JP3751544B2 - Powder sterilization apparatus and method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a powder sterilization apparatus and method for performing sterilization processing on powders that require sterilization (for example, powdery foods such as spices and matcha tea, and various powdery fragrances and chemicals).
[0002]
[Prior art]
Substances such as foods and pharmaceuticals are required to be sterilized due to their properties. 2. Description of the Related Art Conventionally, an apparatus and a method for sterilizing such a substance have been developed.
[0003]
Conventionally, regarding such a sterilization process, an apparatus or a method for performing a sterilization process particularly on a liquid object is well known. For example, those described in JP-A-7-115947 and JP-A-7-289218 are known.
[0004]
Japanese Patent Application Laid-Open No. 7-115947 discloses an invention of an apparatus for sterilizing a fluid or liquid food using a shock wave. The configuration of the apparatus includes an elastic container containing a liquid food, a shock wave generation source, and a shock wave propagation medium interposed between the elastic container and the shock wave generation source. According to the invention described in this publication, the shock wave generated by the shock wave generation source is propagated to the elastic container through the shock wave propagation medium, and the shock wave is given to the fluid food in the elastic container, so that various juices, soft drinks, milk In addition, fluidized or liquid foods such as yogurt are sterilized without heat denaturing proteins and the like in the foods.
[0005]
Japanese Patent Laid-Open No. 7-289218 discloses CO 2 in a sealed container.₂A technique is described in which sterilization is performed by filling a gas, maintaining the pressure at a high pressure, and rapidly reducing the pressure. In the technology described in this publication, a pressure vessel, CO₂It consists of a bag that seals the object to be treated together with gas, a pressurizing pump that injects water for pressurization, and a pressure reducing valve. After the gas is dissolved, the pressure is reduced rapidly to rapidly expand the intracellular gas of the microorganism, and the cell membrane is crushed to sterilize the cell.
[0006]
[Problems to be solved by the invention]
As described above, conventionally, many technical developments have been made regarding sterilization treatment apparatuses and methods particularly for liquid foods. However, in particular, the technology related to sterilization treatment for powdered foods is not sufficiently developed compared to liquid foods. One reason for this is that, until now, bacteria in dry powder foods have not been considered as problematic as compared to liquid foods.
[0007]
Dry powdered foods, especially spices, are completely sterilized because they are not in the breeding environment for fungi due to the deterioration of flavor and pungent taste caused by heating and the antibacterial effect of spices themselves in spices alone. It wasn't. Several thousands of bacteria per gram were accepted, but the danger of inducing the growth of the number of bacteria in the process of food reuse and mixing with other foods was also pointed out. Even in spices, there is no denying the risk of new breeding of bacteria that survived as spores by mixing with other foods.
[0008]
Conventional sterilization methods for powdered food include steam sterilization, microwave sterilization, ultrasonic sterilization or gas sterilization, and pulse electrolysis in addition to external heating. However, these sterilization methods are not suitable for foods or medicines that easily lose their fragrance, such as some spices, green tea, or fragrances, and health foods that contain nutrients that are easily decomposed by heat.
[0009]
In addition, the difficulty of completely sterilizing the powder is mainly due to the fact that the inflow rate of heat is large due to the large surface area of the powder, and it is difficult to adjust the heating because it is easy to change quality. It exists in the point of the fall of the flavor by uniform or stirring. Further, the color of the powder may change due to the sterilization treatment. Due to these problems, some foods have not yet been commercialized.
[0010]
In order to sterilize fragrances and spices without impairing the scent, it is necessary to let heat act only on the bacteria without losing the volatile components that are the source of the scent. In general, bacteria are often present on the surface of each particle constituting the powder, and sterilization is often achieved only by increasing the surface temperature. However, in heat sterilization from the outside, non-uniform heating occurs such that the outer particles are more susceptible to heat and the inner particles are less susceptible to heat, and microwave sterilization requires the effort of humidification. And there is a practical problem such as the uncertain microwave penetration into the inner particles.
[0011]
By the way, regarding the sterilization treatment of the powder, it is considered that sterilization using shock waves is effective. Sterilization using shock waves is also described in the above-mentioned Japanese Patent Application Laid-Open No. 7-115947. However, in the technique described in this publication, fluid or liquid materials are to be treated, and cannot be immediately applied to sterilization of powder having poor fluidity. In particular, since the powder supply and discharge operations are not smoothly performed, it is not suitable for powder sterilization treatment.
