JP2015216875A - Food bacterium separation/concentration apparatus and food bacterium separation/concentration method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a food bacterium separation/concentration apparatus and a food bacterium separation/concentration method.SOLUTION: A food bacterium separation/concentration apparatus (100) is provided, which includes: a sending container (1) for food and drink (f); a first filtration part (2) to which the food and drink (f) to be sent are sent, and by which at least a part of a solid content contained in the food and drink is removed; a second filtration part (3) to which a first filtrate (L1) filtered by the first filtration part is sent, and which captures at least the bacteria of bacteria and spores contained in the food and drink (f); a first pipeline (5) for connecting the first filtration part (2) and the second filtration part (3) to each other; a second pipeline (6) for discharging a second filtrate (L2) filtered by the second filtration part (3); a back washing water sending container (4) for sending back washing water (w) to the second filtration part (3); and flow path switching means (5a) for switching between the flow path of the first filtrate (L1) and the flow path of the back washing water (w). Also provided is a food bacterium separation/concentration method which uses the food bacterium separation/concentration apparatus and the like.

Description

  The present invention relates to a food bacteria separation and concentration apparatus and a food bacteria separation and concentration method. More specifically, the present invention removes much of the solid content from food and drink with a filter medium, and then captures the filtrate with a filter medium through which food bacteria do not pass, and desorbs it from the filter medium with backwash water and collects it. The invention relates to an apparatus for separating and concentrating food bacteria to be collected and a method for separating and concentrating food bacteria.

  Foods and drinks are deteriorated in taste and flavor due to contamination by bacteria and spores formed by some bacteria and their growth, and the value of food and drink is reduced. Furthermore, when contamination by food poisoning bacteria occurs, there is a concern that it may cause food poisoning. Contamination of food and beverages due to bacteria, etc., and their growth, in addition to contamination of raw materials, contamination of food processing facilities, equipment and tools, contamination of processing workers, defects in processes such as washing, heating, storage, distribution and sales Caused by. In any case, in order to prevent the quality of food and drink from being deteriorated and the occurrence of food poisoning, the possibility of contamination and growth of bacteria in all the processes from production and consumption of the food and drink is determined in advance. It is necessary to control the quality by inspecting not only the product but also the number and type of bacteria in each process.

  There are various methods for inspection, but the Food Sanitation Law has established standards and test methods for microorganisms in order to ensure food safety. This test method is used for sampling final products. Often done. However, in addition to such inspections by official methods, a test method that can more immediately detect the occurrence of microbial contamination in the process control process is desired, and as a self-inspection, inspections are performed quickly or simply using a test method. ing. For example, the chromogenic / luminescent enzyme substrate method published in the inspection method based on the Food Sanitation Law can be inspected in a short period of time and is low in cost, so it is suitable for daily voluntary inspection. It is.

  In addition, a method using a hollow fiber membrane and a membrane filter is known for recovering microorganisms, particularly chlorine-resistant pathogenic microorganisms in sample water such as rivers and lakes in tap water and its raw water, not food and drink (for example, Patent Documents 1 and 2). In these recovery methods, the target microorganism in the sample water is separated and concentrated by the hollow fiber membrane, the concentrated target microorganism is separated from the hollow fiber membrane by backwashing, and then the backwash solution in which the target microorganism is concentrated is used as the membrane. It is introduced into a filter, and the target microorganism is further separated, concentrated and recovered.

JP 2004-97087 A JP 2005-143379 A

  In Patent Documents 1 and 2, the target microorganisms are separated and concentrated not from food or drink but from drinking water such as tap water and rivers and lakes of the raw water. Thus, since the object of isolation | separation and concentration is water, many solid content is not contained like food and drink. Therefore, both hollow fiber membranes and membrane filters are used for separation and concentration of target microorganisms. On the other hand, foods and drinks contain a lot of solids, so far, the solids of foods and drinks (including suspensions of foods and drinks) have not been sufficiently removed and separated by filters such as food bacteria, Concentration was difficult. Therefore, it cannot be said that the accuracy of qualitative analysis and quantitative analysis of food bacteria contained in food and drink is high, and it is necessary to improve the accuracy by removing solids and separating and concentrating bacteria.

