Low-temperature tumbling system and process for orienting and softening and inhibiting browning of polygonatum fiber

Abstract

The present application relates to the processing technology field of Rhizoma Polygonati, 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 collection box, a cooling circulation module and an ultraviolet-ultrasonic synergistic treatment unit. The tumbling barrel breaks Rhizoma Polygonati cells and releases juice during rotation, the juice is filtered by the collection box, cooled to 0-10 DEG C by a cooling device, and then recycled and sprayed onto the surface of Rhizoma Polygonati to realize dynamic temperature control; the ultraviolet lamp inhibits the reproduction of microorganisms, the ultrasonic wave destroys the activity of polyphenol oxidase, and the low-temperature environment blocks the browning reaction; the process realizes directional softening of Rhizoma Polygonati fibers under low-temperature conditions by alternating tumbling and standing, synergistically controls the softening rate of fibers and the inhibition efficiency of enzyme activity, and significantly reduces the browning risk. The system takes into account the quality and processing efficiency of Rhizoma Polygonati, is suitable for the industrialized processing of different varieties such as Rhizoma Polygonati and Rhizoma Polygonati, and can be widely applied to the processing technology field of Rhizoma Polygonati.

Description

Technical Field

[0001] This invention relates to the field of Polygonatum processing technology, specifically to a low-temperature tumbling system and process for directional softening and browning inhibition of Polygonatum fibers. Background Technology

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

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

[0004] In addition, the cell structure of Polygonatum ruptures in large numbers, causing its internal nutrients to flow out. During the tumbling process, friction generates heat, causing Polygonatum to continuously heat up. When the tumbling temperature exceeds a certain level, the reproduction rate of microorganisms accelerates dramatically under the influence of a large amount of nutrients. These microorganisms decompose polysaccharides and other organic matter in Polygonatum, producing melanoidins and other products, leading to the browning of Polygonatum fibers.

[0005] Therefore, while the current processing technology for Polygonatum tumbling achieves directional softening of Polygonatum fibers, it is urgent to solve the technical challenge of effectively inhibiting browning in order to ensure the high quality and market competitiveness of Polygonatum products. Summary of the Invention

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] The low-temperature tumbling system for directional softening and browning inhibition of Polygonatum fibers includes a mounting frame and a horizontally placed tumbling drum, as well as a collection box fixed on the mounting frame. The collection box is equipped with an ultraviolet lamp for sterilization. The collection box is also equipped with an ultrasonic device, which is used to destroy the polyphenol oxidase that flows out after the Polygonatum cell wall ruptures.

[0008] The left and right side walls of the collection box have through holes, and the tumbling drum is placed inside the collection box. The side walls of the tumbling drum have evenly spaced drainage holes.

[0009] The rotating rod has one end fixed to the end face of the tumbling drum, and the other end protrudes from the through hole. The end of the rod protruding from the through hole is connected to a driving device.

[0010] A support rod is fixed at one end to the mounting bracket; a support hole is provided on the end face of the tumbling drum away from the rotating rod, and the other end of the support rod extends into the tumbling drum through the through hole and the support hole; the support rod has a cavity inside, and liquid inlet holes are evenly provided at its end inside the tumbling drum.

[0011] The system includes a recovery pipe, a recovery pump, and a cooling device. One end of the recovery pipe is connected to the collection box, and the other end is connected to the cavity inside the support rod. During the rotation of the tumbling drum, the recovery pump drives the recovery pipe to continuously transport the juice from the collection box to the cavity of the support rod, while the cooling device continuously cools the recovery pipe.

[0012] Preferably, the drive device includes a drive motor, a drive shaft and a drive gear, and a driven gear that meshes with the drive gear is fixed on the rotating rod.

[0013] Preferably, it also includes a filter screen disposed in a collection box, the filter screen being horizontally positioned below the tumbling drum, which is used to filter the juice dripping from the tumbling drum.

[0014] Preferably, the bottom of the collection box is funnel-shaped, with a flow guide port at the center of the bottom, and the recovery pipe is connected to the flow guide port.

[0015] Preferably, the funnel-shaped sidewall of the collection box has mounting grooves evenly distributed circumferentially on its inclined surface, the axis of the mounting grooves is parallel to the inclined surface of the sidewall, the ultraviolet lamp is installed in the mounting groove, and a waterproof cover is installed at the opening of the mounting groove.

[0016] Preferably, the ultrasonic device includes transducers, and multiple transducers are evenly distributed circumferentially on the inclined surface of the funnel-shaped sidewall of the collection box.

