JP5386752B2 - Method and apparatus for measuring the number or amount of microorganisms - Google Patents

Description

  The present invention relates to a method and apparatus for measuring the number or amount of microorganisms, and more particularly to a method and apparatus for measuring the number or amount of microorganisms such as bacteria adhering to the surface of an object to be measured.

  When a fresh food is stored or sold, if bacteria adhere to the surface, the food is contaminated by the bacteria, the freshness is lowered, and it eventually decays. Therefore, it is extremely important to know how much bacteria adhere to the surface of fresh food in order to know the freshness of fresh food or the state of spoilage.

  In general, fresh food products have liquid components that leached from the inside and adhere to the surface of the fresh food, and bacteria that exist in the atmosphere enter the liquid portion of the surface and grow, so that the surface of the food is contaminated with bacteria. It is soiled. As the number of bacteria increases, the bacteria eventually enter the food, destroying the tissue and causing decay. Although the attachment of minute bacteria is considered to impart umami to foods and the like, the bacteria cause harm to foods and / or accelerate their decay.

  The measurement of the number of bacteria adhering to the surface of a conventional food has been performed as follows. That is, in the case of the culture method, the surface of the food is wiped with a cotton swab, and if bacteria are present on the surface of the food, the bacteria are transferred into the cotton swab and the swab is placed in a sterile solvent. Soak the bacteria collected in the solvent. Then, the solvent mixed with bacteria is cultured in a medium. For example, when a standard agar medium is used, a solvent that seems to contain the above bacteria is dropped into this medium and cultured at 35 ° C. for 48 hours. Thereafter, the number of bacteria within a certain range is counted at a predetermined magnification under an optical microscope, thereby measuring the number or amount of bacteria.

  The conventional method for measuring the number or amount of bacteria attached to the surface of food is to wipe the bacteria attached to the surface of the food with a cotton swab and immerse in a sterilized solvent, and place this solvent in the medium. Although it is dropped and cultured, and measured with an optical microscope, it is not only time consuming to operate but also cumbersome. Therefore, for example, for foods sold in supermarkets, etc., it is simple and surely and quickly knows how much the food stored or sold is contaminated by bacteria, or whether the bacteria are decaying. There was a problem that could not be.

JP 2005-534336 A

  The subject of this invention is providing the measuring method and measuring apparatus which can measure the number or quantity of microorganisms, such as bacteria adhering to the surface of a to-be-measured object rapidly.

  Another object of the present invention is to provide a method and apparatus for measuring the number or amount of microorganisms such as bacteria adhering to the surface of an object to be measured by a very simple operation.

  Another subject of the present invention is a tool, tool, container, device or the like that comes into contact with food, and the number or amount of bacteria adhering to the portion of these tool, tool, container, or device that comes into contact with food can be quickly and The object is to provide a method and apparatus for simple measurement.

  The above-described problems and other problems of the present invention will be made clear by the technical idea of the present invention described below and the embodiments thereof.

The main invention of the present application is a method for measuring the number or amount of microorganisms adhering to the surface of an object to be measured.
A method for estimating the number or amount of the microorganisms using a change in spectral characteristics of the object to be measured accompanying a decrease in the amount of oxygen supplied to the object to be measured by the microorganism layer attached to the surface of the object to be measured ,
When the oxygen supply amount is reduced by the microorganism layer formed by the microorganisms attached to the surface of the object to be measured, metmyoglobin produced by oxidation of oxymyoglobin derived from the object to be measured or attached to the object to be measured is reduced to myoglobin. The present invention relates to a method for measuring the number or amount of microorganisms that change and utilize the change in spectral properties of the myoglobin .

Here, the object to be measured may be food, and the microorganism may be bacteria, and the number or amount of bacteria attached to the food may be measured. The object to be measured may be meat, and the microorganism may be a bacterium, and the number or amount of bacteria attached to the meat may be measured. In addition, the number or amount of bacteria attached to a portion of the tool, tool, container, or device that comes into contact with food may be measured. Moreover, you may irradiate the light of the wavelength of a visible region. Moreover, you may irradiate the light of a wavelength whose secondary differential value is 578 +/- 5nm.

