JPH09127001A - Nondestructive inspection method for sealed material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a nondestructive inspection method in which the quality of a material sealed inside an enclosed system can be inspected quickly and simply by subjecting the sealed material to a Raman spectrum analysis as it is without opening and destroying its container and measuring a gas composition inside the container. SOLUTION: A sealed material is subjected to a vibrational Raman spectrum analysis without opening its container, and a gas composition inside the sealed container is measured nondestructively. In order to cut off disturbing light originated from diffused reflection due to the sealed container, a sealed preservation container is housed in a container which is provided with an incident-light entrance, a transmitted-light exit and a Raman-scattered-light takeout port which are composed of a material which does not transmit a light-source wavelength. In addition or alternatively, a filter which cuts off only disturbing light or only the light near a detection-light wavelength is used in an optical path, and the vibrational Raman spectrum analysis is performed. In addition, a gas such as oxygen, nitrogen, hydrogen or the like or all of them are combined simultaneously or arbitrarily, and they are measured by the vibrational Raman spectrum analytical method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nondestructive inspection method in a closed system in which a material is sealed, and more specifically, various materials sealed in a closed container are subjected to vibrational Raman spectrum analysis of the gas composition in the headspace of the container. Non-destructive inspection method. That is, a method of analyzing the gas composition in a container without breaking or opening the container in which various materials are sealed,
And, further, it relates to a method of inspecting the quality of a sealing material and the like by proliferating organisms and the like in a sealed container from the obtained gas composition and identifying the proliferated species.

[0002]

2. Description of the Related Art Conventionally, as a closed gas phase gas composition analysis method, there is a method in which a part of the gas in the container is extracted from a sealed container by a syringe and analyzed by gas chromatography. However, this method requires a lot of time and labor, and it is practically difficult to inspect all products when inspecting gas composition in a gas phase such as gas-displaced food, and it is difficult to use this method. , In effect limited to sampling inspections on some of the products.
Further, it is difficult to quickly and accurately measure the gas composition in the container because of the risk of air inclusion when sampling the gas in the container, and the types of gas that can be measured are limited.

On the other hand, there is known a method of measuring nitrogen and oxygen gas in an aseptic drug ampoule by a rotating Raman spectrum analysis method and inspecting whether or not the ampoule has been filled with gas in a predetermined manner. (GLEN FB
AILEY and HERBERT A. MOOR
E, JR. : Journal of the Parent
Teral Drug Association, 3
4 , (2) 127-133 (1980)). However, there is no known method for subjecting the product to Raman spectrum analysis without opening the sealing material and inspecting the quality of the product based on the change in the gas composition in the container due to the growth of microorganisms in the container.

[0004]

Under the background of the prior art described in the preceding paragraph, the present invention is to develop a nondestructive inspection method of gas in a system for a closed system in which a material is sealed, and a microorganism in a sealed container. Oxygen, etc., which is mainly consumed by the growth of, and carbon dioxide, hydrogen, hydrogen sulfide, nitrogen, methane, etc., which are generated by the growth of microorganisms, individually, or all the gases at the same time, or any combination at the same time. The purpose is to develop a rapid and simple quality inspection method for materials sealed in a closed system based on analysis results and these measurement results.

[0005]

As a result of earnest research to achieve the object described in the preceding paragraph, the present inventor has found that when a Raman spectrum analysis is used for a closed system in which a material is sealed, the sealed container is not opened. It has been found that the gas composition in a sealed container can be easily measured nondestructively, and that the quality inspection of the sealing material can be carried out nondestructively based on the measurement result. The present invention has been completed based on such findings.

That is, the present invention provides a method for measuring a gas composition in a container by subjecting the sealed material to Raman spectrum analysis as it is without breaking the container, and a method of measuring the sealed material based on the measurement result. The present invention relates to a nondestructive inspection method for sealing materials, which is characterized by performing quality inspection.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

Examples of the sealing material in the present invention include foods in sealed containers such as sausage and pickles, gas-substituted foods, commercially available water in sealed containers such as "Barber", beverages in sealed containers such as milk, "lentinan" ( Examples thereof include a medicine in a sealed container such as an anticancer agent, and a cosmetic in a sealed container such as a lotion. Gas replacement food is the preservation of food,
For extending the life cycle of food such as extension of shelf life, the air in the container such as a bag containing food is nitrogen, carbon dioxide, etc.
Alternatively, it means a product that is hermetically sealed after being replaced with a mixed gas or the like.

