oxidation and respiration. Under natural ventilation, fresh, shelled pecans typically only last 1-2 months. Within these short months, continuous oxidation leads to rancidity of the kernel oils, while respiration depletes internal nutrients, causing the kernels to shrivel and lose flavor, severely hindering the large-scale development of the pecan industry.

[0003] To extend the shelf life of pecans, the industry has tried various treatment methods. A common technique involves immersing the pecans in a prepared preservation solution, hoping to form a protective film on their surface that blocks oxygen and prevents oil oxidation and rancidity. However, some empty pecans inevitably remain after harvesting. Before implementing measures to extend the shelf life of pecans, it is often necessary to select them to remove empty pecans, otherwise the quality of the same batch of pecans may be affected. However, relying on manual selection is not only labor-intensive but also inefficient. Therefore, the relevant technology needs to be improved and designed. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a pretreatment process and equipment for antioxidant storage of pecans.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution: a pretreatment process for antioxidant storage of pecans, comprising the following steps: S1. Freshly picked and washed walnuts are sorted using pre-processing equipment to remove empty, shriveled, and bad walnuts. S2. Hollow, shriveled and bad pecans are removed and screened by pre-processing equipment to distinguish between small, medium and large fruits. They are then sprayed with an antioxidant and edible coating liquid on different production lines. S3. After the coating liquid is sprayed, small, medium and large fruits are put into different intelligent modified atmosphere integrated machines for modified atmosphere treatment. Combined with low temperature storage, the storage period of shelled pecans is extended to 6-8 months, and the storage period of shelled kernels is extended to 3-4 months. During controlled atmosphere treatment, the oxygen concentration is 2%-5%, the carbon dioxide concentration is 3%-5%, and the remainder is nitrogen.

[0006] By adopting the above technical solutions, the pretreatment equipment can not only screen and remove empty and shriveled kernels, but also distinguish between small, medium, and large kernels, ensuring the uniformity of quality within the same batch of pecans. The pretreatment equipment sprays an antioxidant and edible coating solution onto different production lines, forming an antioxidant protective film on the surface of the pecans, which extends their shelf life to a certain extent. The low-oxygen environment reduces moisture evaporation and nutrient consumption in the kernels, maintaining their freshness and preventing off-flavors caused by oxidation.

[0007] Furthermore, by weight percentage, the edible coating liquid comprises the following raw materials: 2%-3% chitosan, 0.5%-1% tert-butylhydroquinone, 0.1%-0.15% Tween-80, with the balance being water.

[0008] By adopting the above technical solution, the chitosan membrane can block more than 70% of oxygen permeation. Tert-butylhydroquinone, as a highly efficient antioxidant, can inhibit the rancidity of oils and the deterioration of flavor caused by oxidation during the storage of pecans. By capturing free radicals and blocking the oxidation chain reaction, it can delay the decline in the quality of pecans and thus extend their storage period without affecting their edibility. When combined with chitosan, Tween-80 and other components, it can enhance the preservation effect of the coating.

[0009] This application also discloses a pretreatment device according to the aforementioned pretreatment process for antioxidant storage of hickory nuts, including a first frame, a second frame located on one side of the first frame, and a screening mechanism located on the side of the second frame away from the first frame for distinguishing small, medium, and large nuts. A feeding rack and a transfer rack located on one side of the first frame and lower than the feeding rack are fixed on the top of the first frame. The extension direction of the transfer rack is parallel to the extension direction of the feeding rack. A feeding hopper for conveying hickory nuts to the screening mechanism is fixed on the top of the second frame. A feeding conveyor belt and a transfer conveyor belt are respectively installed in the feeding rack and the transfer rack. A near-infrared spectrometer for detecting empty and shriveled nuts in the hickory nuts conveyed by the feeding conveyor belt is installed in the frame on one side of the feeding rack. A transfer component for conveying the hickory nuts that have been conveyed by the feeding conveyor belt and have passed screening to the transfer conveyor belt is installed at the bottom of the feeding rack.

[0010] Furthermore, the transfer assembly includes a fixing plate fixed to the bottom of the feeding rack, a cylinder fixed to the fixing plate, a connecting block fixed to the end of the piston rod of the cylinder, and a transfer plate fixed to the top of the connecting block. The transfer plate has a U-shaped cross-section, with the upper end of the transfer plate near the bottom of the feeding rack and the lower end of the transfer plate near the top of the transfer rack.

[0011] Furthermore, connecting rods are fixed on both sides of the transfer plate, and a baffle block is fixed at the end of the two connecting rods away from the transfer plate. The baffle block is used to block the walnuts on the feeding conveyor belt from continuing to be transported forward during the process of the transfer plate retracting to the bottom of the feeding frame. A collection frame is set on the first frame to collect the fallen empty walnuts.