The main invention related to the measuring device is a light emitting means for projecting light in a predetermined wavelength range,
A light receiving means for receiving light emitted by the light emitting means and modulated according to the number or amount of microorganisms attached to the surface of the object to be measured;
A computing means for computing the number or amount of microorganisms adhering to the surface of the object to be measured from the light intensity by the light receiving means;
Output means for outputting a value computed by the computing means;
When the oxygen supply amount is reduced by using the change in the spectral characteristics of the measurement object due to the decrease in the oxygen supply amount to the measurement object due to the microorganism layer attached to the surface of the measurement object. The present invention relates to a measuring apparatus for measuring the number or amount of microorganisms utilizing the spectral characteristics of myoglobin by reducing meteomyoglobin produced by oxidation of oxymyoglobin originating from or adhering to an object to be measured and reducing it to myoglobin. .

Here, you may have an input means to input the kind of to-be-measured object. The calculation means may calculate the number or amount of microorganisms with reference to a database storing characteristic values corresponding to the type of the object to be measured. In addition, the spectral characteristics associated with the projection of light by the light emitting means in the state where the microorganisms on the surface of the object to be measured are not adhered are measured in advance, and the measured spectral characteristics are also measured. Corrections may be made accordingly. The light emitting means may emit light having a wavelength of 578 ± 5 nm.

The main invention of the present application is a method for measuring the number or amount of microorganisms adhering to the surface of an object to be measured, and a reduction in the amount of oxygen supplied to the object to be measured by a microorganism layer adhering to the surface of the object to be measured. A method for estimating the number or amount of the microorganisms by using a change in spectral characteristics of the object to be measured, wherein an oxygen supply amount is reduced by a microorganism layer formed by microorganisms attached to the surface of the object to be measured. Measurement of the number or amount of microorganisms utilizing the change in the spectral properties of the myoglobin by reducing the metmyoglobin produced by oxidation of the oxymyoglobin derived from or adhering to the measurement object into the myoglobin. It is a thing.

  Therefore, according to the method for measuring the number or amount of such microorganisms, meat-derived oxymyoglobin is obtained by reducing the amount of oxygen supplied to the object to be measured, in particular, the meat layer that is blocked by the microorganism layer formed on the surface of the meat. The metmyoglobin produced by oxidation of is further reduced to produce myoglobin. Such myoglobin exhibits unique spectral characteristics, and it is possible to estimate the number or amount of microorganisms from the thickness of the microbial layer covering the surface of the meat using this spectral characteristic. Or it becomes possible to measure the state of contamination more reliably.

The invention relating to the measuring apparatus includes a light emitting means for projecting light in a predetermined wavelength region, and light emitted by the light emitting means and modulated according to the number or amount of microorganisms attached to the surface of the object to be measured. Light receiving means for receiving light, computing means for computing the number or amount of microorganisms adhering to the surface of the object to be measured from the intensity of light by the light receiving means, and output means for outputting the value computed by the computing means And using a change in spectral characteristics of the object to be measured due to a decrease in the amount of oxygen supply to the object to be measured by the microorganism layer attached to the surface of the object to be measured, measured from or oxymyoglobin to adhere to the object to be measured is to metmyoglobin generated in the reduction oxidation changed to myoglobin, measure the number or amount of microorganisms utilize the spectral characteristics of the myoglobin In which was to so that.

  Therefore, according to the measuring apparatus for measuring the number or amount of such microorganisms, light of a predetermined wavelength range is irradiated on the surface of the object to be measured by the light emitting means, and the intensity depends on the number or amount of microorganisms attached to the surface. It is possible to estimate the number or amount of microorganisms adhering to the surface of the object to be measured from the intensity received by light modulated by changing etc., and the estimated value obtained by this calculation Provides a measuring device that can measure the number or amount of microorganisms adhering to the surface of an object to be measured instantaneously, thereby enabling the measurement of microorganisms by an extremely simple and rapid method. become able to.