  The present invention has been made in view of the state of the prior art as described above, and removes most of the solid content from food and drink with a filter medium through which food bacteria pass, and then captures the filtrate with a filter medium through which food bacteria do not pass. It is another object of the present invention to provide a food bacteria separation and concentration device and a food bacteria separation and concentration method for separating the food bacteria from the filter medium by backwashing water, collecting the collected bacteria, and collecting the food bacteria.

The present invention is as follows.
1. A delivery container for food and drink;
A first filtration unit in which the food and drink delivered from the delivery container is fed, and at least part of the solid content contained in the food and drink is removed;
The first filtrate filtered by the first filtration unit, and the second filtration unit captures at least food bacteria out of food bacteria and spores contained in the food and drink;
A first pipe connecting the first filtration unit and the second filtration unit;
A second pipe for discharging the second filtrate filtered by the second filtration unit;
A backwash water delivery container disposed in the second pipe for feeding backwash water into the second filtration unit;
A flow path switching means disposed in the first pipe for switching the flow paths of the first filtrate and the backwash water;
A food bacteria separation comprising: a valve disposed in the second pipe and opened when the second filtrate is drained and closed when the backwash water is fed into the second filtration unit. Concentrator.
2. The filter medium provided in the first filtration part can be selected and exchanged according to the characteristics of the solid content contained in the food and drink, the filter medium provided in the first filtration part, and the second filtration part The above 1. wherein at least one of the provided filter media is a hollow fiber filter. Separation and concentration apparatus for food bacteria according to 1.
3. A surfactant is blended in at least one of the food and drink and the backwash water. Or 2. Separation and concentration apparatus for food bacteria according to 1.
4). A solid content removing step of feeding food and drink into the first filtration unit and removing at least a part of the solid content contained in the food and drink,
Bacteria capture step of sending the filtrate sent from the first filtration unit to the second filtration unit and capturing at least food bacteria out of food bacteria and spores contained in the food and drink,
At least the food bacteria out of the food bacteria and the spores captured by the filter medium provided in the second filtration unit are detached from the filter medium by backwashing water, and at least the food bacteria and the spores are removed. A method for separating and concentrating food bacteria, comprising a step of preparing a concentrate for obtaining the food bacteria concentrate.
5. The filter medium provided in the first filtration part can be selected and exchanged according to the characteristics of the solid content contained in the food and drink, the filter medium provided in the first filtration part, and the second filtration part 3. The above-mentioned 4. wherein at least one of the provided filter media is a hollow fiber filter. A method for separating and concentrating food bacteria according to 1.
6). 3. The surfactant described above is blended in at least one of the food and drink and the backwash water. Or 5. A method for separating and concentrating food bacteria according to 1.

The apparatus for separating and concentrating food bacteria according to the present invention includes a first filtration unit from which at least a part of solids contained in food and drink is removed, and at least food of food bacteria and spores contained in food and drink. And a second filtration part that captures bacteria (hereinafter abbreviated as food bacteria and the like), and backwash water is fed into the second filtration part.
Because of this configuration, qualitative analysis such as food bacteria in food and drink, solids with large dimensions that affect the accuracy of the analysis are removed from the specimen used for quantitative analysis, so the accuracy of the analysis Can be increased. Moreover, the 1st filtrate from which solid content was removed is sent into a 2nd filtration part, food bacteria etc. are capture | acquired, and the liquid which back-washed this with backwash water is used as a test substance. Therefore, food bacteria contained in food and drink can be separated very efficiently and a concentrated sample can be obtained, and the accuracy of analysis can be further improved.
Moreover, when at least one of the filter medium provided in the first filtration part and the filter medium provided in the second filtration part is a hollow fiber filter, the solid content can be efficiently removed from the food and drink, Food bacteria and the like in the first filtrate can also be efficiently captured.
Furthermore, when a surfactant is blended in at least one of the food and drink and the backwash water, depending on the type of the surfactant, the food bacteria captured by the filter medium provided in the second filtration unit Etc. can be backwashed efficiently, and food bacteria contained in food and drink can be efficiently separated and concentrated. Moreover, when a surfactant is blended in food and drink, although depending on the type of the surfactant, it is possible to efficiently remove the solid content in the first filtration part and pass through the filter medium such as food bacteria.

