Nitrogen-filling fresh-keeping process for rice dumplings

Abstract

The invention discloses a nitrogen-filling fresh-keeping process for rice dumplings. The nitrogen-filling fresh-keeping process comprises the following specific steps: S1, preparing raw materials; s2, packaging preparation; s3, performing vacuum pumping and nitrogen charging; s4, sealing and detecting; and S5, low-temperature storage.

Description

[0001] Technology This invention belongs to the field of glutinous rice ball technology and relates to a nitrogen-filled preservation process for glutinous rice balls. Background Technology

[0002] As a representative of traditional Chinese cuisine, glutinous rice balls (tangyuan) are prone to losing their unique flavor and delicate texture over time after production. To ensure that glutinous rice balls maintain their freshness and deliciousness during storage, transportation, and sales, developing a nitrogen-filled preservation process is particularly urgent. By introducing nitrogen-filled preservation, oxygen can be effectively replaced and the growth and reproduction of microorganisms can be inhibited during packaging, thereby significantly extending the shelf life of glutinous rice balls while preserving their original texture and flavor. This process is not only feasible but also better meets the dual requirements of safety and quality in the modern food industry. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a nitrogen-filled preservation process for glutinous rice balls.

[0004] To achieve the above objectives, the technical solution of the present invention is: a nitrogen-filled preservation process for glutinous rice balls, comprising the following specific steps: S1. Raw material preparation: Spread the glutinous rice balls evenly in a quick-freezing tray, place them in a tunnel-type quick-freezing machine, set the quick-freezing temperature to -30℃ to -35℃, and control the quick-freezing time to 40-60 minutes, so that the center temperature of the glutinous rice balls drops to below -18℃; after freezing, use a vibrating screen to remove the ice crystals on the surface of the glutinous rice balls. S2. Packaging preparation: Activate the heat preservation function of the feeding hopper to maintain the internal temperature at -18℃ to -15℃; open the feeding hopper cover of the processing device, add the quick-frozen glutinous rice balls through the feeding port of the feeding hopper, control the upper end of one of the buffer tubes to be closed, and use the handle to open the control plate so that the metered glutinous rice balls in the buffer tube enter the packaging bag. S3. Vacuuming and Nitrogen Filling: Place the opening of the packaging bag on the lower pressure bar of the lower fixed seat. Activate cylinder one to lower the working rod and the upper lifting seat, causing the upper and lower pressure bars to clamp the opening of the packaging bag. Then, open solenoid valve two to vacuum the inside of the packaging bag through the vacuum pipe. After the vacuum degree reaches -0.09MPa to -0.095MPa, close solenoid valve two. Then, open solenoid valve one, and fill the packaging bag with food-grade nitrogen through the nitrogen supply pipe via the tee connector and telescopic hose. The nitrogen purity is ≥99%, the filling pressure is controlled between 0.12MPa and 0.15MPa, and the filling time is 3-5 seconds, so that the packaging bag bulges into a full state but does not over-expand. S4. Sealing and Inspection: After nitrogen filling is completed, close solenoid valve one, start cylinder two, and drive the electric heating sealing strip to rise. It works with the upper pressure strip to heat seal the opening of the packaging bag. The sealing temperature is set to 160-180℃ and the sealing time is 1-2 seconds. After sealing is completed, cylinder one and cylinder two are reset. Take out the packaged glutinous rice balls and manually check the sealing quality and the appearance of the packaging bag. Discard products with loose seals, damage, or nitrogen leakage. S5. Low-temperature storage: Store the qualified nitrogen-filled packaged glutinous rice balls in a low-temperature cold storage at -18℃ or below, with a temperature fluctuation range not exceeding ±2℃.