It is a structural formula which shows the molecular structure of ATP. It is a principal part expanded sectional view for demonstrating the state in which bacteria generate | occur | produce on the surface of a to-be-measured object. It is a flowchart of the experiment which establishes a theory. It is a graph which shows the change of the amount of ATP with respect to holding time. It is a graph which shows the change of the number of bacteria with respect to retention time. It is a graph which shows the correlation with the quantity of ATP, and the number of bacteria. It is a graph which shows the spectral reflection characteristic with respect to irradiation light. It is the graph which converted the reflective characteristic shown in FIG. 7 into the light absorption characteristic, and subtracted the absorption characteristic of holding time 0h. It is a graph which shows the correlation with a light absorbency and the amount of ATP. It is a graph which shows the change of the reflectance second derivative with respect to irradiation light. It is a graph which shows the correlation with a 318 nm reflectance secondary differential value and the quantity of ATP. It is a graph which shows the correlation with a 578 nm reflectance secondary differential value and the number of general viable bacteria. It is a front view which shows the structure of a freshness measuring apparatus. It is a perspective view of the use condition of the freshness measuring apparatus. It is a block diagram which shows the system configuration | structure of a freshness measuring apparatus. It is a flowchart which shows the measurement operation | movement by a freshness measuring apparatus. It is a flowchart which shows the holding | maintenance operation | movement of the calibration data for correction | amendment. It is a flowchart which shows the measurement operation | movement by the freshness measuring apparatus including the correction | amendment by calibration data.

  The present invention will be described below with reference to embodiments shown in the drawings. The first embodiment of the present invention uses ATP (Adenosine triphosphate) to contact the surface of meat, fish, or vegetables, or the food of tools, tools, containers, and devices that come into contact with the food. The number or amount of microorganisms such as bacteria adhering to the site is measured. ATP is a substance that normally exists in a living body and releases energy necessary for maintaining the functions of plants, animals, and microbial cells, and releases energy when ATP is decomposed. That is, ATP is a high-energy substance having a molecular weight of 507.2 and is involved in various metabolic activities of organisms. It varies depending on the number of phosphoric acid ester-bonded to ribose shown in FIG.

  ATP with three phosphates is changed to ADP (Adenosine diphosphate) by losing one of the phosphates, and AMP (Adenosine monophosphate: monophosphate) when one more phosphate is lost. )become. When ATP is changed to ADP, energy of 7.3 Kcal is released. Such energy is used to maintain cell function.

  On the other hand, it is known that the luminescence of microorganisms changes depending on the amount of ATP. This change in luminescence is a luciferin luciferase reaction. This is similar to firefly luminescence and is a reaction that depends on the amount of ATP. When luciferin reacts with ATP, it becomes adenylate luciferin, and this adenylate luciferin and oxygen are decomposed by oxidative decarboxylation in the presence of the enzyme luciferase as shown below, and are obtained by the process of reaction. Part of the energy appears as a reaction called luminescence. Therefore, ATP can be quantified by quantifying this luminescence. The basic principle of the present invention is that the determined ATP amount corresponds to the number or amount of microorganisms from the determined ATP amount and the spectral characteristics of ATP. In addition, not only microorganisms such as bacteria but also those derived from ATP such as food in the background, by removing the amount of luminescence due to ATP derived from the background, ATP derived from microorganisms The amount can be measured.

  Next, an experiment for establishing the theory of the present invention will be described. In this experiment, as shown in FIG. 2, pork is used as the device under test 20. Here, as for the pork 20 shown to FIG. 2A, the gravy 35 oozes out from the inside with progress of time, and forms a liquid film on the surface of the pork 20 by this. Then, when bacteria 36 in the air adhere to the gravy 35 and the bacteria 35 starts to grow, the surface of the pork as the object to be measured 20 is gradually fouled by the bacteria 36, and the bacteria 36 enters the pork 20 before long. And encourage the corruption.

  In this experiment, Japanese pork was obtained after 3 days of slaughter, cut into an appropriate size except for the pork streak, and stored in a sterile petri dish at 15 ° C. Then, 6 types of samples were prepared 0h (hours), 24h, 48h, 72h, 84h, and 96h after storage. In the experiment, four types are created for each type.

