Low-temperature tumbling system and process for directional softening and browning inhibition of polygonatum sibiricum fibers

Abstract

The invention relates to the technical field of rhizoma polygonati treatment, in particular to a low-temperature tumbling system and process for directional softening and browning inhibition of rhizoma polygonati fibers. The system comprises a tumbling barrel, a collecting box, a cooling circulation module and an ultraviolet-ultrasonic co-processing unit. In the rotating process of the tumbling barrel, rhizoma polygonati cells are crushed to release juice, the juice is filtered by the collecting box, is cooled to 0-10 DEG C by the cooling device, and is circularly sprayed to the surface of rhizoma polygonati, so that dynamic temperature control is realized; an ultraviolet lamp inhibits microbial reproduction, ultrasonic waves destroy the activity of polyphenol oxidase, and a browning reaction is blocked in combination with a low-temperature environment; according to the technology, through alternate operation of rolling and standing, the fiber softening rate and the enzyme activity inhibition efficiency are cooperatively regulated and controlled, directional softening of the rhizoma polygonati fibers is achieved under the low-temperature condition, and meanwhile the browning risk is remarkably reduced. The system gives consideration to the quality and processing efficiency of rhizoma polygonati, and is suitable for industrial processing of different varieties such as rhizoma polygonati with rolled leaves and polygonatum kingianum. The method can be widely applied to the technical field of rhizoma polygonati treatment.

Description

Technical Field

[0001] The present invention relates to the technical field of polygonatum processing, specifically to a low-temperature tumbling system and process for the directional softening of polygonatum fibers and the inhibition of browning. Background Art

[0002] As an important raw material for both medicine and food, polygonatum is increasingly widely used. When processing polygonatum, in order to improve its taste and quality, the tumbling process is often used to promote the directional softening of polygonatum fibers, making the texture of polygonatum more suitable for subsequent processing and consumption.

[0003] However, during the tumbling process, the cells of polygonatum are damaged, which causes the phenolic substances in the vacuoles to come into contact with the polyphenol oxidase in the cytoplasm, thus initiating an oxidation reaction to generate brown polymers, and further leading to the browning of polygonatum fibers.

[0004] In addition, a large number of cell structures of polygonatum are ruptured, and its internal nutrients flow out. Moreover, due to heat generation by friction during the tumbling process, polygonatum continuously heats up. When the tumbling temperature exceeds a certain temperature, with the addition of a large amount of nutrients, the reproduction rate of microorganisms increases rapidly. These microorganisms decompose organic substances such as polysaccharides in polygonatum to produce products such as melanoidins, resulting in the browning of polygonatum fibers.

[0005] It can be seen that at present, while the polygonatum tumbling processing technology realizes the directional softening of polygonatum fibers, it urgently needs to solve the technical problem of how to effectively inhibit browning to ensure the high quality and market competitiveness of polygonatum products. Summary of the Invention

[0006] The purpose of the present invention is to provide a low-temperature tumbling system and process for the directional softening of polygonatum fibers and the inhibition of browning, so as to solve the problems in the prior art that the safety valve is easily misopened due to the easy accidental pulling of the pull rope, interfering with the operation of the gas storage tank, and there is a lack of effective observation means during the test to judge the working state of the safety valve.

[0007] To solve the above technical problems, the present invention provides the following technical solutions:

[0008] A low-temperature tumbling system for the directional softening of polygonatum fibers and the inhibition of browning includes a mounting frame and a horizontally placed tumbling barrel, and further includes a collection box fixed on the mounting frame. An ultraviolet lamp for sterilization is arranged in the collection box; an ultrasonic device is also arranged in the collection box, and the ultrasonic device is used to destroy the polyphenol oxidase flowing out after the rupture of the polygonatum cell wall;

[0009] Through holes are opened on the left and right side walls of the collection box. The tumbling barrel is arranged in the collection box, and drain holes are evenly opened on the side wall of the tumbling barrel;

[0010] A rotating rod, one end of which is fixed on the end face of the tumbling barrel, and the other end extends out from the through hole. The end extending out of the through hole is connected with a driving device;

[0011] A support rod, one end of which is fixed on the mounting frame; a support hole is formed on the end surface of the tumbling barrel away from the rotating rod, and the other end of the support rod passes through the through hole and the support hole and extends into the tumbling barrel; a cavity is arranged inside the support rod, and liquid inlet holes are evenly arranged at the end part thereof arranged inside the tumbling barrel;

[0012] A recovery pipe, a recovery pump and a cooling device, one end of the recovery pipe is communicated with the collection box, and the other end is communicated with the cavity inside the support rod. During the rotation of the tumbling barrel, the recovery pump can drive the recovery pipe to continuously transport the juice in the collection box to the cavity of the support rod, and at this time, the cooling device continuously cools the recovery pipe.