[0017] Preferably, the cooling device includes a cooling box and a compressor refrigeration unit; a recovery pipe passes through the cooling box axially, and a spiral heat exchange tube is circumferentially sleeved on its outer wall. The inner wall of the spiral heat exchange tube is provided with guide fins extending towards the recovery pipe, and the gap between the guide fins and the outer wall of the recovery pipe is ≤1mm; the spiral heat exchange tube is connected to the compressor refrigeration unit through a refrigerant circulation pipeline to form a closed refrigeration circuit.

[0018] Preferably, the outlet temperature of the Polygonatum sibiricum juice in the recovery tube after being cooled by the cooling box is 0-10℃.

[0019] A low-temperature tumbling process for the directional softening and browning inhibition of Polygonatum cyrtonema fibers, using the aforementioned system, includes the following workflow:

[0020] S1. Place the Polygonatum sibiricum raw material into the tumbling drum, start the drive device to drive the tumbling drum to rotate at a speed of 15-25r / min, and simultaneously turn on the ultraviolet lamp in the collection box.

[0021] S2. During the tumbling process, the Polygonatum juice flows into the collection box through the drain hole on the side wall of the tumbling drum. After the tumbling drum rotates for 5-10 minutes, the recovery pump is turned on, and the recovery pipe draws 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 juice temperature is reduced to 0-10℃. The cooled juice is sprayed onto the surface of Polygonatum inside the tumbling drum through the support rod cavity and the liquid inlet hole, thereby cooling the Polygonatum.

[0022] S3. After tumbling for 1 hour, turn off the drive device and the recovery pump, and let it stand for 20-30 minutes; during the standing process, turn on the ultrasonic device to sonicate the juice in the collection box.

[0023] S4. After the settling period, turn off the ultrasonic device and turn on the drive device and recovery pump at the same time to tumble the Polygonatum for 30 minutes.

[0024] S5. After tumbling, turn off the drive device and the recovery pump, and let it stand for 20-30 minutes; during the standing process, turn on the ultrasonic device to sonicate the juice in the collection box.

[0025] S6. Repeat steps S4 to S5 4-6 times.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] 1. The juice, cooled to 0-10℃, is circulated and sprayed, achieving gradual softening of the Polygonatum fibers under low-temperature conditions. Microorganisms and polyphenol oxidases have lower activity at 0-10℃, effectively reducing browning during the tumbling process. The evenly distributed inlet holes at the end of the support rods directly spray the low-temperature juice onto the surface of the Polygonatum, effectively cooling different areas of the plant.

[0028] 2. If there is too much juice in the tumbling barrel, the tumbling of Polygonatum will result in insufficient mechanical friction due to liquid film lubrication, leading to a decrease in softening efficiency. If there is too little juice, the fiber swelling and softening will be hindered, surface dry friction will increase, causing fiber breakage, and local temperature increases will accelerate browning. The combination of drainage holes and inlet holes creates a dynamically circulating thin layer of juice inside the tumbling barrel, improving the tumbling effect of Polygonatum.

[0029] 3. During the settling process, almost all the juice in the tumbling bucket drips into the collection box. Ultrasonic waves are used to destroy the structure of polyphenol oxidase, causing it to lose its activity, thereby reducing the browning of Polygonatum sibiricum. At the same time, the low temperature of the juice can effectively inhibit the rate of enzymatic browning reaction.

[0030] 4. The ultraviolet lamps inside the installation tank are continuously turned on, which can effectively sterilize the microorganisms in the juice, slow down the reproduction rate of microorganisms, and thus slow down the browning rate. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the external structure of the collection box in the embodiment;

[0032] Figure 2 This is a schematic diagram of the internal structure of the collection box from a top-down perspective in the embodiment;

[0033] Figure 3 This is a schematic diagram of the internal structure of the collection box and tumbling drum in cross-section in the embodiment;

[0034] Figure 4 The waterproof cover and collection box are shown in the embodiment, along with an exploded view;

[0035] Figure 5 This is a schematic diagram of the internal structure of the support rod in the embodiment.

[0036] 110. Mounting frame; 120. Tumbling drum; 1201. Drain hole; 1202. Drum door; 130. Collection box; 1301. Guide port; 1302. Mounting groove; 1303. Waterproof cover; 1304. Box door; 140. Ultraviolet lamp; 150. Rotating rod; 1501. Driven gear; 160. Support rod; 1601. Cavity; 1602. Liquid inlet; 1701. Recovery pipe; 190. Filter screen; 210. Cooling box. Detailed Implementation

[0037] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0038] Low-temperature tumbling system and process for directional softening and browning inhibition of Polygonatum odoratum fibers

[0039] Its specific equipment structure is as follows:

[0040] The mounting frame serves as the support component for the entire system. It houses a tumbling drum with a diameter of 1m, and the collection box is fixed to the mounting frame. The tumbling drum is horizontally positioned within the collection box, with evenly spaced drainage holes of 2-3mm diameter on its side walls. A filter screen, horizontally positioned and with a 0.5mm pore size, is also located below the tumbling drum within the collection box.

