Background and methodology:
This study compared the chemical composition and hygienic quality of Finnish organic and conventional milk. Milk from 126 Finnish organic and conventional farms was sampled from January 2000 to November 2001.
Finnish organic milk contained significantly less fat and protein, and it had a lower total bacterial count than conventional milk. Organic milk contained significantly more lactose and had a similar or higher somatic cell count and a similar or lower urea content than conventional milk. Although the differences between organic and conventional milk were rather small, they are of economical significance in large-scale manufacture of cheese.
This study also determined the effects of the exclusion of nitrate and the introduction of a protective culture on the microbiological safety and the counts of Listeria and non-pathogenic enterohemorrhagic Escherichia coli (EHEC) in organic Edam cheese. Nitrate failed to inhibit the growth of EHEC and Listeria. Thus, compared to Edam cheese from conventional milk, Edam cheese from organic milk without added KNO3 poses no additional health risk with respect to Listeria and EHEC. The use of a protective culture containing Lactobacillus rhamnosus LC705, however, inhibited the growth of Listeria in Edam cheeses from organic milk.
Luukkonen, j., Kemppinen, A., Karki, M., Laitinen, H., Maki, M., Sivela, S., Taimisto, A. M., & Ryhanen, E. L.(2005). The effect of a protective culture and exclusion of nitrate on the survival of Enterohemorrhagic E coli and Listeria in Edam cheese made from Finnish organic milk. International Dairy Journal, 15(5), 449-457. Available on-line at: http://dx.doi.org/10.1016/j.idairyj.2004.09.005