JP2013132270A - Yeast and mold detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detector reducing the occurrence of false positive in food containing much oil such as butter and spread, and detecting yeast and mold in an inspection period of about 5 days in regard to many specimens including drinks, pharmaceuticals, etc., other than the above food.SOLUTION: A container body 1 transparent on the whole and sealed with a cap 7 includes a medium storage part 2 and an indicator storage part 3 partitioned by a carbon dioxide permeable film 4 for intercepting a medium for bacteria growth. M-green yeast and mold broth with chloramphenicol added is stored in the medium storage part 2, and a coloration indicator 6 of carbon dioxide is stored in the indicator storage part 3 to form the inspector.

Description

  The present invention relates to a yeast and mold detector, and more particularly to a test tool for detecting yeast and mold in food.

  As a method for detecting yeast and mold in food, for example, a plate culture method using a separation medium such as potato dextrose agar (PDA) or malt extract agar (MA) (see, for example, “Food Sanitation Inspection Guidelines”) is known. ing. In this method, a test object (measurement sample) is directly or after dilution or distribution, cultured using the agar medium for about 5 to 7 days to confirm colony formation.

  However, in the plate culture method, when the object to be inspected is a solid or oil, only a small amount (about 0.1 g) of sample can be used, which is a problem in terms of detection sensitivity. .

  Patent Documents 1 to 3 disclose detection methods using specific regions of genes of yeast and mold, respectively. However, these methods require a special apparatus and a complicated operation for amplifying the gene, and cannot be said to be a simple method. When a gene is directly extracted from a sample, yeasts and molds in the sample are killed, and thus it is difficult to detect them after separating and culturing them. In addition, a test object containing only a certain number of bacteria or less needs to be enriched for several days. In this case, two steps of enrichment and detection are necessary.

  Furthermore, there is a method using the inspection tool described in Patent Literature 4 and Patent Literature 5. This inspection device has a configuration in which a liquid medium and a color indicator of carbon dioxide are separated from each other by a carbon dioxide permeable membrane that blocks the liquid medium and stored in a container. Medium is contained in the container. This test device is marketed under the name “Sensimedia” (registered trademark), and is used to detect yeast in wine and lactic acid bacteria beverages. Potato dextrose medium containing chloramphenicol (potato infestation and glucose as the main components) Sensimedia in which the medium is stored in a container is provided (Non-Patent Document 1).

  In this inspection tool, the color indicator is colored by the carbon dioxide generated by the growth of yeast in the liquid medium passing through the carbon dioxide permeable membrane and reacting with the color indicator. This color density is detected, and the time until color development at a predetermined concentration obtained using the test object and the color development at the predetermined concentration obtained using a standard sample with known bacterial counts is reached. The number of bacteria in the sample is estimated from the comparison with the time until. In addition, since the liquid medium contains chloramphenicol, the growth of hetero-type lactic acid bacteria and other bacteria that produce carbon dioxide is suppressed, and in samples containing a large amount of lactic acid bacteria including homo-type lactic acid bacteria that do not produce carbon dioxide Are reliably detected.

JP 2006-0661152 A International Publication No. 2005/093059 International Publication No. 2007/132589 JP-A-11-178597 Japanese Patent Laid-Open No. 2001-17896

Microbio Inc., “SensiMedia”, [online], [Search September 20, 2011], Internet <URL: http://www.microbio.co.jp/products/sensimedia.html>

  However, the test tool for detecting yeast described in Non-Patent Document 1 includes, for example, butter (milk fat content: 80% by mass or more) and margarine (fat content: 80% by mass or more) having an oil content of 35% by mass or more. ), Fat spread (fat content: 35% or more and less than 80% by weight) and other types of molds present in foods rich in fats and oils such as Aspergillus niger, Cladosporium sp. And Penicillium sp. It may take some time. In other words, if the number of bacteria in the sample is small, the color change in color during the culture period of about 5 days, which is the standard culture period for yeast, is unclear, and there are cases where reliable determination cannot be made (Table 1).

  In addition, the inspection tool must not detect some types of bacteria such as Pseudomonas aeruginosa and Pseudomonas fluorescens. However, like yeast and mold. There was a case where a change in color occurred due to the presence of these bacteria (false positive) (see Table 1).