[0005] The processing device includes a frame, an operating table fixed on the frame, a feeding hopper fixed on the frame, a drive assembly and an air pipe fixed to the frame, the end of the air pipe connected to the first end of a three-way connector via a telescopic hose, the second end of the three-way connector connected to a nitrogen supply pipe, a solenoid valve one installed on the nitrogen supply pipe, the third end of the three-way connector connected to a vacuum extraction pipe, a solenoid valve two installed on the vacuum extraction pipe, a lower fixed seat fixed on the frame, a lower pressure bar fixed on the lower fixed seat, a working rod vertically slidably connected to the frame, the working rod connected to a cylinder one capable of moving up and down, an upper lifting seat fixed on the working rod, an upper pressure bar fixed on the upper lifting seat, and an electrically heated sealing strip that cooperates with the upper pressure bar vertically slidably connected to the lower fixed seat, the electrically heated sealing strip connected to a cylinder two capable of moving up and down.

[0006] The upper part of the feeding hopper is detachably equipped with a cover plate, and the lower part of the feeding hopper has two discharge holes. The lower part of the feeding hopper is fixed with a mounting base, and a cylinder three is horizontally fixed on the mounting base. The piston rod end of the cylinder three is connected to a sealing plate, and under the action of the sealing plate, either discharge hole can be sealed. A buffer tube is fixed at the discharge hole, and a regulating plate is horizontally rotatably mounted on the buffer tube. The regulating plate has a handle.

[0007] The drive assembly includes a bracket, a fourth cylinder, and an intermediate beam. The bracket is fixed to the frame, the fourth cylinder is horizontally fixed to the bracket, a guide sleeve is fixed to the bracket, a guide post is horizontally slidably connected to the guide sleeve, the guide post is fixedly connected to the intermediate beam, the intermediate beam is movably connected to the threaded section of an L-shaped rod, a locking nut is threaded onto the threaded section, the connecting section of the L-shaped rod is fixedly connected to the air pipe, and the piston rod end of the fourth cylinder is fixedly connected to the intermediate beam.

[0008] The feeding hopper also has multiple guide blocks.

[0009] The feeding hopper and buffer tube adopt a structure with heat preservation function.

[0010] By adopting the above technical solution, the beneficial effects of the present invention are: This invention effectively inhibits the growth and reproduction of microorganisms and enzyme activity by deep-freezing glutinous rice balls, laying a solid foundation for subsequent preservation. In the packaging stage, the use of an insulated feeding hopper and a precise metering buffer structure ensures that the glutinous rice balls remain in a low-temperature environment throughout the packaging process, preventing softening and deformation caused by temperature fluctuations. The optimized design of the vacuum extraction and nitrogen filling process can maximize the removal of oxygen from the packaging bag and create a stable inert gas atmosphere inside the bag by precisely controlling the purity of nitrogen, filling pressure, and time, thereby significantly slowing down the rate of fat oxidation and flavor deterioration in the glutinous rice balls. The entire process is closely linked, and the parameters are set scientifically and rationally, achieving effective preservation of glutinous rice balls from quick-freezing to storage, significantly extending their shelf life, while better preserving their original taste, flavor, and nutritional value, meeting the needs of industrial production and market circulation. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the planar structure of the present invention; Figure 2 This is a schematic diagram of the planar structure of the removed portion of the present invention; Figure 3 This is a partial schematic diagram of the present invention; Figure 4 This is a schematic diagram of the planar structure of the feeding hopper in this invention; Figure 5 This is a schematic diagram of the three-dimensional structure of the feeding hopper in this invention. Figure 1 ; Figure 6 This is a schematic diagram of the three-dimensional structure of the feeding hopper in this invention. Figure 2 ; In the diagram, 1. Frame; 2. Upper lifting seat; 3. Air pipe; 4. Operating table; 5. Feed hopper; 5a. Discharge hole; 6. Vacuum extraction pipe; 7. Solenoid valve two; 8. T-connector; 9. Solenoid valve one; 10. Nitrogen supply pipe; 11. Telescopic hose; 12. Cylinder four; 13. Guide column; 14. Guide sleeve; 15. Intermediate beam; 16. Locking nut; 17. L-shaped rod; 18. Lower pressure bar; 19. Lower fixed seat; 20. Electric heating sealing bar; 21. Upper pressure bar; 22. Working rod; 23. Cover plate; 24. Control plate; 25. Buffer tube; 26. Guide block; 27. Sealing plate; 28. Cylinder three; 29. ​​Mounting seat; 30. Bracket. Detailed Implementation

[0012] To further explain the technical solution of the present invention, the present invention will be described in detail below through specific embodiments.