  The experiment shown in FIG. 3 is performed on such a sample. That is, first, a reflection spectrum is obtained by the spectroscope 45 for each type of sample. Moreover, about each sample, the surface is wiped off with the cotton swab in the state put into the petri dish. The cotton swab is pre-moistened with sterilized ultrapure water, and bacteria are collected by wiping the 4 cm × 4 cm area twice in the vertical and horizontal directions. And the tip of this cotton swab was cut off with sterilized scissors, placed in 9 cc of sterilized water and stirred thoroughly, thereby preparing a viable cell suspension. Then, the amount of luminescence of 100 μl of the sample solution of the viable cell suspension was measured with a luminometer, thereby obtaining the amount of ATP.

  Further, in order to count the number of bacteria in the above viable cell suspension, 1 cc of the sample solution was dropped on the culture plate, and then cultured at 35 ° C. for 48 hours. Then, the number of viable bacteria is counted with an optical microscope. That is, in this experiment, three data of ATP amount, viable cell count, and reflection spectrum were obtained for the above six types of pork.

  FIG. 4 shows the amount of ATP quantified with a luminometer for the above six types of pork. That is, the amount of ATP obtained by the luminometer is shown in a graph for each of the storage time after 0 h, 24 h, 48 h, 72 h, 84 h, and 96 h. As is apparent from this graph, it has been confirmed that the amount of ATP increases exponentially until the storage time of 72 h.

  FIG. 5 shows the change in the number of viable cells on the culture plate after 0 h, 24 h, 48 h, 72 h, 84 h, and 96 h after the storage time. As is apparent from this data, it has been confirmed that the viable cell count increases almost exponentially until the storage time is 72 h, and thereafter, it changes to a substantially constant value. This change is almost the same as the change in the ATP amount shown in FIG.

  FIG. 6 shows the results of examining the correlation between the ATP amount and the viable cell count when the ATP content is taken on the horizontal axis and the viable cell count is taken on the vertical axis. Here, it has been confirmed that the number of viable bacteria increases linearly as ATP increases. The correlation coefficient r of both is r = 0.98, which is a very high correlation coefficient. Here, for 6 types of pork having a storage period, data is obtained using 4 samples each, and n = 4 × 6 = 24 data.

Next, the light absorption characteristic by spectroscopic analysis will be described. FIG. 7 shows a reflection spectrum when light is irradiated by the spectroscope 45 shown in FIG. Here, since the absorbance is easier to understand than the reflectance, the relative diffuse reflectance was converted to KM (Kubermunk) absorbance by the Kubelka-Munk equation. Here, Kuberkamunk's equation means the following equation. When R is a relative reflectance, S is a scattering coefficient, and K is an absorption coefficient (proportional to the concentration), the Kubelka-Munk equation is as follows.
K / S = (1-R) ² / 2R
If the spectroscopic data is used directly here, it contains information on the pork body that constitutes the background. Therefore, in order to make analysis difficult, it is preferable to remove the amount of reflection due to the background. FIG. 8 is a KM spectrum obtained by subtracting data after 24 h, 48 h, 72 h, 84 h, and 96 h after using KM absorbance of pork after storage time 0 h as a background data, Show. As is clear from this data, it is confirmed that the absorption peak is high at a wavelength of 270 nm.

  Therefore, when the correlation between the amount of absorption at 268 nm and the amount of ATP was examined in the vicinity of the peak value of 270 nm, the value shown in FIG. 9 was obtained, and it was confirmed that there was a relatively high correlation. That is, it has been confirmed that the ATP amount can be estimated by the light absorption amount around the wavelength of 270 nm.

FIG. 10 shows the case where the light of the wavelength region from the ultraviolet region to the visible region is irradiated to pork of each storage time after storage time 0h, 24h, 36h, 48h, 60h, and 72h. The change of the second derivative value of the reflectance is shown. From this change of the secondary differential value, a high peak is detected in the wavelength region from 318 nm in addition to the above experimental value. When the correlation of the amount of ATP with respect to the secondary differential value of reflectance at this time was examined, a value of correlation coefficient r = 0.94 was obtained as shown in FIG. Therefore, the determination coefficient R ^{2 is} 0.89. Therefore, it is possible to estimate the amount of ATP and the number of general viable bacteria via this amount of ATP by irradiating light having a high correlation coefficient near 318 nm.