  On the other hand, preparing a dedicated inspection tool specialized for foods rich in fats and oils causes an increase in inspection cost, and thus inspection tools that can be applied not only to specific foods but also to various types of foods are desired.

  The present invention has been made based on the above-described background art, and includes a large amount of fats and oils such as butter, margarine, and fat spread (hereinafter, both margarine and fat spread may be referred to as “margarines”). An object of the present invention is to provide a test tool capable of detecting yeasts and molds that are slightly present in food in a test period of about 5 days. Furthermore, an object of the present invention is to provide a test tool that preferably suppresses false positives caused by bacteria belonging to the genus Pseudomonas.

  The inspection tool of the present invention is a yeast and fungus detection tool provided with a medium storage part and an indicator storage part separated by a carbon dioxide permeable membrane for blocking the culture medium for enrichment in a sealable container. The container is provided with a transparent portion through which the inside of the indicator accommodating portion can be seen from the outside, the medium accommodating portion accommodates a medium capable of cultivating yeast or mold, and the indicator accommodating portion accommodates a color indicator of oxygen dioxide, A medium capable of culturing the yeast or mold is 10.0 g ± 1.0 g peptone, 50.0 g ± 5.0 g glucose, 9.0 g ± 0.9 g yeast extract, 2.1 g ± Contains 0.2 g magnesium sulfate, 2.0 g ± 0.2 g potassium dihydrogen phosphate, 0.05 g ± 0.01 g diastase, 0.05 g ± 0.01 g thiamine, and other enrichment ingredients Not included, the pH of the medium is 4.6 ± 0.2 It is 査具.

  According to the inspection tool of the present invention, it is possible to detect yeast and mold in foods and pharmaceuticals in about 5 days, regardless of the amount of fats and oils.

FIG. 1 is a side view of an inspection tool according to an embodiment of the present invention.

  The inspection tool of the present invention includes a medium storage part and an indicator storage part separated from each other by a carbon dioxide permeable membrane that blocks the culture medium for enrichment in a sealable container, and the container is provided from the outside of the indicator storage part. It has a transparent part that can be seen through. The medium storage unit stores a medium capable of cultivating yeast or mold, and the indicator storage unit stores a carbon dioxide color indicator.

  The transparent portion only needs to observe the color of the indicator accommodating portion, and the entire container may be transparent or a part of the container may be transparent. The transparent part is preferably colorless. This is for reliably observing a change in coloration. For example, as shown in FIG. 1, after the cap 7 is detachably attached to the plastic container body 1 which is transparent as a whole by screwing and the medium 5 and the color indicator 6 are stored, as shown in FIG. Is kept sealed until a sample is placed.

  The culture medium storage unit 2 and the indicator storage unit 3 are separated by a carbon dioxide permeable membrane 4 that blocks the permeation of the enrichment culture medium 5, and the carbon dioxide generated in the culture medium storage unit 2 permeates the permeation membrane 4 to indicate the indicator. It reacts with the color indicator 6 accommodated in the accommodating part 3. For example, as shown in FIG. 1, the indicator storage unit 3 is a sealed bag composed of a carbon dioxide permeable membrane 4, and the space in the container other than the space occupied by the indicator storage unit 3 is the medium storage unit 2. Although not shown, the inside of the container can be divided into upper and lower portions by an oxygen dioxide permeable membrane, and one space can be used as a medium containing portion and the other space can be used as an indicator containing portion. As shown in FIG. 1, when the bag-shaped indicator container 3 is configured, the indicator container 3 is accommodated at a position higher than the height of the upper surface of the medium 5 accommodated in the medium container 2. It is preferable to accommodate the culture medium 5 so that the height of the upper surface of the colored indicator 6 is positioned. This is because the color of the color indicator 6 can be observed without being affected by the color of the medium 5. Further, when the inside of the container is divided into upper and lower parts by a permeable membrane, it is preferable to set the indicator accommodating portion below the carbon dioxide permeable membrane. This is for opening the container and adding the sample to the medium. A support member 8 that supports the lower end of the indicator container 3 is provided near the bottom of the container body 1 shown in FIG. The support member 8 is paired with a support member (not shown) provided on the inner surface of the cap 7 so that the upper surface height of the color indicator 6 is positioned higher than the upper surface height of the culture medium 5. The accommodating part 3 is held. Examples of such a configuration of the inspection tool (a configuration excluding the culture medium) include the configurations of various inspection tools described in Patent Document 4 and Patent Document 5, for example.

