Method for determining whether the total number of colonies of long shelf life chicken exceeds the standard

Abstract

The application discloses a kind of detection methods for determining whether the total number of colonies of long shelf life chicken is over standard, comprising the following steps: step A, prepare standard sample and sample to be detected, respectively take out chicken, retain the chicken soup contained in packaging bag for later use;Step B, heat the chicken soup in two samples to 30-40 DEG C in 30-40 DEG C constant temperature water bath respectively, after filtration, respectively pour into sample pool, shake uniformly;Step C, respectively detect standard sample and sample to be detected with transmittance instrument, read transmittance value, according to the difference of the transmittance value of both, make result determination, the application determines whether the total number of colonies is over standard method Simple operation, after selecting standard sample, the detection time of subsequent sample to be detected is generally within 30 minutes, the detection time of traditional national standard GB4789.2 is about 48 hours, the detection time of total number of colonies of subsequent any sample to be detected is significantly shortened.

Description

Technical Field

[0001] This invention belongs to the technical field of meat products, specifically relating to a method for determining whether the total bacterial count of long-shelf-life chicken exceeds the standard. Background Technology

[0002] Currently, commercially available long-shelf-life chicken generally has a shelf life of 6-12 months. Within the shelf life, samples are taken to test the total bacterial count. This test is generally conducted according to the national standard GB4789.2. The sample is diluted with different multiples, incubated at a constant temperature with a culture medium, and then counted. The total bacterial count is then used to determine whether it exceeds the standard. The test takes about 48 hours. This method is complex and time-consuming. Summary of the Invention

[0003] The purpose of this invention is to provide a method for determining whether the total bacterial count in long-shelf-life chicken exceeds the standard, so as to solve the problems of complex operation and long detection time of existing chicken bacterial count detection methods mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a method for determining the total bacterial count in long-shelf-life chicken, comprising the following steps:

[0005] Step A: Prepare standard samples and samples to be tested. Remove the chicken meat separately, and keep the chicken broth contained in the packaging bag for later use.

[0006] Step B: Heat the chicken broth from the two samples to 30-40℃ in a constant temperature water bath, filter, pour into the sample cells, and shake well.

[0007] Step C: Use a transmittance meter to test the standard sample and the sample to be tested respectively, read the transmittance values, and determine the result based on the difference between the two transmittance values.

[0008] Furthermore, the standard sample selected in step A is a long-shelf-life chicken product made with the same process and formula as the sample to be tested; it needs to be packaged and sealed intact, and tested using the national standard method GB4789.2, with the total bacterial count not exceeding the standard.

[0009] Furthermore, the amount of chicken broth contained in the standard sample and the sample to be tested selected in step A is not less than 25 grams.

[0010] Furthermore, step B requires heating the chicken broth to 30-40°C in a constant temperature water bath to make the chicken broth a flowing liquid, and the heating time should not exceed 30 minutes.

[0011] Furthermore, in step B, the filtration process requires filtering the sample using a 40-80 mesh filter to remove any potentially large pieces of meat and seasonings.

[0012] Furthermore, the sample cell in step B is a transparent glass sample cell with a length, width, and height of 3 cm, with a cover, made of glass, and with a light transmittance of over 95%.

[0013] Furthermore, in step C, the transmittance meter uses ordinary visible light as the light source, and the transmittance measurement range is 10%-100%.

[0014] Furthermore, in step C, the sample cell must be clamped during transmittance meter testing.

[0015] Furthermore, the determination method for step C is as follows:

[0016] a. If the transmittance of the sample to be tested is ≥15% lower than that of the standard sample, the total bacterial count of the sample to be tested is deemed to exceed the standard.

[0017] b. If the transmittance of the sample to be tested is 5-15% lower than that of the standard sample, it cannot be determined whether the total bacterial count exceeds the standard, and this invention is not applicable.

[0018] c. If the transmittance of the sample to be tested is ≤5% lower than that of the standard sample, or higher than that of the standard sample, the total bacterial count of the sample to be tested is determined to be within the standard range.

[0019] The main principle of this method is as follows: When chicken meat is contaminated with bacteria, the presence of other bacteria will cause microbial activity in the chicken broth inside the packaging, producing a large amount of metabolic substances. This makes the chicken broth more turbid, increasing its turbidity and thus reducing its light transmittance. By comparing the light transmittance value with that of a standard sample, it is possible to quickly determine whether the total bacterial count of the sample exceeds the standard.

