Fatty acids released from cream by psychrotrophs isolated from bovine raw milk.

The ability of 15 psychrotrophic strains to release fatty acids C-8:0 to C-20:1 from cream by GC/ MS and the substrate specificity of their lipases against selected triacylglycerols (TAG) were studied. The free fatty acids (FFAs) detected in the highest quantities were, in general, those of long (C-16; C-18) and intermediate (C-12; C-14) even-numbered carbon chain and unsaturated C-18:1 and C-18:2. The ability of lipolytic strains to release fatty acids from milk fat varies according to the bacterial genus, among species and even with the strain of a given species. TAG breakdown by psychrotrophs may occur in a greater or lesser extent, but type and amount of released FFAs are not easily predictable. Pseudomonas rhodesiae showed the highest hydrolytic resistance towards all tested fatty acid triglycerides.