[0012]
The technique described in JP-A-7-289218 is applicable to powders, but requires high-pressure holding time and cannot be continuously processed. Has a practical problem of being unsuitable.
[0013]
As described above, conventionally, there is a lack of technical development regarding the sterilization treatment of powder compared to the liquid one, and therefore development of a technology suitable for the sterilization treatment of powder is desired.
[0014]
The present invention has been made in view of such problems, and a first object of the present invention is to provide a powder sterilization apparatus and method capable of sterilizing powders satisfactorily without impairing flavor, flavor and the like. It is in. A second object of the present invention is to provide a powder sterilization apparatus and method capable of performing continuous and repeated sterilization in a short time.
[0015]
  The powder sterilizer according to claim 1A chamber having a cavity into which an electrolyte solution is injected, a tube disposed spirally along the inner wall of the cavity, and containing powder to be sterilized therein, and provided at the top of the chamber. A powder inlet connected to one end of the tube, a powder outlet provided in the lower part of the chamber and connected to the other end of the tube, and an electrode pair for discharge. Shock wave generating means for generating a shock wave by discharging at a tube and applying the shock wave to the powder in the tube;It is equipped with.
[0016]
  In the powder sterilization apparatus according to claim 1, a shock wave can be propagated in the cavity of the chamber.Electrolyte solutionWas injected and the powder was containedtubeIs disposed. AndElectrolyte solutionA shock wave is generated in the cavity in the state of being injected, and the shock waveElectrolyte solutionThroughtubeIt is given to the inner powder, and the powder is sterilized by the shock wave.
  In this powder sterilization apparatus, since the tubes are spirally arranged along the inner wall of the cavity, the area in the cavity is effectively utilized, and a large amount of powder can be processed.
  In this powder sterilization apparatus, powder is continuously fed from one end of the tube according to the sterilization process via a powder inlet provided in the upper part of the chamber. Further, the sterilized powder is continuously discharged from the other end of the tube through the powder discharge port provided at the lower part of the chamber according to the sterilization treatment. As a result, the powder can be continuously taken in and discharged, and a continuous sterilization process can be performed.
  In this sterilizer, a shock wave is generated by using a discharge between a pair of electrodes. For this reason, it becomes possible to repeatedly perform sterilization processing in a short time by generating shock waves continuously.
[0017]
  Claim4In the described powder sterilization apparatus, the shock wave generating means generates a shock wave that generates a temperature rise due to adiabatic compression on the surface of the powder and also generates frictional heat due to surface friction between the powder particles. Is.
[0018]
  This claim4In the described powder sterilization apparatus, a temperature rise due to adiabatic compression occurs on the surface of the powder due to the shock wave, and frictional heat is generated due to surface friction between the powder particles. The powder is sterilized by the surface friction between them.
[0025]
  Claim2The described powder sterilization apparatus further includes a vibration unit that vibrates the entire chamber.
[0026]
  This claim2In the described powder sterilization apparatus, the entire chamber is vibrated according to the sterilization process by the vibration unit.AndThe fluidity of the powder in the tube is increased, and the powder is smoothly taken in and discharged through the tube.
[0029]
  Claim4In the described powder sterilization method, a tube having a powder intake port and a powder discharge port is disposed on the upper and lower sides of a spirally wound along the inner wall of a chamber having a hollow portion, and the interior of the hollow portion is disposed. After disposing an electrode pair for discharge and injecting an electrolyte solution capable of propagating shock waves, while circulating the powder to be sterilized from the powder inlet to the powder outlet in the tube, The powder is sterilized by discharging between the electrode pairs and applying a shock wave in the tube.The
[0030]
  This claim4According to the above-described powder sterilization method, an electrolyte solution capable of propagating shock waves is injected into the cavity in the chamber having the cavity, and the powder containing the powder to be sterilized is accommodated.IsArranged in the cavity. Then, a shock wave is generated in the cavity with the electrolyte solution injected, and the shock wave is tuned through the electrolyte solution.InsideThe sterilization is performed by giving to the powder.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0032]
[First Embodiment]
FIG. 1 shows the configuration of a powder sterilizer according to a first embodiment of the present invention. FIG. 2 is a detailed view of the inside of the chamber body in FIG. The powder sterilization apparatus according to the present embodiment is for performing sterilization processing on powdered foods such as spices and matcha, and powdered fragrances and pharmaceuticals, for example.