The method for separating and concentrating food bacteria according to the present invention includes a solid content removal step in the first filtration unit, a bacteria capture step in the second filtration unit, and food bacteria captured in the second filtration unit by backwashing the food bacteria. And a concentrated solution preparation step for obtaining a concentrated solution.
With such a configuration, food bacteria and the like are efficiently captured from the filtrate from which the solid content has been removed, and this is collected by backwashing. Therefore, separation and concentration of food bacteria and the like from food and drink are efficient. Thus, it is possible to improve the qualitative and quantitative analysis accuracy of food bacteria and the like in food and drink.
Moreover, when at least one of the filter medium provided in the 1st filtration part and the filter medium provided in the 2nd filtration part is a hollow fiber filter, and at least one of food and drink and backwash water is surface active. When the agent is blended, the same actions and effects as in the above-described separation and concentration apparatus are exhibited.

It is a typical front view for demonstrating the structure of the isolation | separation concentration apparatus of food bacteria.

[1] Food Bacteria Separation / Concentration Device The food bacteria separation / concentration device (100) of the present invention includes a food and drink (f) delivery container (1) and a food and drink (f) delivered from the delivery container (1). And a first filtration part (2) from which at least a part of the solid content contained in the food and drink (f) is removed. Moreover, the 1st filtrate (L1) filtered by the 1st filtration part (2) is sent in, and the 2nd filtration by which at least food bacteria are captured among food bacteria and spores contained in food and drink (f). Part (3).

  Furthermore, in order to discharge | emit the 1st piping (5) which connects a 1st filtration part (2) and a 2nd filtration part (3), and the 2nd filtrate (L2) filtered by the 2nd filtration part (3). 2nd piping (6). Moreover, it is arrange | positioned by the 2nd piping (6) and is equipped with the backwash water delivery container (4) for sending backwash water (w) into the 2nd filtration part (3). Furthermore, a flow path switching means (5a) disposed in the first pipe (5) for switching the flow paths of the first filtrate (L1) and the backwash water (w), and the second pipe (6) And a valve (6a) that is opened when the second filtrate (L2) is drained and closed when the backwash water (w) is sent to the second filtration part (3).

Hereinafter, the food bacteria separation and concentration apparatus of the present invention will be described in detail with reference to FIG.
The presence or absence of content, and when it is contained, the content is analyzed, and the hygienic indicator test for food bacteria to be tested includes general viable count, spore count, lactic acid count, coliform group, coliform There are measurements of enterococci and Pseudomonas aeruginosa. As a test for food poisoning pathogenic microorganisms, pathogenic Escherichia coli including enterohemorrhagic Escherichia coli O-157, Staphylococcus aureus, Salmonella spp., Clostridium spp. , Vibrio fulviaris and Vibrio cholera, Progiomonas sigueloides, Bacillus cereus, Campylobacter spp., Yersinia enterocolitica, Listeria monocytogenes, Shigella, Salmonella typhi, and Paratyphi A. Among these bacteria, there are some bacteria, such as Staphylococcus aureus, that are preferably not detected in the Food Sanitation Law established by the Ministry of Health, Labor and Welfare, but many must not be detected. From such a viewpoint, it is necessary to increase the accuracy of the inspection. In addition, even in the self-inspection performed in the process control of the food manufacturer, a quick and highly accurate inspection is required.

  Moreover, it is preferable that the food / beverage (f) does not contain the spore which a part microbe forms other than food bacteria. Examples of the bacteria that form such spores include bacteria of the genus Amphibacillus, Bacillus, Clostridium, Sporosarcina. It is preferable that spores are not detected because the spores have high heat resistance and cannot be completely inactivated even when treated at high temperature, and the food and drink (f) is often contaminated by the spores.

  The food / drink (f) is not particularly limited, and all food / drinks ingested by humans (including raw materials, process products, water for food production, etc.) are to be examined. When the food and drink (f) is a drink, it can be stored in the delivery container (1) for the food and drink (f) as it is and sent to the first filtration section (2). In addition, when the food and drink (f) is a solid or semi-solid food, a liquid such as a physiological saline solution having a mass ratio of 5 to 15 times, particularly 8 to 12 times, is added to the food and food by stomacher treatment or the like. Is then pulverized, then accommodated in the delivery container (1) and delivered to the first filtration section (2). In addition, when a stomacher treatment or the like is performed, a liquid component such as water contained in food is mixed into physiological saline or the like, and this liquid component is directly used in the first filtrate (L1) and the second filtrate (L2) described later. ) And drained together with physiological saline and the like.

