JP2002291454A - Apparatus for sterilizing food - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for sterilizing a food capable of carrying out sterilizing treatment without deteriorating the quality and without using a filter and alleviating restrictions on packaging materials. SOLUTION: This apparatus for sterilizing the food is equipped with a lamp house provided with a xenon lamp and a cooling fan and a power source part. The integrated energy density of optical pulses for irradiating the surface of the food is a value within the range of >=0.5 and <=10 J/cm<2> .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sterilizer using a xenon lamp.

[0002]

2. Description of the Related Art In order to extend the shelf life of food, it is necessary to sterilize the food to reduce the number of bacteria adhering to the food at the time of shipment. Conventional sterilization method 1
For example, flash pulse sterilization using a xenon lamp is known.

[0003] In the flash pulse sterilization, the energy emitted from the lamp is higher than in the sterilization method using an ultraviolet lamp. For this reason, it has a germicidal effect superior to ultraviolet rays. However, in the flash pulse sterilization, there are problems that the flavor and color tone of the food are deteriorated after the light is irradiated on the food, the temperature of the food is increased, and a cooling treatment is required.

[0004] In order to avoid this problem, means for blocking light having a wavelength shorter than 285 nm by a filter or cooling the irradiated food to a temperature of 0 to 7 ° C have been taken.

[0005]

However, 285
Since the wavelength band having a high sterilizing effect is included on the shorter wavelength side than nm, the use of the above filter attenuates the original sterilizing effect of the flash pulse.

[0006] In addition, it takes time to cool the sterilized food.

[0007] Secondary sterilization of heated meat products such as sausages and hams is performed after packaging the food. Excessive heating of the secondary sterilization causes separation of fat and water, and the quality is impaired. Conventionally, a sterilization method called cold sterilization is often used for foods that are difficult to heat sterilize. In the case of performing sterilization by, for example, ultraviolet rays as cold sterilization, a packaging material for wrapping food has a high sterilizing effect.
It is limited to a material that transmits ultraviolet light having a wavelength of 4 nm. Also, in the case of performing the above-mentioned flash pulse sterilization, it is necessary to use a packaging material that transmits a specific wavelength (a wavelength band centered on a wavelength of 254 nm) that also has a sterilizing effect. Therefore, in order to carry out such a sterilization method by light irradiation, the packaging material is limited, so that it is not practical.

[0008] Therefore, there has been a demand for a sterilizer capable of easily performing a sterilization treatment without using a filter and without deteriorating the quality of food. In addition, when sterilizing packaged foods, there has been a demand for a sterilizer capable of relaxing the restrictions on packaging materials as compared with the related art.

[0009]

Therefore, the inventors of the present invention hypothesized that the above-described problem would be caused by an excessive energy value of a light pulse applied to food. Then, while changing the energy density of the light pulse by changing the input current density arbitrarily and suitably, the use conditions of the sterilizing apparatus in various foods were determined by earnest research and experiments, respectively. As a result, sterilization can be performed without adversely affecting the quality (flavor and color) of the food, cooling treatment after the sterilization is not required, and the restriction on packaging materials can be greatly eased as compared with the conventional case. I found a condition.

Therefore, according to the sterilizing apparatus of the present invention, the sterilizing apparatus includes a xenon lamp, a lamp house having a cooling fan, and a power supply unit, and has an integrated energy density of a light pulse emitted from the xenon lamp of 0.5. -10J
/ Cm ² .

[0011] By using such a sterilizing apparatus, it is possible to perform a sterilizing process without deteriorating the quality of food (especially, deterioration of flavor and color tone). In addition, an increase in the surface temperature of the food after sterilization as compared to before sterilization can be suppressed to 5 ° C. or less. Sterilization by this sterilizer has two sterilizing effects, ultraviolet sterilization and instantaneous heat sterilization. Therefore, when sterilizing packaged food, if the ultraviolet ray transmittance of the packaging material is at least 10% and the thickness of the packaging material is 40 μm or less, sterilization can be performed effectively. . Also, 40 μm
Even when a packaging material having a thickness exceeding 3 mm is used, sterilization can be performed by increasing the integrated energy density of the light pulse to be irradiated. Therefore, by using this apparatus, sterilization can be performed substantially regardless of the material of the packaging material. Therefore, the restriction on the packaging material can be remarkably relaxed as compared with the related art.

In using such a sterilizing apparatus,
Preferably, the current density input to the xenon lamp is 10
It is preferable to adjust the energy density of the light pulse on the food surface by changing the energy within the range of 0 to 10000 A / cm ² .

[0013] The integrated energy density for irradiating the food is 0.
To a desired value between 5~10J / cm ^2, to vary the current density to be input to the xenon lamp. The sterilizer includes at least a xenon lamp, a lamp house, and a power supply. The power supply unit has, for example, a transformer and a capacitor. Light pulse irradiation involves first converting a normal AC voltage to a DC voltage by a transformer, and then increasing the input voltage by a capacitor. Thereafter, discharge lighting is performed by inputting a high voltage to the xenon lamp. 1
A current density of 00 A / cm ² can be realized with a commercially available xenon lamp. A current density of 10000 A / cm ² can be realized by increasing the input current (applied voltage) to the xenon lamp.

When the current density is set to a low value within the above range, the desired integrated energy density can be obtained by increasing the distance between the food and the xenon lamp or reducing the number of light pulse irradiations. To

On the other hand, when the current density is set to a high value within the above range, a desired integrated energy density can be obtained by shortening the distance between the food and the xenon lamp or increasing the number of light pulse irradiations. At the same time,
The surface temperature of the food after the sterilization treatment is adjusted so that it does not rise 5 ° C. or more from the temperature before the sterilization treatment.

In using the sterilizing apparatus of the present invention, preferably, the current density input to the xenon lamp is set within a range of 800 to 2070 A / cm ² .

If the current density is within this range, the input voltage to the lamp can be used in the range of 1500 to 3000 V, and the energy density applied to the food can be easily controlled.

Further, according to the sterilizing apparatus of the present invention, particularly when sterilizing livestock meat products and marine products, not only sterilization but also effects of suppressing discoloration and odor can be obtained.

According to the sterilizing apparatus of the present invention, microorganisms such as Escherichia coli, Bacillus subtilis and its spores, lactic acid bacteria, fungi and their spores can be effectively sterilized.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. It should be noted that the drawings merely schematically show the shapes, sizes, and arrangements of the components so that the present invention can be understood, and thus the present invention is not limited to the illustrated examples.

The sterilization apparatus of this embodiment includes at least a xenon lamp (made by Ushio Inc.), a lamp house, and a power supply unit (made by Kyoto Denki Co., Ltd.). Xenon lamps are installed in the lamp house. Further, the lamp house has a cooling fan, and the cooling fan lowers the temperature of the xenon lamp itself by cooling the heat generated by the xenon lamp during light pulse emission. As a result, the life of the xenon lamp is extended. Further, the lamp house is provided with a reflection plate made of aluminum and an irradiation window made of quartz glass. Therefore, the light emitted from the lamp is reflected by the reflection plate, and all the emitted light and the reflected light can be efficiently collected from the irradiation window to the food to be irradiated. The power supply unit has a transformer and a capacitor.

The operation of irradiating a light pulse from the sterilizing apparatus is performed as follows. First, a normal AC voltage of 200 V is converted into a DC voltage by a transformer. Thereafter, the DC voltage is increased by a capacitor. Next, by applying the increased voltage to the xenon lamp as an applied voltage, the xenon lamp is discharged to generate a light pulse.

The irradiation time per light pulse of the sterilizing apparatus of this embodiment is about 190 μsec. The distance from the xenon lamp light source (in this apparatus, the irradiation window of the lamp house) to the object to be irradiated is set to 20 cm.

In such a disinfection apparatus, the integrated energy density of the light pulse is set to a value within the range of 0.5 to 10 J / cm ² , and the integrated irradiation time and the number of irradiations of the light pulse are adjusted to the food after sterilization. Are set so that the rise in surface temperature is 5 ° C. or lower than before the sterilization treatment.

That is, when the integrated energy density of the light pulse is high, the temperature of the food surface rises high. In this case, by increasing the light pulse irradiation interval, the surface of the food is cooled by the surrounding atmosphere each time the light pulse is irradiated. Therefore, even if a desired integrated energy density is achieved by irradiating the light pulse a plurality of times, the temperature rise on the surface of the food can be suppressed to 5 ° C. or less. Further, even if the food is irradiated with the light pulse so that the integrated energy density is within the above-mentioned range, there is no possibility that the quality such as the flavor and color tone of the food is deteriorated.

The light pulse emitted from the xenon lamp contains light having a wavelength from the ultraviolet wavelength region to the infrared wavelength region. Therefore, the sterilization by this light pulse is considered to be due to ultraviolet sterilization and instantaneous heat sterilization. Therefore, not only ultraviolet rays but also heat sterilization is performed. For example, when sterilizing packaged foods, the packaging material only needs to have an ultraviolet transmittance of 10% or more. Further, the thickness of the packaging material may be a thickness in the range of 10 to 40 μm. Also, if the thickness of the packaging material is 40
For those exceeding μm, the integrated energy density of the light pulse is 2.25 J / cm ² or more. Thereby, the food packaged with such a thick packaging material can be sterilized. Therefore, the range of choice of the packaging material is expanded.

[0027]

Next, as an example, a sterilization treatment is performed using the sterilization apparatus of this embodiment, and the sterilization action and effect thereof are examined.

<First Example> As a first example, an example in which various microorganisms are sterilized by using the sterilizer of the above embodiment will be described.

In this embodiment, the current density input to the xenon lamp is 1000 A / cm ² . The irradiation time of one light pulse emitted from the xenon lamp is set to about 1
90 μs. The irradiation interval is one second. The number of light pulse irradiations is two, that is, five times and thirty times.