[0033]
The powder sterilizer 1 is a chamber 2 having a cavity 9 in which a medium capable of propagating shock waves (hereinafter referred to as “shock wave propagation medium”) is injected and a powder 15 to be sterilized is accommodated. And a tube 3 for containing the powder 15 to be sterilized. The powder sterilizer 1 further has a function of generating a shock wave in the cavity 9 in a state in which the shock wave propagation medium is injected, and applying the shock wave to the powder 15 in the tube 3 through the shock wave propagation medium. The shock wave generating means 4 and the vibration part 5 for vibrating the entire chamber 2 are provided.
[0034]
The chamber 2 has a lid 2a and a main body 2b. The material of the chamber 2 is an impact resistant resin such as ultra high molecular weight polyethylene (UHMW). The lid 2a is provided with a liquid inlet 6 and a powder inlet 7. Furthermore, a plurality of through holes 8 are provided in the lid 2a. The lid 2a may be provided with an internal pressure adjusting valve for adjusting the internal pressure in the cavity 9. On the other hand, the main body 2b is formed with a hollow portion 9 for accommodating the tube 3 at the center thereof. The hollow portion 9 is preferably cylindrical. A bolt 10 for fixing the lid 2a is provided around the cavity 9 in the upper surface of the main body 2b. The bolts 10 are arranged at positions corresponding to the through holes 8 provided in the lid 2 a and are provided in the same number as the through holes 8. The bolts 10 are fixed by a nut or a thumbscrew (not shown) while being passed through the through holes 8 at the corresponding positions. Thereby, the lid 2a and the main body 2b are fixed and integrated at the time of sterilization. A powder outlet 11 is provided at a lower portion of the main body 2b.
[0035]
The tube 3 is spirally disposed along the inner wall of the cavity 9 as shown in the drawing for the purpose of ensuring fluidity of the powder 15 and for the purpose of effectively utilizing the area in the cavity 9. It is desirable. However, the tubes 3 are not necessarily bundled so as to be adjacent to each other, and may be arranged, for example, meandering. The upper end of the tube 3 is connected to a powder inlet 7 provided on the lid 2 a of the chamber 2. On the other hand, the lower end portion of the tube 3 is connected to a powder outlet 11 at a lower portion of the main body 2 b of the chamber 2. Although not shown, it is desirable that valves are provided at both ends of the tube 3 respectively. The tube 3 is preferably made of an elastic body such as silicone resin.
[0036]
As shown in FIG. 2, a support frame 21 is provided in the hollow portion 9. If the tubes 3 are firmly fixed to each other or to the inner wall of the cylindrical portion 9, the tubes 3 may be loosely fixed by the support frame 21 because they may be broken upon impact. Is desirable. In FIG. 1, the support frame 21 is not shown for simplification of the drawing. As shown in FIG. 2, a packing 22 is provided on the upper portion of the main body 2b. The tube 3 is suppressed by the packing 22 to such an extent that the spirally wound state does not collapse.
[0037]
The shock wave generating means 4 includes a pair of rod-shaped electrodes 12a and 12b and a power supply unit 13. The rod-shaped electrodes 12a and 12b are made of a material having excellent conductivity, such as copper (Cu). The rod-shaped electrodes 12a and 12b preferably have a shape in which the tips of both the electrodes are pointed conically. The rod-shaped electrodes 12a and 12b are inserted in the horizontal direction from the side surface of the main body 2b, and are in contact with each other so that the tips of the tubes 3 face each other at a position where the tips are exposed to the cavity 9 through the gap of the tube 3 Arranged not to.
[0038]
As a shock wave propagation medium injected into the hollow portion 9, an electrolyte solution such as water is applied in order to generate a discharge between the pair of rod-shaped electrodes 12a and 12b.
[0039]
The power supply unit 13 includes a capacitor 13a, a controller 13b that controls the voltage supplied to the capacitor 13a, and a power source 13c that supplies current and voltage to the capacitor 13a via the controller 13b. Both ends of the capacitor 13a are electrically connected to the rod-shaped electrodes 12a and 12b by a conducting wire 14 as shown.
[0040]
The vibration unit 5 is disposed at the bottom of the chamber 2. The vibration part 5 is provided for the purpose of improving the fluidity of the powder 15 in the tube 3 by vibrating the entire chamber 2 at the time of powder supply to the tube 3 and at the time of discharge.