According to the invention, such a sealed container is
Since the material is subjected to the vibrational Raman spectrum analysis while containing it, at least a part of its wall must be capable of penetrating the light beam into the gas in the container. Ordinary glass bottles, sealed containers such as polyethylene packaging bags can be subjected to Raman spectrum analysis as they are, but for example, when the influence of diffuse reflection on glass tubes, ampoules, etc. is too large, the interference light due to diffuse reflection is blocked. In addition, such influence can be eliminated by using a container having a special shape such as a metal which does not transmit the wavelength of the light source, using a filter, or using both together. As such a container having a special shape, for example, a cylindrical container shown in FIG. 1 can be cited. The diameter of this container can be varied within a certain range depending on the diameters of the glass tube and the ampoule.

For example, a method of subjecting a gas-substituted food to a vibrational Raman spectrum analysis in a hermetically-sealed package can be performed as follows, for example.

If a specially shaped container is used, then FIG.
Samples are stored in this and subjected to vibrational Raman spectrum analysis as shown in FIG. If you use a filter,
As shown in FIG. 2, a filter is placed at an appropriate position in the optical path and subjected to Raman spectrum analysis. Here, as the filter, a filter that can remove only the wavelength of the excitation laser light can be used. In addition, S is a sample (sample), and IPDA is a diode array (Int).
enhanced photodiode arra
y) is meant. In addition, CCD (charge-cou)
PLED device and ICCD (intense)
A fied CCD) or the like can also be used.

Although there are vibration spectra and rotation spectra as spectra, the former is far from the Rayleigh scattering in terms of wavelength and is therefore less likely to be disturbed by diffuse reflection, and the component spectra are sufficiently separated even under low resolution conditions. It is superior to the latter in that it can be inspected, and in the present invention, it is preferable to rely on the vibration spectrum, although it depends on the measurement target. However, in the case of hydrogen, even the rotational spectrum gives the strongest signal in the vicinity of about 580 cm ^-1 , which can be used.

As the light source for Raman spectrum analysis, any light source that does not damage the sample and transmits through the vessel wall of the sealed container can be used regardless of its wavelength. For example, 514.5 nm with laser light of Ar ⁺ -laser,
For example, a wavelength of 488.0 nm or the like. For vibrational spectra, for example, nitrogen, oxygen and carbon dioxide have Raman shifts of 2331, 1555 and 138, respectively.
8cm ^-1 (appearing in 1286Cm ^-1 by Fermi resonance otherwise).

If an isotope such as ¹³ C-glucose is used as a substrate, carbon dioxide generated by metabolism of microorganisms can be measured separately from other carbon dioxide.
Further, the decomposition of the compound, for example, the generation of carbon dioxide by the decomposition system of glutamic acid can be measured regardless of the respiration and metabolism of microorganisms. Solid sealed samples contain ¹ H-N solid water
The product can be inspected by directly measuring it by MR and combining it with the result of gas analysis.

When data is collected using such a device, the collected data is processed, for example, by microorganisms such as bacteria consuming oxygen in a sealed container in which the material is sealed in air at normal pressure, When there is a possibility that carbon dioxide is generated, for example, it can be performed as follows. That is, an empty container similar to the sealed container of the sample filled with air is subjected to Raman spectrum analysis and measured as a blank to correct the instrument. Next, the nitrogen, oxygen, and carbon dioxide in the sealed container of the sample are subjected to Raman spectrum analysis and measured, and the ratio of oxygen to nitrogen and the ratio of carbon dioxide to nitrogen are calculated. When the initial content gas is atmospheric pressure, this value can be used to calculate the absolute amounts of oxygen and carbon dioxide. In addition, of course, it is also possible to quantitatively or semiquantitatively determine the existing amount of carbon dioxide and oxygen based on the absolute intensity comparison with the blank value on the vibrational Raman spectrum, and use these values. or,
Create a standard curve by measuring the value of a known standard gas in which various gases to be measured and nitrogen are mixed in a fixed ratio in advance,
It can also be calculated based on this standard curve.