Here, the relationship between the current density and the energy density is shown in the following equation (1). However, the following equation (1) is limited to the case where an ultraviolet-enhanced xenon lamp having a current density of 1000 A / cm ² or more (hereinafter also referred to as an ultraviolet-enhanced lamp) is used.

Assuming that the energy density is Y and the current density is X, Y = X ^1.9424 × 10 ^-7 (1) From the above equation (1), when the current density is 1000 A / cm ² , the energy density is It is 0.12 J / cm ² , and thus the integrated energy density of the irradiation of five light pulses is 0.6 J / cm ² . Further, the integrated energy density by the 30 light pulse irradiations is 3.6 J / cm ² .

Next, the microorganism to be irradiated with the light pulse is E. coli (Escherichia coli).
JCM1649T), yeast (Saccharomyces cerevisiae JCM7255T) and fungi (Aspergillus niger ATCC164)
04).

A petri dish in which each of these microorganisms is grown is irradiated with a light pulse 5 times or 30 times. After irradiating the cells of each of Escherichia coli and yeast with glutaraldehyde, the cells are further fixed with osmic acid and then stepwise dehydrated with alcohol. For fungi, the irradiated spores are collected, and the spores are subjected to glutaraldehyde fixation, dehydration, and staining. Thereafter, the cells and the spores are respectively placed on a sample stage of an electron microscope, and platinum is vapor-deposited on the cells and the spores on the sample stage by ion sputtering. Thereafter, the surfaces of the cells and the spores are observed with an electron microscope.

The results are shown in FIGS. 1 to 6 together with the state of the surface of the cells and the spores before light pulse irradiation.

FIG. 1 is an electron micrograph of E. coli before light pulse irradiation, and FIG. 2 is a photograph of E. coli after light pulse irradiation 30 times. FIG. 3 is an electron micrograph of fungal spores before light pulse irradiation, and FIG. 4 is a photograph of fungal spores after light pulse irradiation 30 times. FIG.
FIG. 6 is an electron micrograph of the yeast before light pulse irradiation, and FIG. 6 is a photograph of the yeast after light pulse irradiation 30 times.

As a result, as can be seen from any of the figures, the surface layer of the cells (or spores) not irradiated with the light pulse is not damaged, whereas the surface layer of the cells after light pulse irradiation is not damaged. Has its structure destroyed. In addition, the ratio of the cells (or spores) whose surface layer structure was destroyed to the cells (or spores) that were not destroyed was larger in the cells irradiated 30 times than in the cells irradiated 5 times.

Therefore, according to the sterilizing apparatus of the present invention, the surface layer structure of the cells can be destroyed by irradiating light pulses to various cells.

<Second Example> As a second example, the effect of the sterilizing apparatus of the present invention described in the embodiment on the food by the irradiation of the light pulse will be examined.

Hereinafter, points different from the first embodiment will be described, and detailed description of the same points as the first embodiment will be omitted.

In this embodiment, the current density input to the xenon lamp is 1000 A / cm ² . The irradiation time of one light pulse emitted from the xenon lamp is set to about 1
90 μs. The irradiation interval is one second.

The object to be irradiated with the light pulse is, in this embodiment,
Krakow sausage (made by Tonden Farm) and fattening cattle semitendinous muscle. The clark sausage is divided into two equal parts in the major axis direction. The fattening cow semitendinous muscle is used after it is rapidly frozen using liquid nitrogen and then cut at right angles to muscle fibers.

For both samples of clark sausage and fattening cow semitendinosus, two opposing surfaces are irradiated with a light pulse 15 times on each surface.

Thereafter, each sample is fixed with glutaraldehyde in the same manner as in the first embodiment, and further fixed with osmic acid, followed by dehydration with alcohol.

Each sample having undergone such a series of processes is placed on a sample stage of an electron microscope, and platinum is vapor-deposited on the surface of the sample by an ion sputtering process, and then observed using an electron microscope.

The results are shown in FIGS. 7 to 10 together with the state of the surface of each sample before light pulse irradiation.

FIG. 7 is an electron micrograph of a section of the clark sausage before light pulse irradiation, and FIG. 8 is a photograph of a section of the clark sausage after irradiation of a total of 30 light pulses.

In FIG. 7, what looks white are fat globules on the surface of clark sausage. In this figure, it can be confirmed that the surface of the fat globule has irregularities. When such a clark sausage is irradiated with a light pulse using the sterilizing apparatus of the present invention, as shown in FIG. 8, the fat globules have no irregularities and a round smooth surface is formed. You can check. By comparing these FIGS. 7 and 8, it can be seen that the irradiation of the light pulse applied an amount of heat to melt the surface of the fat globule. At the same time,
It is shown that even if irradiation was performed 30 times in total, the accumulated energy was not enough to melt the entire fat globule. Therefore, it was found that the light pulse emitted from the sterilization apparatus of the present invention instantaneously heated the irradiated object.

FIG. 9 is an electron micrograph of a cross section of a fattening cow semitendinosus muscle before light pulse irradiation.
Is a photograph of the fractured surface after irradiating a total of 30 light pulses.

A comparison between FIG. 9 and FIG. 10 shows that the surface of the fractured surface shown in FIG. 9 is relatively smooth,
On the surface of the fractured surface in FIG. 10, countless precipitates such as fluff are seen. The state of the surface as shown in FIG. 10 is very similar to the state in which water-soluble proteins in muscle tissue are eluted and the eluted material is thermally denatured and solidified on the fiber surface, which is seen when heating muscle muscle fibers. Similar. Therefore, it is presumed that the sample of the fattening bovine semitendinoid muscle was also instantaneously heated by the light pulse emitted from the sterilization apparatus of the present invention.

Third Embodiment As a third embodiment, various unpackaged foods are sterilized by using the sterilizing apparatus of the present invention, and the sterilizing effect thereof is examined.

The object to be sterilized is food. Cucumbers (sample No. 6) and carrots (sample No. 7) as vegetables
Banana (sample number 8) as fruit, beef (sample number 5) as meat, salmon (sample number 1) as seafood
2), tuna (sample No. 13) and salmon roe (sample No. 14), soybean (sample No. 9) and red bean (sample No. 10) as beans, dried gourd (sample No. 15) as processed agricultural products, cut rice cake as processed cereals ( Sample No. 16), processed fishery products Sasa kamaboko (Sample No. 11), processed meat products Cracow sausage (Sample No. 1), salami (Sample No. 2) and two types of bacon from different manufacturers (Sample No. 3 Sample No. 4 is manufactured by Hokuren Co., Ltd.), and cheese (sample No. 17), a total of 17 items, is used as a dairy product.

The size of each sample is adjusted so that it has a width of at least 10 cm in a straight line. And lactic acid bacteria (Lactobacillus plantarum (Lactobacillus plantarum) JCM1149T) and 0.85 were prepared in advance so that the number of bacteria would be 10 ⁸ to 10 ⁹ cfu / ml.
Lactic acid bacterium-containing liquid consisting of 100% by weight of sterile physiological saline
These samples were immersed in 300 ml for 3 minutes. Thereby, lactic acid bacteria adhere to the surface of the sample.

Each sample to which the lactic acid bacteria have adhered is sterilized by irradiating a light pulse using a sterilizer.

In this embodiment, the current density input to the xenon lamp is, for example, 1000 A / cm ² . Also,
The irradiation time of one light pulse emitted from the xenon lamp is about 190 μsec. The irradiation interval is one second. The distance (irradiation distance) between the sample and the light source (xenon lamp) is 20 cm. The number of light pulse irradiation is 15 times for one surface of the sample and 15 times for the other surface, for a total of 30 times.

The integrated energy density of the light pulse received on each of the one surface and the other surface of the sample is 1.8 J /
cm ² . Therefore, each sample had a total of 3.6
This means that light having an integrated energy density of J / cm ² has been received.

Next, each sample after the light pulse irradiation was
After placing in a sterilized bag containing 50 ml of 0.85% by weight of sterile physiological saline, the sample was placed on the outside of the bag from outside of the bag.
Massage for 0 seconds.

After removing the sample from the bag,
The poured solution remaining in this bag was used as a sample stock solution, and this sample stock solution was diluted with a diluent (0.85% by weight of sterile physiological saline) to 10 ^1.
From the 1-fold to the 10 ⁶ -fold, dilute solutions are prepared in 10-fold dilution steps.

Next, from these diluents, a diluent of 0.1 m
Inoculate a standard agar medium prepared in a petri dish having a diameter of 9 cm. Then, smear it with a large stick. Put these in the incubator and
Incubate for 48 hours at a temperature of 5 ° C.

Next, a petri dish in which 30 to 300 colonies have occurred is selected, and the number of all colonies that have grown in the petri dish is counted. Let the number of this colony be x.

On the other hand, except for the treatment of irradiating each sample with a light pulse, the same experiment as described above is performed from the attachment of lactic acid bacteria to the measurement of the number of colonies. The number of the colonies is defined as y.

Next, for each sample, the survival rate of lactic acid bacteria is determined from the number x and y of the colonies. The survival rate is obtained by the following equation (2).

(X / y) × 100 (%) (2) The survival rate of each sample is shown in FIG. FIG. 11 shows various sample numbers on the horizontal axis and the survival rate (%) on the vertical axis.

According to FIG. 11, the cheese having the lowest survival rate of lactic acid bacteria was 0.01% for the cheese of sample No. 17. The sample with the highest survival rate is sample number 11
It was 40.84% for bamboo fish. Further, it can be seen that a bactericidal effect can be obtained in any of the samples, that is, various unpackaged foods.

<Fourth Embodiment> As a fourth embodiment, a packaged food is sterilized using the sterilizer of the present invention, and its sterilizing effect is examined.

As the food, a processed meat product such as clark sausage is used. And in this example, as the packaging material,
23 types of packaging materials having different light transmittances and thicknesses are prepared. With these 23 types of packaging materials, sterilization treatment is performed on those packaged with clark sausage to which lactic acid bacteria are adhered under the same conditions, and the difference in the sterilization effect is examined.