[0013] like Figure 1-6As shown, the nitrogen-filled preservation process for glutinous rice balls includes the following specific steps: S1. Raw material preparation: Spread the glutinous rice balls evenly in a quick-freezing tray and place them in a tunnel-type quick-freezing machine. Set the quick-freezing temperature to -30℃ to -35℃ and control the quick-freezing time to 40-60 minutes to lower the center temperature of the glutinous rice balls to below -18℃. After freezing, use a vibrating screen to remove the ice crystals on the surface of the glutinous rice balls to prevent them from sticking together. S2. Packaging Preparation: Activate the heat preservation function of the feeding hopper 5 to maintain the internal temperature at -18℃ to -15℃ to prevent the glutinous rice balls from thawing and softening; open the cover plate 23 of the feeding hopper 5 of the processing device, and add the quick-frozen glutinous rice balls through the feed inlet of the feeding hopper 5. The guide block 26 inside the feeding hopper 5 guides the glutinous rice balls to be evenly dispersed to avoid accumulation and blockage; control the upper end of one of the buffer tubes 25 to be closed, and use the handle to open the control plate 24 to allow the metered glutinous rice balls in the buffer tube 25 to enter the packaging bag; S3. Vacuuming and Nitrogen Filling: Place the opening of the packaging bag on the lower pressure bar 18 of the lower fixed seat 19, start cylinder one, driving the working rod 22 and the upper lifting seat 2 to descend, so that the upper pressure bar 21 and the lower pressure bar 18 cooperate to clamp the opening of the packaging bag; then open solenoid valve two 7, and vacuum the inside of the packaging bag through vacuum pipe 6. After the vacuum degree reaches -0.09MPa to -0.095MPa, close solenoid valve two 7; then open solenoid valve one 9, and nitrogen supply pipe 10 fills the packaging bag with food-grade nitrogen through three-way connector 8 and telescopic hose 11. The nitrogen purity is ≥99%, the filling pressure is controlled at 0.12MPa to 0.15MPa, and the filling time is 3-5 seconds, so that the packaging bag bulges into a full state but does not over-expand. S4. Sealing and Inspection: After nitrogen filling is completed, close solenoid valve 9 and start cylinder 2 to raise the electrically heated sealing strip 20. This strip, in conjunction with the upper pressure strip 21, heat-seals the opening of the packaging bag. The sealing temperature is set to 160-180℃, and the sealing time is 1-2 seconds. Ensure that the seal is tight and there is no air leakage. After sealing, cylinders 1 and 2 are reset. Take out the packaged glutinous rice balls and manually inspect the sealing quality and the appearance of the packaging bag. Discard products with loose seals, damage, or nitrogen leakage. S5. Low-temperature storage: Store the qualified nitrogen-filled packaged glutinous rice balls in a low-temperature cold storage at -18℃ or below. Avoid stacking and squeezing during storage, keep the temperature inside the storage stable, and keep the temperature fluctuation range within ±2℃ to ensure the quality and taste of the glutinous rice balls within the shelf life.

[0014] The processing device includes a frame 1, an operating table 4 fixed on the frame 1, a feeding hopper 5 fixed on the frame 1, and a drive assembly and an air pipe 3 fixedly connected to the frame 1. The end of the air pipe 3 is connected to the first end of a three-way connector 8 via a flexible hose 11. The second end of the three-way connector 8 is connected to a nitrogen supply pipe 10, which is equipped with a solenoid valve 9. The third end of the three-way connector 8 is connected to a vacuum extraction pipe 6, which is equipped with a solenoid valve 7. A lower fixed seat 19 is fixed on the upper part, and a lower pressure strip 18 is fixed on the lower fixed seat 19. A working rod 22 is vertically slidably connected to the frame 1. The working rod 22 is connected to a cylinder that can move it up and down. An upper lifting seat 2 is fixed on the working rod 22. An upper pressure strip 21 is fixed on the upper lifting seat 2. An electrically heated sealing strip 20 that cooperates with the upper pressure strip 21 is also vertically slidably connected to the lower fixed seat 19. The electrically heated sealing strip 20 is connected to a cylinder that can move it up and down.