[0012] By adopting the above technical solution, the near-infrared spectrometer 112 can help determine whether a pecan is empty or shriveled by detecting the internal moisture content. Empty pecans, due to incomplete development, have underdeveloped kernels and their moisture content typically differs from that of normal, plump pecans. Near-infrared spectroscopy can acquire the spectral information of pecans non-contactly, analyze their moisture content based on characteristic absorption peaks, and then establish a discrimination model by combining the difference in moisture content between empty and normal pecans, thereby achieving non-destructive identification of empty pecans. When an empty pecan is detected, the control system of the pre-processing equipment controls the cylinder to operate, causing the piston rod of the cylinder to retract to the bottom of the feeding rack via a connecting block. This prevents pecans rolling off the feeding conveyor belt from rolling onto the transfer conveyor belt via the transfer plate of the transfer component, ultimately causing them to fall into the collection box. Simultaneously, the baffle block can block the pecans on the feeding conveyor belt from continuing to move forward during the retraction of the transfer plate to the bottom of the feeding rack, preventing subsequent pecans from falling into the collection box without proper ripeness selection. When the near-infrared spectrometer determines that the fruit is ripe, the control system controls the cylinder to run and reset the transfer plate. This causes the walnuts that have rolled off the feeding conveyor belt to roll onto the transfer conveyor belt via the transfer plate, and finally enter the screening mechanism through the feeding hopper for further processing.

[0013] Furthermore, a first mounting frame is provided on the side of the second frame away from the first frame. The screening mechanism includes a screening component, which includes a screening barrel rotatably mounted on the first mounting frame and tilted. The tilt angle of the screening barrel is 2-3 degrees. The end of the screening barrel near the second frame is higher than the end of the screening barrel away from the second frame. The end of the screening barrel near the second frame is provided with a feed inlet for the discharge end of the feed hopper to enter. Multiple screening holes are evenly provided on the side wall of the screening barrel. The screening holes on the side wall of the screening barrel are divided into three sections, and the diameter of the three sections of screening holes increases sequentially from the second frame to the side away from the first frame. The screening mechanism also includes a rotating component for driving the screening barrel to rotate. The pretreatment equipment also includes three sets of spraying mechanisms for spraying edible coating liquid onto the screened pecans.

[0014] Furthermore, the screening assembly also includes a spiral protrusion fixed to the inner wall of the screening barrel, and the rotating assembly includes an extension plate fixed to the first mounting frame, a rotary motor fixed to the extension plate, a drive gear fixed to the output end of the rotary motor, and a driven gear fixedly sleeved on the screening barrel and meshing with the drive gear.

[0015] By adopting the above technical solution, after the rotary motor works and drives the drive gear to rotate, the driven gear meshing with the drive gear and the screening barrel fixed to the driven gear will both rotate, so that the pecans entering the screening barrel will roll away from the second frame (the tilt angle of the screening barrel ensures the direction of the pecans' rolling). Under the action of the spiral convex strip, the pecans are screened in sequence through the three screening holes on the side wall of the screening barrel for small, medium and large fruits. The screened fruits enter different production lines for edible coating liquid spraying.

[0016] Furthermore, the spraying mechanism includes a conveying assembly, which includes a second mounting frame disposed on one side of the first mounting frame, a walnut conveying groove fixed to the top of the second mounting frame, and a receiving hopper fixed to one end of the walnut conveying groove for receiving walnuts falling from the screening holes. The intersection of adjacent receiving hoppers is located at the intersection of adjacent screening holes. The walnut conveying groove is inclined at an angle of 2-3 degrees, and the height of the end of the walnut conveying groove near the screening barrel is greater than the height of the end of the walnut conveying groove away from the screening barrel. The spraying mechanism also includes a spraying assembly disposed on the top of the walnut conveying groove.

[0017] Furthermore, multiple arc-shaped mounting plates evenly distributed along the length of the walnut conveying ditch are fixed on the inner bottom wall. Each arc-shaped mounting plate has a rubber speed bump fixed on its inner bottom surface. The height of the middle of the rubber speed bump is greater than the height of its two ends. A V-shaped elastic sheet is fixed between the inner top of the rubber speed bump and the inner bottom wall of the arc-shaped mounting plate. The number of spraying components is equal to the number of rubber speed bumps and their positions correspond one-to-one. The spraying components include a diversion pipe set above the walnut conveying ditch, a nozzle fixed and connected to the bottom of the diversion pipe, a feed pipe fixed and connected to the side wall of the diversion pipe, a solenoid valve set on the feed pipe, and a hose connected to both the feed pipe and the external feeding system. Each diversion pipe has three nozzles, which are respectively oriented towards the area before entering the rubber speed bump, the area reaching the center of the rubber speed bump, and the area after leaving the rubber speed bump.