The clark sausage used has a diameter of 2.5 cm. Then, this is cut into a length of 10 cm to prepare a columnar shape. Thus, the surface area of the clark sausage is 88 cm ² .

A lactic acid bacterium similar to that used in the third embodiment is attached to the clark sausage. Number of lactic acid bacteria is 1
0 ⁸ ~10 ⁹ cfu / ml and made as lactic acid bacteria solution 100 prepared by 0.85 wt% sterile saline
Soak the Krakow sausage in ~ 300 ml for 3 minutes.

Thereafter, the clark sausage to which the lactic acid bacteria have been adhered is vacuum-packaged with each of the 23 types of packaging materials shown in Table 1 below.

[0069]

[Table 1]

The numbers 1 to 23 in Table 1 are the numbers given to the respective packaging materials. Here, the packaging material 1, the packaging material 2,... Further, in the configuration column of Table 1, specific materials constituting each packaging material and their thicknesses are described. In each column of ultraviolet light, visible light, and 254 nm, the transmittance of light of each wavelength or wavelength band is shown as a percentage. The numerical value marked with * in the column of ultraviolet rays indicates the transmittance of ultraviolet rays having a wavelength of 280 nm or more. In the column of thickness, the total thickness (μm) of each packaging material is shown.

The packaging material 1 is NHP-9 (trade name: manufactured by Cowpack Co., Ltd.), and a linear low-density polyethylene (LLDPE) having a thickness of 70 μm is placed outside a stretched nylon film (ONY) having a thickness of 15 μm. Is a packaging material having a structure in which is formed, and transmits 50% of ultraviolet rays and transmits visible light of 60 to 70%.
% Transmission characteristics. In particular, about 30% of light having a wavelength of 254 nm is transmitted.

The packaging material 2 is made of NXL-10 (trade name: manufactured by Cowpack Co., Ltd.) and has a thickness of 60 μm outside the saponified ethylene vinyl acetate copolymer (EVOH) having a thickness of 15 μm.
Is a packaging material in which polyethylene (PE) is formed, transmits 60% of ultraviolet light having a wavelength of 280 nm or more,
It has the property of transmitting 70 to 85% of visible light. Further, light having a wavelength of 254 nm is hardly transmitted.

The packaging material 3 is R-1 (product name) and has a thickness of 2
A 70 μm thick cellulose propionate (CP) was dry-laminated (D) on the outside of 5 μm nylon (NY).
L). Then, 40% of ultraviolet rays having a wavelength of 280 nm or more are transmitted, and visible light is
７５75% transmission. Further, ultraviolet rays having a wavelength of 254 nm are hardly transmitted.

The packaging material 4 is NPU7551 (trade name: manufactured by Cowpack Co., Ltd.). A 55 μm-thick ethylene vinyl acetate copolymer (EVA) is formed outside a 15 μm-thick biaxially stretched nylon film (BONY). The packaging material has a characteristic of transmitting 50% of ultraviolet rays and transmitting about 70% of visible light. In addition, light having a wavelength of 254 nm is transmitted by about 40%.

The packaging material 5 is a 90 μm-thick aluminum foil (Al) manufactured by Far East Polymer Co., and transmits 50% of ultraviolet light having a wavelength of 280 nm or more and transmits 75 to 80% of visible light. Further, light having a wavelength of 254 nm is not transmitted.

The packaging material 6 is B-1 (trade name).
Outside of 5 μm thick nylon (NY), 45 μm thick
This is a structure in which m NBs are bonded by dry lamination (DL). It has the property of transmitting 35% of ultraviolet rays and transmitting 60 to 75% of visible light. Also,
Light having a wavelength of 254 nm is not transmitted.

The packaging material 7 is H-1 (trade name),
A structure in which a 9 μm aluminum foil (Al is adhered by DL) outside a 2 μm biaxially stretched polyester film (polyethylene terephthalate) (PET), and a 70 μm thick cellulose propionate is formed outside the aluminum foil. The light transmission characteristic of the packaging material 7 is not transmitted over the entire wavelength band.

The packaging material 8 is a custom-made product of Icelo Chemical Co., Ltd., and is a non-stretched blown polypropylene film (IPP) having a thickness of 30 μm. This material transmits 45% of ultraviolet light and 65-85% of visible light. Then, about 35% of light having a wavelength of 254 nm is transmitted.

The packaging material 9 is a custom-made product manufactured by Ozaki Light Chemical Co., Ltd., and has a low density polyethylene (LDPE) and a saponified ethylene vinyl acetate copolymer (EVOH) sandwiched therebetween.
And the overall thickness is 60 μm. This material transmits 40% of ultraviolet light and transmits 50 to 75 visible light.
% Transmission. In addition, about 35% of light having a wavelength of 254 nm is transmitted.

The packaging material 10 is a custom-made product manufactured by Plus Industrial Co., Ltd., and is made of nylon (NY) and polyethylene (PE) formed on the outside thereof.
0 μm. This material has a property of transmitting 70% of ultraviolet rays and 80 to 85% of visible light. Also, about 55% of light having a wavelength of 254 nm is transmitted.

The packaging material 11 is a custom-made product manufactured by Plus Industrial Co., Ltd., and is a low-density polyethylene (LDP) having a thickness of 30 μm.
E). This material has a property of transmitting 70% of ultraviolet rays and transmitting 70 to 85% of visible light. In addition, about 58% of light having a wavelength of 254 nm is transmitted.

The packaging material 12 is a custom-made product manufactured by Plus Industrial Co., Ltd., and has a low-density polyethylene (LDP
E). This material has a characteristic of transmitting 70% of ultraviolet rays and transmitting 70 to 85% of visible light.
In addition, about 60% of light having a wavelength of 254 nm is transmitted.

The packaging material 13 is a custom-made product manufactured by Plus Industrial Co., Ltd., and is made of a 30 μm thick ethylene vinyl acetate copolymer (EVA). This material has a property of transmitting 30% of ultraviolet rays and 30 to 65% of visible light. Further, about 20% of light having a wavelength of 254 nm is transmitted.

The packaging material 14 is a custom-made product manufactured by Plus Industrial Co., Ltd., and is made of a 60 μm thick ethylene vinyl acetate copolymer (EVA). This material transmits 35% of ultraviolet light and 35-60% of visible light. Also,
About 25% of light having a wavelength of 254 nm is transmitted.

The packaging material 15 is a custom-made product manufactured by Plus Industrial Co., Ltd. and has a thickness of 30 μm and is made of linear low-density polyethylene (LL).
DPE). This material is capable of
%, And 70-85% of visible light. In addition, about 60% of light having a wavelength of 254 nm is transmitted.

The packaging material 16 is a custom-made product manufactured by Wako Chemical Industry Co., Ltd., and is a linear low-density polyethylene (L
LDPE). This material is capable of
It has the property of transmitting 5% and transmitting 60 to 80% of visible light. Also, about 40% of light having a wavelength of 254 nm is transmitted.

The packaging material 17 is a custom-made product manufactured by Wako Chemical Industry Co., Ltd. and has a thickness of 15 μm and is made of high density polyethylene (HDP).
E). This material has a property of transmitting 2% of ultraviolet light and transmitting 2 to 13% of visible light. Further, about 1.5% of light having a wavelength of 254 nm is transmitted.

The packaging material 18 is a custom-made product made by Fukulex Co., Ltd. and has a thickness of 30 μm and is made of high-density polyethylene (HDP
E). This material is 1.5% UV
It has the property of transmitting and transmitting 2 to 12% of visible light. In addition, about 1.2% of light having a wavelength of 254 nm is transmitted.

The packaging material 19 is made of nylon (NY) and polyethylene (PE) formed on the outside, and has a total thickness of 80 μm. This material is
It has the property of transmitting 30% of ultraviolet rays and 40-60% of visible light. Further, light having a wavelength of 254 nm is hardly transmitted.

The packaging material 20 is made of Klehalon MLB-100.
0 (trade name: manufactured by Kureha Chemical Industry Co., Ltd.), which was composed of polyethylene (PE), polyvinylidene chloride (PVDC) formed outside thereof, and polyolefin (PO) formed further outside thereof. , The total thickness is 65μm
Material. This material has a property of transmitting 20% of ultraviolet rays and transmitting 30 to 60% of visible light. Also,
About 40% of light having a wavelength of 254 nm is transmitted.

The packaging material 21 is made of Besera Pouch (trade name:
Kureha Chemical Co., Ltd.) and stretched nylon film (O
NY) and an unstretched polypropylene film (CPP) provided on the outside thereof, and has an overall thickness of 10
It is a material of 0 μm. This material has a property of transmitting 45% of ultraviolet rays and transmitting 50 to 70% of visible light.
The wavelength of 254 nm is hardly transmitted.

The packaging material 22 is made of a best nylon (trade name:
Ozaki Light Chemical Co., Ltd.), and another nylon (NY) is bonded to the outside of the nylon (NY) by dry lamination (DL), and a linear low-density polyethylene (LLDPE) is dry-laminated on the outside. (DL)
With a total thickness of 70 μm
Material. This material has a property of transmitting 30% of ultraviolet rays and transmitting 40 to 60% of visible light. Also,
About 25% of light having a wavelength of 254 nm is transmitted.

The packaging material 23 is triple nylon (trade name: manufactured by Ozaki Light Chemical Co., Ltd.), and polyethylene (PE) is dry-laminated (DL) outside nylon (NY).
With a total thickness of 65 μm
Material. This material has a characteristic of transmitting 55% of ultraviolet rays and transmitting 60 to 65% of visible light. Also,
About 30% of light having a wavelength of 254 nm is transmitted.

Next, a sterilization process is performed by irradiating each of the samples packed with the above-described 23 types of packaging materials with a light pulse using a sterilizer.