[0015] The upper part of the feeding hopper 5 is detachably equipped with a cover plate 23, and the lower part of the feeding hopper 5 has two discharge holes 5a. The lower part of the feeding hopper 5 is fixed with a mounting base 29, and a cylinder 3 28 is horizontally fixed on the mounting base 29. The piston rod end of the cylinder 3 28 is connected to the sealing plate 27, and under the action of the sealing plate 27, it can close any one of the discharge holes 5a. The cylinder 3 28 drives the sealing plate 27 to move horizontally, which can alternately close the two discharge holes 5a, realize the alternating work of the two buffer tubes 25, and improve packaging efficiency. A buffer tube 25 is fixed at the discharge hole 5a, and a control plate 24 is horizontally rotatably installed on the buffer tube 25. The control plate 24 has a handle. The setting of the buffer tube 25 realizes the quantitative feeding of glutinous rice balls. The falling of glutinous rice balls can be controlled by rotating the handle of the control plate 24. The operation is convenient and the measurement is accurate.

[0016] The drive assembly includes a bracket 30, a cylinder 12, and an intermediate beam 15. The bracket 30 is fixed to the frame 1, and the cylinder 12 is horizontally fixed to the bracket 30. A guide sleeve 14 is fixed to the bracket 30, and a guide post 13 is horizontally slidably connected to the guide sleeve 14. The guide post 13 is fixedly connected to the intermediate beam 15, and the intermediate beam 15 is movably connected to the threaded section of the L-shaped rod 17. A locking nut 16 is threadedly connected to the threaded section. The connecting section of the L-shaped rod 17 is fixedly connected to the air pipe 3, and the piston rod end of the cylinder 12 is fixedly connected to the intermediate beam 15. By adjusting the locking nut 16, the position of the L-shaped rod 17 on the intermediate beam 15 can be finely adjusted, thereby flexibly adjusting the position of the air pipe 3 according to the specifications of the packaging bag, ensuring precise alignment during the vacuuming and nitrogen filling processes. The cylinder 12 drives the intermediate beam 15 to move horizontally along the direction of the guide post 13, causing the air pipe 3 to move synchronously, thereby allowing the air pipe 3 to be inserted or pulled out.

[0017] The feeding hopper 5 also has multiple guide blocks 26; the multiple guide blocks 26 in the feeding hopper 5 are set at an angle, which can guide the glutinous rice balls to be evenly distributed above the two discharge holes 5a, avoiding the obstruction of feeding caused by the accumulation of glutinous rice balls.

[0018] The feeding hopper 5 and the buffer tube 25 adopt a structure with heat preservation function.

[0019] All of the above components are general standard parts or components known to those skilled in the art. Their structure and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0020] The above embodiments and figures are not intended to limit the product form and style of the present invention. Any appropriate changes or modifications made by those skilled in the art should be considered as not departing from the patent scope of the present invention.