[0018] By adopting the above technical solution, the pecans falling from the screening holes of the screening barrel enter their respective receiving hoppers, and then enter the pecan conveying groove. Under the action of different rubber speed belts in the pecan conveying groove, the speed of the pecans conveyed along the groove is kept within a certain range. Due to the V-shaped elastic plate at the bottom of the rubber speed belt, the pecans are effectively turned multiple times during the rolling process. The edible coating liquid input by the external feeding system is pressurized and then fed into the distribution pipe through the hose. Subsequently, the spray nozzles evenly spray the pecans that have passed through the rubber speed belt. After multiple sprays, it is ensured that all sides of the pecans are evenly coated with the edible coating liquid to ensure the antioxidant effect of the pecans.

[0019] Furthermore, an installation block is fixed to the top of the walnut conveying groove. Two installation blocks are provided and located near both ends of the walnut conveying groove. A guide rod parallel to the extension direction of the walnut conveying groove is fixed between the two installation blocks. An adjustment mechanism is provided on the walnut conveying groove to simultaneously adjust the spacing between adjacent arc-shaped installation plates and keep the spacing between the arc-shaped installation plates equal after adjustment. The adjustment mechanism includes an adjustment component and a drive component. The adjustment component includes a U-shaped plate fixed to the top of the arc-shaped installation plate and slidingly engaged with the top of the walnut conveying groove, a sliding ring slidably sleeved on the guide rod, and a linkage rod fixed between the U-shaped plate and the sliding ring. The drive component is fixed to a fixed block at the bottom of the walnut conveying groove, a drive rod rotatably mounted on the fixed block and parallel to the guide rod, and a drive motor fixed to the fixed block and driving the drive rod to rotate. The drive rod is provided with multiple external threads with the same direction of rotation and a pitch that increases exponentially. The number of external threads is equal to the number of U-shaped plates and their positions correspond one-to-one. The external threads on the drive rod penetrate the U-shaped plates and are threadedly connected.

[0020] By adopting the above technical solution, when spraying edible coating liquid on the surface of different varieties of hickory, the required coating thickness may vary. In this case, it is necessary to control the rolling speed of the hickory in the hickory conveying groove. The staff can control the rotation of the drive rod by driving the motor. Since the pitch of different external threads on the drive rod is set in equal proportion, multiple sets of U-shaped plates move synchronously and always keep the distance between adjacent U-shaped plates equal after adjustment. This is manifested as the distance between adjacent rubber speed bumps being equal, so that the staff can adjust the distance between adjacent rubber speed bumps according to the needs of different varieties of hickory.

[0021] In summary, the present invention has the following beneficial effects: 1. In this application, the pretreatment equipment can not only screen and remove empty and shriveled kernels, but also distinguish between small, medium, and large kernels, ensuring the uniformity of quality of pecans within the same batch. The pretreatment equipment sprays an antioxidant and edible coating liquid onto different production lines, forming an antioxidant protective film on the surface of the pecans, which extends their shelf life to a certain extent. The low-oxygen environment reduces moisture evaporation and nutrient consumption in the kernels, maintaining their freshness and preventing off-flavors caused by oxidation. 2. In this application, when the pecans are detected to be empty or shriveled, the control system of the pre-processing equipment controls the cylinder to operate, causing the piston rod of the cylinder to drive the transfer plate to retract to the bottom of the feeding rack via the connecting block. This prevents the pecans rolling off the feeding conveyor belt from rolling onto the transfer conveyor belt via the transfer plate of the transfer component, and they eventually fall into the collection box. At the same time, the baffle block can block the pecans on the feeding conveyor belt from continuing to move forward as the transfer plate retracts to the bottom of the feeding rack, preventing the subsequent pecans from falling into the collection box without being sorted for ripeness. When the near-infrared spectrometer determines that the fruit is ripe, the control system controls the cylinder to operate and causes the transfer plate to reset, thereby causing the pecans rolling off the feeding conveyor belt to roll onto the transfer conveyor belt via the transfer plate, and finally enter the screening mechanism through the feed hopper for further processing. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention; Figure 2 yes Figure 1 Enlarged view of point A in the middle; Figure 3 This is a schematic diagram illustrating the state of the transfer component when removing empty seeds, as described in an embodiment of the present invention. Figure 4 This is a schematic diagram illustrating the structure of the screening mechanism in an embodiment of the present invention; Figure 5 yes Figure 4 Enlarged view of point B in the middle; Figure 6 This is a schematic diagram illustrating the structure of the rubber speed bump according to an embodiment of the present invention; Figure 7 This is a schematic diagram illustrating the structure of the adjustment mechanism in an embodiment of the present invention; Figure 8 yes Figure 4 Enlarged diagram of point C in the middle.