In this embodiment, as in the third embodiment,
The current density input to the xenon lamp is 1000 A / cm
^{Assume 2} . The irradiation time of one light pulse emitted from the xenon lamp is set to about 190 μsec. The irradiation interval is one second. The distance between the sample and the light source (irradiation distance) is 20 cm. The number of times of light pulse irradiation is 15 times for one surface of vacuum-packed clark sausage and 15 times for the other surface, for a total of 30 times.

The integrated energy density of the light pulse received on one side and the other side of the packaged sample is 1.8.
J / cm ² . Therefore, each sample has a total of 3.
It receives light with an integrated energy density of 6 J / cm ² .

Next, the packaging material of each sample after light pulse irradiation was removed, and the clark sausage was reduced to 0.85% by weight.
After placing in a sterilized bag containing 50 ml of sterile physiological saline having a concentration of
Massage for seconds.

Thereafter, the clark sausage is taken out of the bag, and the pour solution remaining in the bag is used as a sample stock solution. This sample stock solution is diluted (0.85% by weight sterile physiological saline)
In 10 ¹ × to 10 ⁶ times, to create each dilution was diluted with 10-fold serial.

Next, 0.1 ml of each of these diluted solutions is taken and inoculated on a standard agar medium prepared in a 9 cm-diameter dish. Then, smear it with a large stick. These are put in an incubator and cultured at a temperature of 35 ° C. for 48 hours.

Next, a petri dish in which 30 to 300 colonies have occurred is selected, and the number of all colonies that have developed in the petri dish is counted. Let the number of this colony be x.

On the other hand, except for the treatment of irradiating light pulses and wrapping with a packaging material on clam sausage having a diameter of 2.5 cm and a length of 10 cm, everything from the adhesion of lactic acid bacteria to the measurement of the number of colonies was the same as described above. Perform the experiment. The number of the colonies is defined as y.

Next, the survival rate of lactic acid bacteria is determined from the numbers x and y of the colonies for each sample having different packaging materials. The survival rate is determined using the same equation (2) ((x / y) × 100 (%)) as in the third embodiment. FIG. 12 shows the survival rate of each sample. FIG. 12 shows the horizontal axis of Table 1
Sample numbers of packaging materials shown in (1)
3) is plotted, and the ordinate represents the survival rate (%).

Referring to FIG. 12 and Table 1, first, all the samples have a bactericidal effect. It can be seen that the higher the transmittance of ultraviolet light, particularly the light of the wavelength of 254 nm, the lower the survival rate, that is, the higher the sterilizing effect. In addition, it was found that the bactericidal effect was higher when wrapped with a thinner packaging material.

Therefore, from the fourth example, it was confirmed that the sterilizing action of the sterilizing device by the light pulse was obtained by the ultraviolet light contained in the light pulse.

<Fifth Embodiment> As a fifth embodiment, the packaging material (packaging material 13) of the sample having the highest sterilization effect in the fourth embodiment and the lowest sterilization effect were obtained. After each food was packaged using the sample packaging material (packaging material 22), a sterilization treatment was performed on these foods by changing the energy density per light pulse generated from the sterilization device.

The food to be packaged is cylindrical clark sausage having a diameter of 2.5 cm and a length of 10 cm as in the fourth embodiment.

After the lactic acid bacteria are attached to the clark sausage in the same manner as in the third and fourth embodiments, the clark sausage is vacuum-packaged with the above two types of packaging materials.

Next, a sterilization process is performed on the two packaged samples by irradiating light pulses using a sterilizer.

[0109] In this embodiment, the current density to be input to the xenon ^{lamp, 1300A / cm 2, 1660A /} cm 2
And 2070 A / cm ² , the energy density per light pulse is 0.15 J / cm ² ,
It was adjusted to be 0.25 J / cm ² and 0.36 J / cm ² .

The three light pulses having different energy densities were respectively irradiated on one surface and the other surface of the sample 30 times, 15 times each. The irradiation time for one light pulse emitted from a xenon lamp is approximately 190μ.
Seconds. The irradiation interval is 1 second. The distance between the sample and the light source is 20 cm.

The cumulative energy density of the light pulse received by each sample by the 30 light pulse irradiations is 4.5 J
/ Cm ² , 7.5 J / cm ² and 10.8 J / cm ² .

Next, in the same manner as in the fourth embodiment, the packaging material of each sample after the light pulse irradiation was removed, and the clark sausage was placed in sterile physiological saline 5 at a concentration of 0.85% by weight.
After placing in a sterilized bag containing 0 ml, knead the silkworm sausage from the outside of the bag for 10 seconds.

Thereafter, the silkworm sausage is taken out of the bag, and the pour solution remaining in the bag is used as a sample stock solution, which is diluted with a diluent in a 10-fold step from 10 ¹ to 10 ⁶ . Thus, dilution of 6 different concentrations are obtained from 10 ¹ times up to 10 ⁶ times.

Next, 0.1 ml of each of these diluted solutions is taken and inoculated on a standard agar medium prepared in a petri dish having a diameter of 9 cm. Then, smear it with a large stick. These are put in an incubator and cultured at a temperature of 35 ° C. for 48 hours.

Next, a petri dish in which 30 to 300 colonies have occurred is selected, and the number of all colonies that have grown in the petri dish is counted. Let the number of this colony be x.

The same experiment as described above was performed from the adhesion of lactic acid bacteria to the counting of the number of colonies, except for the treatment of irradiating light pulses and wrapping the packaging material with clam sausage of 2.5 cm in diameter and 10 cm in length. I do. The number of the colonies is defined as y.

Next, in this embodiment, the survival rate of lactic acid bacteria is determined from the numbers x and y of the colonies for the samples having different light pulse energy densities. This survival rate is calculated by the equation (2) ((x /
y) × 100 (%)). Table 2 shows the survival rate of each sample.

[0118]

[Table 2]

As is clear from Table 2, in the case of using the wrapping material 22 having a low sterilizing effect in the fourth embodiment, the survival rate decreases as the integrated energy density increases. Therefore, by increasing the integrated energy density of the light pulse, the packaged food can be effectively sterilized even if a packaging material that does not easily transmit ultraviolet rays is used. In the sample packed with the packaging material 13 having a high sterilizing effect in the fourth embodiment, a high sterilizing effect was obtained as in the fourth embodiment when the integrated energy density of the light pulse was increased.

<Sixth Embodiment> As a sixth embodiment, changes in the color tone and the surface temperature of food when sterilization is performed using the sterilization apparatus of the present invention will be examined.

In this example, two tests are performed.

First, in the first test, pork (peach slice) and beef (shoulder cut off), which are meat products, are used as food. These pork and beef are, for example, 5
cm, width 15 cm and thickness 5 mm.

The energy density per light pulse of the sterilizer is 0.25 J / cm ² and 0.36 J / cm ^2.
J / cm ² . The number of irradiations is set to 10, 15, and 20 times. The irradiation distance is 20 cm. The irradiation interval is one second.

Then, the surface temperature of the meat food is measured using a contact thermometer using a K-type thermocouple.

The color tone of the meat food is measured by measuring the lightness and chroma using a color difference meter (manufactured by Minolta) based on the Hunter color system.

First, Table 3 shows the results of changes in the surface temperature of pork and beef due to light pulse irradiation.

[0127]

[Table 3]

According to Table 3, when the energy density of the light pulse is set to 0.25 J / cm ² , when pork is irradiated 10 times, the temperature of the pork is increased by 1.3 ° C. as compared with that before irradiation. Irradiation of 15 light pulses raises 2.7 ° C,
The irradiation increased by 3.4 ° C. by irradiation with 20 light pulses. Further, when the energy density of the light pulse is 0.36 J / cm ² , the surface temperature of pork increases by 3.9 ° C. by irradiation of 10 light pulses, and rises by 4.8 ° C. by irradiation of 15 times.
A rise of 4.7 ° C. was observed after 20 irradiations. Therefore, the energy density of one light pulse is 0.36 J / c.
When this light pulse is irradiated 20 times as m ² , the integrated energy density becomes highest, but in this case, the rise in the surface temperature of the pork can be 5 ° C. or less.

Next, for beef, when the light pulse energy density was set to 0.25 J / cm ² , the light pulse was irradiated 10 times, and the temperature increased by 2.6 ° C. as compared to before the irradiation. In irradiation of 15 light pulses, the temperature rises by 4.3 ° C.
The temperature rise of the zero irradiation was also 4.3 ° C. When the energy density of the light pulse is 0.36 J / cm ² , the surface temperature of the beef becomes 2.
The temperature increased by 9 ° C., increased by 3.2 ° C. in 15 irradiations, and increased by 4.6 ° C. in 20 irradiations. Therefore, also in the case of beef, the temperature rise in the sterilization treatment by the light pulse can be 5 ° C. or less.

Next, the change in color tone of these pork and beef is examined.

In this example, two pieces of pork (peach slice) and two pieces of beef (shoulder cut off) having a length of 5 cm, a width of 15 cm and a thickness of 5 mm are used as samples. Immediately before, immediately after light pulse irradiation of these pork and beef,
Measurements are taken after 2, 3, 3 and 7 days. Measurement of color tone is based on Hunter color system (Minolta)
The lightness and chroma are measured using. Then, measurement was made at five different portions for each sample, and a total of 10
An average value is calculated from the measured values. The brightness change is obtained from the L value of the color difference meter. Also, the chroma C is represented by a b ^* value of the red direction a ^* value and yellow directions by the following equation (3).

C = (a ^{* 2} + b ^{* 2} ) ^1/2 (3) FIG. 13 and FIG. 1 show the lightness change characteristics of the above-mentioned pork and beef.
It is shown in FIG. 15 and 16 show the saturation change characteristics. 13 and 14, the ordinate represents lightness and the abscissa represents elapsed time. 15 and 16, the vertical axis represents saturation and the horizontal axis represents elapsed time. The time referred to here is the time from irradiation to 7 days after irradiation.
After irradiation, 1 day, 2 days, 3 days, and 7 days after irradiation.