  The carbon dioxide permeable membrane 4 may be any membrane that can permeate carbon dioxide but can reliably separate the medium 5 and the color indicator 6 without causing ion exchange. The material of the carbon dioxide permeable membrane 4 is not particularly limited. Absent. For example, it may be a film made of unstretched polypropylene, stretched polypropylene, low density polyethylene, high density polyethylene and the like. In addition, a homogeneous film made of silicon rubber or polyalkylsulfone, a porous film made of polytetrafluoroethylene or polysulfone, a composite film of polypropylene and silicon, or a composite film of polypropylene and polyalkylsulfone can be used.

  The color indicator 6 is not particularly limited as long as it is an indicator that reacts with carbon dioxide and develops color. However, when the culture medium 5 exhibits color, it can be distinguished from the color of the color indicator 6. As the color indicator 6, a mixed solution of a carbon dioxide reactant and a pH indicator, for example, an aqueous solution of sodium hydroxide and thymolphthalein, an aqueous solution of sodium hydroxide and phenolphthalein, an aqueous solution of calcium hydroxide, hemoglobin or erythrocytes, In addition to an aqueous solution of a substance containing heme such as blood, aqueous solutions of various color indicators 6 such as methyl violet, methyl orange, congo red, methyl red, bromthymol blue, phenol red, cresol red, and thymol blue can be mentioned. In addition, coloring may be either colored or decolored.

  In the present invention, “yeast and mold” means fungi excluding mushrooms from fungi called fungi, and is used in a manner commonly used by those skilled in the art. Yeast generally refers to Saccharomyces cerevisiae, but in the present invention is not meant to be limited to the bacterium. Examples of the yeast include bacteria belonging to the genus Saccharomyces, Candida, Torulopsis, and Zygosaccharomyces. The fungus means a fungus that does not form a fruiting body and has a mycelium composed of hyphae, and is used in a sense that is commonly used by those skilled in the art. Examples of molds include fungi belonging to the genus Penicillium, Aspergillus, Fusarium, and Cladosporium.

If yeast or mold is present in the sample, carbon dioxide is generated by enrichment. The inspection tool of the present invention uses the color produced by the reaction between the carbon dioxide and the color indicator 6 in the indicator container 3. Under the same culture conditions, the number of bacteria in the test object correlates with the time required to produce a predetermined concentration of color. When the sample prepared from the test object is added to the culture medium, the more bacteria in the sample, the shorter the time required to produce the color at the specified concentration. The smaller the number of bacteria in the sample, That time will be longer. Therefore, using several types of samples (standard samples) whose number of bacteria is known in advance, the relationship between the time and the number of bacteria required to produce a predetermined concentration of color (sensitivity characteristics) is obtained, and then the sample is used. The number of bacteria in the sample (in the test object) can be obtained from the time and sensitivity characteristics required to produce the color of the predetermined concentration measured in this way. In addition, the color density (change in density) generated in a certain time is measured using one standard sample, and the approximate number of bacteria is calculated from the color density measured using the sample when that time has elapsed. Can also be requested. Thus, for example, using a standard sample containing a number of bacteria theoretically 1 × 10 ⁰ diluted, 3 days or 5 days from the start of measurement, in advance measures the change in concentration of color after a lapse of such 7 days a certain time placed, in the case where the concentration change was measured by using a sample is smaller than the change in density was measured in advance, theoretically 1 × 10 ⁰ or less, that allows a determination that the bacteria are not present. Also, when no change in color is observed, it can be determined that the bacteria are not present.