  As described above, it is preferable to use light of 270 nm ± 5 nm, 285 ± 5 nm, 300 ± 5 nm, 320 ± 5 nm, and 380 ± 5 nm as the wavelength for estimating the number or amount of microorganisms. It was found by. Beyond that area, an error will occur in the measured value, or alternatively, the correlation between the KM absorbance and the amount of ATP will be lowered, thereby causing an error.

  As is clear from the above experiments, the absorption wavelengths peculiar to ATP in the surface-adherent bacteria of pork were around 270 nm, 285 nm, 300 nm, 320 nm, and 380 nm. Further, a high correlation was found between the amount of ATP of bacteria on the pork surface and the number of viable bacteria. Further, a positive correlation was observed between the KM absorbance spectrum and the surface ATP amount. Accordingly, the validity of the process of predicting the amount of ATP from the diffuse reflectance spectrum and predicting the number of general viable bacteria from the amount of ATP has been confirmed.

Next, a second embodiment will be described. The spectral characteristic shown in FIG. 10 shows a peak value higher than the peak value at 318 nm, particularly at 578 nm in the visible region. Here, in particular, FIG. 10 shows the secondary differential value of the spectral reflection spectrum of the pork surface as described above, and especially at 578 nm, the secondary differential value is 0 h, 24 h, 36 h, 48 h, and 60 h after. , 72h in order. FIG. 12 shows the result of looking at the correspondence between the secondary differential value and the general viable cell count when the storage time is the above-described time. As the value of the secondary differential value decreases, the number of general viable bacteria increases, and the correlation coefficient is a value of r = −0.92. Accordingly, the determination coefficient R ^{2 is} 0.84. That is, an extremely high value was shown. Further, in the spectral characteristics, it is clear from the change in the peak in FIG. 10 that the visible region changes more significantly than the ultraviolet region.

  The reason why a high correlation was observed at 578 nm in the visible region, not the ultraviolet region, is considered to be as follows. That is, 578 nm is an absorption band unique to myoglobin and its derivatives. It captures the change in reflectivity of irradiated light due to changes in myoglobin derived from pork and the growth of microorganisms. The mechanism is as follows.

  (1) In pork immediately after slicing, myoglobin exists as oxymyoglobin. Oxymyoglobin shows a bright red color.

(2) When oxymyoglobin is oxidized in the presence of oxygen, it changes to metmyoglobin (brown). And at this time, if the microorganisms grow,
(3) A microbial layer is formed on the surface of pork. Due to the lack of oxygen supply to the pork surface by this microbial layer, a reduction reaction occurs, and metmyoglobin changes to myoglobin. Myoglobin is dark purple.

  It is understood from the correlation data shown in FIGS. 10 and 12 that the change in myoglobin accurately reflects the growth of the microorganism. That is, it has been clarified that at 578 nm, the secondary differential value of the reflectance (also the reflectance itself) shows a high correlation with the number of viable bacteria.

  Specific apparatuses for measuring the number or amount of microorganisms based on the principle of the first embodiment and the second embodiment described above are shown in FIGS. As shown in FIGS. 13 and 14, this apparatus includes a main body 10 in which a cabinet has a substantially rectangular parallelepiped shape, and a grip 11 extending downward is attached to the main body 10. The light emitter 12 is attached to the tip of the main body 10 so as to protrude forward. A light receiver 13 is attached to the lower side of the light emitter 12 and on the front side of the main body 10. A display panel 15 and an input button 16 are attached to the side of the main body 10. In contrast, an output display panel 18 is provided on the upper surface of the main body 10, and the output display panel 18 displays the result of the number or amount of microorganisms based on the reflected light received by the light receiver 13. ing.

  As shown in FIG. 14, such a measuring apparatus holds the grip 11 on the lower side of the main body 10 and pushes the measurement button 21 to emit light in a predetermined wavelength range from the light emitter 12 to be measured such as pork. 20, the reflected modulated light from the object to be measured is detected by the light receiver 13, and the number or amount of microorganisms is estimated by calculation processing from the amount of received light.