[0013] Preferably; the driving device includes a driving motor, a driving shaft and a driving gear, and a driven gear meshing with the driving gear is fixed on the rotating rod.

[0014] Preferably; a filter screen is further arranged in the collection box, the filter screen is horizontally arranged and is located below the tumbling barrel, and it is used for filtering the juice dripping from the tumbling barrel.

[0015] Preferably; the bottom of the collection box is funnel-shaped, a diversion port is arranged at the center of the bottom, and the recovery pipe is communicated with the diversion port.

[0016] Preferably; mounting grooves are circumferentially and evenly distributed on the inclined surface of the funnel-shaped side wall of the collection box, the axis of the mounting groove is parallel to the inclined surface of the side wall, an ultraviolet lamp is arranged in the mounting groove, and a waterproof cover is arranged at the notch of the mounting groove.

[0017] Preferably; the ultrasonic device includes a transducer, and a plurality of transducers are circumferentially and evenly distributed on the inclined surface of the funnel-shaped side wall of the collection box.

[0018] Preferably; the cooling device includes a cooling box and a compression refrigeration unit; the recovery pipe axially penetrates through the cooling box, and a spiral heat exchange pipe is sleeved on the outer wall thereof in the circumferential direction. A diversion fin extending towards the recovery pipe is arranged on the inner wall of the spiral heat exchange pipe, and the gap between the diversion fin and the outer wall of the recovery pipe is ≤1 mm; the spiral heat exchange pipe is connected with the compression refrigeration unit through a refrigerant circulation pipeline to form a closed refrigeration loop.

[0019] Preferably; the outlet temperature of the polygonatum sibiricum juice in the recovery pipe after being cooled by the cooling box is 0-10 °C.

[0020] A low-temperature tumbling process for directional softening and browning inhibition of polygonatum sibiricum fibers, using the said system for tumbling, includes the following working processes:

[0021] S1. Place the polygonatum sibiricum raw material into the tumbling barrel, start the driving device to drive the tumbling barrel to rotate at a speed of 15-25 r / min, and simultaneously turn on the ultraviolet lamp in the collection box;

[0022] S2. During the tumbling process, the polygonatum sibiricum juice flows into the collection tank through the liquid discharge holes on the side wall of the tumbling barrel. After the tumbling barrel rotates for 5 - 10 minutes, the recovery pump is turned on, and the recovery pipe extracts the juice from the bottom wall of the collection tank to the cooling device. Under the combined action of the spiral heat exchange pipe and the guide fins in the cooling device, the temperature of the juice is reduced to 0 - 10 °C. The cooled juice is sprayed onto the surface of the polygonatum sibiricum in the tumbling barrel through the cavity of the support rod and the liquid inlet holes, thereby cooling the polygonatum sibiricum.

[0023] S3. After tumbling for 1 hour, the driving device and the recovery pump are turned off, and it is left to stand for 20 - 30 minutes. During the standing process, the ultrasonic device is turned on to ultrasonically treat the juice in the collection tank.

[0024] S4. After the standing ends, the ultrasonic device is turned off, and at the same time, the driving device and the recovery pump are turned on to tumble the polygonatum sibiricum for 30 minutes.

[0025] S5. After the tumbling ends, the driving device and the recovery pump are turned off, and it is left to stand for 20 - 30 minutes. During the standing process, the ultrasonic device is turned on to ultrasonically treat the juice in the collection tank.

[0026] S6. Repeat steps S4 to S5 four to six times.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] 1. The juice cooled to 0 - 10 °C is circulated and sprayed, achieving progressive softening of polygonatum sibiricum fibers in a low - temperature environment. The activity of microorganisms and polyphenol oxidase is relatively low under the condition of 0 - 10 °C, which can effectively reduce the browning phenomenon during the tumbling process of polygonatum sibiricum. The liquid inlet holes evenly distributed at the end of the support rod directly spray the low - temperature juice onto the surface of polygonatum sibiricum, effectively cooling and increasing the temperature of polygonatum sibiricum at different positions.