In FIGS. 13 to 16, the energy density of the light pulse applied to pork or beef is ^two kinds, 0.25 J / cm ² and 0.36 J / cm ² . The number of irradiations was set to 10, 15, and 20 for each energy density. This is because the color tone change was measured at the same time as the surface temperature change. In these figures (FIGS. 13 to 16), the curves with black diamonds indicate that the energy density per light pulse is 0.25.
10 is a characteristic curve when the number of irradiations is set to 10 in J / cm ² . The curve with a black square indicates the light pulse 1
It is a characteristic curve when the energy density per time is set to 0.25 J / cm ² and the number of times of irradiation is set to 15 times. The curve with a black triangle indicates that the energy density per light pulse is 0.25 J / cm ² and the number of irradiations is 2
It is a characteristic curve when it is set to 0 times. In addition, the curve marked with a cross indicates that the energy density per light pulse is 0.3.
6 is a characteristic curve when the number of irradiations is set to 10 at 6 J / cm ² . The curve with a white circle indicates the light pulse 1
It is a characteristic curve when the energy density per time is set to 0.36 J / cm ² and the number of times of irradiation is set to 15 times. The curve with a black circle is a characteristic curve when the energy density per light pulse is 0.36 J / cm ² and the number of irradiations is 20 times. A curve with a white triangle is a characteristic curve in a case where light pulse irradiation is not performed.

Referring to FIGS. 13 to 16, in any case, no significant change was observed in the brightness and saturation of pork and beef before and after light pulse irradiation. In addition, when seven days have passed since the irradiation of the light pulse, both the lightness and the saturation decreased regardless of whether the light pulse was irradiated or not.

Therefore, by performing the sterilization treatment using the sterilization apparatus of the present invention, the rise in the surface temperature of the food due to the light pulse irradiation can be suppressed to 5 ° C. or less. In addition, food can be sterilized without a change in color tone.

Next, a second test is performed. The second test is a meat surface temperature rise test.

First, as a sample corresponding to food, a semitendinous muscle of a waste cow for milk is prepared. The semitendinous muscle is cut to an appropriate size.

As the xenon lamp of the sterilizer, an ultraviolet enhanced lamp is used. The energy density per one light pulse is set to 0.25 J / cm ² ,
And 8 J / cm ² . The energy density per light pulse is 0.25 J / cm ^2.
, The number of irradiations is set to 30, 40 and 50
The temperature change is examined three times. Also,
At this time, the irradiation intervals were 2 seconds, 1 second, and 1/3.
There are three types of seconds.

When the energy density per irradiation of one light pulse is set to 0.08 J / cm ² , the temperature change is examined for two irradiation times of 90 times and 125 times. Further, at this time, the irradiation interval is set to one of 1 second and 1/5 second.

The irradiation distance is set to 20 cm in each case.

Then, the surface temperature of the sample is measured using a contact thermometer using a K-type thermocouple.

The results of this test are shown in Table 4 below.

[0143]

[Table 4]

According to Table 4, first, when the energy density per irradiation of one light pulse is 0.25 J / cm ² , the test results show that the irradiation interval is 2 seconds and the number of irradiations is 30 times. Then, the integrated energy density is 7.5J
/ Cm ² . Then, the surface temperature was 13.7 ° C. before the irradiation, but became 16.5 ° C. after the irradiation. Therefore,
It has risen by 2.8 ° C.

When the irradiation interval is 2 seconds and the number of irradiations is 40, the integrated energy density is 10 J / cm ^2.
Becomes Then, the surface temperature was changed from 15.7 ° C. before the irradiation to 18.6 ° C. after the irradiation. Therefore, 2.9 ° C
It is rising.

Next, when the irradiation interval is 1 second and the number of irradiations is 30, the integrated energy density is 7.5 J / cm.
It becomes ² . The surface temperature of the sample before irradiation with the light pulse was 13 ° C. The temperature after irradiation is 15.9 ° C,
The temperature rose by 2.9 ° C.

The irradiation interval is one second, and the number of irradiations is four.
When it is set to 0 times, the integrated energy density is 10 J / cm ² . The surface temperature of the sample was 16.
After irradiation at 5 ° C, the temperature was 19.9 ° C. Therefore, 3.4 ° C
It is rising.

The irradiation interval is one second, and the number of irradiations is five.
When it is set to 0 times, the integrated energy density is 12.5 J / cm
It becomes ² . The surface temperature of the sample was 1 before irradiation.
After irradiation at 4.4 ° C., the temperature was 17.8 ° C. Therefore, the temperature rises by 3.4 ° C. due to the light pulse irradiation.

Next, when the irradiation interval is set to 1/3 second and the number of irradiations is set to 30, the integrated energy density becomes 7.5 J / c.
m ² . The surface temperature of the sample was 14.5 ° C. before irradiation and 17.2 ° C. after irradiation. Therefore, after irradiation, the temperature was increased by 2.7 ° C. than before irradiation.

When the irradiation interval is 1/3 second and the number of irradiations is 40, the integrated energy density is 10 J / cm ^2.
It is. The surface temperature of the sample was 1 before irradiation.
After irradiation at 6.5 ° C, the temperature was 20 ° C. Therefore, the temperature after irradiation was higher by 3.5 ° C. than before irradiation.

Next, regarding the test results when the energy density per irradiation of one light pulse is 0.08 J / cm ² , when the irradiation interval is 1 second and the number of irradiations is 90, the integrated energy density is as follows. 7.2 J / cm ² .
The surface temperature of the sample was 1 before light pulse irradiation.
It was 4.7 ° C. and after irradiation was 17.4 ° C. Therefore, after irradiation, the temperature is increased by 2.7 ° C. from that before irradiation.

If the irradiation interval is 1 second and the number of irradiations is 125, the integrated energy density is 10 J /
cm ² . The surface temperature of the sample was 16.8 ° C. before the light pulse irradiation, and 19.8 ° C. after the light pulse irradiation.
Therefore, the temperature after irradiation is higher by 3 ° C. than before irradiation.

Next, the irradiation interval is set to １ ／ second. If the number of irradiations is set to 90, the integrated energy density becomes 7.2 J / cm ² . The surface temperature of the sample was 15.1 ° C. before the light pulse irradiation, and 18 ° C. after the light pulse irradiation. Therefore, the temperature after irradiation is 2.9 ° C. higher than before irradiation.

The irradiation interval is 1/5 and the number of irradiations is 1
If 25 times, the integrated energy density is 10 J / cm ²
It is. The surface temperature of the sample was 16.5 ° C. before the light pulse irradiation, and 19.7 ° C. after the light pulse irradiation. Therefore, the temperature after irradiation is 3.2 ° C. higher than before irradiation.

[0155] Thus, the scope in the case where a and 0.08 J / cm ² if the energy density per optical pulse once irradiated with 0.25 J / cm ^2, both the cumulative energy density of 10J / cm ² or less If the sterilization treatment is carried out, the rise in the surface temperature of the food after light pulse irradiation can be suppressed to 5 ° C. or less regardless of the irradiation interval.

<Seventh Embodiment> As a seventh embodiment, unpackaged meat and meat products are sterilized using the sterilization apparatus of the present invention, and changes in the quality of the meat and meat products after light pulse irradiation are examined. In this example, two types of xenon lamps having different wavelengths are prepared.

One of the two types of xenon lamps has a current density of 1000 A / cm ² . In the light pulse emitted from this lamp, when the total radiant energy of light in the wavelength band of 200 to 800 nm is 100%, the wavelength is 2
About 26% of light in the ultraviolet region of 00 to 400 nm and about 74% of light in the visible light region of wavelength 401 to 800 nm.
include.

The other xenon lamp has a current density of 800 A / cm ² . In the light pulse emitted from this lamp, when the total radiant energy of light in the wavelength band of 200 to 800 nm is 100%, the wavelength is 200 to 40.
About 24% of the light in the ultraviolet region of 0 nm and wavelength 401
Approximately 76% of light in the visible light region of 800 nm is contained.

Therefore, in this embodiment, the former xenon lamp is called an ultraviolet enhanced lamp, and the latter xenon lamp is called an infrared enhanced lamp.

Here, the irradiation conditions of the light pulse in this embodiment are as follows: the irradiation distance is 20 cm, and the energy density per light pulse is 0.12 J / cm ² . A fattening cow semitendin-like muscle sliced to a thickness of about 10 mm is prepared as a sample.

The change in the quality of the fattening cow semitendinous muscle was measured for five items: the pH value, the method (browning) rate, the water retention, the odor and the flavor (sensory test) of the light pulse irradiated part and the non-irradiated part. And judge from the result.

The light pulse irradiation part of the fattening cow semitendinoid muscle
One side and the other side of this portion are irradiated with a light pulse 15 times. Therefore, a sample having an irradiated part and a non-irradiated part irradiated with the light pulse from the ultraviolet enhanced lamp and a sample having the irradiated part and the non-irradiated part irradiated with the light pulse from the infrared enhanced lamp are created.

(1) Of the five items for which the above observation is made, first, the pH value is observed as follows.

First, the irradiated part and the non-irradiated part of the fattening cow semitendinous muscle irradiated with the light pulse are cut into small pieces. 5 g is taken out from each of the shreds, and 20 ml of distilled water is added thereto and homogenized. Thereafter, the homogenized product was subjected to 1 revolution at a rotation speed of 3000 revolutions / minute.
Centrifuge for 5 minutes. The pH of the resulting supernatant is measured.

As a result, the pH corresponding to the light-irradiated part and the non-irradiated part of the UV-enhanced lamp was 5.9.
Met. Further, the pH corresponding to the light pulse irradiation part and the non-irradiation part of the ultraviolet enhanced lamp was 5.7.

Therefore, it was found that the irradiation of the light pulse did not affect the pH of the meat, regardless of the current density.

(2) Next, the methation ratio is measured as follows. Metification refers to the conversion of myoglobin, a chromoprotein in muscle, to metmyoglobin. The color changes to brown due to methotization.