  FIG. 15 shows the system configuration of such a measuring apparatus. The light emitter 12 is connected to a drive unit 24, and the light emitter 12 is driven by the drive unit 24 to emit light in a predetermined wavelength range. I have to. The drive unit 24 is controlled by the light emission control unit 25. The light emission control unit 25 is controlled by the control CPU 26. An input operation unit 27 is connected to the control CPU 26. The input button 16 provided on the side surface of the main body 10 constitutes a part of the input operation unit.

  On the other hand, the light receiver 13 is connected to the detection unit 28 and detects light received by the light receiver 13. The detection unit 28 is connected to the calculation CPU 29. The arithmetic CPU 29 is connected to the memory 30. The memory 30 holds a database, and this database holds data indicating the relationship between the storage time and the amount of ATP or myoglobin related to various fresh foods. The arithmetic CPU 29 is connected to the display drive unit 31. The display drive unit 31 drives a display unit including the output display panel 18, and the display unit 18 outputs and displays the number or amount of the measured microorganisms.

  FIG. 16 is a flowchart showing the measurement operation by such a measuring apparatus. When actually performing the measurement, first, the type of fresh food to be measured is input by the input button 16 of the input operation unit 27 of the main body 10. The type of food includes animal food such as meat and fish or vegetable food such as vegetables. If such a type of object to be measured is input, the measurement button 21 provided on the grip 11 is subsequently pressed. Then, when the measurement button 21 is pressed, the light emission control unit 25 activates the light emitter 12 via the drive unit 24, and the light emitter 12 emits light in a predetermined wavelength range.

  Such light is applied to the object to be measured as shown in FIG. Therefore, the light receiver 13 detects the modulated light from the object 20 to be measured. Then, the reflection intensity of the light received by the light receiver 13 is detected by the detection unit 28, and the calculation CPU 29 stores the data of the corresponding measurement object from the database corresponding to the various food types registered in advance by the database 29. And the number or amount of bacteria attached to the surface of the object to be measured is calculated based on such data. The calculation result of the number or amount of microorganisms is displayed on the display unit 18 via the display driving unit 31.

  Since the series of operations shown in FIG. 16 is achieved almost instantaneously after the detection light irradiation, the number or amount of microorganisms in the object to be measured is measured in a very short time. In addition, such a measurement is performed for the degree of contamination of various animal foods and vegetable foods by bacteria according to the type of data stored in the database held in the memory 30 connected to the arithmetic CPU 29. Measurements can be made and it is possible to measure the number or amount of microorganisms in a very wide range. In addition, when measuring the number or amount of microorganisms, as shown in FIG. 14, the object to be measured 20 is simply irradiated with light from the light emitter 12 for a very short time, so that the object to be measured 20 is altered. There is no need to discard the object to be measured after measurement.

  FIG. 17 and FIG. 18 show a calculation operation in which correction is performed using calibration data. In this case, as shown in FIG. 17, the aseptic object is irradiated with detection light and reflected light is detected. Then, the reflection intensity is calculated, and the calculated value of the reflection intensity is stored in the memory 30 as calibration data.

  Next, at the time of measurement, correction is performed using calibration data as shown in FIG. That is, the type of the object to be measured is input, the inspection light is irradiated, the reflected light is detected, and the reflection intensity is calculated. Thereafter, correction is performed using the calibration data acquired by the procedure shown in FIG. 17 and held in the memory 30. Thereafter, the number of viable bacteria is calculated with reference to the database, and the calculation result is displayed on the display unit 18.

  Although the present invention has been described above with reference to the illustrated embodiments, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea of the present invention.

  For example, although the above embodiment is used for obtaining the number of bacteria attached to the surface of edible pork, the present invention is used to measure bacteria attached to the surface of other foods such as fish and vegetables or fruits. It is also possible to use it. The present invention can also be used to detect the number of attached bacteria such as tools, tools, containers, and devices that come into contact with food. For example, in a store such as a supermarket, it can be used to measure the number of bacteria attached to the surface of a knife, cutting board, display case or the like for processing food. Alternatively, it can be used to detect the number of bacteria attached to the surface of a container used for selling food. Alternatively, it can be used to detect the number of bacteria in a portion that comes into contact with food in an apparatus used for processing food in a slaughterhouse or the like. Furthermore, it can also be used to detect the number of bacteria attached to door handles, pulls, faucet faucets, and other parts in medical institutions.