[0041]
In the present embodiment, the tube 3 corresponds to a specific example of “powder container” in the present invention.
[0042]
Next, the operation and operation of the powder sterilizer 1 configured as described above will be described.
[0043]
When the powder 15 is sterilized by the powder sterilizer 1, a shock wave propagation medium such as water is injected into the cavity 9 from the liquid inlet 6 provided in the lid 2a in advance. At this time, the rod-like electrodes 12a and 12b are completely immersed.
[0044]
Next, the powder 15 to be sterilized is supplied from the powder inlet 7. At this time, in addition to using natural fall due to gravity from a high place, gas pressure such as air may be used to pump from the storage tank. Moreover, you may pressurize using a screw. Further, suction may be performed from the powder outlet 11.
[0045]
After filling the inside of the tube 3 disposed in the hollow portion 9 with the powder 15, a large current is generated from the charged capacitor 13 a and discharged between the rod-shaped electrodes 12 a and 12 b. A shock wave generated by this discharge is applied to the tube 3 through a shock wave propagation medium such as water injected into the cavity 9 and immersing the rod-like electrodes 12a and 12b. Since the tube 3 is an elastic body such as a silicone resin, it deforms when it receives an external force. Accordingly, it is possible to give a shock wave to the powder 15 filled in the tube 3. Further, since the tube 3 is not bonded or the like and is gently fixed by the support frame 21, the degree of freedom of deformation is maintained, and damage due to impact can be avoided.
[0046]
The capacitor 13a is discharged once and then automatically recharged. The magnitude of the shock wave can be arbitrarily set by controlling the voltage with the controller 13b or selecting the capacitance of the capacitor 13a. Moreover, since the discharge between the rod-shaped electrodes 12a and 12b can be performed again as soon as the recharge is completed, the number of times of applying the shock wave can be arbitrarily set. The powder 15 is sterilized as described above.
[0047]
After the sterilization, the powder 15 inside the tube 3 is discharged from the powder outlet 11. At the time of discharge, as with the supply, pressurization may be performed with air or the like from the powder inlet 7 side, or suction may be performed from the powder outlet 11 side. Further, when the powder 15 is supplied and discharged, the entire chamber 2 may be vibrated by the vibration unit 5 in order to improve the fluidity of the powder 15. Moreover, the tube 3 is an elastic body, and when it is released from an external force called a shock wave, the tube 3 is restored to its original shape, so that the fluidity of the powder 15 can be maintained.
[0048]
As described above, the powder sterilization process by the powder sterilization apparatus 1 includes the following continuous process in addition to the batch process in which the powder 15 is supplied, sterilized, and discharged every certain amount. Processing is also possible. That is, this is a processing method in which the supply and discharge of the powder 15 are continuously performed simultaneously, and the shock wave is intermittently applied in conjunction with this to perform sterilization. In this case, the moving speed of the powder 15 and the discharge frequency may be adjusted so that the number of shock waves necessary for sterilization is applied.
[0049]
Next, the principle that the powder 15 is sterilized by shock waves in the powder sterilization apparatus 1 will be described with reference to FIG.
[0050]
A shock wave is a compression wave, and the temperature behind it rises instantaneously. However, the compression is relaxed by the expansion wave that follows from the back of the compression wave, and is immediately cooled. Note that the time from the arrival of the compression wave to the arrival of the expansion wave, that is, the compression time is about several microseconds, which is a very short time.
[0051]
As shown in FIG. 3, when the shock wave 32 is applied to the powder 15, the powder particles 31 constituting the powder 15 and the gaps between the powder particles are compressed. In FIG. 3, the position where the shock wave 32 has reached is shown as a shock wave surface 33. On the right side of the shock wave surface 33, no shock wave has reached and the gap between the powder particles 31 is large. On the other hand, the powder particles 31 are crushed on the left side of the shock wave surface 33, and there are almost no gaps between the powder particles. When the shock wave 32 is given to the powder 15, compression (adiabatic compression) is particularly significant in the voids existing in the gaps between the powder particles 31, and the temperature rises. In addition, when the powder particles 31 are compressed, the powder particles 31 collide with each other and rub against each other, so that heat is generated due to surface friction. By these two things, the high temperature part 34 arises around the powder particle 31, and the surface is heated.