[0029] 2. If there is too much juice in the tumbling barrel, the tumbling of polygonatum sibiricum will result in insufficient mechanical friction due to the lubrication of the liquid film, and the softening efficiency will decrease. If the juice is too little, the fiber swelling and softening will be hindered, the surface dry friction will increase, leading to fiber breakage, and at the same time, the local temperature will rise, accelerating browning. The combination of the liquid discharge holes and the liquid inlet holes forms a dynamically circulating thin layer of juice in the tumbling barrel, improving the tumbling effect of polygonatum sibiricum.

[0030] 3. When standing, almost all the juice in the tumbling barrel drips into the collection tank. The ultrasonic wave is used to destroy the structure of polyphenol oxidase, making it lose its activity, thereby reducing the browning of polygonatum sibiricum. At the same time, the low - temperature juice can effectively inhibit the rate of enzymatic browning reaction.

[0031] 4. The ultraviolet lamp in the installation groove is continuously turned on, which can effectively sterilize the microorganisms in the juice, slow down the reproduction speed of microorganisms, and thus slow down the browning speed. Description of the Drawings

[0032] Figure 1Schematic diagram of the external structure of the collection box in the embodiment;

[0033] Figure 2 Schematic diagram of the internal structure of the collection box from a top-down perspective in the embodiment;

[0034] Figure 3 Schematic diagram of the internal structure of the collection box and the tumbling barrel at the cross-section in the embodiment;

[0035] Figure 4 Exploded view of the waterproof cover and the collection box in the embodiment;

[0036] Figure 5 Schematic diagram of the internal structure of the support rod in the embodiment.

[0037] 110. Mounting frame; 120. Tumbling barrel; 1201. Drain hole; 1202. Barrel door; 130. Collection box; 1301. Diversion port; 1302. Installation groove; 1303. Waterproof cover; 1304. Box door; 140. Ultraviolet lamp; 150. Rotating rod; 1501. Driven gear; 160. Support rod; 1601. Cavity; 1602. Liquid inlet hole; 1701. Recovery pipe; 190. Filter screen; 210. Cooling box. Detailed implementation manners

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0039] Embodiment

[0040] Low-temperature tumbling system and process for directional softening and browning inhibition of polygonatum sibiricum fiber

[0041] The specific equipment structure composition is as follows:

[0042] The mounting frame serves as the support component of the entire system. The mounting frame is provided with a tumbling barrel and a collection box. The diameter of the tumbling barrel is 1 m, and the collection box is fixed on the mounting frame; the tumbling barrel is horizontally arranged inside the collection box, and its side wall is evenly provided with drain holes with a diameter of 2 - 3 mm. A filter screen is also provided inside the collection box below the tumbling barrel. The filter screen is horizontally arranged and has a pore diameter of 0.5 mm.

[0043] One end of the rotating rod is fixed to the end face of the tumbling barrel, and the other end extends out of the collection box, and a driven gear is fixed to the extended end. The driving device includes a driving motor, a driving shaft, and a driving gear. The driving gear meshes with the driven gear. The driving motor drives the driving shaft to rotate, and then drives the driving gear and the driven gear to rotate, finally realizing the rotation of the tumbling barrel.

[0044] The rotation speed of the tumbling barrel is between 15 r - 25 r / min. Higher than this speed, more heat is generated due to the friction and temperature rise of polygonatum during the tumbling process, which easily leads to excessive temperature rise of polygonatum and aggravates the browning of polygonatum. Moreover, too high a speed easily causes a large number of polygonatum fiber fractures.

[0045] The specific rotation speed of the tumbling barrel is related to the type of polygonatum. Due to the differences in fiber density, cell wall structure, and enzyme activity among different polygonatum varieties, the rotation speed of the tumbling barrel needs to be adjusted specifically to balance the softening efficiency and quality protection.

[0046] After tumbling, the partial data comparison table of the fiber fracture rate and the rotation speed of the tumbling barrel for some common polygonatum is as follows:

[0047] Polygonatum species Rotation speed (r / min) Fiber breakage rate (%) Polygonatum cyrtonema 18 4.2 Polygonatum cyrtonema 25 15.7 Polygonatum kingianum 22 9.3 Polygonatum kingianum 25 12.4 Polygonatum cirrhifolium 15 2.5 Polygonatum cirrhifolium 20 8.9

[0048] Combined with the data in the above table, set the rotation speed of the tumbling barrel for Polygonatum cyrtonema Hua to 18 - 22 r / min; for Polygonatum kingianum Coll. et Hemsl. to 22 - 25 r / min; for Polygonatum cirrhifolium (Wall.) Royle to 15 - 18 r / min.