[0023] In the diagram: 1. First frame; 11. Loading rack; 111. Loading conveyor belt; 112. Near-infrared spectrometer; 12. Transfer frame; 121. Transfer conveyor belt; 13. Collection frame; 2. Second frame; 21. Feed hopper; 3. Screening mechanism; 31. Screening assembly; 311. Screening barrel; 3111. Feed inlet; 3112. Screening hole; 312. Spiral convex bar; 32. Rotating assembly; 321. Extension plate; 322. Rotary motor; 323. Drive gear; 324. Driven gear; 4. Transfer component; 41. Fixing plate; 42. Cylinder; 43. Connecting block; 44. Transfer plate; 441. Connecting rod; 442. Material stop block; 5. First mounting frame; 6. Spraying mechanism; 61. Conveying assembly; 611. Second mounting frame; 612. Walnut conveying groove; 613. Receiving hopper; 62. Spraying assembly; 621. Diverter pipe; 622. Spray nozzle; 623. Feed pipe; 624. Solenoid valve; 625. Hose; 7. Arc-shaped mounting plate; 71. Rubber speed bump; 72. V-shaped elastic sheet; 8. Mounting block; 81. Guide rod; 9. Adjustment mechanism; 91. Adjustment component; 911. U-shaped plate; 912. Sliding ring; 913. Linkage rod; 92. Drive component; 921. Fixing block; 922. Drive rod; 9221. External thread; 923. Drive motor. Detailed Implementation

[0024] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0025] like Figure 1-8 As shown in the embodiment of this application, a pretreatment process for antioxidant storage of pecans is disclosed, including the following steps: S1. Freshly picked and washed walnuts are sorted using pre-processing equipment to remove empty, shriveled, and bad walnuts. S2. Hollow, shriveled, and bad walnuts are removed and then screened by pre-processing equipment to distinguish between small, medium, and large fruits. They are then sprayed with an antioxidant and edible coating liquid on different production lines. S3. After the coating liquid is sprayed, small, medium and large fruits are put into different intelligent modified atmosphere integrated machines for modified atmosphere treatment. Combined with low temperature storage, the storage period of shelled pecans is extended to 6-8 months, and the storage period of shelled kernels is extended to 3-4 months. During controlled atmosphere treatment, the oxygen concentration is 2%-5%, the carbon dioxide concentration is 3%-5%, and the remainder is nitrogen.

[0026] The pre-processing equipment not only sieves and removes empty and shriveled kernels, but also distinguishes between small, medium, and large kernels, ensuring consistent quality within the same batch of pecans. By spraying an antioxidant and edible coating solution onto different production lines, the equipment forms a protective antioxidant film on the surface of the pecans, extending their shelf life to some extent. The low-oxygen environment reduces moisture evaporation and nutrient loss from the kernels, maintaining their freshness and preventing off-flavors caused by oxidation.

[0027] In this embodiment, the edible coating liquid, by weight percentage, comprises the following raw materials: 2%-3% chitosan, 0.5%-1% tert-butylhydroquinone, 0.1%-0.15% Tween-80, with the balance being water. The chitosan membrane can block more than 70% of oxygen permeation. Tert-butylhydroquinone, as a highly efficient antioxidant, can inhibit problems such as oil rancidity and flavor deterioration caused by oxidation during the storage of pecans. By capturing free radicals and blocking the oxidation chain reaction, it slows down the decline in pecan quality, thereby extending its shelf life without affecting the edibility of the pecans. Combined with chitosan, Tween-80, and other components, it can enhance the preservation effect of the coating.

[0028] This application also discloses a pretreatment device according to the aforementioned pretreatment process for antioxidant storage of pecans, including a first frame 1, a second frame 2 located on one side of the first frame 1, and a screening mechanism 3 located on the side of the second frame 2 away from the first frame 1 for distinguishing small, medium, and large pecans. A feeding rack 11 is fixed to the top of the first frame 1, and a transfer rack 12 located on one side of the first frame 1 and lower than the feeding rack 11. The extension direction of the transfer rack 12 is parallel to the extension direction of the feeding rack 11. The second frame... The top of the body 2 is fixed with a feed hopper 21 for conveying hickory nuts to the screening mechanism 3. The feeding frame 11 and the transfer frame 12 are respectively equipped with a feeding conveyor belt 111 and a transfer conveyor belt 121. A near-infrared spectrometer 112 for detecting empty and shriveled hickory nuts conveyed by the feeding conveyor belt 111 is installed in the frame on one side of the feeding frame 11. A transfer component 4 for conveying hickory nuts that have been conveyed by the feeding conveyor belt 111 and have passed screening to the transfer conveyor belt 121 is installed at the bottom of the feeding frame 11.

