JPH11192078A - Sterilization of vegetable food by low energy electron beam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for sterilizing a vegetable food by which any raw material can be sterilized at a low cost without deteriorating the vegetable food. SOLUTION: This method for sterilizing a vegetable food in a dried state by irradiating the vegetable food with low energy electron beams comprises a step for supplying the vegetable food so as to form a constant layer thickness by vibration, a step for dropping the supplied vegetable food on a belt conveyer to invert the vegetable food, and irradiating the surface of the vegetable food with the low energy electron beams, and a step for conveying and gathering the vegetable food irradiated with the low energy electron beams.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for disinfecting vegetable foods, which comprises irradiating the surface of vegetable foods such as spices and dried vegetables with a low energy electron beam, and sterilizing the surface of the vegetable foods with this electron beam. In particular, while rotating and moving the vegetable food, when falling, inverting the vegetable food with a low-energy electron beam to sterilize only the surface of the vegetable food, so as not to impair the flavor of the vegetable food, etc. The present invention relates to a method for sterilizing plant foods.

[0002]

2. Description of the Related Art With the growth of processed foods in recent years, the demand for vegetable foods such as various spices, herbs, dried vegetables and the like has been increasing, and there is an urgent need for higher quality. In addition, a plant material having stricter microbial standards has been required to confirm safety. Various methods have been devised to meet this demand, but in Japan, as a method of sterilizing a dried product in a dry state, it is general to achieve the purpose by bringing raw materials into parallel contact with a superheated steam flow.

[0003]

The main stream used in the food industry is the air-flow sterilization method. However, since this method brings the raw materials into parallel contact with the superheated steam flow, there is a loss of flavor. However, depending on the type of the target material, it was not possible to use a versatile sterilization method in some cases.

Accordingly, an object of the present invention is to provide a method for disinfecting a vegetable food, which solves the above-mentioned drawbacks, does not deteriorate the vegetable food, can sterilize any raw material, and suppresses a rise in cost. Is to do.

[0005]

In order to achieve the above object, a method for sterilizing a vegetable food according to the present invention according to the first aspect of the present invention comprises irradiating a dry vegetable food with a low-energy electron beam to produce the vegetable food. A method of sterilizing food, wherein the step of supplying the vegetable food to a certain layer thickness by vibration, and dropping the vegetable food on a belt conveyor, inverting, at this time, on the surface of the vegetable food The method is characterized by comprising a step of irradiating a low energy electron beam, and a step of transporting and collecting the vegetable food irradiated with the low energy electron beam.

According to a second aspect of the present invention, there is provided a method for sterilizing a vegetable food, wherein the vegetable food is dried by sunlight or mechanically.
It is characterized in that it is at least one selected from spices, herbs, dried vegetables, nuts, dried fruits and crude drug raw materials crushed to a size of not more than mm.

In a third aspect of the present invention, there is provided a method for sterilizing a vegetable food, wherein the irradiation with the low energy electron beam is performed by an electron beam having an energy of 1,000,000 electron volts or less.

The dried and ground vegetable food to be treated in the method for sterilizing vegetable food according to the present invention includes various spices, herbs (pepper, pepper, paprika, coriander, cumin, turmeric, Ginger, onion, garlic, tarragon, thyme, parsley, cardamom, mustard, salmon, etc., dried vegetables (carrot, bell pepper, onion, onion, ginger, etc.), dried fruits, nuts, extract powder, etc. Can be

In the method for sterilizing plant foods according to the present invention, a low-energy electron beam of 1,000,000 eV or less, preferably 50 eV or less is used.

[0010] In order to achieve the above object, a plant food sterilizing apparatus according to the present invention comprises a vibrating device for rotating and moving the plant food, and a vibrating device for transferring the plant food to at least a belt conveyor. An electron beam irradiation device for irradiating a low-energy electron beam when rotating and falling.

[0011] The vibrating device according to the present invention comprises a trough having a predetermined inclination with respect to a horizontal plane, which serves as a passage for moving the irradiated vegetable food while rotating, and fixing the trough to a fixed portion to fix the trough. It is composed of a buffer mechanism for promoting vibration and a vibration drive source for applying vibration to the trough.

