SN/T 1615-2005Microbiology of food and animal feeding stuffs. Horizontal method for the enumeration of psychrotrophic microorganisms (English PDF)

Foreword

This standard is equivalent to ISO 17410:2001 "Food and animal feed microbiology - the method of counting microbiological microorganisms" (English).

For ease of use, this standard makes the following editorial changes.

a) The word 'this international standard' is changed to 'this standard'.

b) use a decimal point '. 'Replace the comma as a decimal point,'.

c) Remove the preface to international standards.

This standard is proposed and managed by the National Certification and Accreditation Administration.

This standard was drafted. Henan Entry-Exit Inspection and Quarantine Bureau of the People's Republic of China.

1 Scope

This standard specifies the 6.5 °C colony counting method for psychrophilic microorganisms.

This standard applies to the counting of psychrophilic microorganisms in food and animal feed.

2 Normative references

The terms of the following referenced standards are incorporated herein by reference. For dated reference standards, followed by any changes or revisions do not apply; however, parties to the agreement based on this standard are encouraged to explore the possibility of using the latest version of the referenced standards below.

Sex. For undated references, the latest edition is applicable.

ISO 6887-1 Food and animal feed microbiology - microbiological test sample preparation including initial suspension and ten-fold dilution Liquid---Part 1. General rules for preparation of sample initial suspension and ten-fold dilution ISO 7218 Microbiological study of food and animal feed - General rules for microbiological examination ISO 8261 Milk and milk products - preparation and dilution of microbiological test samples

3 Terms and definitions

The following terms and definitions apply to this standard.

Bacteria, molds, and yeasts that count colonies are formed under the specific conditions of this standard.

4 Principle

4.1 Make two agar plates with non-selective solid medium. If the original product is liquid, use the specified amount of test sample solution, other products.

Use a specified amount of the initial suspension of the test sample, in order to avoid the influence of heat, surface inoculation. Under the same conditions, each dilution test the samples were inoculated separately with two agar plates.

4.2 Place the plate in a 6.5 ° C incubator for 10 days in aerobic culture.

4.3 Calculate the number of microorganisms per ml or gram of sample by the number of colonies obtained from agar plates.

5 Medium and diluent

Current laboratory operations are available in accordance with ISO 7218.

Unless otherwise specified, all reagents are of analytical grade and the water is distilled water, deionized water or purified water. If the prepared medium and reagents cannot be used immediately. Unless otherwise stated, they can be stored in a dark environment at 3 °C ± 2 °C without any change in the composition of the medium.

The storage period is not more than one month.