GB/T 4789.27-2008 in English

《GB/T 4789.27-2008食品卫生微生物学检验 鲜乳中抗生素残留检验》由361（国家卫生健康委员会）归口，主管部门为国家卫生健康委员会。
本标准规定了鲜乳中抗生素残留的检验方法。
本标准的第一法适用于鲜乳中能抑制嗜热链球菌的抗生素的检验；
第二法适用于鲜乳中能抑制嗜热脂肪芽胞杆菌卡利德变种的抗生素的检验，也可用于复原乳、消毒灭菌乳、乳粉中抗生素的检测。

1 Scope

This standard specifies method for examination of antibiotic residue in fresh milk.
Method I of this standard is applicable to the examination of antibiotics inhibiting streptococcus thermophilus in fresh milk; Method II is applicable to the examination of antibiotics inhibiting bacillus stearothermophilus var.calidola-ctis in fresh milk and it is also applicable to the examination of antibiotics in reconstituted milk, sterilization milk and milk powder.

Method I Streptococcus Thermophilus Inhibition Method

2 Principle

After the sample is subjected to sterilization at 80℃, add bacterium solution of streptococcus thermophilus into it. Streptococcus thermophilus begins to proliferate after being cultured for a certain period. Then add metabolic substrate 2, 3, 5- triphenyl tetrazolium chloride (TTC); if this sample contains no antibiotic or the antibiotic concentration is lower than the detection limit, streptococcus thermophilus will continue to proliferate and reduce TTC to red substance. Otherwise, if the sample contains bacteriostat higher than the detection limit, streptococcus thermophilus will be inhibited, thus the indicator TTC will not be reduced and will keep the original color.

3 Equipment and Materials

Foreword I
1 Scope
Method I Streptococcus Thermophilus Inhibition Method
2 Principle
3 Equipment and Materials
4 Bacteria Species, Culture Mediums and Reagents
5 Examination Procedures
6 Operation Steps
7 Report
Method II Bacillus Stearothermophilus Inhibition Method
8 Principle
9 Equipment and Materials
10 Bacteria Species, Culture Mediums and Reagents
11 Examination Procedures
12 Operation Steps
13 Report
Appendix A (Normative) Culture Mediums and Reagents