[0052]
By the way, when the high temperature part 34 arises and the surface of the powder particle 31 is heated, heat conduction from the surface of each powder particle 31 to the inside should occur. However, since the expansion wave coming from behind the shock wave propagates to the powder 15 in a shorter time than the time required for heat conduction from the surface to the inside of each powder particle 31, each powder particle 31 is immediately cooled. Therefore, the temperature rise inside the powder particles 31 can be avoided.
[0053]
Thus, when a shock wave is applied to the powder 15, only the surface of the powder particles 31 where bacteria are present is heated by instantaneous heating by adiabatic compression and frictional heat generated by friction due to high-speed movement of the powder particles 31. The powder 15 is sterilized.
[0054]
As described above, according to the powder sterilization apparatus 1 according to the present embodiment, the shock wave is applied to the powder 15, the instantaneous heating by the adiabatic compression, and the frictional heat generated by the friction by the high-speed movement of the powder particles 31. Thus, only the surface of the powder particles 31 where bacteria are present is indirectly heated, so that the aroma component of the powder 15 is not volatilized, and the flavor and flavor of the powder 15 are not impaired. Can be sterilized. Further, sterilization can be performed without causing a color change.
[0055]
Further, according to the present embodiment, the powder supply into the tube 3 and the powder discharge from the tube 3 can be continuously performed. A shock wave can be given to the powder 15, and as a result, sterilization can be performed repeatedly and continuously.
[0056]
Moreover, by arranging the tube 3 in a spiral shape, the powder 3 can be transported without any delay, and the tube 3 filled with the powder 15 can be accommodated in the cavity 9 for a longer time, so that sterilization can be performed efficiently. It can be carried out.
[0057]
Furthermore, since the powder 15 to be sterilized is sterilized in the tube 3 in an isolated state and can be discharged in the isolated state, the aseptic state after sterilization can be maintained.
[0058]
Thus, according to the powder sterilization apparatus 1 according to the present embodiment, the powder 15 can be sterilized continuously and repeatedly in a short time without impairing the flavor, flavor and color of the powder 15.
[0059]
[Example]
Next, the sterilization performance of the powder sterilizer 1 according to the present embodiment is shown as Example 1. Further, in Example 2 of the powder sterilization apparatus similar to the powder sterilization apparatus 1 according to the present embodiment, evaluation of influence on fragrance and the like by sterilization treatment is shown as Example 2.
[0060]
<Example 1>
FIG. 4 is an explanatory view showing the sterilization effect of soybean powder by the powder sterilizer 1. The vertical axis in FIG. 4 is the number of bacteria per gram contained in soybean flour. The number of bacteria before and after the shock wave is applied once for the number of general bacteria, the number of coliforms and the number of heat-resistant bacteria. It is a comparison.
[0061]
In this embodiment, the chamber 2 is a rectangular parallelepiped having a size of 500 mm long × 500 mm wide × 400 mm high. The inner diameter of the cylindrical cavity 9 is 300 mmφ, and the cavity 9 of the chamber 2 has a capacity of about 3L. A tube 3 having an inner diameter of 15 mmφ is wound 17 times along the inner wall of the hollow portion 9. The capacity of the capacitor 13a was 40 μF and was charged to 20 kV.
[0062]
As shown in FIG. 4, a sterilization rate of about 10% was obtained for the number of general bacteria and the number of heat-resistant bacteria. In addition, the water-soluble nitrogen index, which is an index of the degree of alteration, changes only by about 2 to 3%, and it can be said that protein denaturation is very small.
[0063]
Moreover, when the sterilization effect by the powder sterilization apparatus 1 was investigated with respect to the dry powder food | flour whose diameter of a powder particle is about 1 mm or less and a water content is less than 20%, one shock wave is made to act. A sterilization rate of 50% to 90% was obtained. In addition, it was possible to further reduce the number of bacteria by repeatedly applying a shock wave.
[0064]
<Example 2>
5A and 5B show the results of principal component analysis of a scent when sterilization is performed using a powder sterilizer similar to the powder sterilizer 1. FIG. FIGS. 6A and 6B show the configuration of the powder sterilizer used in this embodiment. In this embodiment, a copper tube-encapsulated shock wave sterilizer 60a (FIG. 6A) that explodes explosives to generate a shock wave, and an underwater discharge shock wave sterilizer 60b that utilizes discharge in water (FIG. 6B). )) And two types of devices were used. First, the configuration and operation of these devices will be described.