The fattening cow semitendinosus muscle irradiated with light pulses from the ultraviolet-enhanced lamp and the infrared-enhanced lamp is sliced into small pieces, and 10 g each is taken out. Then, 50 ml of cooled distilled water was added thereto and mixed, and then, at a temperature of 4 ° C., 30 ml.
Leave for a minute to extract the pigment in the muscle tissue. Then 4 ℃
Centrifugation is performed for 15 minutes at a rotation speed of 8000 rpm while maintaining the temperature. The resulting supernatant is filtered using 5B filter paper. The filtrate thus obtained was adjusted to pH 6.8 using a 1N aqueous sodium hydroxide solution.
Prepared between ~ 7.0. Then, 503 nm of this liquid
And the absorbance at a wavelength of 540 nm. Then, the methation ratio is calculated from the ratio of these absorbances.

The storage temperature of the sample fattening cow semitendinal muscle was:
The temperature is set to 17 ° C. for the ultraviolet enhanced lamp. Further, the temperature is set to room temperature for the infrared enhanced lamp.

When a UV-enhanced lamp is used, the measurement of the methoxide ratio is performed immediately after the irradiation with the light pulse and after 48 hours from the irradiation. When an infrared-enhanced lamp is used, the irradiation is performed immediately after irradiation of a light pulse and after 24 hours have passed from irradiation.

The values of the calculated methionization rate are shown in Tables 5 and 6 below together with the methation rate values when no light pulse is irradiated.
Shown in

Table 5 shows the methoxide conversion rate when an ultraviolet enhanced lamp was used. Table 5 shows, as comparative examples, the value of the methoxide ratio when no light pulse is irradiated and the value of the methoxide ratio when an ultraviolet lamp is used. Table 6 shows the methoxide conversion rate when an infrared enhanced lamp is used.

[0173]

[Table 5]

[0174]

[Table 6]

According to Table 5, the methation rate immediately after irradiating the fattening cattle semitendinosus muscle with a light pulse from the ultraviolet enhanced lamp was 25.
%Met. Then, the metformation ratio at the time point when 48 hours had elapsed after the irradiation with the light pulse was 45%. On the other hand, when no light pulse is applied, the meth- odization rate was 28%, but has increased to 69% after 48 hours. In addition, when a conventional ultraviolet lamp was used, the methazation ratio was 22% immediately after the light pulse irradiation, whereas
After a lapse of 8 hours, the methoxide conversion rate is 70%.

Next, according to Table 6, the methionation rate immediately after irradiating the fattening cattle semitendinous muscle with a light pulse from the infrared enhanced lamp was 8%. Then, after irradiating the light pulse, 24
At the time when the time had elapsed, the methation ratio was 12%. On the other hand, in the case of the sample not irradiated with the light pulse, the initial 8
% Had increased to 18% after 24 hours.

In the case of using an ultraviolet-enhanced lamp, the methazation rate of the sample is increased by 20% as compared with that immediately after the irradiation. On the other hand, in the non-irradiated part, the degree of increase of the
1%. When an ultraviolet lamp was used, the degree of increase in the methazation rate was 48%. Therefore, it was found that the progress of methotization was suppressed by irradiation with the ultraviolet enhancing lamp, that is, the fading could be suppressed. In addition, since ultraviolet lamps work to promote methotmetrization, whereas UV-enhanced lamps suppress methotmetration, the color tone holding effect by suppressing methotmetration is equivalent to that of conventional ultraviolet lamps. It was found that this was a unique action and effect that could not be obtained from a sterilizer.

When the infrared-enhanced lamp was used, the methoxide conversion rate of the sample was increased by 4% as compared with that immediately after the irradiation. On the other hand, in the non-irradiated portion, the degree of increase in the
6%. Therefore, it was found that the progress of methotization can be suppressed even in the infrared enhanced lamp.

Therefore, the irradiation of the light pulse emitted from the sterilizing apparatus of the present invention can suppress the progression of the formation of myoglobin in the fattening cow semitendinosus muscle. It is considered that the same action and effect can be obtained for fish such as tuna and bonito containing myoglobin in muscle tissue.

(3) Next, the water retention of the fattening cattle semitendinous muscle irradiated with the light pulse is observed.

For the measurement of water retention, 3 g each of 5 fattening cattle semitendinosus muscles, for example, to which light pulses have been irradiated are collected. After sandwiching these pieces with different filter papers, using a rheometer (manufactured by San Kagaku), 10 kg
And hold for 60 seconds. As a result, the ratio of the amount of extruded water that has exuded is measured.

As a result, the water content of the fattening cow semitendinous muscle without irradiation with light pulses was 84.7% by weight, and the water content of fattening cow semitendinous muscle irradiated with light pulses using an ultraviolet enhanced lamp was obtained. Is 88.1% by weight, and the water content of the fattening cow semitendinosus muscle irradiated with a light pulse using an infrared enhanced lamp is 86.9.
% By weight.

Therefore, it was found that irradiation of light pulses from the sterilizing apparatus of the present invention hardly affected the water retention of food.

(4) Next, the odor of the fattening cow semitendinosus muscle irradiated with the light pulse is observed.

The method of measuring the odor is as follows. First, 30 g of fattening cow semitendinosus muscle irradiated with a light pulse is collected. Next, this is put in a bag, deaerated and sealed, and then heated at a temperature of 70 ° C. for 90 minutes. After that, an odor meter (manufactured by Riken Keiki)
The odor is measured using.

Here, the odor of the non-irradiated portion is set to 100. As a result, the odor of the portion irradiated with the light pulse from the ultraviolet enhanced lamp was 77.9. The odor of the part irradiated with the light pulse from the infrared enhanced lamp was 9%.
6.0.

Therefore, it was found that the odor of the portion irradiated with the light pulse was suppressed. In particular, the effect of suppressing the odor in the portion irradiated with the light pulse from the ultraviolet enhanced lamp was high.

(5) Next, a sensory test is performed on the fattening cow semitendinosus muscle irradiated with the light pulse. The sensory test in this example was performed by randomly sampling 14 fattened beef semitendinosus muscles exposed to light pulses and tasting them in a salad oil and decocted in hot water. Will be

Table 7 below shows the results of the evaluation.

[0190]

[Table 7]

First, when the fattening cow semitendinoid muscle was fried,
Those that were not irradiated with the light pulse had a bad smell of meat, whereas those that were irradiated with the light pulse were often evaluated as having no or light odor.

Next, when the fattening cow semitendinous muscle was bathed in water, 50% to 60% of the respondents answered that there was no difference in taste and odor between those irradiated with light pulses and those not irradiated. Met. As another opinion, those who irradiated the light pulse of the ultraviolet-enhanced lamp had no odor, and the taste of the meat itself was felt more rich. In addition, the person irradiated with the light pulse had a strong meat-like taste, but when using the UV-enhanced lamp, a slight roughness was felt. In addition, there was an opinion that when an infrared enhanced lamp was used, it felt somewhat hard.

Therefore, it was found that irradiation of the light pulse emitted from the sterilizing apparatus of the present invention did not adversely affect the sensory characteristics (eg, taste and smell) of the food. In addition, by performing the sterilization treatment using the sterilization apparatus of the present invention, for unpackaged unheated food,
It was found that it did not adversely affect the taste and odor of the food and had an effect of further suppressing odor.

<Eighth Embodiment> As an eighth embodiment, unpackaged seafood is sterilized by using the sterilizer of the present invention, and a change in the quality of the seafood after irradiation with light pulses is examined. . In this example, the current density is 1000 A /
using a UV enhanced lamp cm ^2. The irradiation condition of the light pulse is such that the irradiation distance is 20 cm and the energy density per light pulse is 0.12 J / cm ² . Then, one side and the other side of the sample are irradiated with light pulses 15 times each. As a sample, in this example:
Prepare the body muscles of the bluefin and yellowfin tuna, respectively. For bluefin tuna and yellowfin tuna, a frozen product sliced to a thickness of about 10 mm is naturally thawed and used.

First, the odor is measured. 30 g is collected from the body muscle of the bluefin tuna irradiated with the light pulse. The sample is put in a bag, degassed, and sealed. Then, the odor in the bag is measured using an odor meter (RIKEN KEIKI).

The odor was measured without irradiation, with a light pulse from a UV-enhanced lamp, immediately after irradiation with a light pulse from an ultraviolet lamp, or with a UV-enhanced lamp. 5 days after irradiation of the light pulse, and 5 days after irradiation of the light pulse from the ultraviolet lamp.

As a result, assuming that the odor of the non-irradiated light pulse was 100, the odor immediately after the irradiation of the light pulse from the ultraviolet enhanced lamp was 88.5. Further, the odor immediately after the irradiation of the light pulse from the ultraviolet lamp was 96.3. After 5 days from the irradiation of the light pulse from the ultraviolet enhancing lamp, the odor was 97.9.
Met. The odor was 117.2 after 5 days from the irradiation of the light pulse from the ultraviolet lamp.

As described above, the odor of the body muscles of the bluefin tuna irradiated with the light pulse from the ultraviolet enhancing lamp is suppressed not only immediately after the light pulse irradiation but also after storage for 5 days after the irradiation. Moreover, it turned out that the odor control effect is higher than the case where an ultraviolet lamp is used.

Next, using the body-side muscle of yellowfin tuna as a sample, the methionization rate is measured.

The body muscle of the yellowfin tuna, which has been irradiated with the light pulse from the ultraviolet enhancing lamp, is cut into small pieces using a food processor, and 20 g of each is collected. After adding 50 ml of cooled distilled water to the collected one and mixing, the mixture was allowed to stand at 4 ° C. for 30 minutes to extract the pigment in the muscle tissue, and 1N
PH 6.8 to 7.0 using an aqueous sodium hydroxide solution.
Prepare during Then, while maintaining the temperature of 4 ℃,
Centrifuge at 8000 rpm for 15 minutes. The resulting supernatant is filtered using 5B filter paper. 503 nm and 540 nm of the filtered filtrate
The absorbance of light having a wavelength of is measured. Then, the methation ratio is calculated from the ratio of these absorbances.