[0049] Support holes are provided on the end face of the tumbling barrel far from the rotating rod. One end of the support rod is fixed on the mounting frame, and the other end passes through the mounting box and the end face of the support hole and extends into the interior of the tumbling barrel. The tumbling barrel can rotate around the support rod driven by the rotating rod. To strengthen the fixation of the tumbling barrel and prevent the axial movement of the tumbling barrel during rotation, a limit plate can be provided on the support rod to achieve axial limit of the tumbling barrel.

[0050] The bottom of the collection box is funnel-shaped, and a diversion port is provided at the center of its bottom. The recovery pipe is connected to the diversion port, and the other end passes through the cooling box and is connected to the cavity inside the support rod. The part of the support rod extending into the tumbling barrel is evenly provided with liquid inlet holes with a diameter of 0.5 mm communicating with the cavity. The juice in the collection box re-enters the tumbling barrel through the recovery pipe and the liquid inlet holes.

[0051] Before the juice in the recovery pipe enters the cavity of the support rod, it first passes through the cooling box. The cooling box is provided with an external spiral heat exchange tube, and heat conduction fins are provided on the spiral heat exchange tube. The distance between the heat conduction fins and the outer wall of the heat exchange tube is less than 1 mm. It cooperates with the refrigeration unit of the compressor to cool the juice in the recovery pipe to 0 - 10 °C;

[0052] UV lamps (wavelength 254 nm, power 30 W) and ultrasonic transducers (frequency 20 kHz, power density 50 W / L) are circumferentially distributed on the funnel-shaped side wall of the collection box;

[0053] The UV lamp is used for sterilization, and ultraviolet rays can induce the photolysis of aromatic amino acids such as tryptophan and tyrosine in polyphenol oxidase, destroy its active center (copper ion binding site), and reduce the enzyme activity.

[0054] The Polygonatum sibiricum Redoute juice was only treated with ultraviolet light of different wavelengths for 30 minutes, and its sterilization rate, residual rate of polyphenol oxidase activity, and polysaccharide loss rate are shown in the following table:

[0055]

[0056] Taking all aspects into consideration, ultraviolet light with a wavelength of 254 nm was selected in this embodiment.

[0057] The ultrasonic transducer is used to ultrasonically destroy the polyphenol oxidase in the juice. Ultrasonics can destroy the protein structure of the enzyme through principles such as the cavitation effect..

[0058] Taking Polygonatum cirrhifolium (Wall.) Royle as an example, the specific usage process of the above device is as follows:

[0059] Step 1: Place the Polygonatum sibiricum Redoute raw material into the tumbling barrel, with the loading amount being, start the driving device to drive the tumbling barrel to rotate at a speed of 20 r / min, and simultaneously turn on the ultraviolet lamp in the collection box.

[0060] Step 2: During the tumbling process, the Polygonatum sibiricum Redoute juice flows into the collection box through the drainage holes on the side wall of the tumbling barrel; after the tumbling barrel rotates for 5 - 7 minutes, turn on the recycling pump, and the recycling pipe extracts the juice from the bottom wall of the collection box to the cooling device. Under the combined action of the spiral heat exchange tube and the guide fins of the cooling device, the temperature of the juice is reduced to 0 - 3 °C; the cooled juice is sprayed onto the surface of the Polygonatum sibiricum Redoute in the tumbling barrel through the cavity of the support rod and the liquid inlet hole, thereby cooling the Polygonatum sibiricum Redoute.

[0061] Remark 1: The cell wall of Polygonatum cirrhifolium (Wall.) Royle is relatively thin, and the juice is generated relatively quickly during the tumbling process. Therefore, after the tumbling barrel rotates for 5 - 7 minutes, the collection box can collect a considerable amount of juice, and at this time, the recycling pump can be turned on for the recycling operation of the juice. Correspondingly, for Polygonatum cyrtonema Hua, it is 7 - 9 minutes, and for Polygonatum kingianum Coll. et Hemsl., it is 10 minutes.