[0041] One end of the rotating rod is fixed to the end face of the tumbling drum, and the other end extends out of the collection box with a driven gear fixed to the extended end. The driving device includes a drive motor, a drive shaft and a drive gear. The drive gear meshes with the driven gear. The drive motor drives the drive shaft to rotate, which in turn drives the drive gear and the driven gear to rotate, ultimately realizing the rotation of the tumbling drum.

[0042] The tumbling drum speed should be between 15r and 25r / min. If the speed is higher than this, more heat will be generated by friction during the tumbling process, which may cause the Polygonatum to overheat and aggravate the browning of the Polygonatum. In addition, if the speed is too high, a large number of Polygonatum fibers may break.

[0043] The specific rotation speed of the tumbling drum is related to the type of Polygonatum. Different varieties of Polygonatum have different fiber densities, cell wall structures and enzyme activities, so the rotation speed of the tumbling drum needs to be adjusted accordingly to balance softening efficiency and quality protection.

[0044] The following table compares some data on fiber breakage rate and tumbling speed of some common Polygonatum species after tumbling:

[0045] Types of Polygonatum Rotational speed (r / min) Fiber breakage rate (%) Polygonatum multiflorum 18 4.2 Polygonatum multiflorum 25 15.7 Yunnan Polygonatum 22 9.3 Yunnan Polygonatum 25 12.4 Curly-leaved Polygonatum 15 2.5 Curly-leaved Polygonatum 20 8.9

[0046] Based on the data in the table above, the tumbling speed of Polygonatum multiflorum was set to 18-22 r / min; that of Polygonatum yunnanense was set to 22-25 r / min; and that of Polygonatum sibiricum was set to 15-18 r / min.

[0047] A support hole is provided on the end face of the tumbling drum away from the rotating rod. One end of the support rod is fixed to the mounting bracket, and the other end passes through the mounting box and the end face of the support hole, extending into the interior of the tumbling drum. The tumbling drum can rotate around the support rod under the drive of the rotating rod. In order to strengthen the fixation of the tumbling drum and prevent the tumbling drum from moving axially during rotation, a limiting plate can be set on the support rod to limit the axial movement of the tumbling drum.

[0048] The bottom of the collection box is funnel-shaped, with a guide port at the center of the bottom. The recovery pipe is connected to the guide port, and the other end passes through the cooling box and connects to the cavity inside the support rod. The part of the support rod that extends into the tumbling barrel has evenly spaced liquid inlet holes with a diameter of 0.5 mm that connect to the cavity. The juice in the collection box re-enters the tumbling barrel through the recovery pipe and the liquid inlet holes.

[0049] The juice in the recovery pipe enters the cavity between the support rods and first passes through the cooling box. The cooling box is equipped with an outer spiral heat exchange tube with heat-conducting fins. The distance between the heat-conducting fins and the outer wall of the heat exchange tube is less than 1mm. Together with the compressor refrigeration unit, it cools the juice in the recovery pipe to 0-10℃.

[0050] The funnel-shaped sidewall of the collection box is circumferentially distributed with ultraviolet lamps (wavelength 254nm, power 30W) and ultrasonic transducers (frequency 20kHz, power density 50W / L).

[0051] Ultraviolet lamps are used for sterilization, and ultraviolet light can induce photolysis of aromatic amino acids such as tryptophan and tyrosine in polyphenol oxidase, destroying their active sites (copper ion binding sites) and reducing enzyme activity.

[0052] The sterilization rate, polyphenol oxidase activity residue rate, and polysaccharide loss rate of Polygonatum sibiricum juice were obtained by treating the juice with ultraviolet light of different wavelengths for 30 minutes. The results are shown in the table below.

[0053] Ultraviolet wavelength (nm) Sterilization rate (%) Polyphenol oxidase activity residual rate (%) Polysaccharide loss rate (%) 254 98.5 10 1.5 265 99.5 13 1.8 222 97.3 7 1.0

[0054] Taking all factors into consideration, this embodiment selects ultraviolet light with a wavelength of 254nm.

[0055] Ultrasonic transducers are used to destroy polyphenol oxidase in juice by ultrasonication. Ultrasound can destroy the protein structure of enzymes through principles such as cavitation effect.