[0065]
The copper tube enclosed shock wave sterilizer 60 a includes a main body 61, a copper tube 62, a core (copper bar) 63, and a power supply unit 64. The main body 61 includes a gantry 611, an outer cylinder 612, and a spacer 613. The outer cylinder 612 is fixed to the gantry 611. A copper tube 62 is disposed inside the outer cylinder 612. The gap between the outer cylinder 612 and the copper tube 62 is filled with an explosive 65 as an energy source of shock waves, and both ends are plugged with spacers 613. A core 63 is disposed at the center of the copper tube 62, the gap 66 is filled with powder 66 to be sterilized, and both ends are plugged with spacers 611. Further, an electrode 641 connected to a capacitor (not shown) is connected to the explosive 65 by a conducting wire 642.
[0066]
Regarding the sterilization method, the explosive 65 is exploded from one end of the copper tube 62 to generate a shock wave, and the copper tube 62 filled with the powder 66 is crushed inside. At this time, the shock wave is reflected at the center of the copper tube 62 and further reflected at the inner wall of the copper tube 62. These reflections are repeated several times to generate a high pressure inside the copper tube 62, but the heating time is very short. Further, the core 63 prevents the temperature from rising excessively. In this way, the powder is sterilized by being instantaneously heated by the shock wave propagating from the outside to the inside of the copper tube 62.
[0067]
On the other hand, the underwater discharge type shock wave sterilizer 60b shown in FIG. 6B is an apparatus that uses discharge energy as an energy source of shock waves. The powder 66 is filled between an outer cylinder 612 fixed to the gantry 611 and a vinyl tube 67 disposed on the inside. The inside of the vinyl tube 67 is filled with water 68 as a shock wave propagation medium. The tips of the electrodes 69a and 69b are opposed to each other in the water 68. In the underwater discharge type shock wave sterilizer 60b, a shock wave is generated by the discharge between the electrodes 69a and 69b, the shock wave is propagated to the powder 66 through the water 68, and the powder 66 is instantaneously heated to sterilize. Is made.
[0068]
Next, the analysis results shown in FIGS. 5A and 5B will be described. In the present Example, it analyzed using white pepper (FIG. 5 (A)) and matcha (FIG. 5 (B)) as sample powder. The processing conditions of these sample powders were those sterilized by a copper tube-enclosed shock wave sterilizer 60a, sterilized by an underwater discharge type shock wave sterilizer 60b, and heated until immediately before being burnt by a 400W microwave oven (matcha is Three conditions were set for 1 minute and white pepper was heated for 30 seconds each, and untreated (control) was added for comparison purposes. Moreover, about evaluation, the fragrance measurement of the sample powder which performed each process using the fragrance sensor was performed, and the magnitude | size of the change with respect to control was compared. In addition, the color change in the sample powder before and after each treatment was also observed.
[0069]
5A and 5B, 18 dimensional analysis of scent is performed using 18 scent sensors, and two main components are defined using the standardized values, and the two defined The main components are plotted in a two-dimensional plane. The vertical axis represents the first main component, and the horizontal axis represents the second main component. In FIGS. 5A and 5B, the size of the value itself is not very meaningful, and scents can be compared based on the difference in relative distance between the analysis results. That is, if the relative distance between the analysis results is short, it can be determined that they have a similar scent.
[0070]
As shown in FIGS. 5 (A) and 5 (B), the paste sterilized by the copper tube-encapsulated shock wave sterilizer 60a was greatly affected by explosives, and the scent changes were significant for both white pepper and matcha tea. Furthermore, not only the fragrance but also the discoloration was conspicuous. In addition, the heat treatment with a microwave oven had a short processing time with white pepper and the change in scent was slightly small, but the color change was large, and in matcha, both the scent and color were large. It was.
[0071]
On the other hand, in what was sterilized by the underwater discharge type shock wave sterilizer 60b having substantially the same sterilization principle as the powder sterilizer 1 shown in FIG. The effect on color was small. For both pepper and matcha, the changes in fragrance and color were almost unrecognizable by smell and color sense, and good results were obtained.
[0072]
[Second Embodiment]
Next, a second embodiment of the present invention will be described. In the following description, components that are substantially the same as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted as appropriate.
[0073]
In the first embodiment, the example in which the tube 3 is used to continuously process the powder has been described, but in the present embodiment, an example in which the sterilization process is performed without using the tube 3 is described. To do.