[0062] Remark 2: The polyphenol oxidase activities in different Polygonatum sibiricum Redoute are different, and the decrease in temperature will affect the molecular diffusion of the nutrients in the Polygonatum sibiricum Redoute. Therefore, the lower the temperature to which the juice is appropriately reduced is not necessarily better. Considering the above factors, the polyphenol oxidase activities and the recommended temperature for reducing the temperature of the juice of some types of Polygonatum sibiricum Redoute are shown in the following table:

[0063] Polygonatum species Polyphenol oxidase activity (U / g) Recommended cooling temperature of juice (°C) Polygonatum cirrhifolium 180-280 0-3 Polygonatum kingianum 120-200 3-5 Polygonatum cyrtonema 80-150 5-8

[0064] Step 3: After tumbling for 1 hour, turn off the driving device and the recycling pump, and let it stand for 20 - 30 minutes; during the standing process, turn on the ultrasonic device with a frequency of 20 kHz and a power density of 50 W / L to ultrasonically treat the juice in the collection box; destroy the polyphenol oxidase in the juice.

[0065] Step 4: After the standing still ends, turn off the ultrasonic device, and at the same time turn on the driving device and the recovery pump to knead the polygonatum sibiricum. At this time, the degree of rupture of the cell wall of the polygonatum sibiricum is relatively high, and the juice secretion speed is accelerated. Therefore, the kneading and rolling time this time is set to 30 minutes.

[0066] Step 5: After the kneading and rolling ends, turn off the driving device and the recovery pump, and let it stand still for 20 - 30 minutes; during the standing still process, turn on the ultrasonic device, and the values of its power frequency, etc. are the same as those in Step 3 to ultrasonically destroy polyphenol oxidase in the juice in the collection box.

[0067] Step 6: Continuously repeat Step 4 to Step 5 for 4 times.

[0068] Note: Different types of polygonatum sibiricum S6 require different numbers of repetitions. The polygonatum cirrhifolium has a thinner cell wall and its fibers are more easily broken, so the number of repetitions is set to 4 times; for polygonatum cyrtonema represented by polygonatum cyrtonema, because the cell wall has a medium thickness and the fiber toughness is relatively high, the number of repetitions is set to 5 times; for high-fiber density varieties represented by polygonatum kingianum, the number of repetitions is set to 6 times.

[0069] The following table shows the data relationship between the limit fracture rate, the polysaccharide yield in the juice and the number of repetitions in Step 6 for some types of polygonatum sibiricum.

[0070] Polygonatum species Number of repetitions in step 6 Polysaccharide yield (%) Fiber breakage rate Polygonatum cirrhifolium 4 88.5 9.2 Polygonatum cirrhifolium 5 90.1 15.7 Polygonatum cyrtonema 5 82.3 12.4 Polygonatum cyrtonema 6 85.6 18.9 Polygonatum kingianum 6 78.4 14.2 Polygonatum kingianum 7 81.3 21.5

Claims

1. A low-temperature tumbling system for directional softening and browning inhibition of polygonatum fiber, comprising a mounting frame (110) and a horizontally placed tumbling barrel (120), characterized in that: It also includes a collection box (130) fixed on the mounting frame (110), wherein an ultraviolet lamp (140) for sterilization is arranged in the collection box (130); an ultrasonic device is also arranged in the collection box (130), and the ultrasonic device is used to destroy the polyphenol oxidase that flows out after the cell wall of Polygonatum cyrtonema is ruptured; Through holes are provided on the left and right side walls of the collection box (130), the rolling and kneading barrel (120) is arranged in the collection box (130), and drainage holes (1201) are evenly provided on the side walls of the rolling and kneading barrel (120); A rotating rod (150), one end of which is fixed on the end surface of the rolling and kneading barrel (120), and the other end of which extends out of the through hole, and the end of which extends out of the through hole is connected to a driving device; A support rod (160) is fixed at one end on the mounting frame (110); a support hole is provided on the end surface of the rolling and kneading barrel (120) away from the rotating rod (150); the other end of the support rod (160) passes through the through hole and the support hole and extends into the rolling and kneading barrel (120); a cavity (1601) is provided inside the support rod (160), and liquid inlet holes (1602) are evenly provided at the end thereof disposed in the rolling and kneading barrel (120); A recovery pipe (1701), a recovery pump and a cooling device, one end of the recovery pipe (1701) is connected to the collection box (130), and the other end is connected to the cavity (1601) inside the support rod (160). During the rotation of the tumbling barrel (120), the recovery pump can drive the recovery pipe (1701) to continuously transport the juice in the collection box (130) to the cavity (1601) of the support rod (160), and at this time, the cooling device continues to cool the recovery pipe (1701).