Claims

1. A nitrogen-filled preservation process for glutinous rice balls, characterized in that, The specific steps include the following: S1. Raw material preparation: Spread the glutinous rice balls evenly in a quick-freezing tray, place them in a tunnel-type quick-freezing machine, set the quick-freezing temperature to -30℃ to -35℃, and control the quick-freezing time to 40-60 minutes, so that the center temperature of the glutinous rice balls drops to below -18℃; after freezing, use a vibrating screen to remove the ice crystals on the surface of the glutinous rice balls. S2. Packaging preparation: Activate the heat preservation function of the feeding hopper to maintain the internal temperature at -18℃ to -15℃; open the feeding hopper cover of the processing device, add the quick-frozen glutinous rice balls through the feeding port of the feeding hopper, control the upper end of one of the buffer tubes to be closed, and use the handle to open the control plate so that the metered glutinous rice balls in the buffer tube enter the packaging bag. S3. Vacuuming and Nitrogen Filling: Place the opening of the packaging bag on the lower pressure bar of the lower fixed seat. Activate cylinder one to lower the working rod and the upper lifting seat, causing the upper and lower pressure bars to clamp the opening of the packaging bag. Then, open solenoid valve two to vacuum the inside of the packaging bag through the vacuum pipe. After the vacuum degree reaches -0.09MPa to -0.095MPa, close solenoid valve two. Then, open solenoid valve one, and fill the packaging bag with food-grade nitrogen through the nitrogen supply pipe via the tee connector and telescopic hose. The nitrogen purity is ≥99%, the filling pressure is controlled between 0.12MPa and 0.15MPa, and the filling time is 3-5 seconds, so that the packaging bag bulges into a full state but does not over-expand. S4. Sealing and Inspection: After nitrogen filling is completed, close solenoid valve one, start cylinder two, and drive the electric heating sealing strip to rise. It works with the upper pressure strip to heat seal the opening of the packaging bag. The sealing temperature is set to 160-180℃ and the sealing time is 1-2 seconds. After sealing is completed, cylinder one and cylinder two are reset. Take out the packaged glutinous rice balls and manually check the sealing quality and the appearance of the packaging bag. Discard products with loose seals, damage, or nitrogen leakage. S5. Low-temperature storage: Store the qualified nitrogen-filled packaged glutinous rice balls in a low-temperature cold storage at -18℃ or below, with a temperature fluctuation range not exceeding ±2℃.

2. The nitrogen-filling preservation process for glutinous rice balls according to claim 1, characterized in that, The processing device includes a frame, an operating table fixed on the frame, a feeding hopper fixed on the frame, a drive assembly and an air pipe fixed to the frame, the end of the air pipe connected to the first end of a three-way connector via a telescopic hose, the second end of the three-way connector connected to a nitrogen supply pipe, a solenoid valve one installed on the nitrogen supply pipe, the third end of the three-way connector connected to a vacuum extraction pipe, a solenoid valve two installed on the vacuum extraction pipe, a lower fixed seat fixed on the frame, a lower pressure bar fixed on the lower fixed seat, a working rod vertically slidably connected to the frame, the working rod connected to a cylinder one capable of moving up and down, an upper lifting seat fixed on the working rod, an upper pressure bar fixed on the upper lifting seat, and an electrically heated sealing strip that cooperates with the upper pressure bar vertically slidably connected to the lower fixed seat, the electrically heated sealing strip connected to a cylinder two capable of moving up and down.

3. The nitrogen-filling preservation process for glutinous rice balls according to claim 2, characterized in that, The upper part of the feeding hopper is detachably equipped with a cover plate, and the lower part of the feeding hopper has two discharge holes. The lower part of the feeding hopper is fixed with a mounting base, and a cylinder three is horizontally fixed on the mounting base. The piston rod end of the cylinder three is connected to a sealing plate, and under the action of the sealing plate, either discharge hole can be sealed. A buffer tube is fixed at the discharge hole, and a regulating plate is horizontally rotatably mounted on the buffer tube. The regulating plate has a handle.

4. The nitrogen-filling preservation process for glutinous rice balls according to claim 2, characterized in that, The drive assembly includes a bracket, a fourth cylinder, and an intermediate beam. The bracket is fixed to the frame, the fourth cylinder is horizontally fixed to the bracket, a guide sleeve is fixed to the bracket, a guide post is horizontally slidably connected to the guide sleeve, the guide post is fixedly connected to the intermediate beam, the intermediate beam is movably connected to the threaded section of an L-shaped rod, a locking nut is threaded onto the threaded section, the connecting section of the L-shaped rod is fixedly connected to the air pipe, and the piston rod end of the fourth cylinder is fixedly connected to the intermediate beam.

5. The nitrogen-filling preservation process for glutinous rice balls according to claim 2, characterized in that, The feeding hopper also has multiple guide blocks.

6. The nitrogen-filling preservation process for glutinous rice balls according to claim 3, characterized in that, The feeding hopper and buffer tube adopt a structure with heat preservation function.

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