  The delivery container (1) is not particularly limited, and a predetermined amount of food (f) can be accommodated, and the food (f) is delivered to the first filtration unit (2) by pressurizing the upper space. Containers that can be used can be used. As a delivery container (1), a syringe is mentioned, for example. If it is a syringe, it has an accurate scale, and can easily inhale a predetermined amount of food and drink (f), and the amount of food and drink (f) delivered to the first filtration unit (2). It is preferable because it is easy to check. Furthermore, automation is possible by attaching a drive that can control the movement of the plunger of the syringe.

  The 1st filtration part (2) into which food and drink (f) is sent from the delivery container (1) is formed at the end of the delivery container (1) in order to feed the food and drink (f) into the first filtration part (2). And an outer container provided with a delivery port to which the delivered delivery port is connected. The material of the outer container is not particularly limited, and various synthetic resins or metals are used. Moreover, the filter medium (2a) is disposed inside the outer container, the food and drink (f) sent from the inlet is filtered, and the first filtrate (L1) is sent out from the outlet of the outer container, It circulates through the first pipe (5) and is sent to the second filtration part (3).

  At a 1st filtration part (2), at least one part of the solid content contained in food and drink (f) is removed. This at least a part means that a solid content having a large size, that is, a solid content that becomes a contaminant from the viewpoint of accuracy of analysis does not pass through the filter medium (2a) and is captured. On the other hand, even if it is solid content, it is solid content with a small dimension which permeate | transmits a filter medium (2a), and solid content which does not have big influence on analysis precision permeate | transmits a filter medium (2a), and the 1st filtrate (L1 ) And sent to the second filtration unit (3) together with food bacteria and the like.

  As described above, in order to obtain a first filtration part (2) in which solid content that can be said to be a contaminant is removed as much as possible and food bacteria and the like preferably pass through the filter medium (2a), the filter medium ( The opening of 2a) is preferably 5 to 50 μm, particularly 6 to 20 μm, and more preferably 8 to 12 μm. Moreover, the ratio which can permeate | transmit foodstuff bacteria etc. through a filter medium (2a) measures the number of bacteria of the food / beverage (f) which passed the filter medium (2a), and the food / beverage before passing the filter medium (2a) ( This can be confirmed by calculating the ratio of f) to the number of bacteria. Moreover, a filter medium (2a) can be selected and replaced | exchanged according to the characteristic of solid content contained in food and drink (f).

  The second filtration unit (3) also includes an exterior container, and a filter medium (3a) is disposed inside the exterior container. The material of an exterior container is not specifically limited, Various synthetic resins or metals are used similarly to the 1st filtration part (2). Furthermore, the end portion of the first pipe (5) is connected to the outer container, and the first filtrate (L1) is sent to the second filtration unit (3) by the channel setting of the channel switching means (5a). It is. Moreover, the 2nd filtrate (L2) filtered by the filter medium (3a) distribute | circulates the 2nd piping (6), and is drained. In this case, the valve (6a) is open.

  In the second filtration unit (3), food bacteria and the like contained in the first filtrate (L1) are captured. Moreover, at least a part of the small-sized solid content that has passed through the filter medium (2a) and contained in the first filtrate (L1) is also captured. In the second filtration part (3), it is preferable that food bacteria and the like are captured by the filter medium (3a) as much as possible, and the whole amount of food bacteria and the like is captured by the filter medium (3a) and becomes the second filtrate. (L2) preferably contains no food bacteria or the like. As described above, in order to obtain the second filtration part (3) in which the whole amount of food bacteria and the like is preferably captured by the filter medium (3a), the opening of the filter medium (3a) is 0.001 to 0.5 μm. In particular, it is preferably 0.05 to 0.45 μm, more preferably 0.10 to 0.45 μm. Furthermore, the rate at which food bacteria and the like are captured by the filter medium (3a) is determined by measuring the number of bacteria in the food (f) (waste liquid) that has passed through the filter medium (3a), and the food and drink before passing through the filter medium (3a). This can be confirmed by calculating the ratio of (f) to the number of bacteria.