2. The low-temperature tumbling system for directional softening and browning inhibition of polygonatum fiber according to claim 1 is characterized by: The driving device comprises a driving motor, a driving shaft and a driving gear, and a driven gear (1501) meshing with the driving gear is fixed on the rotating rod (150).

3. The low-temperature tumbling system for directional softening and browning inhibition of polygonatum fiber according to claim 1 is characterized in that: The invention also comprises a filter screen (190) arranged in the collection box (130); the filter screen (190) is arranged horizontally and is located below the tumbling and kneading barrel (120); and is used for filtering the juice dripping from the tumbling and kneading barrel (120).

4. The low-temperature tumbling system for directional softening and browning inhibition of polygonatum fiber according to claim 1, characterized in that: The bottom of the collecting box (130) is funnel-shaped, and a flow guide port (1301) is provided at the center of the bottom, and the recovery pipe (1701) is connected to the flow guide port (1301).

5. The low-temperature tumbling system for directional softening and browning inhibition of polygonatum fiber according to claim 4 is characterized in that: The collecting box (130) has mounting grooves (1302) evenly distributed circumferentially on the inclined surface of the funnel-shaped side wall, the axis of the mounting groove (1302) is parallel to the inclined surface of the side wall, the ultraviolet lamp (140) is arranged in the mounting groove (1302), and a waterproof cover (1303) is arranged at the notch of the mounting groove (1302).

6. The low-temperature tumbling system for directional softening and browning inhibition of polygonatum fiber according to claim 4, characterized in that: The ultrasonic device comprises a transducer, and a plurality of transducers are evenly distributed circumferentially on the inclined surface of the funnel-shaped side wall of the collecting box (130).

7. The low-temperature tumbling system for directional softening and browning inhibition of polygonatum fiber according to claim 1, characterized in that: The cooling device comprises a cooling box (210) and a compressor refrigeration unit; the recovery pipe (1701) penetrates the cooling box (210) in the axial direction, and a spiral heat exchange pipe is circumferentially sleeved on the outer wall thereof, and the inner wall of the spiral heat exchange pipe is provided with a guide fin extending in the direction of the recovery pipe (1701), and the gap between the guide fin and the outer wall of the recovery pipe (1701) is ≤1mm; the spiral heat exchange pipe is connected to the compressor refrigeration unit through a refrigerant circulation pipeline to form a closed refrigeration circuit.

8. The low-temperature tumbling system for directional softening and browning inhibition of polygonatum fiber according to claim 7, characterized in that: The outlet temperature of the Polygonatum sibiricum juice in the recovery pipe (1701) after being cooled by the cooling box (210) is 0-10°C.

9. A low-temperature tumbling process for directional softening and browning inhibition of polygonatum fiber, characterized in that: The system according to any one of claims 1 to 8 comprises the following working process: S1, placing the raw material of Polygonatum odoratum into a tumbling and kneading barrel (120), starting a driving device to drive the tumbling and kneading barrel (120) to rotate at a speed of 15-25 r / min, and simultaneously turning on the ultraviolet lamp (140) in the collection box (130); S2, during the rolling and kneading process, the polygonatum juice flows into the collection box (130) through the drainage hole (1201) on the side wall of the rolling and kneading barrel (120); after the rolling and kneading barrel (120) rotates for 5-10 minutes, the recovery pump is turned on, and the recovery pipe (1701) extracts the juice from the bottom wall of the collection box (130) to the cooling device, and the spiral heat exchange tube and the guide fin of the cooling device cooperate to reduce the temperature of the juice to 0-10°C; the cooled juice is sprayed onto the surface of the polygonatum in the rolling and kneading barrel (120) through the cavity (1601) of the support rod (160) and the liquid inlet hole (1602), thereby cooling the polygonatum; S3, after tumbling for 1 hour, turn off the driving device and the recovery pump, and let it stand for 20-30 minutes; during the standing period, turn on the ultrasonic device to perform ultrasonic treatment on the juice in the collection box (130); S4, after the standing period, turn off the ultrasonic device, turn on the driving device and the recovery pump at the same time, and roll and knead the polygonatum for 30 minutes; S5, after the tumbling is completed, the driving device and the recovery pump are turned off, and the juice is left to stand for 20-30 minutes; during the standing period, the ultrasonic device is turned on to ultrasonicate the juice in the collection box (130); S6. Repeat steps S4 to S5 4-6 times.

Images