[0074]
FIG. 7 shows a configuration of a powder sterilization apparatus according to the second embodiment of the present invention. The powder sterilization apparatus 70 according to the present embodiment is different from the powder sterilization apparatus 1 (FIG. 1) of the first embodiment mainly in place of the tube 3 at the bottom of the cavity 9. This is a portion provided with a sheet 71 covering the powder or the container containing the powder. The powder to be processed in the powder sterilization apparatus 70 may be in a packed state in a commercialization stage, for example. In the present embodiment, the vibration part 5 (FIG. 1) is not necessarily provided.
[0075]
The powder sterilizer 70 according to the present embodiment includes the chamber 2 and electrodes 72a and 72b. The electrodes 72 a and 72 b are electrically connected to the current supply unit 13 by the conducting wire 14. The configuration of the current supply unit 13 is the same as that in FIG.
[0076]
The chamber 2 includes a lid 2a and a main body 2b as in the first embodiment. In FIG. 7, although not shown, like the powder sterilization apparatus 1 shown in FIG. 1, the lid 2a and the main body 2b are fixed to each other by a bolt 10 and a nut during sterilization. A liquid inlet 6 is provided in the lid 2a. On the other hand, the main body 2b is provided with a hollow portion 9 at the center thereof.
[0077]
In the present embodiment, a sheet 71 is provided for the purpose of covering the powder placed on the bottom of the cavity 9 or a container containing the powder, etc. and isolating it from the shock wave propagation medium. The sheet 71 is made of an elastic body such as silicone resin, for example. The electrodes 72 a and 72 b have an L shape, are arranged so as to pass through the lid 2 a, and the leading ends thereof are opposed to each other in the cavity 9. Further, it is desirable that the tip portions of the electrodes 72a and 72b have a conical pointed shape so that discharge can be easily performed.
[0078]
Next, the operation and operation of the powder sterilizer 70 configured as described above will be described.
[0079]
The powder sterilization apparatus 70 according to the present embodiment stores a certain amount of powder in the cavity 9, opens the lid 2a every time sterilization is completed, and stores the next powder. This is a batch process that repeats the operation.
[0080]
The procedure for batch processing is as follows. First, the lid 2a is opened, and the powder to be sterilized is placed on the bottom of the cavity 9, and the sheet 71 is placed so as to cover it. Next, the lid 2 a and the main body 2 b are fixed, and a shock wave propagation medium of an electrolyte such as water is injected from the liquid inlet 6. At this time, the powder 71 is separated from the shock wave propagation medium by the sheet 71. After the tips of the electrodes 72a and 72b are sufficiently immersed, a current is supplied from the current supply unit 13 to generate a discharge between the electrodes 72a and 72b.
[0081]
The shock wave generated by this discharge propagates to the sheet 71 through the shock wave propagation medium, and further propagates to the powder 15 isolated by the sheet 71. Since the sheet 71 is an elastic body, the sheet 71 is deformed when subjected to an external force, so that a shock wave can act on the powder 15. The principle that the powder 15 is sterilized by the shock wave is the same as that in the first embodiment. This sterilizes the powder.
[0082]
As described above, according to the powder sterilization apparatus 70 according to the present embodiment, the powder 15 can be sterilized with a simpler configuration than the powder sterilization apparatus 1.
[0083]
In addition, this invention is not limited to said each embodiment, A various deformation | transformation implementation is possible. For example, in the powder sterilization apparatus 70 (FIG. 7), the powder 15 to be sterilized is sealed in advance in a container made of an elastic body such as silicone resin, and this sealed container is directly put into the cavity 9. Then, it may be immersed in an electrolyte solution and sterilized.
[0084]
In this way, only the sealed container is taken out while the electrolyte solution is stored in the cavity 9, and then another sealed container containing unsterilized powder is put in, so that the batch process can be continuously and smoothly performed. Can be done. Further, since the powder 15 can be sterilized while being sealed in the container, a factor that bacteria are mixed after sterilization can be avoided and the aseptic condition can be easily maintained. Furthermore, the batch processing can be continued by automating the loading and unloading of the container in which the powder 15 is sealed.
[0085]
By the way, the present invention only uses discharge as one means for generating a shock wave, and does not directly energize the powder. This is different from the energization pulse electrolysis method. The present invention is also different from sterilization by ultrasonic waves. That is, sterilization using ultrasonic waves has a smaller compression wave amplitude than a shock wave and a large attenuation due to propagation, so that the action is effective only on the powder surface. From this, it is considered that ultrasonic waves are not suitable for sterilization of powdered foods.