[0029] The near-infrared spectrometer 112 can help determine whether a pecan is empty or shriveled by detecting its internal moisture content. Empty pecans, due to incomplete development, have less plump kernels, and their moisture content typically differs from that of normal, plump pecans. Near-infrared spectroscopy technology can acquire the spectral information of pecans non-contactly, analyze their moisture content based on characteristic absorption peaks, and then establish a discrimination model by combining the difference in moisture content between empty and normal pecans, thus achieving non-destructive identification of empty pecans.

[0030] The transfer assembly 4 includes a fixing plate 41 fixed to the bottom of the loading rack 11, a cylinder 42 fixed to the fixing plate 41, a connecting block 43 fixed to the end of the piston rod of the cylinder 42, and a transfer plate 44 fixed to the top of the connecting block 43. The transfer plate 44 has a U-shaped cross-section. The upper end of the transfer plate 44 is located near the bottom of the loading rack 11, and the lower end of the transfer plate 44 is located near the top of the transfer rack 12.

[0031] Connecting rods 441 are fixed on both sides of the transfer plate 44. The ends of the two connecting rods 441 away from the transfer plate 44 are fixed with a baffle block 442. The baffle block 442 is used to block the walnuts on the feeding conveyor belt 111 from continuing to be transported forward during the process of the transfer plate 44 retracting to the bottom of the feeding frame 11. A collection frame 13 is provided on the first frame 1 for collecting the fallen empty walnuts.

[0032] When the pecans are detected to be empty or shriveled, the control system of the pre-processing equipment controls cylinder 42 to operate. This causes the piston rod of cylinder 42 to retract the transfer plate 44 to the bottom of the feeding rack 11 via connecting block 43. This prevents the pecans rolling off the feeding conveyor belt 111 from rolling onto the transfer conveyor belt 121 via the transfer plate 44, ultimately falling into the collection box 13. Simultaneously, the baffle block 442 prevents the pecans on the feeding conveyor belt 111 from continuing to move forward as the transfer plate 44 retracts to the bottom of the feeding rack 11, avoiding the situation where unripe pecans fall into the collection box 13. When the near-infrared spectrometer 112 determines that the fruit is ripe, the control system controls cylinder 42 to operate and reset the transfer plate 44. This causes the pecans rolling off the feeding conveyor belt 111 to roll onto the transfer conveyor belt 121 via the transfer plate 44, and finally enter the screening mechanism 3 through the feed hopper 21 for further processing.

[0033] A first mounting frame 5 is provided on the side of the second frame 2 away from the first frame 1. The screening mechanism 3 includes a screening component 31, which includes a screening barrel 311 rotatably mounted on the first mounting frame 5 and inclined. The inclination angle of the screening barrel 311 is 2-3 degrees. The end of the screening barrel 311 closer to the second frame 2 is higher than the end of the screening barrel 311 away from the second frame 2. The end of the screening barrel 311 closer to the second frame 2 is provided with a discharge end for the feed hopper 21. The feed inlet 3111 is used to enter the screening barrel 311. Multiple screening holes 3112 are evenly arranged on the side wall of the screening barrel 311. The screening holes 3112 on the side wall of the screening barrel 311 are divided into three sections, with the diameter of the three sections increasing sequentially from the second frame 2 towards the side away from the first frame 1. The screening mechanism 3 also includes a rotating component 32 for driving the screening barrel 311 to rotate. The pretreatment equipment also includes three sets of spraying mechanisms 6 for spraying edible coating liquid onto the screened pecans. The screening component 31 also includes a spiral protrusion 312 fixed to the inner wall of the screening barrel 311. The rotating component 32 includes an extension plate 321 fixed to the first mounting frame 5, a rotary motor 322 fixed to the extension plate 321, a drive gear 323 fixed to the output end of the rotary motor 322, and a driven gear 324 fixedly sleeved on the screening barrel 311 and meshing with the drive gear 323.

[0034] After the rotary motor 322 operates and drives the drive gear 323 to rotate, the driven gear 324 meshing with the drive gear 323 and the screening barrel 311 fixed to the driven gear 324 both rotate, causing the pecans entering the screening barrel 311 to roll away from the second frame 2 (the tilt angle of the screening barrel 311 ensures the direction of the pecans' rolling). Under the action of the spiral protrusion 312, the pecans are screened in sequence through the three screening holes 3112 on the side wall of the screening barrel 311 for small, medium and large fruits. The screened fruits enter different production lines for edible coating spraying.