  The following medium is used as a medium for enrichment of yeast and mold. For example, in 1000 ml of medium, 10.0 g ± 1.0 g peptone, 50.0 g ± 5.0 g glucose, 9.0 g ± 0.9 g yeast extract, 2.1 g ± 0.2 g magnesium sulfate, The pH of the solution was adjusted to 4.6 ± 0.2, containing 0.0 g ± 0.2 g potassium dihydrogen phosphate, 0.05 g ± 0.01 g diastase, 0.05 g ± 0.01 g thiamine. Medium. This medium does not contain other components for enrichment, but may contain an appropriate amount of bromocresol green as a pH indicator for observing changes in the pH of the medium. A medium containing a pH indicator is known as M-green yeast and mold broth (medium) (see, for example, “Food Sanitation Inspection Guidelines” above). M-green yeast and mold broth contains about 0.026 g of bromocresol green in 1000 ml of medium of the above composition. Since coloration due to the reaction between carbon dioxide and the color indicator 6 occurs, a medium that does not contain a pH indicator is preferably used, but the presence or absence of the pH indicator in the medium is not limited as long as coloration is determined. Therefore, a commercially available medium labeled with the name M-Green Yeast and Mold Broth (but not including agar) can be used. In addition, although the culture medium which has the same composition as the said culture medium is marketed also as M-green yeast and agar culture medium containing agar, in this invention, the culture medium which does not contain agar is used.

  The medium preferably contains a bacterial growth inhibitor. The bacterial growth inhibitor is a component that prevents bacterial growth. Since M-green yeast and mold broth contains components necessary for bacterial growth, there is a risk that the bacteria may grow. For this reason, if a sample that does not contain yeast or mold contains bacteria, it may be determined that the sample contains yeast or mold as a result of the reaction of the color indicator. Bacterial growth inhibitors are used to eliminate this possibility. The bacterial growth inhibitor is a component that preferably prevents bacterial growth without affecting the growth of yeast or mold. This component is an antibiotic, the antibiotic is a β-lactam antibiotic, an aminoglycoside antibiotic, a tetracycline antibiotic, a chloramphenicol antibiotic, a macrolide antibiotic A ketolide antibiotic and may be a polyene macrolide antibiotic. Typically, one or more of these antibiotics are used.

  When butter and margarine are test objects, butter and margarine may contain bacteria belonging to the genus Bacillus. Therefore, the inspection tool must not detect these bacteria as yeast or mold (the growth of the bacterium belonging to the genus Bacillus). To be suppressed). In addition, butter and margarines generally do not contain bacteria of the genus Pseudomonas, but it is desirable that false positives caused by these bacteria be eliminated. Furthermore, for example, in a method for detecting yeasts and molds based on food hygiene inspection guidelines, there is a situation where chloramphenicol antibiotics are used in order to suppress bacterial growth. From such a viewpoint, chloramphenicol is preferable as the antibiotic. In the test device according to the present invention, a medium that does not contain a cell growth inhibitor may be used. For example, since butter and margarines generally do not contain bacteria belonging to the genus Pseudomonas, it is possible to determine that yeast and mold have been detected without inhibiting the growth of these bacteria. Because the presence of bacteria of the genus Pseudomonas is determined to have yeast and mold (false positives), the specimen (product) is treated as a retest target and the shipment of defective products is suspended. is there.

  The addition amount of the bacterial growth inhibitor is appropriately determined by those skilled in the art according to the type of antibiotic and the type of bacteria to be inhibited from growing. For example, when the antibiotic is chloramphenicol, the amount added to the liquid medium is 0.0001 mg / ml to 10 mg / ml, preferably 0.001 mg / ml to 1.0 mg / ml, more preferably 0.01 mg. / Ml to 0.5 mg / ml.

  The medium of the present invention may contain a surfactant. When the test object contains fats and oils, it is considered that the test object is not sufficiently mixed with the culture medium, and the bacterial cells in the test object cannot be sufficiently detected. In particular, in the case of foods with a high fat content, such as butter and margarines (for example, foods with a fat content of 35% by mass or more), they may not be detected. This is because the addition of the surfactant helps to disperse the test object in the culture medium to ensure the detection of the bacterial cells. Further, the addition of a surfactant helps to increase the amount of the sample that can be added to the medium, and plays a role of improving the detection sensitivity of the bacterial cells.

