SN/T 2552.2-2010Microbiological examination method for milk and milk products hygiene. Part 2: Preparation of test samples, initial suspensions and decimal dilutions (English PDF)

Foreword

SN/T 2552 "Milk and dairy products Hygienic science test methods" is divided into thirteen sections.

--- Part 1. Guidance on sampling;

--- Part 2. Preparation of test sample dilution;

--- Part 3. yeast, mold colony count;

--- Part 4. Psychrophile microbial colony counts;

--- Part 5. Salmonella testing;

--- Part 6. Citrobacter inspection;

--- Part 7. Enterobacter cloacae inspection;

--- Part 8. Proteus mirabilis and inspection;

--- Part 9. Klebsiella test;

--- Part 10. Enterobacter sakazakii immunofluorescence test;

--- Part 11. Bacillus cereus Isolation and counting;

--- Part 12. monocytogenes Listeria detection and counting;

--- Part 13. Pseudomonas Isolation and counting.

This section is SN/T 2552 Part 2.

This section drafted in accordance with GB/T 1.1-2009 given rules.

This part of ISO 8261:2001 "Milkandmilkproducts-Generalguidanceforthepreparationoftest samples, initialsuspensionsanddecimaldilutionsformicrobiologicalexamination "consistent degree of modification Use, the main differences are as follows.

--- According to GB/T 1.1 standard and the Chinese habit for some formatting has been modified;

--- Some of the statements apply to international standards to apply to our standard formulation;

--- Deletion of Article 4 of the original principle.

This section proposed and managed by the National Certification and Accreditation Administration Committee.

This part of the Chinese Academy of Inspection and Quarantine, Shanxi People's Republic of China Exit Inspection and Quarantine, People's Republic of China Jiangsu Entry-Exit Inspection and Quarantine People's Republic of China, Shandong, Inner Mongolia, People's Republic of China Entry-Exit Inspection and Quarantine Bureau, People's Republic of China Tianjin Entry-Exit Inspection and Quarantine People's Republic of China Shanghai, People's Republic of China Shenzhen Entry-Exit Inspection and Quarantine of Guangxi People's Republic of China, People's Republic of China Jilin Entry-Exit Inspection and Quarantine Bureau, People's Republic of China Guangdong Entry-Exit Inspection and Quarantine Bureau, People's Republic of China Fujian Exit Inspection and Quarantine is responsible for drafting.

1 Scope

This section SN/T 2552 specifies the method of sample preparation and dilution of milk and dairy products for microbiological examination.

This section applies to milk and dairy products used to prepare the diluted sample for microbiological examinations.

2 Normative references

The following documents for the application of this document is essential. For dated references, only the dated version suitable for use herein Member, undated references, the latest edition (including any amendments) applies to this document.

The total number of school inspection colonies GB 4789.2 national food safety standards of food hygiene microbiologically SN/T 2552.1 milk and dairy hygiene microbiology test methods - Part 1. Guidance on sampling

3 Terms and Definitions

The following terms and definitions apply to this document.

Laboratory sample laboratorysamples Samples sent to the laboratory for testing or examination.

Breast milk

Normal breast secretions extruded from a mammal, no additives and not extract any component from it.

Dairy milkproduct

With milk as raw material, the use of all or part of component processing from the liquid, semi-solid or solid products.

The initial suspension (initial dilution) Weighed sample to be detected or quantified after mixed with 9 volumes of dilutions from a suspension, solution or eluent. If there are large particles, may Stirring. In some cases, if 1.9 suspensions too viscous, can increase the volume of diluent; if need thicker than 1.9 first Dilution in order to obtain the test results, it is appropriate to reduce the dilution volume, but the description of the test results should take into account these factors. in case the number of bacteria per gram of sample is less than 10 uses the first dilution; in the case of lower bacterial content, may be considered appropriate to reduce the dilution volume of.

4 Equipment and Materials

4.1 Dry heat sterilization and heat sterilization devices.

4.2 homogenizer.

4.3 for mechanical stirring.