[0035] The spraying mechanism 6 includes a conveying assembly 61, which includes a second mounting frame 611 disposed on one side of the first mounting frame 5, a walnut conveying groove 612 fixed to the top of the second mounting frame 611, and a receiving hopper 613 fixed to one end of the walnut conveying groove 612 for receiving walnuts falling from the screening hole 3112. The intersection of adjacent receiving hoppers 613 is located at the intersection of adjacent sections of screening hole 3112. The walnut conveying groove 612 is inclined, with an inclination angle of 2-3 degrees. The height of the end of the walnut conveying groove 612 near the screening barrel 311 is greater than the height of the end of the walnut conveying groove 612 away from the screening barrel 311. The spraying mechanism 6 also includes a spraying assembly 62 disposed on the top of the walnut conveying groove 612.

[0036] Multiple arc-shaped mounting plates 7, evenly distributed along the length of the walnut conveying ditch 612, are fixed on the inner bottom wall. A rubber speed bump 71 is fixed to the inner bottom surface of each arc-shaped mounting plate 7. The height of the middle of the rubber speed bump 71 is greater than the height of its two ends. A V-shaped elastic sheet 72 is fixed between the inner top of the rubber speed bump 71 and the inner bottom wall of the arc-shaped mounting plate 7. The number of spraying components 62 is equal to the number of rubber speed bumps 71, and their positions correspond one-to-one. The spraying components 62 include those installed in the walnut conveying ditch 612. The system includes a diversion pipe 621 above the 12, a nozzle 622 fixed to and connected to the bottom of the diversion pipe 621, a feed pipe 623 fixed to and connected to the side wall of the diversion pipe 621, a solenoid valve 624 installed on the feed pipe 623, and a hose 625 connected to both the feed pipe 623 and the external feeding system. Each diversion pipe 621 has three corresponding nozzles 622, which are respectively oriented towards the area before entering the rubber speed bump 71, the area reaching the center of the rubber speed bump 71, and the area after leaving the rubber speed bump 71.

[0037] Pecans falling from the screening holes 3112 of the screening barrel 311 enter their respective receiving hoppers 613, and then enter the walnut conveying groove 612. Under the action of different rubber deceleration belts 71 in the walnut conveying groove 612, the speed at which the walnuts are conveyed along the walnut conveying groove 612 is kept within a certain range. Due to the setting of the V-shaped elastic plate 72 at the bottom of the rubber deceleration belt 71, the walnuts are effectively turned over multiple times during the rolling process. The edible coating liquid input by the external feeding system is pressurized and then input into the diversion pipe 621 through the hose 625. Then, the nozzle 622 evenly sprays the walnuts that have passed through the rubber deceleration belt 71. After multiple sprayings, it is ensured that all sides of the walnuts are evenly coated with edible coating liquid to ensure the antioxidant effect of the walnuts.

[0038] Two mounting blocks 8 are fixed to the top of the walnut conveying groove 612, located near both ends of the groove. A guide rod 81 parallel to the extension direction of the groove is fixed between the two mounting blocks 8. An adjustment mechanism 9 is provided on the groove 612 to simultaneously adjust the spacing between adjacent arc-shaped mounting plates 7 and keep the spacing between the arc-shaped mounting plates 7 equal after adjustment. The adjustment mechanism 9 includes an adjustment component 91 and a drive component 92. The adjustment component 91 includes a U-shaped plate 911 fixed to the top of the arc-shaped mounting plate 7 and slidingly engaged with the top of the groove 612, and a guide rod 81 slidably fitted onto the guide rod. The sliding ring 912 and the linkage rod 913 fixed between the U-shaped plate 911 and the sliding ring 912, the drive assembly 92 fixed to the fixed block 921 at the bottom of the walnut conveying groove 612, the drive rod 922 rotatably mounted on the fixed block 921 and parallel to the guide rod 81, and the drive motor 923 fixed on the fixed block 921 and driving the drive rod 922 to rotate, the drive rod 922 is provided with multiple external threads 9221 with the same direction of rotation and the pitch increasing in multiples, the number of external threads 9221 is equal to the number of U-shaped plates 911 and the positions correspond one-to-one, the external threads 9221 on the drive rod 922 pass through the U-shaped plate 911 and are threadedly connected.