  Surfactants include, for example, anionic surfactants (fatty acid salts, sodium alphasulfo fatty acid ester, etc.), cationic surfactants (alkyltrimethylammonium salts, dialkyldimethylammonium salts, etc.), amphoteric surfactants ( Alkylamino fatty acid salts, alkylbetaines, alkylamine oxides, etc.), nonionic surfactants (sucrose fatty acid ester sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, fatty acid alkanolamide, etc.). One or more surfactants are used. The surfactant is added to the medium at a concentration that does not affect the growth of the cells in the sample. The concentration of the surfactant in the medium can be appropriately changed according to the test object, but is generally 0.0001 to 5.0 w / v%, preferably 0.01 to 3.0 w / v%, more preferably It is 0.1-2.0 w / v%.

The amount of the culture medium is appropriately determined in consideration of the inner volume of the container body 1 and the capacity of the indicator container. The standard of the amount of the culture medium is such that the number of bacteria of 1 × 10 ⁸ to 1 × 10 ⁰ cfu can be detected. Specifically, although depending on the volume of the culture medium storage unit 2 and the container body 1, the storage volume of the culture medium is generally 1 to 20 ml per container, and preferably 4 to 4 for a container of about 16 ml capacity. 6 ml. When the sample is in a liquid state, the medium 5 having a high concentration composition prepared so that the final concentration after adding the sample is substantially the above concentration is accommodated in the medium accommodating unit 2.

  For example, yeast and mold in the test object are cultured by, for example, preparing a sample to be added to the medium from the test object, adding the sample to the liquid medium contained in the test tool, and sealing the container. And the step of measuring the color density of the indicator storage unit after a predetermined time has elapsed from the start of the culture and the step of comparing the density with a predetermined color density.

  The density of the color to be compared is determined by various methods. For example, instead of a sample added to the medium, a method based on the color concentration obtained by adding the same amount of sterile medium or water and culturing, or coloring with a color indicator immediately after the start of culture And a method based on the color concentration obtained by adding a sample with a known number of bacteria to the medium and culturing. Among these, from the viewpoint of easy determination, a method based on the color concentration of the presentation indicator immediately after the start of culture is preferably employed. This is because it is only necessary to observe the color change.

  Then, the reference color density is compared with the color density obtained using the specimen, and the color density obtained using the sample is the same as the reference color density. If it is determined that the concentration is low, it can be determined that yeast or mold having the same or lower number of bacteria as the reference color density is present in the sample. Further, if no change in color is observed, it can be determined that yeast and mold are not present in the sample.

  In addition, as described above, from the sensitivity characteristics obtained by measuring the time required to produce a predetermined concentration of color using several samples (standard samples) having a known number of bacteria in advance, the bacteria in the sample You can also find a number.

  As a method for preparing the sample to be added to the culture medium, weigh out an appropriate amount of the test object according to the amount of medium accommodated and use it as a sample, or use the measured amount of the measurement object as a non-selective medium or water. There is a method in which a sample is dissolved or suspended in a suitable medium. The preparation method is appropriately selected according to the characteristics of the measurement object, for example, whether it is solid or liquid, the expected number of bacteria, and the like.

  The inspection object is a food (including products and raw materials), and can be a medicine. Also preferred are butter and margarines. The test tool of the present invention is used for foods with high fat content such as butter and margarine, yeast such as Aspergillus niger, Cladosporium sp., Penicillium sp. This is because it can detect mold and mold.

  The amount of the sample added to the medium 5 is appropriately adjusted according to the type of the test object, the estimated number of bacteria, the amount of medium used, and the like. For example, in the case of an inspection tool containing 1 to 20 ml of medium, a 0.01 to 10 g sample or a 0.01 to 10 ml sample is used.

  The container to which the sample has been added is sealed and cultured at around 25 ° C. for a fixed time, preferably 5 to 7 days. At this time, it may be cultured in a stationary state or may be cultured in a shaken state. When yeast or mold is present, the color indicator is colored, and the color concentration changes with time. At the stage of culturing, the color density is measured and compared with the standard color density. In this manner, the presence or absence of yeast or mold in the sample can be detected.