  Examples of the form of the filter medium (2a) and the filter medium (3a) include hollow fiber, bobbin, roll, pleat and disk (flat membrane) types. The material of each of these filter media is not particularly limited. Examples of the material of the filter medium include polyolefin resins such as polyethylene and polypropylene, and polyamide resins such as nylon 6 and nylon 66. Moreover, the nonwoven fabric and net material which use cotton, glass fiber, etc. can also be used. Furthermore, in the case of the filter medium (3a) for performing precise filtration, resin materials such as polyether sulfone, polysulfone, polytetrafluoroethylene, polyvinylidene fluoride, polycarbonate, and cellulose acetate that can uniformly prepare the pore diameter are used. It can be used alone or in combination with a nonwoven fabric or a net material.

  As the filter medium (2a) and the filter medium (3a), the filter medium of any material in any of the above forms may be used. The filter medium (2a) and the filter medium (3a) are used in any of the above forms of the filter medium, the removal efficiency of the solid content contained in the food and drink (f) by the filter medium (2a), and the filter medium It is preferable to select and use from the viewpoints of the capture efficiency of food bacteria and the like by (3a) and the elimination efficiency of food bacteria and the like from the filter medium (3a) by backwash water.

  The second pipe (6) is provided with a backwash water delivery container (4) for feeding backwash water (w) to the second filtration section (3). The backwash water delivery container (4) is disposed at the end of the second pipe (6) connected to the outer container of the second filtration part (3), and the backwash water is supplied to the second filtration part (3). (W) is sent. The backwash water delivery container (4) is not particularly limited, and the backwash water (w) can be sent to the second filtration unit (3) by pressurizing the upper space, and a predetermined amount of backwash water is provided. A container capable of feeding (w) into the second filtration part (3) can be used.

  An example of the backwash water delivery container (4) is a syringe. If it is a syringe, since the exact scale is attached | subjected and a predetermined amount of backwash water (w) can be easily sent into a 2nd filtration part (3), it is preferable. Furthermore, if a drive unit that can control the movement of the plunger of the syringe is attached, backwashing can be automated. Backwash water (w) includes physiological saline, ion-exchanged water, distilled water, peptone-added physiological saline, phosphate buffered diluted water, phosphate buffered physiological saline, etc. stipulated by the Food Sanitation Law. Can be used. In addition, by feeding backwash water (w) into the second filtration unit (3), food bacteria captured by the filter medium (3a) is detached from the filter medium (3a) and collected as a concentrated liquid such as food bacteria. can do. In this case, the bacteria concentrate can be collected from the other end not connected to the second filtration part (3) of the first pipe (5) by setting the flow path of the flow path switching means (5a). Further, the valve (6a) is closed when the backwash water (w) is fed.

  In addition, the flow path for sending the first filtrate (L1) to the second filtration part (3), the backwash water (w) is sent to the second filtration part (3), and the end of the first pipe (5) Examples of the flow path switching means (5a) used for switching to the flow path for collecting the bacterial concentrate from the above include a three-way valve.

  Further, a check valve is provided near the position where the flow path of the first pipe (5) is branched, and on the second filtration part (3) side, and the bacteria are separated from the position where the flow path is branched. By providing a valve on the side from which the concentrate is collected, it can also function as the flow path switching means (5a). In this case, the second filtrate (L2) can be discharged as drainage by closing the valve provided on the side where the bacteria concentrate is collected and opening the valve 6a. On the other hand, when sending backwash water (w) to the second filtration part (3) and collecting the bacteria concentrate, the valve 6a is closed and the valve provided on the side where the bacteria concentrate is collected is opened. Thus, the bacterial concentrate can be collected.

  As described above, food bacteria and the like captured by the filter medium (3a) by the backwash water (w) can be detached from the filter medium (3a). In this case, it is preferable that 90% or more, particularly 95% or more of the food bacteria and the like captured by the filter medium (3a) is desorbed from the filter medium (3a), and it is more preferable that the entire amount is desorbed. Although it is not easy to desorb the entire amount, it is possible to desorb 95% or more. Moreover, the ratio which can be made to detach | desorb is the number of living bacteria of the sample liquid before filtering with a filter medium (3a), and the number of living bacteria of the microbe concentration liquid obtained by carrying out backwashing after filtering with a filter medium (3a). And can be confirmed by calculating the ratio.