The storage temperature of the sample tuna is 5 ° C. The measurement of the methoxide ratio is performed immediately after the irradiation with the light pulse and after 5 hours from the irradiation.

Table 8 below shows the calculated values of the metformation ratio together with the values of the metformation ratio when no light pulse was irradiated and the values of the metformation ratio when an ultraviolet lamp was used.

[0203]

[Table 8]

According to Table 8, the methazation rate immediately after irradiating the yellowfin tuna with the light pulse from the ultraviolet enhanced lamp was 39%.
Met. The metformation ratio at the time when 5 hours had elapsed after the irradiation with the light pulse was 39%.

On the other hand, the methoxide conversion rate of the portion not irradiated with the light pulse was 45% at first, but became 43% after 5 hours.

The methionization rate immediately after irradiating the yellowfin tuna with the light from the ultraviolet lamp was 43%, but after 5 hours, it was 46% and increased by 3%.

Thus, when the ultraviolet-enhanced lamp was used, the degree of increase in the methazation ratio did not change even after 5 hours from the irradiation of the light pulse, whereas the ultraviolet lamp was used. In this case, the degree of increase of the methoxide ratio after 5 hours from the irradiation was 3%.

Therefore, while the light from the ultraviolet lamp promotes methotmetrification, the light pulse from the ultraviolet-enhanced lamp contains light having the wavelength of the ultraviolet lamp, despite the fact that it contains light of the wavelength of the ultraviolet lamp. Has been suppressed. This action is an action that cannot be obtained with a sterilizer having an ultraviolet lamp, and can be said to be an action unique to the sterilizer of the present invention.

As described above, by performing the sterilization treatment using the sterilization apparatus of the present invention, it is possible to suppress the fading of the pigment in the muscle of the fish and shellfish and the odor.

<Ninth Embodiment> As a ninth embodiment, the sterilizing effect of microorganisms by the sterilizing apparatus of the present invention will be examined.

In this embodiment, the xenon lamp is
Two types of lamps are used: an ultraviolet enhanced lamp having a current density of 1000 A / cm ² and an infrared enhanced lamp having a current density of 800 A / cm ² .

In a test for examining the bactericidal effect of the ultraviolet-enhanced lamp, a gram-negative bacterium, Escherichia coli ATCC112, was used as a microorganism.
29), Gram-positive Bacillus subtilis (Bacillus satilis (B
acillus subtillis) ATCC9372) and two lactic acid bacteria (Lactbacillus plantarum).
arum) JCM1149T and Weissela Viridescence (We
Use issella viridescens) JCM1174T). In addition, a Bacillus subtilis spore (Eiken Chemical: Bacillus subtilis spore solution) which is a bacterial spore is used. As fungi, black mold (Aspergillus niger ATCC 16404) and yeast (Saccharomyces cerviger)
evisiae) JCM7255T) is used.

In a test for examining the bactericidal effect of the infrared-enhanced lamp, lactic acid bacteria (Lactobacillus plantarum), bacterial spores, Bacillus subtilis spores, and fungi, black mold and yeast were used as microorganisms. Used.

First, a microorganism is prepared.

[0215] Here, Escherichia coli, Bacillus subtilis, for two of lactic acid bacteria and yeast, respectively in the number of bacteria ¹⁰⁷ to
^Use a bacterial solution prepared in advance so as to have a concentration of ¹¹ cfu / ml. After centrifuging each bacterial solution, discard the supernatant. After adding 0.85% by weight of sterile physiological saline to the precipitated cells, the cells are washed by centrifugation. Thereafter, the supernatant is discarded, and 0.85% by weight of sterile physiological saline is added to the remaining cells. This is used as a test bacterial solution. As the Bacillus subtilis spore, a commercially available bacterial solution is used. As for black mold, the prepared spore solution is used as it is as a test bacterial solution.

Each bacterial solution was further diluted 10 ¹ to 10 ¹⁰ times, and 0.1 ml of the diluted bacterial solution was uniformly spread on a flat medium prepared in a 9 cm diameter petri dish using a conical rod. You. Thereby, a test sample is obtained.

As the flat medium, a medium suitable for each microorganism is used. For example, a nutrient agar medium (manufactured by Oxoid) is used for Escherichia coli, Bacillus subtilis and Bacillus subtilis spores. GAM for two kinds of lactic acid bacteria
Use a medium (Nissui Pharmaceutical). For black mold and yeast, a potato dextrose agar medium (manufactured by Oxoid) is used.

Next, various microorganisms in the petri dish prepared as described above are irradiated with light pulses from a xenon lamp provided in the sterilizing apparatus of the present invention.

In this example, the irradiation conditions are as follows: the irradiation distance (the distance between the xenon lamp and the petri dish) is 20 cm;
0.12J energy density per light pulse irradiation
/ Cm ² and the irradiation interval is 1 second. The number of times of irradiation is 1 to 30 times.

[0220] The test sample that has been irradiated with the light pulse is immediately cultured in an incubator.

The culturing conditions are, for example, 3 for E. coli.
Incubate for 24 hours at a temperature of 7 ° C. Bacillus subtilis and Bacillus subtilis spores are cultured at a temperature of 30 ° C. for 24 hours. Lactic acid bacteria and yeast are cultured at a temperature of 30 ° C. for 48 hours, and black mold is cultured at a temperature of 24 ° C. for 48 to 72 hours.

Then, after counting the number of colonies appearing on the flat medium, the survival rate is calculated.

The results are shown in FIGS. 17 to 27 as characteristic diagrams of the survival rate with respect to the number of light pulse irradiations. FIG.
FIG. 23 is a characteristic diagram of each microorganism when an ultraviolet enhanced lamp is used. FIGS. 24 to 27 are characteristic diagrams of each microorganism when an infrared-enhanced lamp is used. Each figure is
The horizontal axis shows the number of irradiations (times), and the vertical axis shows the survival rate (%).

FIG. 17 is a characteristic diagram of E. coli. According to FIG. 17, the survival rate of Escherichia coli can be reduced to about 1 × 10 ⁻³ % (0.0001%) by irradiation of three light pulses. About 1 × 10 for 30 irradiations
^{A -6} % survival rate.

FIG. 18 is a characteristic diagram of Bacillus subtilis. According to FIG. 18, the survival rate of Bacillus subtilis can be reduced to about 1 × 10 ⁻⁶ % by five light pulse irradiations.

FIG. 19 is a characteristic diagram of Bacillus subtilis spores. According to FIG. 19, irradiation of the light pulse four times gives
The survival rate of Bacillus subtilis spores can be 1%. Then, by 30 irradiations, the survival rate can be reduced to 0.1%.

FIG. 20 is a characteristic diagram of lactic acid bacteria (Lactobacillus plantarum). According to FIG. 20, the survival rate of lactic acid bacteria (Lactobacillus plantarum) can be reduced to about 1% by irradiation of three light pulses, and 1 × 10 ⁻⁴ % after 30 irradiations. The following survival rates can be achieved.

FIG. 21 is a characteristic diagram of lactic acid bacteria (Vaicela viridescence). According to FIG. 21, it is possible to reduce the survival rate of lactic acid bacteria (Vaicela viridescence) to about 1 × 10 ⁻⁴ % by irradiating five light pulses.

FIG. 22 is a characteristic diagram of black mold. According to FIG. 22, the survival rate of black mold can be reduced to about 5% by irradiating the light pulse 30 times.

FIG. 23 is a characteristic diagram of yeast.
According to FIG. 23, the survival rate of the yeast can be reduced to about 1 × 10 ⁻³ % by irradiating 10 light pulses.

Therefore, in the sterilizing apparatus using the ultraviolet enhanced lamp, a good sterilizing effect was obtained for all the microorganisms tested.

Referring to FIGS. 17 to 23, when the light pulse was irradiated five times, the lactic acid bacteria had the highest bactericidal effect, followed by Escherichia coli, Bacillus subtilis, yeast, Bacillus subtilis spores, and black mold. The effect was high. In addition, the light pulse is set to 10
When irradiated twice, the bactericidal effect is higher in the order of lactic acid bacteria, Bacillus subtilis, Escherichia coli, yeast, Bacillus subtilis spores, and black mold. Further, when the light pulse was irradiated 30 times, the bactericidal effect was higher in the order of Escherichia coli, lactic acid bacteria, Bacillus subtilis, yeast, Bacillus subtilis spores, and black mold.

Next, reference is made to FIGS. 24 to 27 which are characteristic diagrams using an infrared enhanced lamp.

FIG. 24 is a characteristic diagram of Bacillus subtilis. According to FIG. 24, the survival rate of Bacillus subtilis can be reduced to about 1% by five light pulse irradiations. With 30 irradiations, a survival rate of about 0.1% can be achieved.

FIG. 25 shows lactic acid bacteria (Lactobacillus
FIG. According to FIG.
For example, the irradiation rate of lactic acid bacteria is about 1 ×
10 ^-Four%. Irradiate 10 more times
1 × 10^-6% Survival can be achieved.

FIG. 26 is a characteristic diagram of black mold. According to FIG. 26, irradiation of the light pulse 20 times
The survival rate of black mold can be reduced to about 0.1%.
With 30 irradiations, the survival rate is 0.1% or less.

FIG. 27 is a characteristic diagram of yeast.
According to FIG. 27, the survival rate of the yeast can be reduced to 1 × 10 ⁻⁴ % or less by irradiating the light pulse ten times.
Further, by 30 irradiations, the survival rate can be reduced to 1 × 10 ⁻⁵ % or less.

Therefore, it was found that the use of the infrared-enhanced lamp provided a certain degree of bactericidal effect against the three types of microorganisms tested.

Referring to FIGS. 24 to 27, when the infrared-enhanced lamp is used, the bactericidal effect is obtained in the order of lactic acid bacteria, yeast, Bacillus subtilis spore, and black mold regardless of the number of light pulse irradiations. Was high.

