AS 1766.3.11-1991

1 - AS 1766.3.11-1991 FOOD MICROBIOLOGY - EXAMINATION OF SPECIFIC PRODUCTS - DAIRY PRODUCTS - TEST FOR PENICILLIN
1 - PREFACE
1 - METHOD
1 - 1 SCOPE
1 - 2 PRINCIPLE
1 - 3 REAGENTS AND MATERIALS
1 - 3.1 Inhibitor-free reference sample
1 - 3.2 Penicillinase solution
1 - 3.3 Penicillin G
1 - 3.4 Nutrient agar slopes
1 - 3.5 Plate count agar,
2 - 3.6 Tryptone dextrose yeast extract (TDY) broth (see Appendix A),
2 - 3.7 Test organism*,
2 - 3.8 Ethanol
2 - 3.9 Sodium carbonate
2 - 4 APPARATUS
2 - 4.1 Rimless bacteriological test tubes,
2 - 4.2 Petri dishes
2 - 4.3 Paper discs
2 - 4.4 Pipette
2 - 4.5 Forceps
2 - 4.6 Callipers
2 - 4.7 Incubator
2 - 5 SAMPLES
2 - 5.1 Storage of samples
2 - 5.2 Preparation of test samples
2 - 6 CULTURES OF TEST ORGANISM
2 - 6.1 Maintenance of stock culture
2 - 6.2 Preparation of test culture
3 - 7 PROCEDURE
3 - 7.1 Preparation of seeded plates
3 - 7.2 Preparation of reference curve
3 - 7.3 Testing of test samples
4 - 7.4 Confirmation of penicillin
4 - 8 INTERPRETATION OF RESULTS
4 - 8.1 Inhibitory substances not detected
4 - 8.2 Penicillin present in sample
4 - 8.3 Inhibitory substances other than penicillin
4 - 8.4 Penicillin and other inhibitory substances
4 - 9 REPORT
4 - 10 REFERENCES
5 - APPENDIX A - TRYPTONE DEXTROSE YEAST EXTRACT (TDY) BROTH.

This Standard sets out a disc assay method using Bacillus stearothermophilusfor testing milk and other dairy products for penicillin at or above a level of 0.003 µg/mL(0.005 IU/mL).

This Standard sets out a disc assay method using Bacillus stearothermophilus for testing milk and other dairy products for penicillin at or above a level of 0.003 µg/mL (0.005 IU/mL).NOTES:1 For further reading on the test see Ref. 1.2 The method may be used as either a qualitative or a quantitative test.3 Other inhibitory substances to which the test organism is sensitive may also be detected non-specifically.4 This Method is intended as the reference method. There is another disc assay method (Ref. 2) and also a tube method (Ref. 3) which may be quicker or more convenient for non-reference purposes e.g. routine quality control.