[0020] Compared with existing technologies, this invention provides a method for determining whether the total bacterial count in long-shelf-life chicken exceeds the standard, which has the following beneficial effects:

[0021] The method for determining whether the total bacterial count exceeds the standard is simple to operate. After the standard sample is selected, the detection time for subsequent samples is generally within 30 minutes. The traditional national standard GB4789.2 takes about 48 hours. The detection time for the total bacterial count of any subsequent sample is significantly shortened. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] This invention provides a method for determining whether the total bacterial count in long-shelf-life chicken exceeds the standard. The method for detecting the total bacterial count in long-shelf-life chicken includes the following steps:

[0024] Step A: Prepare standard samples and samples to be tested. Remove the chicken meat separately, and keep the chicken broth contained in the packaging bag for later use.

[0025] Step B: Heat the chicken broth from the two samples to 30-40℃ in a constant temperature water bath, filter, pour into the sample cells, and shake well.

[0026] Step C: Use a transmittance meter to test the standard sample and the sample to be tested respectively, read the transmittance values, and determine the result based on the difference between the two transmittance values.

[0027] Furthermore, the standard sample selected in step A is a long-shelf-life chicken product made using the same process and formula as the sample to be tested. It must have intact packaging and be properly sealed, and be tested using the national standard method GB4789.2, with the total bacterial count not exceeding the standard.

[0028] Furthermore, the amount of chicken broth contained in the standard sample and the sample to be tested selected in step A shall not be less than 25 grams.

[0029] Further, step B requires heating the chicken broth to 30-40℃ in a constant temperature water bath until it becomes a flowing liquid. The heating time should not exceed 30 minutes.

[0030] Furthermore, in step B, the filtration process requires filtering the sample using a 40-80 mesh filter to remove any potentially large pieces of meat and seasonings.

[0031] Furthermore, the sample cell in step B is a transparent glass sample cell with a length, width, and height of 3 cm, with a cover, made of glass, and with a light transmittance of over 95%.

[0032] Furthermore, in step C, the transmittance meter uses ordinary visible light as the light source, and the transmittance measurement range is 10%-100%.

[0033] Furthermore, in step C, the sample cell must be clamped during transmittance meter testing.

[0034] Furthermore, the determination method for step C is as follows:

[0035] a. If the transmittance of the sample to be tested is ≥15% lower than that of the standard sample, the total bacterial count of the sample to be tested is deemed to exceed the standard.

[0036] b. If the transmittance of the sample to be tested is 5-15% lower than that of the standard sample, it cannot be determined whether the total bacterial count exceeds the standard, and this invention is not applicable.

[0037] c. If the transmittance of the sample to be tested is ≤5% lower than that of the standard sample, or higher than that of the standard sample, the total bacterial count of the sample to be tested is determined to be within the standard range.

[0038] The main principle of this method is as follows: When chicken meat is contaminated with bacteria, the presence of other bacteria will cause microbial activity in the chicken broth inside the packaging, producing a large amount of metabolic substances. This makes the chicken broth more turbid, increasing its turbidity and thus reducing its light transmittance. By comparing the light transmittance value with that of a standard sample, it is possible to quickly determine whether the total bacterial count of the sample exceeds the standard.

[0039] Example 1

[0040] The sample to be tested was vacuum-packed brand A braised chicken. The standard sample was a commercially available vacuum-packed brand A braised chicken from the same batch (the total bacterial count was tested according to GB 4789.2 and the result was not detected, indicating the total bacterial count did not exceed the standard). The packaging of the sample to be tested was cut open, the chicken meat was removed, and 25 grams of chicken broth from the bag was taken. The broth was heated in a 30-40℃ constant temperature water bath to 30℃ for 8 minutes. The seasoning residue in the solution was filtered through a 40-mesh filter cloth. 20 grams of the sample was taken with a pipette and dropped into the sample cell. The sample was then clamped with a transmittance meter for testing. The transmittance was 67%. The transmittance of the standard sample was 70% using the same method. The transmittance of the sample to be tested was 3% lower than that of the standard sample, and the result was determined to be that the total bacterial count did not exceed the standard.