In addition, the germicidal effect of the same microorganism was higher in the apparatus using the infrared enhanced lamp.

According to the document "Handbook of Applied Sterilization and Eradication, Science Forum, 1985", the resistance of Escherichia coli, Bacillus subtilis, Bacillus subtilis spores, black mold, and yeast to ultraviolet light is as follows. Bacillus subtilis,
It is known that E. coli is higher in order.

Therefore, the order in which the levels of resistance to ultraviolet light are high corresponds to the exact reverse of the order of the bactericidal effect described above. That is, the higher the resistance to ultraviolet light, the lower the bactericidal effect. Therefore, it is suggested that the bactericidal effect of the sterilizing apparatus of the present invention in this embodiment is the effect of ultraviolet sterilization.

Here, a K-type thermocouple is installed at a position where the irradiation distance of each of the ultraviolet enhanced lamp and the infrared enhanced lamp is 20 cm. Then, an optical pulse is applied to the K-type thermocouple. FIG. 28 shows the relationship between the number of light pulse irradiations and the temperature change of the K-type thermocouple at this time.

FIG. 28 shows the number of irradiations (times) on the horizontal axis.
The vertical axis indicates the temperature rise (Δ ° C.). And
A curve with a black circle indicates the characteristics of the ultraviolet enhanced lamp, and a curve with a cross indicates the characteristics of the infrared enhanced lamp.

According to FIG. 28, the number of light pulse irradiations is three.
Up to the same time, a similar temperature increasing tendency is observed in both the ultraviolet enhanced lamp and the infrared enhanced lamp. When the number of irradiations is four or more, the degree of temperature rise is larger in the light pulse irradiation by the ultraviolet enhanced lamp than in the light pulse irradiation by the infrared enhanced lamp.

The light pulse from the ultraviolet enhanced lamp contains about 2% more light in the ultraviolet wavelength region than the light pulse from the infrared enhanced lamp. For this reason, the degree of temperature rise is considered to be smaller than in the case of the infrared enhanced lamp. However, referring to FIG. 28, the degree of temperature rise is larger in the case of the ultraviolet enhanced lamp. Therefore, it is considered that the wavelength other than the ultraviolet light contributes to the temperature rise in the light pulse irradiation using this lamp. In addition, comparing the sterilizing effect of the ultraviolet-enhanced lamp and the infrared-enhancing lamp, the infrared-enhancing lamp has a higher sterilizing effect according to the above test. Therefore, in the sterilization treatment using the xenon lamp, it is considered that not only sterilization by ultraviolet rays but also sterilization by heating greatly influences.

Therefore, in the sterilization treatment using the sterilization apparatus of the present invention, it is considered that a sterilization effect can be obtained by both the action of ultraviolet sterilization and the action of sterilization by heating.

[0248]

As is apparent from the above description, the sterilizing apparatus of the present invention includes a xenon lamp, a lamp house having a cooling fan, and a power supply. Then, the integrated energy density of the light pulse emitted from the xenon lamp is set to a value within the range of 0.5 to 10 J / cm ² .

By using such a sterilizing apparatus, it is possible to perform a sterilizing treatment without deteriorating the quality of food (especially, deterioration of flavor and color tone). In addition, an increase in the surface temperature of the food after sterilization as compared to before sterilization can be suppressed to 5 ° C. or less. Sterilization by this sterilizer has two sterilizing effects, ultraviolet sterilization and instantaneous heat sterilization. Therefore, when sterilizing packaged food, if the ultraviolet ray transmittance of the packaging material is at least 10% and the thickness of the packaging material is 40 μm or less, sterilization can be performed effectively. . Furthermore, even when the thickness of the packaging material exceeds 40 μm, sterilization can be effectively performed by increasing the integrated energy density of the light pulse. Therefore, the restriction on the packaging material can be eased as compared with the related art.

Further, when the meat and fishery products and the marine foods are treated using this sterilizing apparatus, the effects of sterilizing, suppressing discoloration and suppressing odor can be obtained.

The sterilizing apparatus can sterilize bacteria and their spores and fungi and their spores.

[Brief description of the drawings]

FIG. 1 is a photograph of E. coli before light pulse irradiation.

FIG. 2 is a photograph of Escherichia coli after irradiation with a light pulse 30 times.

FIG. 3 is a photograph of a fungal spore before light pulse irradiation.

FIG. 4 is a photograph of fungal spores after 30 light pulse irradiations.

FIG. 5 is a photograph of a yeast before light pulse irradiation.

FIG. 6 is a photograph of a yeast after irradiation of a light pulse 30 times.

FIG. 7 is a photograph of a section of clark sausage before light pulse irradiation.

FIG. 8 is a photograph of a cross section of clark sausage after a total of 30 light pulse irradiations.

FIG. 9 is a photograph of a section of a fattening cow semitendinosus muscle before light pulse irradiation.

FIG. 10 is a photograph of a cross section of a fattening cow semitendinosus muscle after a total of 30 light pulse irradiations.

FIG. 11 is a diagram showing the survival rate of lactic acid bacteria in each sample of the third example.

FIG. 12 is a diagram showing the survival rate of lactic acid bacteria for explanation of the fourth embodiment.

FIG. 13 is a lightness change characteristic diagram of pork for explaining the sixth embodiment.

FIG. 14 is a graph showing lightness change characteristics of beef, used for explaining the sixth embodiment.

FIG. 15 is a graph showing a change in color saturation of pork for explaining the sixth embodiment.

FIG. 16 is a graph showing beef saturation change characteristics for explaining the sixth embodiment.

FIG. 17 is a diagram illustrating the bactericidal effect of Escherichia coli when an ultraviolet-enhanced lamp is used for explaining the ninth embodiment.

FIG. 18 is a diagram illustrating the bactericidal effect of Bacillus subtilis when an ultraviolet-enhanced lamp is used for explaining a ninth embodiment.

FIG. 19 is a diagram illustrating the bactericidal effect of Bacillus subtilis spores when an ultraviolet-enhanced lamp is used for the description of a ninth embodiment.

FIG. 20 illustrates a lactic acid bacterium (Lactobacillus plantaru) using an ultraviolet-enhanced lamp, which is described in the ninth embodiment.
It is a figure which shows the sterilization effect of m).

FIG. 21 illustrates a lactic acid bacterium (Weissella viridescens) using an ultraviolet-enhanced lamp, which is used to explain the ninth embodiment.
It is a figure which shows the sterilization effect of.

FIG. 22 is a diagram illustrating the bactericidal effect of black mold when an ultraviolet-enhanced lamp is used for explaining the ninth embodiment.

FIG. 23 is a diagram illustrating the bactericidal effect of yeast when an ultraviolet-enhanced lamp is used, for explanation of a ninth embodiment.

FIG. 24 is a diagram illustrating the bactericidal effect of Bacillus subtilis spores when an infrared-enhanced lamp is used for explaining the ninth embodiment.

FIG. 25 illustrates a lactic acid bacterium (Lactobacillus plantaru) using an infrared-enhanced lamp for explaining the ninth embodiment.
It is a figure which shows the sterilization effect of m).

FIG. 26 is a diagram illustrating the bactericidal effect of black mold when an infrared enhanced lamp is used for explaining the ninth embodiment.

FIG. 27 is a diagram illustrating the bactericidal effect of yeast when an infrared-enhanced lamp is used, for explanation of a ninth embodiment.

FIG. 28 is a characteristic diagram showing a relationship between the number of light pulse irradiations and a change in the temperature of a K-type thermocouple for the description of a ninth embodiment;

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) A61L 2/10 A23B 4/00 B (72) Inventor Shuji Yoshikawa 589-4 Bunkyodaidorimachi, Ebetsu, Hokkaido Inside the Food Processing Research Center (72) Inventor Toshiharu Kanno 2-1 Egan vs. Goose Hokkaido Hokkaido Electric Power Company Research Institute (72) Inventor Yoshiaki Doi 2-1 Ebetsu City vs. Goose Hokkaido Hokkaido Electric Power Company Research Institute F Term (reference) 4B021 LA01 LA41 LP06 LP10 LT03 LW03 LW04 4C058 AA21 BB02 BB06 DD03 KK02 KK05 KK21

Claims (7)

[Claims] 1. A food sterilizing apparatus comprising a xenon lamp, a lamp house having a cooling fan, and a power supply unit, wherein the integrated energy density of a light pulse applied to the surface of the food is 0.5 J / cm ² or more. A food sterilizing apparatus characterized in that the value is within a range of 10 J / cm ² or less. 2. The food sterilizer according to claim 1, wherein the current density input to the xenon lamp is 100 A.
An apparatus for sterilizing food, wherein the energy density of the light pulse is adjusted by changing the energy density within a range of not less than 1 / cm ^{2 and not} more than 10000 A / cm ² . 3. The food sterilizer according to claim 1, wherein the current density input to the xenon lamp is 800A.
An apparatus for sterilizing food, wherein the energy density of the light pulse is adjusted by changing the energy density within a range of not less than / cm ^{2 and not} more than 2070 A / cm ² . 4. The food sterilizing apparatus according to claim 1, wherein the food is irradiated with ultraviolet light and heated simultaneously and instantaneously. Sterilizer. 5. The food sterilizing apparatus according to any one of claims 1 to 4, wherein, in using the apparatus, sterilizing a food packaged with a packaging material among the foods. A food sterilizing apparatus characterized in that sterilization is possible regardless of the material of the packaging material. 6. The food sterilizing apparatus according to any one of claims 1 to 4, wherein when the apparatus is used to sterilize a meat product and a marine product among the food, sterilization and fading are performed. An apparatus for sterilizing food, wherein the effects of suppression and odor suppression are obtained. 7. An apparatus for sterilizing food according to claim 1, wherein said apparatus is used to produce bacteria and spores of said bacteria, and fungi and spores of said fungi. An apparatus for sterilizing food, wherein sterilization of food is possible.