[0086]
【The invention's effect】
  As described above, claims 1 to3The powder sterilizer according to any one of claims 1 to 5 or claim4According to the described powder sterilization method, an electrolyte solution capable of propagating shock waves is injected into the cavity of the chamber and a tube for containing the powder is contained.TheA shock wave is generated in the cavity while being placed in the cavity and the electrolyte is injected, and the shock wave is passed through the electrolyte to the tube.InsideTherefore, the powder can be sterilized satisfactorily without impairing the flavor and flavor.
[0087]
  SpecialThe skySince the tubes are spirally disposed along the inner wall of the cave, the area in the cavity is effectively used, and a large amount of powder can be processed easily.
[0088]
  MaTThe powder is continuously fed from one end of the tube according to the sterilization process through the powder inlet provided in the upper part of the chamber, and other than the tube through the powder outlet provided in the lower part of the chamber. By continuously discharging the sterilized powder from the end according to the sterilization treatment, it is possible to easily take in and discharge the powder continuously, and a continuous and large-scale sterilization treatment is possible.
[0089]
  And claims2According to the described powder sterilization apparatus, the whole chamber is vibrated according to the sterilization process by the vibration unit.FlourI'm continuously feeding my body into the tubeSea urchinIn this case, since the fluidity of the powder in the tube is increased, the powder can be taken in and discharged through the tube smoothly. Thereby, a continuous sterilization process can be performed even better.
[Brief description of the drawings]
FIG. 1 is a partially cutaway perspective view showing a configuration of a powder sterilizer according to a first embodiment of the present invention.
FIG. 2 is a perspective view of a chamber body in the powder sterilizer shown in FIG. 1 as viewed from above.
FIG. 3 is an explanatory diagram showing the principle that powder is sterilized by shock waves.
FIG. 4 is an explanatory diagram showing the sterilization performance of soybean powder by the powder sterilizer according to Example 1 of the present invention.
FIG. 5 is an explanatory diagram showing a principal component analysis result of a scent according to Example 2 of the present invention.
FIG. 6 is a cross-sectional view showing a configuration of a powder sterilizer according to Embodiment 2 of the present invention.
FIG. 7 is a perspective view showing a partially broken structure of a powder sterilizer according to a second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1,70 ... Powder sterilizer, 2 ... Chamber, 2a ... Lid, 2b ... Main body, 3 ... Tube, 4 ... Shock wave generating means, 5 ... Vibrating part, 6 ... Liquid inlet, 7 ... Powder intake, 8 ... Through hole, 9 ... cavity, 10 ... bolt, 11 ... powder outlet, 12a, 12b ... rod electrode, 13 ... power supply, 13a ... capacitor, 13b ... controller, 13c ... power supply, 14 ... conductor, 15 ... Powder, 21 ... support frame, 22 ... packing, 31 ... powder particles, 32 ... shock wave, 33 ... shock wave front, 34 ... high temperature part, 71 ... sheet, 72a, 72b ... electrode.

Claims (4)

A chamber having a cavity into which an electrolyte solution is injected;
A tube that is spirally disposed along the inner wall of the cavity, and contains powder to be sterilized inside,
A powder inlet provided at the top of the chamber and connected to one end of the tube;
A powder discharge port provided at a lower portion of the chamber and connected to the other end of the tube;
A shock wave generating means that has a discharge electrode pair, generates a shock wave by discharging between the electrode pair in the electrolyte solution, and applies the shock wave to the powder in the tube. Powder sterilizer.   Furthermore, the powder sterilizer of Claim 1 provided with the vibration part which vibrates the said whole chamber. The shock wave generating means may generate a temperature rise due to adiabatic compression to the surface of the powder, claim, characterized in that to generate a shock wave that can cause a frictional heat generated by surface friction between the powder particles 1 or The powder sterilizer according to claim 2 . A tube having a powder intake port and a powder discharge port is disposed above and below in a spiral manner along the inner wall of the chamber having the hollow portion, and an electrode pair for discharge is disposed inside the hollow portion. After placing and injecting electrolyte solution,
Dispersing the powder to be sterilized from the powder intake to the powder discharge port in the tube, and discharging the powder between the electrode pairs to give a shock wave to the tube to sterilize the powder. A method for sterilizing powder, characterized in that:

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