  The present invention can be used to detect the number of bacteria attached to the surface of fresh food such as meat and fish.

DESCRIPTION OF SYMBOLS 10 Main body 11 Grip 12 Light emitter 13 Light receiver 15 Display panel 16 Input button 18 Output display panel 20 Object 21 Measurement button 24 Drive part 25 Light emission control part 26 Control CPU
27 Input Operation Unit 28 Detection Unit 29 CPU for Calculation
30 Memory 31 Display Drive Unit 32 Display Unit 35 Meat Juice 36 Bacteria 41 Luminometer 43 Culture Plate 45 Spectroscope

Claims (12)

In a method for measuring the number or amount of microorganisms adhering to the surface of an object to be measured,
A method for estimating the number or amount of the microorganisms using a change in spectral characteristics of the object to be measured accompanying a decrease in the amount of oxygen supplied to the object to be measured by the microorganism layer attached to the surface of the object to be measured ,
When the oxygen supply amount is reduced by the microorganism layer formed by the microorganisms attached to the surface of the object to be measured, metmyoglobin produced by oxidation of oxymyoglobin derived from the object to be measured or attached to the object to be measured is reduced to myoglobin. A method for measuring the number or amount of microorganisms that change and utilize changes in the spectral properties of the myoglobin .   2. The method for measuring the number or amount of microorganisms according to claim 1, wherein the object to be measured is food, and the microorganism is bacteria, and the number or amount of bacteria attached to the food is measured. . The number or amount of microorganisms according to claim 1 or 2, wherein the object to be measured is meat, and the microorganism is a bacterium, and the number or amount of bacteria attached to the meat is measured. How to measure.   The measurement object is a tool, tool, container, or device that comes into contact with food, and measures the number or amount of bacteria attached to a portion of the tool, tool, container, or device that comes into contact with food. A method for measuring the number or amount of microorganisms according to claim 1. The method for measuring the number or amount of microorganisms according to claim 1 , wherein light having a wavelength at which the spectral characteristic shows a peak value is irradiated. 6. The method for measuring the number or amount of microorganisms according to claim 5 , wherein light having a wavelength in the visible region is irradiated. 7. The method for measuring the number or amount of microorganisms according to claim 6 , wherein the second derivative is irradiated with light having a wavelength of 578 ± 5 nm. A light emitting means for projecting light in a predetermined wavelength range;
A light receiving means for receiving light emitted by the light emitting means and modulated according to the number or amount of microorganisms attached to the surface of the object to be measured;
A computing means for computing the number or amount of microorganisms adhering to the surface of the object to be measured from the light intensity by the light receiving means;
Output means for outputting a value computed by the computing means;
When the oxygen supply amount is reduced by using the change in the spectral characteristics of the measurement object due to the decrease in the oxygen supply amount to the measurement object due to the microorganism layer attached to the surface of the measurement object. A measuring device that measures the number or amount of microorganisms that utilize the spectral characteristics of myoglobin by reducing methomyoglobin produced by oxidation of oxymyoglobin that originates or adheres to an object to be measured, and changes to myoglobin . - 9. The measuring apparatus for measuring the number or amount of microorganisms according to claim 8 , further comprising an input means for inputting the type of the object to be measured. The number or amount of microorganisms according to claim 9 , wherein the calculating means calculates the number or amount of microorganisms with reference to a database storing characteristic values according to the type of the object to be measured. Measuring device to measure. Measure the spectral characteristics associated with the projection of light by the light emitting means in a state where the microorganisms on the surface of the object to be measured whose number or amount of adhered microorganisms are not adhered, and according to the measured spectral characteristics The measuring apparatus for measuring the number or amount of microorganisms according to claim 8 , wherein correction is performed. 9. The measuring apparatus for measuring the number or amount of microorganisms according to claim 8, wherein the light emitting means irradiates light having a wavelength of a second derivative value of 578 ± 5 nm.

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