According to the knowledge of the inventor of the present invention, such a gas having a large change in the gas composition in the sealed container obtained by Raman spectrum analysis, for example, a microorganism such as a microorganism or a pest in the sealing material consumes oxygen. In the case where carbon dioxide is generated and the carbon dioxide / oxygen ratio is increased, it is determined that these organisms grow and the quality is deteriorated. Further, by comparing the gas composition during packaging with the gas composition during the product distribution process or storage process, it is possible to identify the growth status and contamination status of organisms in the hermetically sealed product, the identification of the grown species. Further, according to the present invention using the Raman spectrum analysis method, it is possible to inspect, for example, a gas-displaced food product whether or not the desired gas composition has been packaged. This inspection can be performed continuously by installing an analytical instrument on the line of the product manufacturing process, and thus the quality inspection of the product can be performed easily and easily.

In this way, the quality inspection in the manufacturing process or distribution process of the product, which conventionally takes time and labor, can be performed extremely quickly and easily without opening the product.

[0018]

The present invention will be further described with reference to the following examples.

Example 1 PBYG medium (Bactopeptone 0.5%, beef extract 0.3%, yeast extract 0.
1%, glucose 1%. In addition, Brachymona
In the case of S. denitrificans, a medium supplemented with 0.2% potassium nitrate was used), and various strains shown in Table 1 below were statically cultured in a sealed vial at 37 ° C. for 3 days. Clostridium sporo
Genes were statically cultured in an anaerobic box. Cand
ida albicans and Aspergillus
The niger was statically cultured at 28 ° C. for 3 days in a sealed vial. Then, the relationship between the growth and the gas generation state was investigated by the vibrational Raman spectrum analysis method.

[0020]

[Table 1]

The cultured vials were subjected to vibrating Ramanskull analysis without opening, and it was tested whether changes in the gas composition in the vials could be investigated by vibrating Ramanskull analysis when microorganisms grew.

The results are also shown in Table 1. From these results, it was shown that the gas composition in the sealed container can be measured nondestructively by Raman spectrum analysis, and by extension, the Raman spectrum analysis method can be used for quality inspection including microbial control of products. .

Example 2 PBYG medium (Bactopeptone 0.5%, beef extract 0.3%, yeast extract 0.
1%, glucose 1%) to Salmonella t
Yphimurium was inoculated and statically cultured at 37 ° C., and the gas composition in the sealed vial during the culture was measured by vibrational Raman spectrum analysis. On the other hand, the vial after the gas composition measurement was opened, and the number of viable bacteria in the middle of the culture was spread on the agar plate medium having the above medium composition and measured. Then, it was investigated whether or not there is a correlation between the degree of microbial growth and the change in carbon dioxide / oxygen. The measurement results are shown in Table 2 below.

[0024]

[Table 2]

As shown in Table 2, there is a positive correlation between the degree of growth of microorganisms and the change in carbon dioxide / oxygen, and vibrational Raman spectrum analysis is applied to microbial control of products. It was shown that it can be used for quality inspection.

Example 3 Majifile was replaced with a mixed gas of 60% nitrogen and 40% carbon dioxide in a polyethylene container and sealed, and the sealed product was stored at 5 ° C. for 4 days. The changes were non-destructively measured by vibrational Raman spectroscopy. The viable cell count was measured by the same method as in Example 1. The results are shown in Table 3 below.

[0027]

[Table 3]

As shown in Table 3, the gas composition of the gas phase sealed by the Raman spectrum analysis could be measured nondestructively even in the actual gas-substituted food. It was shown that it is possible to calculate the degree of growth of the viable cell count in the product from the increase in the carbon dioxide photon count.

Example 4 A commercially available natural water “Barber” poly-container product was stored at 5 ° C. and the number of viable bacteria and the gas composition in the gas phase in the container were nondestructively stored in the same manner as in Example 3. It was measured by a vibrational Raman spectrum analysis method. The results are shown in Table 4 below.