[0039] When spraying edible coating liquid onto the surface of different varieties of hickory nuts, the required coating thickness may vary. In this case, it is necessary to control the rolling speed of the hickory nuts in the walnut conveying groove 612. The operator can control the rotation of the drive rod 922 by driving the motor 923. Since the pitches of the different external threads 9221 on the drive rod 922 are set in equal proportions, multiple sets of U-shaped plates 911 move synchronously and always maintain the equal spacing between adjacent U-shaped plates 911 after adjustment. This is manifested as the equal spacing between adjacent rubber speed bumps 71, so that the operator can adjust the spacing between adjacent rubber speed bumps 71 according to the needs of different varieties of hickory nuts.

[0040] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A pretreatment process for antioxidant storage of pecans, characterized in that, Includes the following steps: S1. Freshly picked hickory nuts are successively dehulled, washed, rinsed, and dried. Then, they are sorted by pre-treatment equipment to remove empty, shriveled, and bad nuts. S2. Hollow, shriveled and bad pecans are removed and screened by pre-processing equipment to distinguish between small, medium and large fruits. They are then sprayed with an antioxidant and edible coating liquid on different production lines. S3. After the coating liquid is sprayed, small, medium and large fruits are put into different intelligent modified atmosphere integrated machines for modified atmosphere treatment. Combined with low temperature storage, the storage period of shelled pecans is extended to 6-8 months, and the storage period of shelled kernels is extended to 3-4 months. During controlled atmosphere treatment, the oxygen concentration is 2%-5%, the carbon dioxide concentration is 3%-5%, and the remainder is nitrogen.

2. The pretreatment process for antioxidant storage of pecans according to claim 1, characterized in that, By weight percentage, the edible coating liquid comprises the following raw materials: 2%-3% chitosan, 0.5%-1% tert-butylhydroquinone, 0.1%-0.15% Tween-80, with the balance being water.

3. A pretreatment device for the pretreatment process of anti-oxidative storage of pecans according to any one of claims 1 or 2, characterized in that: The system includes a first frame (1), a second frame (2) located on one side of the first frame (1), and a screening mechanism (3) located on the side of the second frame (2) away from the first frame (1) and used to distinguish small, medium and large fruits. The top of the first frame (1) is fixed with a feeding rack (11) and a transfer rack (12) located on one side of the first frame (1) and lower than the feeding rack (11). The extension direction of the transfer rack (12) is parallel to the extension direction of the feeding rack (11). The top of the second frame (2) is fixed with a feeding hopper (21) for conveying walnuts to the screening mechanism (3). The feeding rack (11) and the transfer rack (12) are respectively equipped with a feeding conveyor belt (111) and a transfer conveyor belt (121). A near-infrared spectrometer (112) is installed in the frame body on one side of the feeding rack (11) to detect empty and shriveled walnuts in the feeding conveyor belt (111). A transfer component (4) is installed at the bottom of the feeding rack (11) to transfer the qualified walnuts conveyed by the feeding conveyor belt (111) to the transfer conveyor belt (121).

4. The pretreatment equipment for the pretreatment process of pecan antioxidant storage according to claim 3, characterized in that: a transfer... The component (4) includes a fixing plate (41) fixed to the bottom of the loading rack (11), a cylinder (42) fixed to the fixing plate (41), a connecting block (43) fixed to the piston rod end of the cylinder (42), and a transfer plate (44) fixed to the top of the connecting block (43). The transfer plate (44) has a U-shaped cross-section. The upper end of the transfer plate (44) is located near the bottom of the loading rack (11), and the lower end of the transfer plate (44) is located near the top of the transfer rack (12).

5. The pretreatment equipment for the pretreatment process of anti-oxidative storage of pecans according to claim 4, characterized in that: a transfer... Connecting rods (441) are fixed on both sides of the plate (44). The two connecting rods (441) are fixed with a baffle block (442) at the end away from the transfer plate (44). The baffle block (442) is used to block the walnuts on the feeding conveyor belt (111) from continuing to be transported forward during the process of the transfer plate (44) retracting to the bottom of the feeding frame (11). A collection frame (13) is set on the first frame (1) for collecting the fallen empty walnuts.

6. The pretreatment equipment for the pretreatment process of pecan antioxidant storage according to claim 4, characterized in that: The second frame (2) has a first mounting frame (5) on the side away from the first frame (1). The screening mechanism (3) includes a screening component (31), which includes a screening barrel (311) rotatably mounted on the first mounting frame (5) and tilted. The tilt angle of the screening barrel (311) is 2-3 degrees. The end of the screening barrel (311) closer to the second frame (2) is higher than the end of the screening barrel (311) and farther away from the second frame (2). At one end of the screening barrel (311), near the second frame (2), there is a feed inlet (3111) for the discharge end of the feed hopper (21) to enter. The side wall of the screening barrel (311) is evenly provided with a plurality of screening holes (3112). The screening holes (3112) on the side wall of the screening barrel (311) are divided into three sections. The diameter of the three sections of screening holes (3112) increases sequentially from the second frame (2) to the side away from the first frame (1). The screening mechanism (3) also includes a rotating component (32) for driving the screening barrel (311) to rotate, and the pretreatment equipment also includes three spraying mechanisms (6) for spraying edible coating liquid onto the screened pecans.

