ESSENTIAL MICROBIAL GROUPS TO BE MONITORED IN MILK FOOD SAFETY.

The Dairy Standard Agency and Milk SA regularly engage with authorities to include dairy safety standards into legislation. The SA dairy regulations (R.1555 of 21 November 1997) are under revision with considerations for internationalisation, which amongst others, include focusing on only Enterobacteriaceae instead of Escherichia coli (E. coli) and coliforms. Since these indicator organisms are vital for dairy product safety and hygiene, this potential regulatory change could impact the South African dairy industry's monitoring practices. In the study cited, the relevance of E. coli, coliforms and Enterobacteriaceae as hygiene and food safety indicators in milk in South Africa, along with species identification, was therefore assessed.

Pasteurised milk samples (bulk and packaged) were analysed over four years, using the bioMérieux TEMPO® for bacterial enumeration and MALDI-TOF for species identification in packaged pasteurised milk.

The results showed that 54% of samples (n=1819) met the criteria set by R.1555 (<10 cfu/ml) for coliform counts in pasteurised milk, 88% (n=1819) were compliant for E. coli as per R. 1555 (absent), and 68% (n=1801) had Enterobacteriaceae counts under 100 cfu/ml. The MALDI-TOF analyses identified 84 species, including 22 Enterobacteriaceae. With regard to packaging, milk in sachets had significantly higher coliform counts, indicating possible inferior hygiene compared to other packaging methods.

Conclusions: Although specifications for Enterobacteriaceae have not been incorporated into the South African milk regulations, this study underscores the importance of specifications and reaffirms the potential significance of E. coli and coliforms as indicator organisms within the SA dairy industry. Therefore, at this stage, all groups (E. coli, coliforms and Enterobacteriaceae) are envisaged to be included in the revised regulations (R.1555), as the results do not support the international notion that the Enterobacteriaceae should suffice.