[0056] Taking Polygonatum curcuma as an example, the specific operating procedure of the above-mentioned device is as follows:

[0057] Step 1: Place the Polygonatum sibiricum raw material into the tumbling drum, start the drive device to drive the tumbling drum to rotate at a speed of 20 r / min, and simultaneously turn on the ultraviolet lamp in the collection box.

[0058] Step 2: During the tumbling process, the Polygonatum juice flows into the collection box through the drain hole on the side wall of the tumbling drum. After the tumbling drum rotates for 5-7 minutes, the recovery pump is turned on, and the recovery pipe draws 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 juice temperature is reduced to 0-3℃. The cooled juice is sprayed onto the surface of Polygonatum inside the tumbling drum through the support rod cavity and the liquid inlet hole, thereby cooling the Polygonatum.

[0059] Note 1: *Polygonatum curcumum* has thinner cell walls, resulting in faster sap production during tumbling. Therefore, after 5-7 minutes of tumbling in the tumbling drum, a considerable amount of sap can be collected in the collection box, at which point the recycling pump can be activated for sap circulation. The corresponding timeframes are 7-9 minutes for *Polygonatum multiflorum* and 10 minutes for *Polygonatum yunnanense*.

[0060] Note 2: The polyphenol oxidase activity varies among different types of Polygonatum, and lowering the temperature will affect the molecular diffusion of nutrients within the Polygonatum. Therefore, the optimal temperature for reducing the juice is not necessarily the lower the better. Considering the above factors, the recommended cooling temperatures for polyphenol oxidase activity and juice of some Polygonatum species are shown in the table below:

[0061] Types of Polygonatum Polyphenol oxidase activity (U / g) Recommended cooling temperature for juice (°C) Curly-leaved Polygonatum 180-280 0-3 Yunnan Polygonatum 120-200 3-5 Polygonatum multiflorum 80-150 5-8

[0062] Step 3: After tumbling for 1 hour, turn off the drive device and the recovery pump, and let it stand for 20-30 minutes. During the standing period, turn on the ultrasonic device at a frequency of 20kHz and a power density of 50W / L to sonicate the juice in the collection box to destroy the polyphenol oxidase in the juice.

[0063] Step 4: After the settling period, turn off the ultrasonic device and turn on the drive device and recovery pump to tumble the Polygonatum. At this time, the cell walls of Polygonatum are more ruptured and the juice secretion speed is faster. Therefore, the tumbling time is set to 30 minutes.

[0064] Step 5: After tumbling, turn off the drive device and the recovery pump, and let it stand for 20-30 minutes. During the standing process, turn on the ultrasonic device with the same power and frequency values ​​as in step 3 to ultrasonically destroy the polyphenol oxidase in the juice in the collection box.

[0065] Step 6: Repeat steps 4 and 5 consecutively, four times in total.

[0066] Note: The number of repetitions required for S6 varies depending on the species of Polygonatum. For Polygonatum sibiricum, which has a thinner cell wall and more easily broken fibers, the number of repetitions is set to 4. For Polygonatum sibiricum, which is represented by Polygonatum multiflorum, the number of repetitions is set to 5 because the cell wall is of medium thickness and the fibers are more resilient. For high fiber density varieties, such as Polygonatum yunnanense, the number of repetitions is set to 6.

[0067] The table below shows the relationship between the cleavage rate, polysaccharide yield in the juice, and the number of repetitions in step 6 for some types of Polygonatum.

[0068] Types of Polygonatum Number of repetitions in step 6 Polysaccharide yield (%) Fiber breaking rate Curly-leaved Polygonatum 4 88.5 9.2 Curly-leaved Polygonatum 5 90.1 15.7 Polygonatum multiflorum 5 82.3 12.4 Polygonatum multiflorum 6 85.6 18.9 Yunnan Polygonatum 6 78.4 14.2 Yunnan Polygonatum 7 81.3 21.5