7. The pretreatment equipment for the pretreatment process of anti-oxidative storage of pecans according to claim 6, characterized in that: The screening assembly (31) also includes a spiral protrusion (312) fixed to the inner wall of the screening barrel (311), and the rotating assembly (32) includes an extension plate (321) fixed to the first mounting frame (5), a rotary motor (322) fixed to the extension plate (321), a drive gear (323) fixed to the output end of the rotary motor (322), and a driven gear (324) fixedly sleeved on the screening barrel (311) and meshing with the drive gear (323).

8. The pretreatment equipment for the pretreatment process of pecan antioxidant storage according to claim 6, characterized in that: The spraying mechanism (6) includes a conveying assembly (61), which includes a second mounting frame (611) disposed on one side of the first mounting frame (5), a walnut conveying groove (612) fixed to the top of the second mounting frame (611), and a receiving hopper (613) fixed to one end of the walnut conveying groove (612) for receiving walnuts falling from the screening hole (3112). The intersection of adjacent receiving hoppers (613) is located at the intersection of adjacent screening holes (3112). The walnut conveying groove (612) is inclined, with an inclination angle of 2-3 degrees. The height of the end of the walnut conveying groove (612) near the screening bucket (311) is greater than the height of the end of the walnut conveying groove (612) away from the screening bucket (311). The spraying mechanism (6) also includes a spraying assembly (62) disposed on the top of the walnut conveying groove (612).

9. The pretreatment equipment for the pretreatment process of pecan antioxidant storage according to claim 8, characterized in that: Multiple arc-shaped mounting plates (7) evenly distributed along the length direction are fixed on the inner bottom wall of the walnut conveying groove (612). Each arc-shaped mounting plate (7) has a rubber speed reduction belt (71) fixed on its inner bottom surface. The height of the middle part of the rubber speed reduction belt (71) is greater than the height of its two ends. A V-shaped elastic sheet (72) is fixed between the inner top of the rubber speed reduction belt (71) and the inner bottom wall of the arc-shaped mounting plate (7). The number of spraying components (62) is equal to the number of rubber speed bumps (71) and their positions correspond one-to-one. The spraying components (62) include a diversion pipe (621) set above the walnut conveying groove (612), a nozzle (622) fixed and connected to the bottom of the diversion pipe (621), a feed pipe (623) fixed and connected to the side wall of the diversion pipe (621), a solenoid valve (624) set on the feed pipe (623), and a hose (625) connected to both the feed pipe (623) and the external feeding system. Each diversion pipe (621) has three nozzles (622), which are respectively oriented towards the area before entering the rubber speed bump (71), reaching the center of the rubber speed bump (71), and leaving the area after exiting the rubber speed bump (71).

10. The pretreatment equipment for the pretreatment process of pecan antioxidant storage according to claim 9, characterized in that: The top of the walnut conveying groove (612) is fixed with an installation block (8). There are two installation blocks (8) and they are located near the two ends of the walnut conveying groove (612). A guide rod (81) parallel to the extension direction of the walnut conveying groove (612) is fixed between the two installation blocks (8). The walnut conveying groove (612) is provided with an adjustment mechanism (9) for simultaneously adjusting the spacing between adjacent arc-shaped installation plates (7) and keeping the spacing between the adjusted arc-shaped installation plates (7) equal. The adjustment mechanism (9) includes an adjustment component (91) and a drive component (92). The adjustment component (91) includes a U-shaped plate (911) fixed to the top of the arc-shaped installation plate (7) and slidingly engaged with the top of the walnut conveying groove (612), and a slide sleeve on the guide rod (81). The drive assembly (92) consists of a moving ring (912) and a linkage rod (913) fixed between the U-shaped plate (911) and the sliding ring (912). The drive assembly (92) is fixed to a fixed block (921) at the bottom of the walnut conveying groove (612), a drive rod (922) rotatably mounted on the fixed block (921) and parallel to the guide rod (81), and a drive motor (923) fixed on the fixed block (921) and driving the drive rod (922) to rotate. The drive rod (922) is provided with multiple external threads (9221) with the same direction of rotation and a pitch that increases in multiples. The number of external threads (9221) is equal to the number of U-shaped plates (911) and their positions correspond one-to-one. The external threads (9221) on the drive rod (922) pass through the U-shaped plate (911) and are threadedly connected.

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