  Next, the present invention will be described based on the following examples. The following embodiments are merely examples, and the present invention is not limited to the following embodiments.

(Contrast with existing products)
M-supplemented sensimedia (product number SM008: comparative product) for yeast detection on the market and chloramphenicol (manufactured by SIGMA) added at 0.01 w / v% instead of the sensimedia medium. Detection was attempted for the bacteria shown in Table 1 using the inspection tool of the present invention (Example 1) containing Green Yeast and Mold Broth (manufactured by DIFCO & BBL). Each inspection tool contains 4 ml of medium in a 16 ml tube. In addition, the description in parentheses in the bacterial species column of Tables 1 to 4 indicates the origin of the bacteria. The origin is unknown for bacterial species not listed.

  Fat spread (trade name “Smooth Soft”, manufactured by Meiji Co., Ltd.), which is an inspection object, was dissolved at 40 ° C., and various types of bacteria shown in Table 1 were inoculated to prepare samples. The test tool to which 1.0 g of the sample was added was turned over and the sample and the medium were mixed thoroughly, and then cultured at 25 ° C. for 5 days. On the third day, the fourth day, and the fifth day after the start of the culture, changes in the color tone of the color indicator were confirmed. The results are shown in Table 1. In the table, “+” indicates a case where a change in color tone (yellowing) is observed, and “−” indicates a case where a change in color tone (yellowing) is not recognized. Further, “(+)” in the table indicates that no change in color tone was observed in the upper part of the color indicator, and a change in color tone was observed in the lower part of the color change indicator, indicating that the change in color tone was unclear.

  According to this, while the comparative test tool could not detect these bacteria correctly from the sample inoculated with a small number of Aspergillus niger, Cladosporium sp., And Penicillium sp. In the test tool of Example 1, these bacteria were correctly detected from the sample inoculated with 1 cfu of bacteria per gram. Moreover, although Pseudomonas fluorescens was detected in the comparative inspection tool, the bacteria were not detected in the inspection tool of Example 1, and the occurrence of false positives was suppressed.

  From the experiment of Example 1, it was confirmed that 1 cfu / g yeast and mold were detected in the 5-day culture period in the case of a fat spread with a high fat content in the inspection tool of Example 1.

  The effect of adding chloramphenicol was confirmed. The test tool of the present invention containing M-green yeast and mold broth (manufactured by DIFCO & BBL) containing no chloramphenicol, instead of the test tool of the test product 1 and the culture medium of the test tool of the test product 1 Using the product 2), detection was attempted for the bacteria shown in Table 2. The test method is the same as in Example 1 except that 5 ml of the medium is accommodated in each inspection tool.

  As a result, in the test device of Example 1 using a medium containing chloramphenicol, 1 cfu / g of Cladosporium sp. And Penicillium sp. Bacteria were detected in the culture period of 5 days. In the test device of Example 2 using a medium containing no call, a culture period of 3 to 4 days was detected for these bacteria. In addition, Pseudomonas fluorescens was detected in the test tool of Example Product 2, but the bacteria were not detected in the test tool of Example Product 1, and the occurrence of false positives was suppressed.

  From the experiment of Example 2, it was confirmed that 1 cfu / g yeast and mold were detected in a culture period of about 4 days even for foods with a high fat content in the test device to which chloramphenicol was not added. It was done. Therefore, chloramphenicol may be used when it may be judged that yeast or mold has been detected by bacteria belonging to the genus Pseudomonas (when it can be excluded as a defective product) or when contamination by bacteria is clearly excluded. The inspection period is shortened by using an inspection tool using a medium that does not contain.

  Various butters and margarines were used as inspection objects, and detection was attempted using the inspection tool of Example Product 1. Salted butter (Meiji Co., Ltd., trade name “Salted Perch Butter 450 g”), saltless butter (Meiji Co., Ltd., trade name “Unsalted Perch Butter 450 g”), fermented butter (Meiji Co., Ltd.) , "Fermented perch butter 450g"), margarine, smooth soft, olive soft (Meiji Co., Ltd., trade name "Meiji material travel extra virgin olive soft"), cake margarine (Meiji Co., Ltd., trade name "Meiji") Cake margarine "). The fat content of these inspection objects is 50% or more. The test method is the same as the method of Example 2 (using an inspection tool to which chloramphenicol was added). The results are shown in Tables 3 and 4.