Claims

1. A low-temperature tumbling system for directional softening and browning inhibition of Polygonatum odoratum fibers, comprising a mounting frame (110) and a horizontally placed tumbling drum (120), characterized in that: It also includes a collection box (130) fixed on the mounting frame (110), and a UV lamp (140) for sterilization is installed inside the collection box (130); the collection box (130) is also equipped with an ultrasonic device, which is used to destroy the polyphenol oxidase that flows out after the cell wall of Polygonatum sibiricum is ruptured. The left and right side walls of the collection box (130) are provided with through holes, and the tumbling barrel (120) is placed inside the collection box (130). Drainage holes (1201) are evenly provided on the side walls of the tumbling barrel (120). The rotating rod (150) has one end fixed to the end face of the tumbling drum (120) and the other end protruding from the through hole. The end of the rod protruding from the through hole is connected to a driving device. A support rod (160) is fixed at one end to a mounting bracket (110); a support hole is provided on the end face of the tumbling drum (120) away from the rotating rod (150), and the other end of the support rod (160) extends into the tumbling drum (120) through the through hole and the support hole; a cavity (1601) is provided inside the support rod (160), and liquid inlet holes (1602) are evenly provided at the end of the support rod (160) located inside the tumbling drum (120). The recycling pipe (1701), recycling pump, and cooling device are provided. One end of the recycling 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 drum (120), the recycling pump can drive the recycling 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 continuously cools the recycling pipe (1701). The system is configured to perform a low-temperature tumbling process for the directional softening and browning inhibition of Polygonatum odoratum fibers, including the following workflow: S1. Place the raw material of Polygonatum into the tumbling drum (120), start the drive device to drive the tumbling drum (120) to rotate at a speed of 15-25 r / min, and simultaneously turn on the ultraviolet lamp (140) in the collection box (130). S2. During the tumbling process, the Polygonatum juice flows into the collection box (130) through the drain hole (1201) on the side wall of the tumbling barrel (120). After the tumbling barrel (120) rotates for 5-10 minutes, the recovery pump is turned on, and the recovery pipe (1701) draws the juice from the bottom wall of the collection box (130) to the cooling device. Under the combined action of the spiral heat exchange tube and the guide fins of the cooling device, the juice temperature is reduced to 0-10℃. The cooled juice is sprayed onto the surface of Polygonatum inside the tumbling barrel (120) through the cavity (1601) of the support rod (160) and the liquid inlet (1602), thereby cooling the Polygonatum. S3. After tumbling for 1 hour, turn off the drive device and the recovery pump, and let it stand for 20-30 minutes. During the standing process, turn on the ultrasonic device to sonicate the juice in the collection box (130). S4. After the settling period, turn off the ultrasonic device and turn on the drive device and recovery pump at the same time to tumble the Polygonatum for 30 minutes. S5. After tumbling, turn off the drive device and the recovery pump, and let it stand for 20-30 minutes. During the standing process, turn on the ultrasonic device to sonicate the juice in the collection box (130). S6. Repeat steps S4 to S5 4-6 times.

2. The low-temperature tumbling system for directional softening and browning inhibition of Polygonatum odoratum fibers according to claim 1, characterized in that: The drive device includes a drive motor, a drive shaft and a drive gear, and a driven gear (1501) that meshes with the drive gear is fixed on the rotating rod (150).

3. The low-temperature tumbling system for directional softening and browning inhibition of Polygonatum odoratum fibers according to claim 1, characterized in that: It also includes a filter screen (190) disposed in a collection box (130), the filter screen (190) being horizontally disposed and located below the tumbling drum (120), which is used to filter the juice dripping from the tumbling drum (120).

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

5. The low-temperature tumbling system for directional softening and browning inhibition of Polygonatum odoratum fibers according to claim 4, characterized in that: The funnel-shaped sidewall of the collection box (130) has mounting grooves (1302) evenly distributed circumferentially on its inclined surface. The axis of the mounting groove (1302) is parallel to the inclined surface of the sidewall. The ultraviolet lamp (140) is installed in the mounting groove (1302), and a waterproof cover (1303) is installed at the opening of the mounting groove (1302).

6. The low-temperature tumbling system for directional softening and browning inhibition of Polygonatum odoratum fibers according to claim 4, characterized in that: The ultrasonic device includes transducers, and multiple transducers are evenly distributed circumferentially on the inclined surface of the funnel-shaped sidewall of the collection box (130).

7. The low-temperature tumbling system for directional softening and browning inhibition of Polygonatum odoratum fibers according to claim 1, characterized in that: The cooling device includes a cooling box (210) and a compressor refrigeration unit; the recovery pipe (1701) passes through the cooling box (210) axially, and a spiral heat exchange tube is circumferentially sleeved on its outer wall. The inner wall of the spiral heat exchange tube is provided with guide fins extending towards the recovery pipe (1701), and the gap between the guide fins and the outer wall of the recovery pipe (1701) is ≤1mm; the spiral heat exchange tube 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 odoratum fibers according to claim 7, characterized in that: The outlet temperature of the Polygonatum sibiricum juice in the recovery tube (1701) after being cooled by the cooling box (210) is 0-10℃.

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