Further, the method for sterilizing vegetable food according to the present invention is carried out using a low energy electron irradiation device. Such devices include a filament for emitting electrons, an accelerating means for accelerating electrons emitted from the filament,
Scanning means for scanning the electrons accelerated by the acceleration means,
It is provided with a filament power supply capable of supplying electric power for lighting the filament, a high-voltage power supply for applying an accelerating voltage to the accelerating means, and a vacuum pump for keeping a vacuum in the apparatus.

[0013] Further, as the sterilizing apparatus for vegetable food, a trough having a predetermined inclination with respect to a horizontal plane is provided as a passage through which the vegetable food moves while rotating, and the trough is fixed to a fixed portion to vibrate the trough. A vibration drive source for providing vibration to the trough,
A vibrating device for rotating and moving the vegetable food, a filament for emitting electrons, an accelerating means for accelerating the electrons emitted from the filament, a scanning means for scanning the electrons accelerated by the accelerating means, and a filament for lighting the filament A power supply, a high-voltage power supply for applying an accelerating voltage to the accelerating means, and a vacuum pump for keeping the inside of the device vacuum, wherein at least rotation of the vegetable food moving while being rotated by the vibrating device, the surface of the vegetable food when dropped An electron beam irradiator that irradiates energy electron beams to the device, a supply unit that supplies the vegetable food to the vibrating device, a transport unit that includes a belt conveyor that transports the sterilized vegetable food, and a belt using the transport unit. A collecting means for collecting the vegetable foods conveyed by the conveyor and a housing for shielding the electron beam are provided.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 are for explaining the embodiment of the present invention. Here, FIG.
FIG. 2 is a perspective view, partially cut away, showing an example of a sterilizing apparatus for realizing a method of sterilizing a vegetable food. FIG. 2 is a cross-sectional view of the same device.

In these figures, a plant food sterilizing apparatus 1 includes a vibrating device 3 for rotating and moving vegetable foods such as spices and dried vegetables, and a vibrating device 3 for rotating and moving the plant food. The apparatus 3 includes an electron beam irradiation device 5 that can irradiate a vegetable food with a low energy electron beam of 1,000,000 electron volts or less when falling on the belt conveyor 113 while rotating at the end of the device 3.

The electron beam irradiation device 5 has a rectangular parallelepiped housing 7 made of lead or the like in order to shield an electron beam to be irradiated. The vibration device 3 is disposed inside the housing 7. At the end of the vibrating device 3, the vegetable food that moves while rotating is rotated while the belt conveyor 11 is rotating.
3 to fall. The scanning tube 51 of the electron beam irradiation device 5 is located immediately above the plant food that falls while rotating. The surface of the vegetable food that rotates and falls at this position is evenly irradiated with a low energy electron beam of 1,000,000 electron volts or less.

Further, a food supply means 9 is arranged from the outside of the housing 7 to the supply end portion of the vibrating device 3, and the food supply means 9 connects the plant to the supply end via the input port of the vibrating device 3. Sexual foods are being supplied.

Further, a conveying means 11 including a belt conveyor 113 is disposed below the vibration device 3. At the end of the trough of the vibrating device 3, the vegetable food that moves while rotating on the trough by the vibration of the vibrating device 3 is irradiated with a low-energy electron beam on the entire surface when falling while rotating on the belt conveyor 113, and the plant food is planted. The entire surface of the sex food is sterilized.

The transporting means 11 includes a collecting means 1 at the right end of the drawing.
3 are disposed so that the sterilized vegetable foods conveyed by the belt conveyor 113 of the conveying means 11 can be collected.

FIG. 3 is a front view showing an example of the vibrating device 3 used in the plant food sterilizing apparatus 1, and FIG. 4 is a side view of the vibrating device 3. The vibration device 3 will be described with reference to FIG. 3, FIG. 4, FIG. 1 and FIG.