  The test device of Example 1 reliably detects yeasts and molds during the 5-day culture period, while the conventional test device did not detect Pseudomonas bacteria or Bacillus bacteria detected as false positives. .

  As compared with butter and margarines, detection was attempted using normal milk (about 3 to 4% by mass), which is a low-fat content food, and apple juice, which is a non-fat content food. A sample was prepared by inoculating the test object with bacteria at room temperature. The test tool to which 1.0 ml of the sample was added was turned over to thoroughly mix the sample and the medium, and then cultured at 25 ° C. for 7 days. The results are shown in Table 5. From these results, in the test instrument of Example 1, yeast and mold were reliably detected in the culture period of 4 to 5 days, while bacteria of the genus Pseudomonas and Bacillus were not detected. From the experiment of Example 4, with the inspection tool of Example Product 1, yeast and mold are detected in a culture period of about 5 days from a food with a low fat content and a food with a fat-free content (not containing fat). It was confirmed.

  Unsalted butter (trade name “Unsalted perch butter 450 g” manufactured by Meiji Co., Ltd.) was used as an inspection object, and the influence of the surfactant was examined. The test method is the same as the method of Example 2 (using an inspection tool to which chloramphenicol was added). The results are shown in Table 5.

  From this experimental result, it was confirmed that the addition of the surfactant did not affect the detection of yeast and mold. Moreover, it was confirmed that the addition of the surfactant did not affect the detection of bacteria of the genus Pseudomonas and Bacillus.

  According to the present invention, even in foods such as butter and margarines with a high fat content, even in foods with a low fat content or no fats, a 1 g sample can be used in a culture period of 5 to 7 days. A test tool that can reliably detect molds belonging to the genus Candida, Penicillium, Aspergillus, Cladosporium, etc. present at about 1 cfu .

DESCRIPTION OF SYMBOLS 1 Container body which is transparent as a whole 2 Medium storage part 3 Indicator storage part 4 Carbon dioxide permeable membrane

Claims (6)

In a hermetically sealable container, a yeast and fungus detector comprising a medium container and an indicator container separated by a carbon dioxide permeable membrane that blocks the enrichment medium,
The container includes a transparent portion through which the inside of the indicator container can be seen from the outside,
The medium containing part contains a medium capable of cultivating yeast or mold,
The indicator storage unit stores a color indicator of oxygen dioxide,
A medium capable of cultivating the yeast or mold,
In 1000 ml of medium, 10.0 g ± 1.0 g peptone, 50.0 g ± 5.0 g glucose, 9.0 g ± 0.9 g yeast extract, 2.1 g ± 0.2 g magnesium sulfate, 2.0 g Contains ± 0.2 g potassium dihydrogen phosphate, 0.05 g ± 0.01 g diastase, 0.05 g ± 0.01 g thiamine, no other enrichment components, and a medium pH of 4.6 Inspection tool that is ± 0.2.   The test tool according to claim 1, wherein the culture medium does not contain a pH indicator that hinders observation of coloration of the color indicator. In a hermetically sealable container, a yeast and fungus detector comprising a medium container and an indicator container separated by a carbon dioxide permeable membrane that blocks the enrichment medium,
The container includes a transparent portion through which the inside of the indicator container can be seen from the outside,
The medium containing part contains a medium capable of cultivating yeast or mold,
The indicator storage unit stores a color indicator of oxygen dioxide,
The inspection tool whose medium which can culture said yeast or mold is M-green yeast and mold culture medium.   The test | inspection tool for yeast or mold of any one of Claims 1-3 in which the culture medium which can culture | cultivate the said yeast or mold contains a bacterial growth inhibitor.   The test device for yeast or mold according to claim 4, wherein the bacterial growth inhibitor is a chloramphenicol antibiotic.   The inspection tool for yeast or mold according to any one of claims 1 to 5, wherein the medium capable of culturing the yeast or mold contains a surfactant.

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