Furthermore, in any case of food and drink (f) prepared by processing fluids such as beverages and solid and semi-solid foods by stomacher treatment or the like (f), the concentration rate of the bacterial concentrate is: The volume of food and drink (f) that is housed in the delivery container (1), flows through the first filtration part (2) and is fed into the second filtration part (3), and the bacteria concentrate obtained by backwashing From the volume, it can be calculated by the following formula. This concentration ratio is preferably 5 times or more, particularly preferably 10 times or more, and more preferably 50 times or more and higher. Thus, if it is a bacteria concentration liquid with a high concentration magnification, even if it is food / beverage (f) which contains only a small amount of bacteria, it will become possible to analyze with high precision.
Concentration magnification (times) = [volume of food and drink (f) housed in the delivery container (1) and circulated through the first filtration part (2) and sent to the second filtration part (3)] / [backwashing Volume of bacterial concentrate obtained in this way]

  Moreover, the qualitative and quantitative analysis methods for food bacteria and the like contained in the bacterium concentrate and the analytical equipment used therefor are not particularly limited. For example, an optical detector such as a microcolony inspection device or an inspection device based on a flow cytometry method can be used. Furthermore, the bacteria concentrate can be collected in vials, ampoules, etc. and used for analysis. The analysis method may be a conventional plate colony counting method or ATP method. In addition, the bacteria concentrate can be analyzed by circulating a tube connected to the first pipe 5 and directly feeding it to an analytical instrument.

  A surfactant can be blended in at least one of the food and drink (f) and the backwash water (w). Thereby, food bacteria and the like can be separated and collected more efficiently, and a concentrated liquid having a higher concentration can be obtained. Surfactant may be blended in food and drink (f) and backwash water (w), or may be blended only in either one. In order to efficiently collect food bacteria and the like and to obtain a concentrated liquid with a higher concentration, it is preferable to mix the surfactant with at least backwash water (w).

  The surfactant is not particularly limited, but it is preferable to select and use a surfactant having a good collection efficiency depending on the material of food bacteria, food and drink, and filter media. Examples of the surfactant include nonionic surfactants such as sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, glycerin fatty acid ester, and polyethylene glycol fatty acid ester. Specific examples of this surfactant include, for example, sorbitan monooleate, sorbitan monolaurate, sorbitan monostearate, polyoxyethylene (20) sorbitan monostearate, polyoxyethylene (20) sorbitan tristearate, poly Oxyethylene (20) sorbitan monolaurate, polyoxyethylene (20) sorbitan monooleate, polyoxyethylene (20) sorbitan trioleate, glycerol α-monostearate, polyethylene glycol (2) monostearate, polyethylene glycol ( 10) Monostearate, polyethylene glycol (25) monostearate, polyethylene glycol (23) monocetyl ether and the like. Further, the concentration of the surfactant in the backwash water (w) is not particularly limited, but may be 0.001 to 0.1% by mass, particularly 0.003 to 0.05% by mass.

[2] Method for Separating and Concentrating Food Bacteria The method for separating and concentrating food bacteria of the present invention includes a solid content removing step for removing at least a part of the solid content contained in the food and drink (f), and the food and drink (f). Bacteria capture step for capturing food bacteria contained in the filter, and food bacteria captured by the filter medium (3a) are desorbed from the filter medium (3a) by backwash water (w) to obtain a concentrated liquid A liquid preparation step.

  The apparatus used for the method for separating and concentrating food bacteria of the present invention is not particularly limited, and for example, the apparatus for separating and concentrating food bacteria of the present invention (100) can be used. In this case, the solid content removing step is performed by the feeding container (1) of the food and drink (f) and the first filtering unit (2), and the bacteria capturing step is performed by the second filtering unit (3), and the concentrated solution is prepared. The process is performed as described above by the second filtration unit (3) and the backwash water delivery container (4).