In these figures, the vibration device 3 is configured as follows. Trough 3 for passage of vegetable foods
As shown in FIG. 4, 1 has a U-shaped cross section having a bottom surface 32 and side walls 33, 33 standing on both sides of the bottom surface 32. Further, as shown in FIG. 3, the trough 31 has the bottom surface 32 at a predetermined angle with respect to the horizontal plane. The trough 31 is fixed from a fixing portion of the housing 7 by a buffer mechanism 34. In this embodiment, the buffer mechanism 34 facilitates vibration with a coil spring 35 interposed therebetween, and fixes the trough 31. The buffer mechanism 34 is configured to promote the vibration by the coil spring 35 and to fix the trough 31. The coil spring 35 can be used in place of the coil spring 35 as long as it has a function of mechanically fixing the rubber body, the air spring, and the vibration damper. Further, vibration driving sources 36, 36 are provided below the trough 31. The vibration driving source 36 is formed of, for example, an electromagnetic vibrator, and the electromagnetic vibrator has a power source 37.
Are electrically connected. When the power supply 37 operates according to the operation of the apparatus, power is supplied from the power supply 37 to the electromagnetic vibrator, and vibration is generated. By changing the frequency of the power supply 37, the electromagnetic vibrator can change the vibration frequency. In the above embodiment, the vibration drive source 36 is configured by an electromagnetic vibrator, but may be configured by an air vibrator or a motor drive. In this case, the air vibrator requires an air supply source, and the motor drive requires a motor power supply. At one end of the trough 31, an input port 39 having a square flange 38 is arranged.

FIG. 5 is a view showing the structure of an electron beam irradiation device 5 used in the plant food sterilizer 1. This figure 5
The electron beam irradiation device 5 will be described with reference to FIGS.

First, the electron beam irradiation apparatus 5 has an accelerating tube 52 at the top, and a scanning coil unit 53 under the accelerating tube 52.
And a divergent scanning tube 51 is arranged below the scanning coil unit 53. The electron beam irradiation device 5 is arranged in such a positional relationship that the plant food to be sterilized immediately below the irradiation window foil 54 of the scanning tube 51 falls onto the belt conveyor 113 while rotating. The acceleration tube 52 has a built-in filament 55 for emitting electrons and a group of accelerating electrodes 62 for accelerating the electrons emitted from the filament 55. The filament 55 is electrically connected to the filament electrode 56, and power is supplied from the filament electrode 56 to the tungsten filament 55. The acceleration electrode group 62 is electrically connected to a voltage dividing resistor 57. One end of the voltage dividing resistor 57 is connected to the filament 55 and is electrically connected to the negative electrode of the high voltage power supply 58. The other end of the voltage dividing resistor 57 is grounded via an ammeter 59. Further, the positive electrode of the vacuum high voltage power supply 58 is grounded via an ammeter 60. The electrons accelerated by the acceleration electrode group 62 are scanned by the scanning coil unit 53. Therefore, although not shown, the scanning coil unit 53 is connected to a scanning power supply. The inside of the scanning tube 51 and the accelerating tube 52 is a vacuum pump 61.
The operation of the vacuum pump 61 keeps the interior of the scanning tube 51 and the acceleration tube 52 at a vacuum.

As shown in FIGS. 1 and 2, the food supply means 9 includes an inlet hopper 91 disposed outside the housing 7 and a vegetable food stored in the inlet hopper 91. The communication pipe 92 is provided with a communication pipe 92 for transporting the communication pipe 7 into the inside, and an intermediate hopper 93 to which the end of the communication pipe 92 is fixed. The discharge port of the intermediate hopper 93 is
The trough 31 communicates with the inlet 38.

The conveying means 11 comprises water-cooled main rollers 111 and 112 which are spaced apart from each other, and a belt conveyor 11 which is stretched over these water-cooled main rollers 111 and 112.
3, auxiliary rollers 114 and 115 for giving an optimal tension to the belt conveyor 113, and a scraper 116 provided below the side surface of the water-cooled main roller 112 of the belt conveyor 113 to scrape the vegetable food adhered to the belt conveyor 113. Have. The water-cooled main roller 111 is rotated by a motor (not shown).

