Preview

Comparison of methods for quantifying butyric acid bacteria in milk

As part of a milk processor’s annual winter campaign for monitoring the contamination of raw milk with anaerobic spores harmful to cheese – also called butyric acid spores – the analysis methods currently used in Switzerland (MPN method according to CNERNA and filtration method according to Bourgeois) are compared with a new method (SY-LAB). To this end, 93 milk samples from silage-free and 217 samples from non-silage-free milk production were examined with all three methods. In the latter group, the new method delivered more impressive results than the other methods, thanks to its greater precision and a very large measurement range of 44 to 19,000 spores/L. In the milk samples from silage-free milk production, the new method detected spores in only 9 % of the samples, the filtration method in 29 % (detection level of 25 spores/L) and the MPN method in 44 % of the samples (detection level of 53 spores/L). In combining the filtration method’s advantage of specificity with the robustness of MPN methods, the new method could offer advantages not just for silo milk, but also for silo-free milk, despite its lower sensitivity.

Full PDF

Comparison of methods for quantifying butyric acid bacteria in milk

Download full version (307 Kb.) German

Download full version (311 Kb.) French

To the archive