  Moreover, the method for separating and concentrating food bacteria of the present invention usually includes the following other steps in addition to the above-described three essential steps. For example, the food and drink (f) subjected to the stomacher process or the like as necessary is provided with a food and drink sending process for sending the food and drink (f) from the sending container (1) to the first filtration unit (2). Moreover, the liquid feeding process which sends the filtrate (L1) from which at least one part of solid content was removed from a 1st filtration part (2) to a 2nd filtration part (3) is provided. Furthermore, the liquid filtration process (L2) by which the food bacteria etc. were capture | acquired by the 2nd filtration part is provided with the drainage process discharged | emitted from the edge part of the 2nd piping 6 as a drainage liquid. Moreover, the microbe concentration liquid collection process which aseptically collects the microbe concentration liquid which flows out from the edge part of the 1st piping 5 and the analysis process which analyzes qualitatively and quantitatively with an analytical instrument are provided.

Hereinafter, the present invention will be described specifically by way of examples.
Example 1
Using the food bacteria separation and concentration apparatus 100 illustrated in FIG. 1, a bacterial concentrate was prepared using the following food and drink f.
As a food, raw vegetables were collected in a 25 g stomacher-treated bag, 225 mL of physiological saline 9 times in mass ratio was added thereto, and pulverized by the stomacher treatment. Thereafter, the physiological saline containing the crushed raw vegetables was transferred from the stomacher bag to a beaker, and this food and drink f was inhaled into a 100 mL syringe used as the delivery container 1.

  Next, the suction port of the syringe was inserted into the inlet provided in the outer container of the first filtration unit 2, and the food and drink f were fed into the first filtration unit 2. As the exterior container, a resin container (the shape in the plane direction is circular) in which a flat film having a diameter of 25 mm can be installed is used as shown in FIG. In addition, a first filter medium 2a made of nylon resin and having an aperture of 10 μm was disposed in the middle portion of the outer container in the thickness direction. Thereby, the solid content of the dimension which can be said to be a contaminant which hinders analysis accuracy was removed, and the 1st filtrate L1 containing food bacteria etc. and the solid content of a small dimension was obtained. Thereafter, the first filtrate L1 is circulated in the first pipe 5 connected to the lower surface side of the outer container, the flow path of the three-way valve 5a disposed in the first pipe 5 is adjusted, and the second filtration is performed. It was fed into the second filtration unit 3 from the first pipe 5 whose one end was connected to the exterior container of the unit 3.

  The second filtration unit 3 includes a column-shaped outer container, and a hollow fiber filter (hollow fiber filter medium) made of polysulfone resin and having a mesh size of 0.4 μm is disposed as the second filter medium 3a inside the outer container. As a result, the food bacteria and the like and at least a part of the small-sized solid content are captured by the second filter medium 3a, and only the liquid component is substantially connected from the second filtration unit 3 to the outer container 6 by the second pipe 6. It circulated through the inside and was discharged as drainage from the end of the second pipe 6 through the opened valve 6a.

  Subsequently, the physiological saline which is the backwash water w was sent into the 2nd filtration part 3 from the backwash water delivery container 4 inserted in the feed port of the backwash water w provided in the 2nd piping 6. FIG. A syringe having a capacity of 10 mL was used as the backwash water delivery container 4. In this case, the valve | bulb of the flow path connected with the valve | bulb 6a and the 1st filter medium 2a was closed, the microbe concentration liquid was flowed out from the edge part of the 1st piping 5, and it extract | collected to the vial. In addition, the bacterial concentrate collected in this way was subjected to analysis.

  In this embodiment, food and drink f prepared by stomacher treatment using physiological saline is sent twice to the first filtration unit with a 100 mL syringe used as the delivery container 1, and a total of 200 mL of food and drink f is used. did. And the food bacteria etc. which were contained in this 200 mL food-drinks f were removed from the filter medium 3a with the physiological saline used as the backwash water w, were collected, and 1 mL of bacteria concentrated liquid was extract | collected. . Therefore, when it is assumed that the total amount of food bacteria and the like passes through the filter medium 2a and is captured by the filter medium 3a, and the total amount of food bacteria and the like is detached from the filter medium 3a by the backwash water w and collected. The food bacteria contained in the concentrate is concentrated 200 times.