The collecting means 13 includes a conveyor outlet hopper 131 and the belt conveyor outlet hopper 13.
And a tank 132 for storing the sterilized vegetable food.

The operation of the thus constructed plant food sterilizer will be described below. When the power of the plant food sterilizer 1 is turned on, the degree of vacuum inside the scanning tube 51 and the accelerating tube 52 is detected. If the degree of vacuum is not reached, the vacuum pump 61 is operated to operate the scanning tube 51 and the accelerating tube. 52, the degree of vacuum inside is increased. Note that if a predetermined degree of vacuum is maintained, the vacuum pump 61 does not operate.

Next, power is supplied to the filament power supply 56, the high-voltage power supply 58, the power supply 37, and the motor for rotating the water-cooled main roller 111 while the predetermined degree of vacuum is maintained. As a result, the vibration device 3 operates, the electron beam irradiation device 5 operates, and the transport unit 11 operates.

Then, the vegetable food of the target material stored in the inlet hopper 91 is supplied to the intermediate hopper 93 through the communication pipe 92. The vegetable food stored in the intermediate hopper 93 is supplied from a discharge port provided at the bottom of the intermediate hopper 93 to the supply end via the input port 38 of the trough 31 of the vibration device 3.

As a result, the vegetable food moves while rotating on the trough 31 which is vibrated by the vibration drive source 36 of the vibration device 3. Such a vegetable food moves while rotating on the trough 31 of the vibration device 3, and when the vegetable food falls on the belt conveyor 113 while rotating at the end of the trough 31, the electron beam irradiation device 5 The surface of each individual vegetable food is uniformly irradiated with the low energy electron beam emitted from the scanning tube 51.

Examining the low-energy electron beam used here, the low-energy electron beam has a much lower penetrating power than an electron beam or a gamma ray, and has a larger property than an ultraviolet ray. . Also, spices, herbs, carrots, onions, potatoes, beans,
In the case of vegetable foods such as dried vegetables such as peppers, bacteria, molds, microorganisms, and the like often adhere and grow on the surfaces thereof. Therefore, using the low-energy electron beam, bacteria, mold, and the like adhered to the surface of the vegetable food.
Only microorganisms and the like are sterilized and the low-energy electron beam is prevented from penetrating inside the vegetable food, thereby preventing the deterioration or deterioration of the flavor, taste, and food components of the vegetable food.

In the case of an electron beam, the energy absorption coefficient (K value) and the effective depth are fixedly determined by the applied voltage.
It is required to control the layer thickness to 1 mm to 5 mm. This is difficult in the case of vegetable raw materials having different shapes and bulk specific gravities, so that the desired object can be achieved by rolling the surface portion with large bacterial contamination and thereby effectively irradiating it.

The sterilized vegetable food thus treated is conveyed on the belt conveyor 113 of the conveying means 11 and conveyed to the conveyor outlet hopper 13 of the collecting means 13.
Fall to 1. The sterilized vegetable food collected by the conveyor outlet hopper 131 is stored in the tank 132.

According to the method for sterilizing plant foods by the low energy electron beam of the present invention and the sterilizing apparatus used for the same, the following advantages are obtained. (1) Only the surface of the vegetable food is sterilized, the flavor is not dissipated, and the quality of the vegetable food is not deteriorated. (2) Suitable for sterilization of all plant foods. (3) No equipment for using chemicals or superheated steam is required, and running costs can be significantly reduced.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the sterilizing apparatus 1 for vegetable foods, an irradiation window 54 of a scanning tube 51 of an electron beam irradiation apparatus 5 and a vibrating apparatus 3 are provided.
Of the trough 31 to the bottom surface 32 is, for example, 50 [m
m]. The width of the trough 31 is, for example, 500
[Mm]. The width of the belt conveyor 113 is, for example, about 600 [mm].

[Calculation of Processing Amount] The energy absorption coefficient and effective penetration depth when irradiating a vegetable food with a low energy electron beam are as shown in Table 1.