[0030]

[Table 4]

As shown in Table 4, it was demonstrated that commercially available water can be used to measure the degree of growth of microorganisms in a nondestructively sealed state and is useful for quality control.

Example 5 The herb enclosed in a hermetically sealed glass ampoule was stored at room temperature for 2 months, and CO ₂ / O ₂ in the gas phase inside the ampoule was measured non-destructively by Raman spectrum analysis over time. At the same time, the ampoule was directly placed in a gas measuring tube for NMR measurement, and the water content in the solid phase was measured non-destructively by ¹ H-NMR. CO ₂ , O
₂ and the ampoule whose water content was measured were opened and the viable cell count was measured by the same method as in Example 1. The result is the fifth
It is shown in the table.

[0033]

[Table 5]

As shown in Table 5, the CO ₂ / O ₂ value and the relative water content increased as the number of viable bacteria in the product increased, and the water content measurement by Raman spectrum analysis and ¹ H-NMR was performed. It has been shown to be effective in the quality inspection of herbal products.

Example 6 PBYG medium (0.5% bactopecton, 0.3% beef extract, 0.1% yeast extract,
Glucose 1%) was used to produce E. coli as shown in Table 6 below. co
Li was statically cultured at 37 ° C. for 3 days in a sealed vial.

Then, the hydrogen in the gas phase of the sealed vial was adjusted to 580.
It was measured by rotational Raman spectroscopy at cm ^-1 .
On the other hand, the viable cell count was measured by the same method as in Example 1. The results are shown in Table 6 below.

[0037]

[Table 6]

As shown in Table 6, it was found that hydrogen in a sealed vial can be measured by the rotational Raman spectrum analysis method.

[0039]

According to the present invention, in a closed system in which a material is hermetically sealed, the gas composition in the hermetically sealed container can be easily and nondestructively measured by Raman spectrum analysis without opening the hermetically sealed container. As a result, quick and easy quality inspection of various products becomes easy.

[Brief description of the drawings]

FIG. 1 illustrates a container in which a hermetically sealed container is to be stored when performing Raman spectrum analysis.

FIG. 2 illustrates the position of a filter to be placed in the optical path when performing Raman spectrum analysis.

FIG. 3 illustrates a chart of nitrogen measured by a vibrational Raman spectrum analysis method.

FIG. 4 illustrates a chart of oxygen and carbon dioxide measured by a vibrational Raman spectrum analysis method.

Front Page Continuation (72) Inventor Shigeru Yamanaka 1-1, Suzuki-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Ajinomoto Co., Inc. Central Research Laboratory

Claims (6)

[Claims] 1. A nondestructive inspection of a sealing material, characterized by subjecting the sealing material to a vibrational Raman spectrum analysis as it is without opening the sealing container to nondestructively measure a gas composition in the sealing container. Law. 2. A container having an incident light inlet, a transmitted light outlet, and a Raman scattered light extraction port, which is made of a material that does not transmit a light source wavelength, in order to block disturbing light originating from irregular reflection by the hermetically sealed container, the hermetically sealed storage container The method according to claim 1, wherein the vibration Raman spectrum analysis is carried out by housing and / or using a filter for blocking only the interfering light or transmitting only in the vicinity of the detection light wavelength in the optical path. 3. Oxygen, nitrogen, carbon dioxide, carbon monoxide,
Individual gases such as sulfur dioxide, hydrogen sulfide, methane and hydrogen,
The method according to any one of claims 1 and 2, wherein all or all of them are measured simultaneously or in any combination by a vibrational Raman spectrum analysis method. 4. The method according to any one of claims 1 to 3, wherein the sealing material is a food product, a gas-substituted food product, commercially available water, a beverage, a pharmaceutical product, a cosmetic product, etc., contained in a container. 5. The method according to any one of claims 1 to 4, wherein the sealing material is directly subjected to vibrational Raman spectrum analysis without opening the sealed container to nondestructively measure the gas composition in the sealed container. In addition, a nondestructive product inspection method characterized by nondestructively measuring water in a sealed solid material by ¹ H-NMR and performing product inspection based on a fixed value on both sides. 6. The method according to claim 1, wherein hydrogen in the sealed container is measured by rotational Raman spectrum.