Test example 1
A test solution was prepared by mixing 0.5 ml of E. coli in 2000 mL of physiological saline so as to be present in 1 mL. Thereafter, using this test solution, a bacterial concentrate was obtained in the same steps as in Example 1, collected in a vial, and quantitatively analyzed by a plate culture method. And the recovery rate of the bacteria was calculated from the following formula from the number of bacteria in the test solution and the number of bacteria in the bacteria concentrate. The recovery rate was 75%.
Bacterial recovery rate (%) = [(the number of bacteria in the bacteria concentrate) / the number of bacteria in the test solution 2000 mL] × 100

  Moreover, various surfactants were mix | blended with the physiological saline used as the backwash water w, the bacteria concentrate was obtained similarly, and it extract | collected to the vial. Thereafter, quantitative analysis was performed by a plate culture method, and the recovery rate was calculated. Table 1 shows the recovery rates when each surfactant is used and the recovery rate when the surfactant is not blended is 100%.

  As shown in Table 1, although there was a difference depending on the type of the surfactant, it was confirmed that the recovery rate was improved by adding the surfactant to the backwash water w.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention depending on the purpose, application, and the like. For example, as the delivery container 1 and the backwash water delivery container 4, various liquid containers equipped with a liquid feed pump and a flow meter and capable of accurately adjusting the flow rate can be used.

  The present invention can be used in the technical fields of qualitative and quantitative analysis of food bacteria contained in food and drink. In particular, the solid content that is contained in food and drink and becomes a contaminant that hinders the analysis accuracy is removed in advance, and a liquid in which bacteria are concentrated is used, so that the analysis accuracy can be improved.

  DESCRIPTION OF SYMBOLS 100; Separation and concentration apparatus of food bacteria, 1; Delivery container, f; Food and drink after stomacher treatment, 2; First filtration part, 2a; Filter medium provided in the first filtration part, 3; Second filtration part, 3a A filter medium provided in the second filtration unit, 4; backwash water delivery container, w; backwash water, 5; first pipe, 5a; flow path switching means (three-way valve), 6; second pipe, 6a; valve.

Claims (6)

A delivery container for food and drink;
A first filtration unit in which the food and drink delivered from the delivery container is fed, and at least part of the solid content contained in the food and drink is removed;
The first filtrate filtered by the first filtration unit, and the second filtration unit captures at least food bacteria out of food bacteria and spores contained in the food and drink;
A first pipe connecting the first filtration unit and the second filtration unit;
A second pipe for discharging the second filtrate filtered by the second filtration unit;
A backwash water delivery container disposed in the second pipe for feeding backwash water into the second filtration unit;
A flow path switching means disposed in the first pipe for switching the flow paths of the first filtrate and the backwash water;
And a valve connected to the second pipe and opened when the second filtrate is drained and closed when the backwash water is fed into the second filtration section. apparatus.   The filter medium provided in the first filtration part can be selected and exchanged according to the characteristics of the solid content contained in the food and drink, the filter medium provided in the first filtration part, and the second filtration part The apparatus for separating and concentrating food bacteria according to claim 1, wherein at least one of the provided filter media is a hollow fiber filter.   The apparatus for separating and concentrating food bacteria according to claim 1 or 2, wherein a surfactant is blended in at least one of the food and drink and the backwash water. A solid content removing step of feeding food and drink into the first filtration unit and removing at least a part of the solid content contained in the food and drink,
Bacteria capture step of sending the filtrate sent from the first filtration unit to the second filtration unit and capturing at least food bacteria out of food bacteria and spores contained in the food and drink,
At least the food bacteria out of the food bacteria and the spores captured by the filter medium provided in the second filtration unit are detached from the filter medium by backwashing water, and at least the food bacteria and the spores are removed. A method for separating and concentrating food bacteria, comprising a step of preparing a concentrate for obtaining the food bacteria concentrate.   The filter medium provided in the first filtration part can be selected and exchanged according to the characteristics of the solid content contained in the food and drink, the filter medium provided in the first filtration part, and the second filtration part The method for separating and concentrating food bacteria according to claim 4, wherein at least one of the provided filter media is a hollow fiber filter.   The method for separating and concentrating food bacteria according to claim 4 or 5, wherein a surfactant is blended in at least one of the food and drink and the backwash water.

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