[0037]

[Table 1]

Here, the processing area S is calculated using the following equation (1). First, the electron volt is set to 500 keV, and the energy absorption coefficient (ΔE / ΔR) is set to 2.80 [Me].
V · cm ² / g], the electron current I is 20 [mA], the irradiation efficiency η is 90 [%], and the irradiation dose D is 10, S = W × V × 60 = 2.8 × 20 × 0. 9 × 6000 = 302,400 [cm ² / min].

Therefore, the processing amount is 302,400 × 0.
063 × 60/1000 = 1.144 [ton / hr].

Irradiation dose (D) = (energy absorption coefficient) × electron current (mA) × irradiation efficiency × 10 ³ / processing area (S) (1) When calculated for each electron volt, Table 2 below.

[Table 2]

Table 3 shows the number of microorganisms (number / g) when the spices were treated by irradiating a low-energy electron beam with the plant food sterilizer 1 described above.

[0042]

[Table 3] However, processing with a layer thickness of 3 mm, 500 keV and 20 mA

[0043]

As described above, the method for sterilizing vegetable foods according to the present invention moves the vegetable foods while rotating them, and lowers the energy consumption of the vegetable foods when the vegetable foods are rotated or dropped. By irradiating the electron beam, the surface of the vegetable food is evenly sterilized, and thus has the following effects.

(1) Only the surface of the vegetable food is sterilized, the flavor is not dissipated, and the quality of the vegetable food is not deteriorated. (2) Suitable for sterilization of all plant foods. (3) No equipment for using chemicals or superheated steam is required, and running costs can be reduced.

Further, the plant food sterilizing apparatus according to the present invention moves the vegetable food while rotating it with the vibrating device, and applies the electron beam irradiation device to the vegetable food rotating by the vibrating device. Irradiation with a low-energy electron beam sterilizes only the surface of the vegetable food, and thus has the following effects. (1) Only the surface of the vegetable food is sterilized, the flavor is not dissipated, and the quality of the vegetable food is not deteriorated. (2) Suitable for sterilization of all plant foods. (3) Equipment for using chemicals or superheated steam is not required, and running costs can be reduced.

The apparatus for sterilizing plant foods according to the present invention has the same effect as the apparatus for sterilizing plant foods, and also automatically performs a series of processes from the delivery of the plant foods to the end of sterilization. Can be hygienic.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing a plant food sterilizer according to the present invention.

FIG. 2 is a cross-sectional view of the plant food sterilizer.

FIG. 3 is a front view showing a configuration example of a plant vibration device used in the plant food sterilizer.

FIG. 4 is a side view of the vibration device.

FIG. 5 is a diagram showing an example of the configuration of an electron beam irradiation device used in the plant food sterilizer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sterilizer of vegetable food 3 Vibration apparatus 5 Electron beam irradiation apparatus 7 Housing 9 Food supply means 11 Transport means 13 Collection means 31 Trough 32 Bottom surface 33 Side wall 34 Buffer mechanism 36 Vibration drive source 37 Power supply 51 Scanning tube 52 Acceleration tube 53 Scanning coil unit 55 Filament 56 Filament power supply 57 Voltage dividing resistor 58 High voltage power supply

Claims (3)

[Claims] 1. A method for irradiating a low-energy electron beam to a dried vegetable food to sterilize the vegetable food, comprising: supplying the vegetable food to a certain layer thickness by vibration; Plant food is dropped and inverted on a belt conveyor,
At this time, the step of irradiating the surface of the vegetable food with a low-energy electron beam, and the step of transporting and recovering the vegetable food irradiated with the low-energy electron beam, wherein the vegetable food is characterized by comprising: Sterilization method. 2. The vegetable food is dried in the sun or mechanically and spun, herbs, and crushed to a size of 10 mm or less.
The method for sterilizing a vegetable food according to claim 1, wherein the method is at least one selected from dried vegetables, nuts, dried fruits, and crude drug materials. 3. The method according to claim 1, wherein the irradiation with the low energy electron beam is performed by using an electron beam having an energy of 1,000,000 electron volts or less.