[0041] In the control experiment 1, the sample to be tested was tested according to the national standard GB4789.2. The total number of colonies was not detected, and the result was that the total number of colonies did not exceed the standard.

[0042] Example 2

[0043] The sample to be tested was vacuum-packed brand B braised chicken. The standard sample was a commercially available vacuum-packed brand B braised chicken from the same batch (the total bacterial count was tested according to GB 4789.2 and the result was not detected, indicating the total bacterial count did not exceed the standard). The packaging of the sample to be tested was cut open, the chicken meat was removed, and 25 grams of chicken broth from the bag was taken. The broth was heated in a 30-40℃ constant temperature water bath to 35℃ for 12 minutes. The seasoning residue in the solution was filtered through a 60-mesh filter cloth. 20 grams of the sample was taken with a pipette and dropped into the sample cell. The sample was then clamped with a transmittance meter for testing. The transmittance was 63%. The transmittance of the standard sample was 61% using the same method. The transmittance of the sample to be tested was 2% higher than that of the standard sample, and the result was determined to be that the total bacterial count did not exceed the standard.

[0044] In the control experiment 2, the sample to be tested was tested according to the national standard GB4789.2. The total number of colonies was not detected, and the result was that the total number of colonies did not exceed the standard.

[0045] Example 3

[0046] The sample to be tested was a vacuum-packed braised chicken produced in a laboratory pilot test. The standard sample was a vacuum-packed braised chicken sample of brand C with the same formula and process (the total bacterial count of the product was tested according to GB 4789.2, and the result was not detected, and the total bacterial count did not exceed the standard). The packaging of the sample to be tested was cut open, the chicken meat was taken out, and 25 grams of the residual chicken broth in the bag was taken. The broth was heated to 40°C in a constant temperature water bath at 30-40°C for 18 minutes. The seasoning residue in the solution was filtered through an 80-mesh filter cloth. 20 grams of the sample was taken with a pipette and dropped into the sample cell. The sample was clamped with a transmittance meter and tested. The transmittance was 48%. The transmittance of the standard sample was 67% using the same method. The transmittance of the sample to be tested was 19% lower than that of the standard sample, and the result was that the total bacterial count exceeded the standard.

[0047] In control experiment 3, the samples to be tested were tested according to the national standard GB4789.2, and the total bacterial count was 58 × 10⁻⁶. 5 The result was that the total bacterial count exceeded the standard.

[0048] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for determining whether the total bacterial count in long-shelf-life chicken exceeds the standard. Includes, characterized in that: Step A: Prepare standard samples and samples to be tested. Remove the chicken meat separately, and keep the chicken broth contained in the packaging bag for later use. Step B: Heat the chicken broth from the two samples to 30-40℃ in a constant temperature water bath, filter, pour into the sample cells, and shake well. Step C: Use a transmittance meter to test the standard sample and the sample to be tested respectively, read the transmittance values, and determine the result based on the difference between the two transmittance values; The standard sample selected in step A is a long-shelf-life chicken product made with the same process and formula as the sample to be tested; it needs to be packaged and sealed intact, and tested using the national standard method GB4789.2, with the total bacterial count not exceeding the standard; The amount of chicken broth in the standard sample and the sample to be tested selected in step A shall not be less than 25 grams. Step B requires heating the chicken broth to 30-40℃ in a constant temperature water bath to make the chicken broth a flowing liquid; the heating time should not exceed 30 minutes. The filtration process in step B requires filtering the sample with a 40-80 mesh filter to remove any large pieces of meat and seasonings that may be present. The sample cell in step B is a transparent glass sample cell with a length, width, and height of 3 cm, with a cover, made of glass, and with a light transmittance of over 95%. In step C, the transmittance meter uses ordinary visible light as its light source, and the transmittance measurement range is 10%-100%. In step C, the sample cell must be clamped during transmittance meter testing; The determination method for step C is as follows: a. If the transmittance of the sample to be tested is ≥15% lower than that of the standard sample, the total bacterial count of the sample to be tested is determined to be excessive; b. If the transmittance of the sample to be tested is 5-15% lower than that of the standard sample, it cannot be determined whether the total bacterial count exceeds the standard, and this method is not applicable. c. If the transmittance of the sample to be tested is ≤5% lower than that of the standard sample, or higher than that of the standard sample, the total bacterial count of the sample to be tested is determined to be within the standard range.